Document K6eaM3bdynzYDzwvv0LqnzMJr
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PLAINTIFFS EXHIBIT
JM-1683 Comments of
Johns-Manville Corporation
with respect to
Notice of Proposed Rulemaking Occupational Exposure to Asbestos
(Federal Register October 9,1975)
Occupational Safety and Health Administration U.S. Department of Labor .
April 1976
Johnt-ManvM* Corporation
o*C'mac 90**
April 9, 1976
Docket Officer Docket 8-033 U. S. Department of Labor Boom N-3620 200 Conatitution Avanua Washington, DC 202X0
Gentlemen:
As the Xargast producer of asbestos fiber in the Western world and the Xargast manufacturer of asbestoscontaining products in the C.S., Johns-Manville (J-M) is vitally concerned with osha' Notice of rroposau Ruieoaxang - occupational Exposure to Asbestos, as published in the Federal Register on October 9, 1975 (hereinafter referred to as the 'Proposal*).
As soon as the Proposal was published, J-K formed a task force to review the Propoaal in its entirety, with special attention to its scientific basis. Instead of again reviewing our efforts in this regard, attached as Exhibit A is a copy of J-M's letter of January 8, 1976 to the OSHA Docket Officer. This letter outlines the nature and extent of these efforts, as support lor our request for an extension of the comment period. The purpose of the coassents hereinafter set forth is to report on these efforts and the resulting conclusions.
In addition to this cover letter and Exhibit A, six reports are attached as additional Exhibits B-G. Each of these latter Exhibits reviews in considerable detail cur major concerns and contentions with regard to the Proposal and the premises upon which it is based.
On peg# 47652 of the Propcsal, OSHA liets a series of 16 "major issues raiaed in this proposal.* In Section V of the Proposal, OSHA identifies further issues and questions ar.d invites comments thereon. Each of these issues end questions is specifically addressed in one or more of the attached Exhibits. Thersfore, there is no nesd to list
Pnukst 1 0 \ - ~ z Paqe 2
April 3. i-j.t
these issues sr.d cover letter.
sur answers theri'-.o in th.s
r/ICVPAT ICNAI SAPtTY '.''l HEALTH ACT OF 131C
ieri.tr. '!, of the Imps; tonal Safety and Health Act cre.nafter referred to as the "Act'i, states the
tsr.qre3310r.ai purpose cf the Act as being "...to assure sc far as possirie ever-/ working aan and vorar. tn the hatior. safe a.td ..= aithf..i working utndiliens...'
Seeder. 6 !h; f 5 i : r t.-.e Act providrs that-
'T.-.e Secretary, i.t promulgating standards dealing
with toxic ratertals or harmful physical agents under this subsection, shall set t.-.e standard
which moat adequately assures, to the extent feasible, on the basis of the best available evidence, that no employe* v< ' 1 suffer c.itoriui impairment of health or functional capacity even if such employee has regular exposure to ths hazard dealt with by such standard for the period of his working life. Development of standards under this subsection shall be based upon research, demonstrationa, experiments, and such other information as may be appropriate. In addition to the attainment of the highest degree of health and safety protection for the employee, other considerations shall be the latest available scientific data in the field, the feasibility of ths standards, and experience gained under this and other health and safety laws. Whenever t..H...viu,e, u*ie stu..derd
promulgated shall be expressed in terms oj objective criteria ar.d of the performance desired.'
It is clear that it was never Congress' intent for the Secretary of Labor, vher. croouigating health standards to attempt or, in fact, to provide absolute protection
to all employees from all possible hazards, known or unknown Protection is -- be provided "to tr.e extent feasible.' The Act simply does not deal in absolutes. Nowhere in the Act or in the legislative history is there any indication that loot protaction is mandated. In fact, the contrary is true. Senator Javits, author cf the phrase 'to the extent feasible* stated:
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which night be interpreted to require absolute nealth and safety In all cases, regardless of feasibility, and the Administration bill, which contains no criteria for standards at all.*
S.Rep. No. 91-1202, 91st Cong., 2d Sess., at 58; Legit. Hist, at 197.
It is totally unrealistic to believe that any standard or senes of standards can protect everyone from every conceivable hazard or risk. The National Academy of Science in considering the effect of toxic substances, has recognized this fact, by stating, 'The Academy con siders that the intent of Congress in using the phrase 'maximum contaminant levels which should be recommended... in order to protect the health of persons from any Vnovr. or anticipated adverse effects' < to provide for recomnendations -hat ore consistent with the best scientific !,, c.visage recognizing that absolute safety cannot be guar anteed. *
The best available medical evidence fully supports the position that a standard for exposure to asbestos of 2 fibers/cc will provide protection from asbestos-related health risks. The problem of human susceptibility is such that, short of the agent being completely absent, which is not possible under any circumstances, we will have little
hope of saying that any level will provide absolute protection to every individual who might be exposed. There will always be a few individuals out of "any millions who might be so susceptible fut various reasons that levels
which completely protect 99.999 percent of the population night fail with 0.001 percant. It is totally unrealistic to believe that absolutely everybody can be protected
from any and all risks.
TCXICOLOGICAL CONSHERATIONS Of EXPOSURE TO ASBESTOS
1. OSHA's Rationale for the Reduction of the Asbestos Standard
'
In the October 9, 197S Federal Register Notice, OSHA has proposed, among other things, to lower the permissible exposure limit from 2 fibers per cubic centimeter for an 8-hour time-weighted average exposure to 0.5 fiber/cc.
The following is provided by OSKA as its rationale for this proposed reductioni *The development of this
Docket Officer Pegs 4 April 9, 1976
proposal is premised on racant medical and scientific evidence as to increased health hazards associated with occupational exposure to asbestos. Since the promulgation of the U.S. permanent asbestos standard (June 7, 1972), considerable new information has been forthcoming on the toxic effects of asbestos. This has been in two areasi In the widening spectrum of cancers associated with asbestos exposure, and in various manifestations of asbestos disease in individuals exposed to relatively low concentrations of dust.' It is this 'new information* that represents the sole rationale for the reduction of the standard.
J-M's Review of the Medical References Cited by OSKA
We have reviewed in considerable detail all of the references cited by OSHA, and conclude from this study that these references totally fail to provide any sound *nev information*, as OSHA contends, as a basis or rationale tor the Proposal. Specifically, no 'new information has been forthcoming on the toxic effects of asbestos.'' since June 1972, that justify the substantial modifications being proposed by OSHA. In fact, new information not referred to by OSHA strongly suggest that 2 or perhaps mors fibers/cc is not associatsd with an sxcess incidsncs of pulmonary canesr. In addition, we have reviewed all available non-clted relevant scientific publications and data sources, and find that these reinforce our conclusions as to the absence of any scientific basis for the Proposal to reduce the 8-hour time-weighted average airborne exposure to asbestos from 2 fiberVce to 0.5 fibsr/ec. The results of our dstailsi r--14ew r* set forth in Exhibit B attached hereto.
There ere three glering and fatal deficiencies in the Troposali (1) A comparison of the scientific literature available prior to 1972 with that appearing thereafter, provide no data to supprt tna oSHA intention that 'considerable new information has been forthcoming on the toxic affects of asbestos*) (2) Preliminary, unpublished and non-pear reviewed studies have been cited by OSHA as important segments of the 'new information on the toxic effects of asbestos) and (3) Vital facts pertinent to the British standard end other British studies have been grossly misrepresented.
un JinU nIf
1 0" * "
Docket Pag- 6 April 9.
!s! The Rglgrancea Cited by CSHA Are Either Mot Valid or Contain No "Saw In formation *
In support of \.t* proposed rule change fc* asbestos exposure, CSKA lists 42 references as evidence that there has been considerable "new information' on the toxic .effects of asbestos. Of these 42 cited references there are only 4 or 3 key papers.
Two of trese references, numbers IS and 14, should be considered in tandem. Those are papers published in 1968 by Dr. Knox and hi3 associates at Turner Brothers Asbestos Co. in the [,'r.ited Kingdom, and a tore recent paper published in 1972 by Dr, Lewir.schr., successor to Dr. Knox. The original study of Dr. Knox was the one on whicn the British Occupational Hygiene Society relied on heavily when establishing the target of 2 fibers/cc as the desirable work r"'ircrjtc.-. - m ane United ''gdom. Dr. bewinsohn, in subsequently following tne same population, looked at the original material of Dr. Knox, as well, as the follow-up material, and using quite different criteria, drew some conclusions contrary, it was felt, to those observed by Dr. Knox. But, most important of all, the conclusion was that Dr. Lewinsohn indicated that he saw some evidence of asbestos related disease in the population that had entered the workplace subsequent to 1951. This posed the serious question as to whether, if ir. leed these workers had uniformly been exposed to 2 fihers/cc or lees since 1951, was 2 fibers/cc a valid standard Tor the protection of individuals occupationally exposed to asbestos?
In January of 1976, representatives of the Asbestos Information Association/North America (AIA/NA) and J-H visited the Turner Brothers Asbestos Co. and the two units in the united Kingdom that had M.-n studying :he "BA popula-iun: Proressor Coll at Oxford University, whose group had been responsible for the mortality study of the TBA population, and Dr. Berry, a statistician, who is at uie Pneumoconiosis Research Unit in Hales, U.K., whose group has been studying the morbidity experience cf the TBA population. They have beer, following this group in terms of the statistics of tha illnesses they have exhibited. Dr. Doll and his associates have been following this group in terms of thair death experience.
I I
Docket Officer
Pag* 6 April 9, 1976
The group visiting TEA and the two U.K. units consisted of (11 Dr. Han* wu, Professor of Medicine at Tuiane University, and President of -ha American Thoracic Society ,'AIA/NA) , (2) Sr. Georg* Wright, a medical consultant to
J-M, (3) Dr. Gerald Chase, a biostatistician/epideraiologist employed by J M and (4) Mr. William Haiti*, Chief of Industrial Hygiene for J-M.
As a result of this visit, we were specifically advised
by the authors of the papers in the United Kingdom,
that they, as one, war* reluctant to draw conclusions
from their papers in relation to the OSHA Proposal.
Second, they refused to draw the same conclusions that
OSHA drew from their publication. Third, they felt
that any conclusions from their studies were premature
lr. view of the ongoing character of their studies,
with additional information still to be forthcoming
prior to the development of any conclusions. Finally,
with regard to OSHA's conclusions from reference 30,
Doll and his associate* *id nothing about the specific
alrcorne concentrations of asbestos to which this worker
population was exposed. Therefore, conclusions in
relationship to exposures cannot be made.
-
In January 1976, a sub-committee of the British
Occupational Hygiene Society met and re-examined thair
recommendation of several years ago that a target of
2 flbers/cc represented a level of exposure that would
protect workmen. The BCHS sub-committee met for a
day in January, and indicated that they would say
nothing or take no action to modify their original
position until a follow-up study on mortality by Dr.
Doll and his associates at Oxford was completed. From
our discussions with Dr. uon, we learned that approxi
mately 6 months would be necessary to conclude this
study. At that time, he would be willing to make a
conclusion. With regard to the morbidity study by
Cr. Berry and his associates, the BOHS sub-coralttea
again decided to await the completion of that study,
which they felt would take a minimum of 6 months, but
more likely 9 to 12 months. In consequence, we have
the paradoxical situation where the promulgators of
the data upon which the OSHA Proposal are based are
unwilling to make the firm conclusions that clearly
have been made by OSHA.
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Docket Officer Page 7 April 9, 1976
A crucial misunderstanding **-'7 1 paraiata in tha U.S. with regard to thaaa atudiea of TBA'a taxtila workers, whan Dr. Lewinaohn indicated that ha saw some avidanca of aabaatoa ralatad diaaaae in tha population atudiad by Dr. Knox (which had antarad tha workforce ainea 1951), concern aroaa in tha U.S. aa to whether a THA parmiaaible expoeure limit of 2 fibera/ec waa adequate. Thoaa who expreaaed thia concern have aaaumed that the worker population atudiad, waa, in fact, expoaed to THA airborne concentrationa of aabaatoa fibers below 2 fibara/cc. Tha facta are to tha contrary. Through tha cooperation of THA, tha AIA/NA and J-M repraaentativea ware provided auamaries of TBA expoeure maaauremanta that permit thaaa expoaurea to be viewed iii the framework of tha current and oropoaed OSHA regulationa. The expoaure of the TBA*worker population being, in fact, aubstantially in axcaaa of 2 fibara/cc, tha Lewinaohn data indicating an axcaaa of hiaeass cannot form the bawl* fsr an inference that auch axcaaa of diaeaae ia aaaoclatad with low levela of aabaatoa expoeure. In making auch an inference OSHA haa committed a groaa error in judgment and interpretation.
The atudias on 'tha TBA taxtila population to data have only reported mean expoaure levels, by department and process (1968). A considerable portion of Exhibit B attached hereto is devoted to the problems inherent in attempting to use averages rather than specific individual exposures as a basis for quantifying risk factors for use in the development of standards. The TBA studies in the past have averaged exposures in rslation to jobs, areas of w**wsure, individual workers, years of exposure, etc. While these data can be informative, unless properly understood, it can be importantly misleading. Tha averaging of exposures camouflages tha true range of individual exposures, which generally are substantially higher than the mean figures rspcxteu.
Any discussion of exposure history and expoaure levels, demands a clear understanding cf the currant and proposed OSHA asbestoe standard and the problems inherent in attempting to look at averages rather than specific individual data points in the critical assessment of exposure. The current aa well as the proposed OSHA asbestos standard wisely does not allow employers to average tha exposure of workers engaged in different activities or to average over several days or months
CocV.et Offlcei
Page 3 April 3, 1373
of exposures. The limitations inherenc in iooxing at such averages a: ir.-.Cu. uf hazard or a baais for standard* ara obvioua. However, OSHA has raliad cn studias whole authors have done what OSHA does not permit employers to do> that is, avsrage exposures.
The current OSHA asbestos standard, which will ba effective on July 1, 197$, requires that each individual employee's exposure be controlled so that no individual employee is exposed to more than 2 fibars/cc on an 4-hocTV'A basis. If we analyze the TBA exposures in 19$6 by the current or proposed OSHA standards, the highest 1966 average fiber count given in the 30HS (1968) publication, was 8 fibers/cc. However, cased on the unpublished, detailed summaries of the exposure measurements provided to us in January 1976 by TBA, there were at least two operations in 1966 giving
average fiber counts in excess of 2S fibers/cc. These 'ummaries of TBA rpccur: r.uieuiaments also suggest ..-.at approximately 40% of the sampling stations routinely yielded sample values in excess of 10 fibers/cc. These exposure summaries are from 41 reported sampling areas. In all, approximately 70% of the sampling stations routinely gave fiber counts in excess of S fibers/cc.
It must be pointed out that these measurements, from which the exposure summaries were prepared, occurred 10 years ago, same IS years or more following the on-set of the routine monitoring in 1951; in other words, between 1951 and 1966 or later. Furthermore, these measurements were taken after extensive environmental control efforts by TBA in the post 1951 period. Therefore, it is obvious that concentrations of asbastos fibers were even greater during tne period 1951-1966, or later.
It has never been suggested by the British, nor can it
'
reasonably or responsibly be construed by others, that
the post 1951 TBA workforce has, in its entirety, been exposed to an environment comparable to that called for
pursuant to the July 1, 1976 mandate of the current
CSKA asbestos standard, or the British standard. The TBA workforce at the British textile plant has historically
had very high exposures to asbestos, as at all ether manufacturing establishments.
& >
Docket Officer Page 9 April 9, 1976
CSBA should have bean aware and i* charged with knowledqa in 1972, that the post 1951 TBA
workforce were not uniformly exposed to TWA airborne concentrations of asbestos fibers below 2 fibers/cc. This fact should have been patently clear to OSHA from the naan exposure levels reportsd in the earlier studies of this population and from the testimony of Or. Stephen Holmes and Stuart G. Luxon at the Advisory Coasaittea Hearings on OSHA's 1972 proposed asbestos standard. On March 15, 1972, Dr. Holmes, at the OSHA Advisory Committee hearings, stated (pages 152-153) i
"We have certainly not reached 2 (fibers) per cc in the general field of in-plant and out-of-plant,
asbestos work in the United Kingdom...and it is certainly not true hare in the textile side of the Industry that all operations...can be controlled in the present state of knowledge down to 7 (fibers oer ro uc -~a llu^ expected to be getting there
yet. In the present state of knowledge, certain textile operctions -- the carding, spinning, etc. -
do not gat down to 2 (fibers) per cc generally. Certain very high-quality operations may well do it, but thS general situation is that we are not
yet, throughout the British industry, achieving the 2 (fibers) per cc ultimate goal.'
Farther testimony in this regard was presented at the
OSHA Advisory Committee hearings on .March 17, 1972 by
Stuart G. Luxon, Her Majesty's Superintending Chemical
Inspector of Factories and Director of the Industrial
Hygiene Unit, Department of Sr.plryr.ur.t, U.S. Mr. Luxon
testified that (page 4667) i
.
*Th)a figure of 2 fibers per cc should be related
u a time-weighted personal exposure over a working day, although for practical purposes we have chosen to measure this concentration by sampling over a 4-hour period.'
*We know that thara will be processea where even given a hloh standard of control, the nature of the operation makes the achievement of such a level vary difficult.*
Tj 7i
Docket Officer Page '' April 9, 17
'Certain textile processes and handling of sheets of rnauration board may ba cltad aa
particular examples-'
*lt (tha making of textiles) oparataa In a diffarant category wbere you have dlffarant concantratlona. Tha concentration levels fluctuate vary widely. I think a great deal has bean done in tha United kingdom, and a great research effort has bean carried out in tha process of revamping of materials, revamping our methoda process, and tha problaa is coning within sight of tha lower levels that ara mentioned.' (emphasis added)
To emphasize tha inconclusive nature of tha studies
of the TBA textile population, the BOHS sub-coanittee is only now undertaking a complete review, updating, __ enlarging, validating and reanalyzing of the available information on TBA employees. Hot even preliminary findings or rscommendations are evailaols at this time.
.
To sum up the important points on these studies, not only has thebe been no 'new information' available since 1972 with respect to dose-response relatione, the BOBS sub-committee is only now generating the first information they consider appropriate since 19<8, and which may be considered 'new' when available.
f-
The next 'key' paper cited by OSHA in the Proposal is
reference IS, by Drs. Anderson and Salikoff at al, which is still in oreea. This paper reports the appearance of mesothelioma in fasU.ly msphers of asbestos workers. Here again, tha erroneous and ill-founded 'assumption
was made that exposure in the home would appear at least, upon superficial observation, to be a light exposure. After all, the members of the family were
net in the workplace. Over and above other deficiencies
in this study, is the erroneous assumption that house hold exposures to asbestos have been minimal in dose
relationship concept. The precise opposite is more likely the truth. As recognised by Salikoff and others, the Impregnation of drapes, rugs, furniture, etc. with asbestos fibers and the constant reauspension of fibers in the respirable range creates an exaggerated hatard. Once asbestos is carried home by the workman, it accumulate
Docket Officsr Pag* 11 April 9, 19^6
in the hoir.e, and its pr--c- tha home ii likaly tc be permanent. Cnca it gats into tha ruga, for example, it become* resuspended by movements such as brushing and walking and therefore, family members are getting a 2-hour a day, 7-day a weak exposure, relatively speaking, rather than a partial exposure. Of greater concern; is tha fact that the entire population of the family, including the very young and the very old, are exposed. Experimental and clinical data on the induction of cancer establish that tha very young an more susceptible to the effect of carcinogens. This fact provides the basis for regularly using young animals in the laboratory in testing agents for their ability to induce cancer. Furthermore, in the home environment, an exaggerated opportunity is present for co-factors to be operating, such as smoking and household pulmonary irritants. These household exposures also provide an opportunity for repetitive n-ch. short pak exposures duo iu the snaking out of work clothes. Lacking specific dust counts over the appropriate time period, any conclusion that the exposures were minimal is totally unacceptable. In summary, not only has this paper not produced any `new information* which was not available prior to 1972, it has made erroneous assumptions regarding house hold exposures which fatally flaw the conclusions reached by the authors and OSHA.
The next `key* paper cited by OSHA is reference 25, the paper by Drs. Newhouse and Berry, which reports on mesothelioma in the Cape Asbestos workers. On the basis of the mathematical model that Dr. Berry constructed, he anticipated that the attaux rate for workers in the Cape Aebestoa factory, now torn down, and in which exposures were high, that some lit of tha workers would probably contract mesothelioma. This is a startling figure, particularly since Dr. Selikoff and his associates predicted, and still maintain, that their mschesctlcsl model only gives them a potential attack rate of 79, tragic surely, but certainly not 11%. Statistical review of *< mathematical medal used by Drs. :;ewhousa and Berry, shows in the eyes of competsnt statisticians that it is one that is subject to question, as is specifically discussed in Exhibit B. The authors themselves recognize the limitations of their study, stating, `It should be stressed that the population we ere considering were all first exposed to asbestos pricr to 1964 and most of them before 1951. Therefore, the conditions responsible are not those which should be achieved today.*
I
Docket Off car Page 12 Aprli. ., i7*
The naxt *kay* papar la OSHA rafaranca 41. This papar raporta tha raaaarch afforta of Dra. Gilliam, Leman, Wagoner and their aaaociataa at NIOSB. Thla study of tha HoMStaka Hina was flrat givan at tha Saw York Academy of Sciancaa Confaranca on Carcinoganaaia in March 197!, and raportad an axcaaa of both lung cancer and pneumoconiosis in thia population. Thay attributad tha axcaaa to tha praaanca of a fora of aabaatoa in cvsamingtonlte-grunarite ora. Tha HIOSB group totally dismissed tha poaaibility that thia axcaaa waa caused by otharpotantial lung cancar hazarda praaant in tha mine, auch aa azsanic and radon daughtera. Tha incraaaa in fibroaia waa arronaoualy attributad to aabaatoa, rather than to free cryatalline ailica, known to be praaant in the mine in aubetantial quantities, or any othar acar producing duat.
Our review of thia paper givaa us very serious concern. A lengthy discussion of what was wrong wi*-h this paper, -
m forth in Sxhibit B, attached hereto. This papar, as cited and relied on by OSHA, was obviously a crude first draft, and does not represent tha type of document upon which substantial conclusions may be drawn and daciaions made. In support of this statement is tha fact that the papar has been rewritten and substantively altered two times since the original draft.
It is stated by OSBA that tha Proposal is based on "considerable new information...on tha toxic affects of asbestos. This has been in two areasi in tha widening spectrum of cancers associated with asbestos exposure and in various manifestations of asbestos disease in ir.divif--rl; axposed to relatively low concentrations of dust." This claim by OfBA is clearly baaed on an incomplete and unscientific review and assessment of tha available data. OSBA has not prasantad even a scintilla of "new evidence* to support a proposed reduc*- 'n of tha permissible exposure limits to 0.5 fiber/uc. The reterences cited by OSBA (1) contain no "new information*i and/or (2) are based on arroneoua assumptions and therefore reach conclusions which are not valid; and/or (3) do not support tha conclusions reached by OSHA.
1
Docket Officer Page 13
April 9, 1976
*e have thoroughly reviewed the antira cecucd of OSHA's 1972 aabaatoa rulemaking proceed!,,.*, and find it raplata with referencee and data regarding "the widening spectrum of cancera aaaociatad with aabaatoa exposure* and the `various manifestations of aabaatoa diaaaaa in individuala axpoaad to (so-called) relatively low coneentrationa of duet.*
Aa indicated pravioualy, wa have reviewed in conaiderable detail all of tha rafarencea cited by OSRA. This review ia aat forth In Exhibit B. Baaad on thia review, there
ia nothing that qualifiaa aa "now information*. All wa can find ia a replication of the findinga and diacuaaiona of riak already known in 1972. Reiteration
of what ia known cannot be conaidarad to be "new information*.
(b) The Riak of Asbestos-Associated Cancer and the
Incidence of ahetcs Disease in Individuala
Allegedly Expoaedto Relatively Low Coneentrationa
of Duat Ware Conaidarad In Establishing the Current
Aabaatoa Standard
On page 47657 of.tha Proposal, it ia atated that!
*OSBA alao believea sufficient oadical and scientific evidence has now bean accumulated
to warrant tha daaignation of aabaatoa aa a human carcinogen. Therefore, it ia incumbent upon OSHA to propose the establishment of safe guards to protect tha lives of affected workers.*
It is difficult for us to understand any justification
for the above quoted statement. It is .fair ttf say that in 1972, asbestos was well recognized world-wide
as a human carcinogen. The evidence introduced into the record of OSHA's 1972 aabaatoa rulemaking proceedings would alone justify such a designation. Furthermore, a careful review of the record of the 1972 rulemaking
proceeding clearly indicates that the risk of cancer was considered in arriving at the July 1, 1976 standard of 2 fibers/cc, not withstanding OSHA'a contention to the contrary.
Pace 1` April 3, 1976
"Zr<SP.. i.-. ::: 1971 dccurc.-.i e.-.iiiiC 'C..-<--i ... i-.r a Secomr-tdcd Stir,duo_. . .Ccupational Exposure to Asi;ei:o" , caccmr.ended the estatlls.nr.ent of 4 2 fiber standard and, ch Document 11 replete with evidence supporting the increased rr.cider.ce of career and mesothelioma among individual* occupationally exposed to asbeeros
At the C3HA Advisory Committee Hearings cr. asbestos -..'. fenruary-Karch 1 " 72 , betr. Drs. Powell mi Wagoner, co-authors cf t.-.e MCSH Criteria Document, were present to explain tr.e NICE;: recommendations to the Advisory C.c.Tjr.ittee members. In this regard, it is most relevant to specifically pit tie statements made by Drs. Powell and Wagoner to the advisory Committee relating to the cchsiderahior.3 ta.-eo into account by MOSH m reaching its reccmaendaticr..
In discussing hcv dlCEh irii.su at its recommendation for a standard of 2 fibers/cc, Dr. Pcvell stated to the Advisory Committee on February 3, 1972 (pages 93-92! that:
One of the major studies that we utilized in our determination was the work that was done in Great Britain, where the evaluation was made by the British Hygiene Society, ar.d then their regulations came out...
...they came up with a hundred fiber years, as you know, as being essentially their basis for saying that probably there would only be one percent asbestosis.
...their exposures were based on essentially a EO-year working lifetime.
...on this basic, thic cams out to be two (.leu per cc years.
...One cf the thi..ga that we did consider was that in this country we normally think that our workers rsaliy are only employed for about 30 years in any one industry, and based upon 30 years, this turns out to be 3.3 fibers F#r cc on a yearly basis.
Docket Officer Page IS April 9, 1976
...McDonald in hi* work in tha nina* in Canada u*ed 40 yaar*. The British usad SO. ACGIH uses 30.
...We utilizad this as one of our basic pieces of information to basa our recommendations on. It se*nad to ba fairly good. Than wa fait that we had to add something else because of the' possibility of lung cancer and so forth. That wa* where our '2' case jrom. ba looked at McDonald's data, which hasbean widely quoted, and we looked at Selikoff's information, which does not have tha good dose response relationship." (emphasis added)
On February 14. 1972, Dr. Wagoner stated to tha OSHA Advisory Committee members (page 36) that:
'i would like to make two comments. I believe the statement was made that I was referring only to the malignant response in my preparation of the data. This is not so -- the UXOSH package and myself both-addressed ourselves to asbestos(is) and the malignant response in our decision, or our interpretation of the data for 2 fibers."
It is patently clear from the above WIOSH statements before the OSHA Advisory Comittee that NIOSH did, in fact, consider the risk of lung cancer and mesothelioma in arriving at its recommended standard of 2 fibers/cc.
On page 47654 of the Proposal OSHA states that, "This extension of the initial data within recent years now requires refocusing of OSHA's concern from a primary function of prevention of asbestosis with the expectation of concomitant reduction in the incidence of asbastueassociated cancer, to a new orientation, that of primary concern with the prevention of asbestos-cancer." However, the record fails to substantiate OSHA's allegation that the prevention of asbestos-associated cancers was not considered in the promulgation of the current asbestos standard. OSEA further goes on to state, "There is an additional logic in this reorientation. Reduction of asbestos exposure to levels sufficient to prevent asbestosis is known, at least in some instances, to be insufficient to prevent asbestos-cancer." OSHA then states, "On the other hand, a reduction of asbestos
A
Dock** Officer Page 1* Apri.i , ls*7
exposure to an extant aufficlant to prevent asbestos* associated cancer will alao prevent asbestoeis.* Our review of all of the available evidence on asbestosaaaociatad cancar laada to tha inescapable eoncluaion that thara ia absolutely no data of any kind to support thia eoncluaion by OSHA. Furthermore, thla atatanant ia a tacit admission on tha part of OSHA that thara ia an aabaatoa diaaasa does*response, and a thraahold.
zinnyHmm
Baaad on our datailad raviaw of tha antira racord of
OSHA'a 1972 aabaatoa rulemaking procaading, it ia fair
to aay that tha axparta who partieipatad in tha procaading
diffarad aharply in thair opiniona aa to whathar tha
tandard ahould raauiin at 5, or be rsiucwd to 2. It --
is alao fair to aay that tha avidanca introduead into
tha procaading did not aatabliah any ona poaition as
being claarly correct. Tha Secretary of Labor ultimately
resolved thia controversy by establishing a 2 fiber
standard, affective July 1, 197*. During thia
~
rulemaking procaading, not a shred of medical avidanca r"
was introduced to aupport a standard below 2 fibers/cc,
except for a few 'emotional* arguments. The dispute
focused between a standard of S versus 2. Unless thara
is, in fact, new medical evidence, which has become
available since 1972 to support the need for an even
further reduction of the permissible exposure limits,
tha limits must remain unchanged.
Our review of all of the references cited.by OSHA and all available non-cited relevant scientific publications
and data sources indicatesi
1. It is patently obvious that tha *naw Inform*'.ion*
on asbestosia cited by OSHA is not new and provides no avidanca that a 2 fiber/cc standard will have any adverse Impact on morbidity or mortality.
2. It was well documented in 1972 that soma occupational
groups exposed to asbestos have been at high risk of bronchogenic cancer. No *new information* is available. Subsequent studies and updates of continue
Dock*!; Offiv* Page 17 April 9, 19<t
studies m' -c-c fr.ucd to support this very Barrie concluBlon -he dat- _re consistent witn the premise that exposure levels low enough to eliminate ascestosls will also eliminate a detectable increased risk c bronchogenic cancer.
3. The epidemiology of pleural and peritoneal " mesothelioma has not been clarified in the period since 1972. The "new information" cited by OSHA comes from a manuscript supporting a dose-response for nesotnelioma and suoporting markedly reduced risks at the present time.
4. There is no evidence to indicate that a standard of 2 fibers/co -ill result in any increased ri3k of gastro-ir.testmal cancer.
5. There are inadequate data to put the question of
an excess risk
cir.rcr of me larynx, oropharynx
and esophagus in correct perspective. Out in
any event, where these excesses have been annotated,
the populations have been exposed to asbestos well
above 2 fibers/cc.
With regard to the reported incidence of various manifestations of asbestos disease in individuals allegedly exposed to relatively low concentrations of dust, the assumption that these exposures were
relatively low is erroneous. The precise opposite is more likely the truth.
We conclude following our review of both the OSHA cited and non-citeadd ' literature that a standard of 2 fibcrs/oc is adequate?
In this regard, on March 10, 1976 the Mining Enforcement and Safety Administration (MESA) promuioated a permanent
standard for exposure to asbestos in surface coar mines and surface work areas of underground coal nines. The standard established a 2 fiber/cc permissible exposure limit. An identicol proposal was initially published by the U. S. Bureau of Mines on November 7, 1972. It is fair to conclude that MESA has either rejected the "new information" cited by OSHA in the Proposal or has deemed it insignificant or not in fact "new", inasmuch.
n i n ii u Juu
iul U *t^O * '0 i
..-Syio'wh "v`v-
Oocket Ofr.cer Page 19 April 3, Liie
as the mtsa rouieticr. vis prcmuigatad 1 ;..ui.LUa followi-c r-'bliciti;... of the OSHA Proposal. MESA
was certainly fraa to publish a new proposed regulation in reapor.ie to the OSHA Propoaal. Furthermore, NIOSH was free to recommand to MESA a lowar exposure level for asbeatca in coal mining during the paat 6 months. One must therefore assume that MESA agrees with the conclusions that a standard of 2 fibers/cc is adequate to prevent any detectable increase of asbestos related cisease.
We urge OSHA to carefully study Exhibit B, attached hereto.in which the 42 references listed by OSHA in the Proposal have been reviewed to (a) determine the accuracy of the experimental data; (b) evaluate the industrial hygiene procedures used in measuring exposures; (c) validate the bioatatistical tests for significance or non-significance: {d; determine the structure of two -.':diec from epidemiological and statistical viewpoints: and (e) relate the conclusions to the data giver..
_
The results of this review indicate that OSHA was misquided in citing these references in support of its Proposal. OSHA relied on conclusions that can be seriously questioned as to validity and significance. To arrive at any occupational health atandard, OSHA oust raly on valid data, not on the (insupportable concluaions of authors. OSHA has been derelict m its responsibility to verify the data it has used, and we indict this agency for non-critically and egregiously
threatening an industry.
CONSIDERATIONS CONCERNING CARCINOGENICITY
'
On page 47656 of the Proposal, OSHA states:
"In considering the controversial issue of carcinogenicity,
OSHA is relying upon not only the new data reviewed abovt, but the leading scientific principles and opinions believed to reflect the research conclusions of inter national cancer experts, which were developed since or not known to OSHA at the time that the original atandard was promulgated.1' (emphasis added)
Docket Officer Page 19 April 9, 1976
Despite CSKA's contention that icier*--ic prlnciplaa and
opinion* of major anunt were developed since or not known to OSHA at the time of the promulgation of the 1972 standard, this statement must be regarded as unsupportable rhetoric,
since there is an absence of any bibliographic references as a basis for this position. A critical review of carcir.ogenesis literature through 1979 does not reveal a single
conceptual advance in mechanisms oi carcinogenesis over the past decade-!
OSHA has chosen tha irresponsible option of being guided by unsupportable data and disregarding other data in reaching tha following conclusions stated in Section III, Certain Considerations Concerning Carcinogenicity, on page 47656 of the Proposal:
1. "Prudent policy would therefore seem to indicated
that every reasonable measure should be taken to eli'imats huu-an exposure to chemical compounds as soon as their carcinogenic nature is identified.
2. Because of the variability of individual response to carcinogens and other factors, tha concept of a 'no effect' or 'threshold level' may have little real significance on the basis of existing knowledge.
3. The threshold concept for carcinogens is, at present, ora a matter of responsible regulatory policy than a precise, scientific determination." (emphasis added)
Our critical review of the carcinogenesis literature throuoh
1975 is attached hereto as Exhibit
our review leads us
to the following conclusions:
'
1. A dose must exist below which a carcinogen is ineffective.
Chemical carcinogens of every known category, chemical composition, and steric configuration produce sere
cancers when administered in large doses than smaller ones, and a dose-response curve can be demonstrated for graduated doses.
2. A threshold level exists below which a biological system will not exhibit any adverse effects from exposure to a carcinogenic agent. Chemical carcinogens can be administered at dose levels which yield no cancers in laboratory animal models and, which neither shortened the animals life span nor result in destonstrable
,i 'inn u j uu
, 1*0
Oockst 'fflcer
Page 20
April >
C
abnormalities in metabolic and physiological capaoiilties. Tin l* clearly a no-effect (threshold) ievsl.
3. Thera axiit* an array of environmental situations in which exposure to chemical carcinogens has failed to result In an increased incidence of cancer. The clear implication is that indeed a sub-threshold level for exposure exists in actuality.
.'MONITORING AND MEASURING AIRBORNE CCUCSNTRATICNS OF ASBESTOS riEo?"
1. OSHA Was Negligent In Its Responsibility To Stay Abreast of the Technology end Scientific Knowledge Related to Monitoring and Measuring Airborne Concentrations ot Asbestos Fibers
The Proposal states in paragraph (' yor.itcrl.-.r c.. "< wu w ch&c s
"The purpose of all monitoring required by this paragraph is to measure accurately the airborne concentrations of asbestos fibers in a workplace to which employees would be exposed if they worked in the area without the use of personal protective equipment, such as respirators. Monitoring shall be performed in a manner reasonably calculated to satisfy this purpose." (emphasis added]
Exhibit D attached hereto concludes that the accuracy of the complete monitoring and measurement process has not been adaq'^t*1!- ---;-Vcf cr.d is net clearly understood by either OSEA or NIOSH. Conclusions and recommendations have been made by OSHA and NICSH using inappropriate and inadequate data.
Incredibly, the OSHA Proposal raccrrer.ds a NIOSH document ("wGPKS/NIoSH Membrane Filter Method for Evaluating Airborne Aabeatos Fibers" by Nelson A. Leidel, Stephan G. Bayer and Ralph D. Zumtalde) on measuring airborne asbestos fiber concentrations that specifically concludes that there la a low statistical precision and accuracy below airborne fiber concentrations of 1 0 fibers/cc. while at the same time. OSHA is proposing to accurately
1
iu*r Pace 7 1
April 9, 197?
hi tor
measure fiber concentration* at and
tele- th:
posed standard of 0.5 flber/cc. It i*
obvious that CS!LA has been negligent in its responsibility
to stay abreast of the technology and scientific knowledge
related to monitoring and measuring airborne concentrations
of asbestos fiters.
2. NIOSK Is Responsible for Generating Considerable Confusion anj Misunderstanding Concerning the Frec.sion of the Entire Monitoring Process
It is clearly documented in the attached Exhibit 3, that NIOSH has even overstated the precision (claiming it is better than any available data support) of the entire monitoring and measuring procedure for airborne concentrations of asbestos fibers m the range where NICSH claims it has been successfully applied, by referencing inadequate and inappropriate ai-uiies.
Some of the visible NIOSK effort, such as the PAT program,
is highly commendable. However, some of the NIOSH reports, are, at best, inadequate. NIOSH is responsible for generating considerable confusion and misunderstanding concerning the precision of the entire monitoring process. We believe that NIOSH has an obligation to publish
competent scientific reports. The complete lack of scientific rigor cn the part of NIOSH, in this regard, is inexcusable.
3. There Are No Data Available to Support a Conclusion That the Standard Method Recommended by OSHA and NIOSH Is Sufficiently Pr--P.cuulatorv Purpose's". Particularly At Airborne Concentrations Below 2 Flbers/CC
Exhibit D, attached hereto, reports on our investigation of the empirical precision of the entire process for the estimation of airborne asbestos fiber corcentroticns. Based uper. our investigation, we conclude that there are no data available to support a conclusion that the standard
______
_
___________ _______________ low
^ fibers/^co. Thia conclusion is extremely important
inasmuch as OSHA health standards can be, and are, enforced
in the abaolute sense. OSHA published permissible exposure
limits are not promulgated or enforced as a 'goal", as
is tha case, fer example, with the British asbestos
Page 22 April 3, 1376
standard. If a permissible exposure limit of 0.5 wara in fact promulgated ss proposed, and if oasad on a complianca inapaction an OSKA industrial r.ygienist was to raport an airborne concantration of 0.6 asbestos fibara, a citation would ba iaauad. At tha aama tima, tha industrial hygienist for an employer might wall find less than 0.S fiuer/cc present. Based on tha results of our studies, tha uncontrollable variables in the antira monitoring process causa tha co-efficient of variation to increase to such an axtent when monitoring and measuring small airborne concentrations of asbastos fibers, that one would hava to find a concentration of asbestos fibers above 3 fibers/cc to be reasonably secure in the determination that tha levels ara, in fact, above 0.S fiber/cc. Since the empirical precision of the entire monitoring process is subject to so many uncontrollable variables, the equitable enforcement of a permissible exposure limit of 0.5 fibers/cc becomes inpracticable, if not impossible. Controlled laboratory studies, theoretical investigations, and most importantly, actual workplace sampling, have shown that the monitoring process cannot distinguish between 0.5 fiber/ce and 2 fibers/cc.
Based on J-Mls recently completed, in-house study on the precision of tha entire monitoring process, as reported in Exhibit 0, we have concluded that the accuracy and precision of the entire monitoring process, as alleged by KIOSH, is clearly not supported by the data presented from our own study. It has also shown that othar NIOSH data also contradict the claimed accuracy and preciaion. It is obvious that to propose the use of a single co-efficient of variation of a tingle segment to describe the entire monitoring process,.in all environments, is to ignore the facts. The variation of the entire monitoring proceaa depends on many factors, among them other airborne contaminants. Although more data ara needed to verify it, logic iould dictate that all other factors being equal, these uncontrollable variables in the entire monitoring process, would cause the co-efficient of variation to increase for smaller airborne ashnttes fiber concentrations. This points cut the fact that it becomes virtually Impossible to monitor in the framework of a compliance-no compliance situation, in the range of concentration! below 2 fibers/cc.
Docket Officer Page 23 April f, 1376
In Exhibit 0 we have alao reviewed all availabla lltaratnra on tha antira aabaatoa monitorin? procaaa, and we conclude that tha problem of tha inherant variation of tha procaaa haa baan mlsraprose..L*d and miaundaratood. While it may be tha beat practical method available, it haa vary limited preciaion, particularly in lovar ranges of airborne fibara. An actual airborne fiber concentration of 0.3 fiber/cc will routinely produce sample counta of 2 fibers/cc or more. A solution generally offered to improve tha preciaion of tha antira monitorin? procaaa, ia to increaae tha number of aicroacoplc fialda and/or fibara countad. This ia an expansive, time-consuming effort that perpetuates tha mlaconcaption that fiber variation of tha filter and microscope slide ia tha only source of variation of any importance. This mlaconcaption ia discussed in detail in Exhibit 0.
In stating tha juatlfication for tha Proposal, OSHA states or. page 47633 of tha Proposal that:
*!n addition, OSHA believes that new research davalopawnta regarding tha harmful effects of asbestos exposure, as well as advances in monitoring and protective technology, make re-examination of the previous standard's
premises and general structure desirable.* (ea^hasis added)
This statement must be regarded as unsupportable rhetoric, since there is an absence of any bibliographic references as a basis for OSHA'a allegations of `advances in monitoring.* As a matter of fact, 'advances in monitoring* do not exist and recent studies all are in the direction of shoving serious limitations of vhat at one time vas thought to' be good monitoring methods.
Zn conclusion, it is impossible to monitor a difference be tween 0.3 fiber/cc and 2 flbers/ce in tha workplace using a monitoring process that cannot distinguish between 0.5 fiber/cc and 2 flbers/cc. Turthermore, there are no known modifications to the method that would permit such monitoring.
Docket Officer
Pig* 24 April 9. 1976
TSCHNibcgicAi feasibility if attaining a o.s fiber/cvbic
CENT IHE'.'iA 7Wa A; duANL
RATION IF ASBEST'i TIBER
IN THE y.'CP.k?LACE~
1. OSHA's Rilicr.a. for a 0.5 Flber/CC Standard
Before discussing the technological feasibility of
attaining a permissible exposure limit of 0.5 fiber/cc,
it must be noted that OSHA states in the Proposal that
a permissible exposure limit of 0.5 fiber/cc was selected
ir. lieu of "no detectable concentrations" because of
technological and economic "feasibility." However,
OSHA offered no evidence whatsoever in the Proposal
o iimonr. one "feasibility" of a permissible exposure
ilr.it of 0.5 fiber/cc. Again, this statement by OSHA
must be regarded as 'insupportable rhetoric. Not only
should OSHA have provided such evidence in the Proposal,
it m.u3t set forth such evidence m ar.y standard
intimately pror.ilgated. Based on our own evaluation,
we believe that sufficient evidence does not exist to
support a determination that a oerris'i' >> exposure
1 in" * -f l.E f.ber/cc is, m fact, technologically
feaeibie to attain.
2. Analysis of the Technological Feasibility of Attaining a 0.5 Fllser/CC Permissible Exposure limit
Exhibit E attached hereto provides an in-depth analysis of the technological feasibility of attaining a 0.5 fiber/cc permissible exposure limit at J-H facilities manufacturing asbestos-containing products.
(a) Despite a 40-Year Effort to Control Airbcrne Concentrations of Asbestos Fibers, There Is Nc Existing Techno1 mm, -- "-'fcr-ily Bodice TWA
Exposures to Below-0.5 F/CC, Regardless of What Efforts We Exert
For many years, J-M has continued to install and upgrade mechanical exhaust ventilation >/--i, modify process
equipment, and --`.tiodice new work practices in its plants manufacturing asbestos-containing products, in an effort to reduce the airborne concentrations cf asbestos fiber to which its employees are exposed. These
Socket officer Page ;* April 9 , 1976
procedures have been continuously upgraded and improved as the 'state of the art* of dust control advanced.
Dust control mechanisms which wa installed prior to December 1971, whan tha Threshold Limit value or
permissible exposure limit for asbestos dust was S mppcf, wars not designed solely to achieve S mppcf, but ware designed to attain the lowest possible airborne
concentration of asbestos dust in the workplace, with the goal of reducing exposures below that level in all of our asbestos-using operations. He employed what we considered, at tha time of installation, to be the best
available technology.
Efforts to control airborne concentrations of asbestos
fiber at J-M facilities dates at least as far back as
the mid-1930's.
--
Surveys performed by our industrial hygiene laboratories,
using the impinger technique, revealed that by 1970/
wa were close to achieving our goal; approximately
90% of our monitored asbestos-using work stations were
under the then existing TLV. In December 1971, OSHA
promulgated its emergency standard for exposure to
asbestos dust, which specified an. 8-hour time-weighted
average exposure limit of 5 fibers/ec, as determined by
the membrane filter/personal air sampler technique. An
analysis of our industrial hygiene data in early 1972
showed that, due to the change in the required monitoring
technique, only 60% of our work stations complied with
the then new OSH* evnosure limit; contreeted to over
90% compliance with tha previous TLV.
_
Following tha promulgation of OSHA's emergency standard in December 1971, J-M immediately initiated programs to comply. These programs ware further intensified
after promulgation of the permanent standard, with its _ requirement of an expoaure limit of 2 fibers/cc by July 1, 1976. As in the past, our programs wera not primarily assigned to acnieve 9 fibers/ce or 2 fibers/ec, but rather, were targeted towards achitvlng the lowest possible level, with tha minimum goal of all work stations being below 2 fibers/cc by July 1, 1976. He employed
what ve considered tc ta the best available dust control technology, and instltutad practices and procass codifica tions that wera davalopad for thosa situations where wa bellevad available dust control technology would not be adequate. In some instances whara control was not feasible, the product was abandoned.
3y mid-1975, it appeared that our environmental control and other efforts would be successful. Industrial
hygiene surveys showed approximately 90% compliance with the July 1, 197$ limit of 2 fibars/cc.
When OSHA published the October 9, 1975 Proposal, we examined our industrial hygiene data to determine our compliance status. This examination indicated that as a result of our intensive past endeavors, 451 of our monitored work stations were in comnl i nc ith th piupoaea permissible exposure limit of 0.5 fiber/cc (subject to the precision of the monitoring method as
discussed in Exhibit 0). This figure does not take into account the discontinuance ofc operations and products which have been abandonee because of our inability to' meet even the current OSHA asbestos standard.
It must be clearly understood that the attainment of
45% of our monitored work stations below the proposed
Permissible Exposure Limits, in no way implies, let alcr.e
assumes, that the application of best available technology
can similarly reduce airborne concentrations of asbestos
fibers at all of the remaining work stations. To tha
contrary, best available t^.:...l.~y
already been
applied to most of these work stations. It is fair to
conclude that 45% of our monitored work stations do
comply with tha proposed Permissible Exposure Limits,
cr.ly because best available technology was successful
.it these stations, and was not successful tc the same
extent m other procesa steps in our facilities where
the same control efforts were made. Certain process
steps have major problems and still regularly produce
airborne concentrations of asbestos fibers well above
0.5 fiber/cc, with tone process steps sven above
2 fibars/cc, despite our efforts to install the best
available dust control technology.
Our study of these problem areas has convinced us that in many instances, application of best available technology will not enable these process steps to meet the proposed Permissible Exposure Limits. Entirely
Locicet Office Page 27 Abril 7. :9?
.T .3'. it; we'.` -cped ; -ir mtees t:\at
In summary, we
not ieer. success!-1 in reducing
employee TWA exrrsiros to airborne -; ir.ter.tr sticns of
isceitci fiber* ceiow 2 flLers/rc at all work stations,
aespite the consider ab!.** ef forte of many years standing.
There is no technology to 'unifont.iy reduce ?WA exposures
to below 0.5 fiher./cc, irrespective of what efforts we exert.
(b) A Permissible Exposure Limit of 0.5 Fihrs/c<~ will Require the Virtual Elimination of Any Airborne Concentrations oi Asbestos
The enorruus effort and expense which is involved in
virtually eliminating the airborne presence of any substance,
assuming it is even possible at all, must be recognized
and appreciated. The promulgation of a Permissible
Exposure limit of 0.5 fiber
-cul-
require
cue Viti-ui elimination of any release of asbestos
fiber from manufacturing processes into the workplace.
This would be necessary in order to take into account
the ambient background levels of asbestos.
Furthermore, in order to operate under a Permissible Exposure Limit of 0.5 fiber/cc, one mu3t, in fact, design and operate below this limit, in order to avoid periodic uncontrollable fluctuations above the limit. Therefore, the technological effort and cost involved will be further Increased in magnitude, assuming such levels could be achieved.
Obviously, substantial accomplishments have been made in the past 40 year: to reduce airborne concentrations of asbestos fibers to which workers are exposed. As is well recogniied in general environmental controls, the technological effort and cost involved in achievir.o a 95* reuuction. for example, in the cmiisior. of a pollutant, can be increased by several multiples in
order to achieve a further reduction of several mere percentage points. This is certainly tne case with respect to achieving any further reductions in airborne concentrations of asbestos fibers to which our employees
are exposed.
Pag* 23 April 9, 1976
How ttino no* 13 unnecesszrily high in anclhi aima can influence costs ws explained L, Transportation Secretary Coleman in a recent ipeech:
'Kith the fund* provided in the rail act we can eliminate the deferred maintenance that hae accumulated along the corriders since 1969, rehabilitate the bridges, and improve signaling and control systems to permit safe travel at speeds of 120 miles per hour. We will, in effect, achieve smooth, reliable service which permit consistent trip times of two hours 40 minutes between Washington and New York, and three hcurs 40 minutes between New York and Boston, all at lass than half the cost of the investment required to reduce those times by another 10 minutes Washington to New York and 40 minutes New York to Boston.' (emphasis added)
, . Ins July 1. 1976 Mandated Standard of 2 Flbers/CC Must Remain Unchanged
Pursuant to Section 6(b) (5) of the Act, the Secretary of Labor is .authorized to set standards which 'most adequately assures, to the extent feasible, on the basis of the best available evidence, that no employee will suffer material impairment of health or functional capacity...* (emphasis added). This authority also obligates the Secretary to weigh the benefits to employees against the burdens on employers. In the instant case, the best available evidence would appear to Indicate that a TWA Permissible Exposure Limit of 2 fibers/cc will not have any adverse impact on morbidity or mortality. OSHA's conclusions to the contrary are based on the conclusions of certain researchers, which are not even supported by the data gathered by these researchers. In other Cases, OSHA h-a reached certain conclusions from the doth not even reached by the researchers themselves.
The aubetantial uncertainties which do, in fact, exist as to the feasibility of uniformly achieving a Permissible Exposure Limit at any level below 2 fibers/cc must outweigh any conceivable benefit to employees, particular! inasmuch as OSHA has totally failsd to prove any such benefit in fset. Furthermore, in Industrial Union Department, Ail-CIO, et al., v. James D. Hodgson
Docket Officer Page 23 April 9. 1976
(499P. 2d 679), the U. S. t._rt of Appeals held that:
"Congress does not appear to have intended to protect employees by putting their employers out of business - either by requiring protective devices unavailable under existing technology or by making financial viability generally impossible.* (emphasis added)
Inasmuch as existing technology will not be sufficient to uniformly reduce airborne concentrations of asbestos fibers to any level below 2 fibers/cc, the July 1, 1976 mandated standard of 2 fibers/cc must remain unchanged. OSHA has selected its proposed Permissible Exposure Limit solely on feasibility. However, existing technology will not uniformly achieve such a limit.
OlHA APPKOACH
1. OSHA Must Consolidate the Hearing on the Proposal to Revise the Existing Asbestos Standard for the Construction Industry with the Hearings on This Proposal
The Proposal states, *It is OSHA's intention to develop and propose a separate revision to the existing asbestos standard for the construction industry... the uniqueness of the construction industry itself (viz., the multiplicity of non-flxed workplaces, and utilization of high transient workforces) strongly suggests separate treatment."
He agree that there are certain unique factors present in the construction environment, and not present in a manufacturing environment, which warrant special attention, including, but perhaps not limited to, a modified, approach to compliance.
The Proposal further states that, "Cpon publication of the proposal to revise the existing asbestos standard for the construction industry, OSHA will consider the possibility of consolidated hearings on that proposal and the proposal contained herein for all other covered employments."
Cocker Officer Page 30 April 9. 19 O'
We strcr.TLv urc**
'*o*"?',T'li-its *J".c hc^ri.r.~s
on -r.e proposal on
*V; o^i-'.ir.g asbestos
for f.-.e ccfistruciior. industry wit.-. the
heari.-.gs or. r.-.is Proposal. The manufacturing and
construction ..-.i-stry segments are so intimately
related, that to io otherwise would be a grave mistake
. a.-.d would result m a gross injustice to the entire
asbestos industry. The majority of J-M's asbestos-
ccntaini.-.g products ar<: either directly sold to or
u.tim-iteiy used or installed by the construction
industry. Therefore, any proposal to revise the
existing asbestos standard for the construction industry
will most definitely nave a very significant impact
on J-M and other manufacturers of asbestos-containing
products. Asbestos product manufacturers have a vital
need to know the effect the construction industry
standard will have on the continued use of asbestos-
containing products in construction. Will there still
be a market to justifv th co*t of oompi^auus in
--i.lecturing? At the same time, the construction
industry nas a vital need to know the status of the
continued availability of asbestos-containing products.
Therefore, we strongly urge OSHA to postpone hearings on this Proposal until such time as a proposal to revise the existing asbestos standard for the construction industry is published and hearings on both can be scheduled jointly. There can be no logical reason to duplicate testimony and evidence relating to such natters as toxicological considerations of exposure to asbestos, considerations concerning carcinogenicity, monitcring and measuring airborne concentrations of asbestos fibers,
etc.
2. OSHA Must Adopt a Uniform Approach Towards Peculating Carcinogens
Tt is apparent that the Proposal di*fers in crgsmroticn
and requirements from other current and proposed OSHA
standards covering carcinogenic substances. Although
it is obvious
certain previsions of OSHA's health
standards need to be modified to be appropriate for
application with respect to specific substances, it is
mandatory that the general format of all health standards
covering carcinogenic substances bs identical in view
of the stated OSHA position on dose-responss and
threshold. Needless languags variations bstvser. such
standards ars inconsistent with the objective of the
OSHA/NIOSR Standards Completion Project of enabling
n n in i i 1" (X
UU * T
Pocks? Officer Pag* 31 April 9. 1976
cmplcysrs to better understand ana comply with xisting OSHA safety and health standards. The commonality of the provisions within health standards will greatly assist employers In the understanding and administration of this and the increasing number of other standards. Inasmuch as unnecessary
uniformity In provisions will facilitate maximum applicability to various standard*. Employers would be relieved of concern for the possible significance of minor wording variations between analogous paragraphs in different standards. Therefore, we urge OSHA to revise the epeciflc language in the promulgated standard to conform with the specific language set forth in other current and proposed OS HA standards coverning carcinogenic subetancea, as has been done in Exhibit 0 attached hereto. W* strongly believe that such an approach will beneficially assist employers in the understanding of and compliance with thl; ctunduid.
furthermore, we have a serioua question regarding the basic approach by OSHA with regard to regulating occupational axpoauras to asbestos, versus osha's approach towards regulating other carcinogenic substances in the workplace. In the proposal, OSHA reaches the following conclusionss
1. 'Prudent policy would therefore seem to indicate that every reasonable measure should be taken to eliminate human exposure to chemical compounds as soon as their carcinogenic nature is identified.
2. Because of the variability of individual response to carcinogens end other factors, the conce'pt of a single 'no effect' or 'threshold level' may have little real significance on the basis of existing knowledge.
2. OSHA recognizes that thsre is no assurance of a safe exposure for a substance with known carcinogenic property, in this case asbestos, and thus there should be no detectable concentrations.'
In only one existing occupational health standard, the Standard for Occupational Exposure to Vinyl Chloride (29 Cflt 1910.1018), has OSHA taken a standards tatting
. mk " ^
I j
'1 ,1
1 m fl fl
9
I )'
|
Docket Officer Page 12 April 9, 1976
individuals ara occupationally axpoaad, yet 3SHA has not applied these conclusions to all such substances. Not only do va baliava that such an approach is not warranted frem a health standpoint, but the literal applicatlsr. ,,f the above stated conclusions to all carcinogenic substances in the
workplace would inevitably result in the complete shutdown of U.S. Industry. For the reasons set forth in Exhibit C attached hereto, OSHA's conclusions and actions in this regard ara erroneous, and frightening in the extreme.
Certain very clear and obvious distinctions must be
made between the facts known regarding the health
effects of vinyl chloride and the state of knowledge
of the vinyl chloride and PVC industry (regarding the
technological feasibility of controlling airborne emissions
of vinyl chloride) prior to October 4, 1974. First, little
knowledge was available at the time regarding the health
effects of vinyl chloride and the levels of exposure
responsible
----t the known health effects, in order
to establusn a dose-repcr>; relationship. Prior to
January 1974, there wasn't even a reported association
between occupational exposure to vinyl chloride and angio
sarcoma of the liver. By October 4, 1974, fewer than 20
cases of angiosarcoma of the liver were reported worldwide
among employee* and former employees occupationally ex
posed to vinyl chloride. No detailed exposure data for
these individuals were available, nor are they available
even now. Prior to January 1974, industry, the medical
community, and appropriate government agencies were not
following populations occupationally exposed to vinyl
chloride, from a monitoring or health standpoint. The
announcement by B.F. Goodrich and NIOSH in January 1974
was unanticipated by industry and the medical community
in both the U.S. and abroaa. ibis is not the case with
respect to asbestos. A great deal of knowledge has been
developed over the years, as is well evidenced in
Exhibit B, to support a conclusion that a TWA Permissible
Exposure Limit of 2 fibers/cc will not result in any
detectable increase in incidence or asbestss-relatwd
disease.
Second, in Is fair to say that prior to January 1974,the vinyl chloride and PVC industry had no basis upon which to determine whether or net it could develop and introduce engineering and work practice controls to reduce TWA exposures to below 1 part per million. They had never tried. In the pest, control efforts were solely criented
.) i n n ') .) u u
,,
1-0
Duukei Officer Page 33 April 9, 1976
tu the exposure level* protecting against the development cf acroosteoiysis and an exploaion hazard. Tney did r.ot have the benefit of many years of experience in controlling occupational exposures to vinyl chloride. This is not the case with regard to asbestos, as is wall evidenced in Exhibit E attached hereto. He have been working continuously for approximately 4C years to install mechanical exhaust ventilation systems, modify process equipment and introduce new work practices in an effort to reduce airborne concentrations of asbestos fibers in the workplace. These efforts represented the application of best available technology at the time. Despite considerable efforts of many years standing, we have not even been successful in reducing employee TWA exposures to airborne concentrations of asbestos fibers below 2 fibers/cc at all work stations. At the present time and based upon our extensive documentaM* experience, we can accurately stale cnat there is no *vioting iwcnnology to uniformly reduce TWA exposures to below 0.5 fibers/cc, irrespective of what efforts we exert.
Therefore, it is neither appropriate nor justifiable for OSEA to taktf the same regulatory approach towards asbestos as has been taken with regard to occupational expoaure to vinyl chloride.
3. Proposed Section 1910.1001 Must Be Rewritten Consistent with the Beet Available Evidence
Aa is clearly evidenced from the preceding discussions, many of the prevision* 1.. u* proposed Section 1910.1001, as set forth in the Proposal, are not supported by the best available evidence. Rather than attempting to summarize each and every one of our concerns, they cannot be expressed any more eloquently than has been dene in Exhibit F attached hereto. Exhibit F ii'REFACi) sets forth Our concerns in detail. Exhibit G attached hereto, is a rewrite of the proposed Section 1910.1001. Section 1910.1001 has been rewritten in accordance with the applica tion of tne best available medical evidence. Exhibit F, toe PREFACE, sets forth our concerns, and provides sound support for the additions, deletions and modifications proposed.
Locket Officer Page 24 April 3. 1376
wV.n.w31Ui'
Aa la wall recognized. l! the goals of the Occupational
Safety and Health Act are to be achieved, voluntary
compliance and cooperation by employers and employees ia
eaaantial. However, OSHA'a proposed reviaion of the currant
aabeatoa standard ia arbitrary and capricious and discourages
voluntary compliance. OSKA ia discouraging employers from
installing beat available technology to achieve compliance,
by unneceasarily and without any valid justification,
propoaing to drastically change a standard only recently
promulgated, and not yet even completely in effect. What
assurances does industry havs that OSHA will not propose
even further modifications ir. a few more years? Industry
nas made a staggering investment in terms of manpower,
ef.ort and coat in the past 3>i years to achieve compliance
with the current 5 fiter/cc standard and the July 1, 1376
standard of 2 fibers/cc. It is likely that many of these
investment* may
have hsan ,,.ade at ali, or different
approaches taken and different investments made, if Industry
had been directed in 1972 to reduce ail TWA airborne
concentrations of asbestos to below 0.5 fiber/cc.
In certain process steps in various industry s-'oments, best
available technology will not reduce TWA airt .ie concentration)
of asbestoe to below 0.5. It ia also likely that certain,
if not many, employers would have abandoned various operations
and products, in view of the serious uncertainties as to
whether any efforte wou'd have been sufficient ^o reduce
TWA exposures to below O.S fiber/cc. Furthermore, there
are many instances where employers would not have utilized
certain sngineering controls installed in t*--
?v yea-s,
if thay knsw at the time that a Permissible Exposure Limit
of 0.5 fibers/cc would be mandated in the near future.
Large multi-plant employers, with more than one manufacturing
plane producing asbestos-containing products, will likely
pilot-test new engineering technology and equipment. That
is, they will introduce it liist in gust one manutacturing
facility. If it is successful in reducing airborne
concentrations to below the Permissible Exposure Limit
(e.g. 2 fibers/cc), then it will be applied to the remaining
facilities. However, if the pilot installation indicates
that the technology and equipment is only successful in
reducing airborne concentrations of asbestos to within a
range of 1-2 fibers/cc, the employer would have been
foolish to have applied such technology and equipment at
all of his remaining plants, if he had knowledge that the
mandated Permissible Exposure Limit wculd be reduced in
Docket Officer Page 3} April 9, 1976
the near future to 0.5 fiber/cc. Such employer would likely and prudantly chooaa to forestall auch further application and investment, and devote his resources towards developing new and advanced technology. In many instances, substantial investments have been aide which cannot reduce airborne concentrations of asbestos to below 0.5 flber/cc. and nay ultimately be abandoned.
A critical review of the best available evidence dictates that the OSHA Proposel should not be adopted for the following reasonai
1. A TWA standard of 2 fibers/cc will not have any adverse impact on the morbidity or mortality of individuals occupationally exposed to asbestos.
2. The OSHA/NIOSH recommended monitoring method is unable to distinguish between 0.S fiber/cc and 2 fibers/cc in workplace monitoring, thereby rendering the 0.5 fiber/cc proposed Permissible Exposure Limit moot and a fiction.
3. There is no existing technology to uniformly rdu'-' TWA exposures ts bwluw o.s tioer/cc, regardlees of the efforts exerted.
OSHA's actions in making this Proposal, whan viewed in light of the best available evidence, are so contrary to auch evidence as to be arbitrary, negligent and untenable.
In the unlikely event that the completion of ongoing studies of ths Turner Brothers Asbestos Co. employees and others in the next 2-3 year? Yield data that question this standard, a scientifically sound reappraisal will be in order. In the meantime, there la clearly no evidence to indicate that any excess incidence of asbestos-related disease will result from such an interim decision.
Finally, we request that OSEA schedule a hearing with reaperc to this Proposal. At the hearing, we will introduce evidence consistent with the objections raised herein.
'-try truly yours,
?.i chard P. Carter, Manager Government Affairs
T3XI
i'IO'* ;
; s.;cocr: 1.5*.= i * re
r. e ir.i zzr
tie.
jo^tratos,'
tod i i i :a t; r '.'lew . ; ~
; 3 *. i
S lC7
3o r.i.-:
:
:al IF cIXPGS . .'o TO ASisLbT-i
zz.'?z$\ :-ie cr.an'je for asoes*os "x:r;uc . .SHA
-r's 33 ev.io'.ce mat mere r.ss oeer. - Ljra5l ir.r t . x : c effects of 350estC3.
' - j 11 j
is st'-Jv 1 -\r y
1 .f me references cites C-SHA. t r 3 ". tr.cse references, cr'oiier'd ^ s so-r.ri "new infatuation. \: 03HA - ^ 1 ^ i r tne f c tc' ? - *. . ;'',rr*fir3'.
on tr.e toxic effects ' i
;. tr.e 3jr.star.11 s;
*"J
v.i' ifir r. :ri; :jM0n3
r :e : r. f^
r"" .ji ns .3
i
..= t.r.J row:
,,s c:tj; i?'-
JC.;;cv :n
:.-vd surnurt
: :r tne ^reposal: ,1, a cor.c i r ..0 of tr.e
li'.-'utj!-;
reliable prior *o 1972 aim mat acne u r i r.a liter reveals to data
to support r:,e jSlin contention tout 1 cons 1 derao le new : -. 1 0 rm 311 on
-----r:"
on me toxic etrects or asbestos : '2>
preliminary, unpublished ana r.or.peer-teview ir.om mov ..'-er,
cited oy OSHA as '...iportant segments o the r.ew information' on
tr.e toxic effects of asoestos: (11 certain of tnese oreliminary
ur.puolished papers suffer trom serious flaws and inaccuracies; and
(4) fact3 pertinent to tr.e Uritisn standard and otr.er dtitisn
studies nave seen grossly misrepresented.
It is clear tnat the 42 listed references on wnicn tr.e case is
made for a new standard are almost exclusively eoidemolog ical
studies. For tnis reason it is imperative tnat there is a common
understanding of tne terms that are generally used ar.d cf tne
:i;or pitfalls characterizing the methods employed. We relieve
tr.at the following d 1 **''ussir-
c""~ert v< *-h r,.rrr.\y
accepted authoritative principles of epidemiology and
0 .ostatistics.
2---- acts a"d Terminology
.1 croup or. population, sucn a3 a factor/ labor force identifisd for study, is often referred to as the study car.crt. in most studies, tr.e data collected on tne conoft's experience relative to a specific disease le.g. cases of lung cancer or deaths attributes to lung cancec) are Presented m summary, and treguently. tacuiar form. Ine two terms routinely u3ed to describe or cnatactenze a copulation's experience relative to a specific disease are incidence and grevalenc*. The population may ce a wcrxers study oonort.'tne resT3ents"ot a geographical area, an etnmc jroup. or
\r., it can 5* del i.m td &y arv specific
: ? f * r s i r> t
"" . .
of a di**a* ioc <j Ojujiitiofi
~ e r new ns** of tnat disease in -.h*
pop j i .11; vn or i-.q a soesttied period of tine (e.?. fi7< vears, on*
` : O . i? we*'*;, oivuinj t;.* nu*o*r of new cases ` incidence) I o jrvi in j ; oc:;lat;on cy me total nurcoer of oeoole ir. the
cop jI : t kn. .
. a'., i.'.ose w r. c c r, t e n c i a 11 y n i o n t r. v/ e cprtracted
tr.e l.irone ir- c -1 ^: . *. o to as tr.e rutcec at ris<. rives the
ciPeoc rate tor tne occu latter.. TO* incidence cote, sa tr.e
r ,:r :: :: corcarisor,. alicw3 c~e to 'contrast pop j 1 a : - ns of
iitfecvnt size .ir.j r.a r ac t c i s t: : 3 socn as variations it
residence, sex, race, smoxmo statjs, etc., in c-crr.s ji ac.*sc;tic
aiseas* ;atejor:os. Coer. j tr.*s* characteristics, ar.d as many
jtr.ers as t:/ t- designed- can serve to identify a scogcoup.
*, r - r * i - ^ etcerience way oe unovn or
rn o*
associated with nr. identifiable secqroup (for examcie ni^n ljnq
cancer r*re>' i -.*.*%/./ - i4r#*o s.'o*ers!, the peculations ac*
;,j ji: :.y i-.-iied into ip?ropmt subgroups (as with the example
jpove, or stucy and oresentation of disease data. To define a
population mote crec '-ly, aop'opciate additional descriptors nay
oe apoiieo. As one e -Die .r. tne case of lung cancer incidence,
sex and ape cay oe used, - for example .ten Oetween tne ages cf "i.l
and d4, at wmc.n time tne data would be that of aje-soecffic '
Incidence . Depending on tne disease, the ooculati'
av a"i rioTe : -
t ion . or.J ...e c.x/ objectives, data may oe
,,ceciicaiiy reported *n re-ation to nanv different factors.
The otevalence of a disease for a population refers to the total number o~cases, botn new and already existing, in tne oooulation during a specified period of time or at a soecific ooint in time, as for example, a one-year period, a five-year period, or one day for that matter. ay dividing the number of cases of a disease by the population at cisK, prevalence rates can be defined in a manner analagous to incidence raies. The term death rates is applied to the incidence of all deaths in a population,'that is the population s total mortality experience. Wnen deaths are furtner identified as to "cause,' tne information is idenrff>"d tne cause-specific rate and the oooul*zio -ay fv--or -e cnaricterize37'if one'wisnes. oy additional descriptors as noted
above.
population conort-raortality studies utilizing casue-specific death cates furthar characterized by age, sex, race etc analyzed in -elation to geographic locations, nations, states, or regions are a major component of the available information on the toxic
effects of asoestos.
Generally speaxing, the mortality experience of an exoosed cohort is compared with the mortality experience of a nonexgoiejT* population, when a cause-specific death rate is^excessively nion for tne exposed cohort wnen compared with the cause-specific death
rite for tne nonexposed copulation, the exposure experience 13 suspect in the causation. An ideal design for population health studies calls for the designates population of interest to o
n u
3
identified, quantified, 'pprnjrlatsly J.a<.nuu * tu it* cr.ar sc tsr 1 s tics i#.g. saoxlng nablts oc exposure levels), and tollovid tnrougn tia* t. measure and cacord tn* naalth
xpanancaa, most particularly in ralation to tn* anvironmental tactor* ot intaraat. Tn* observing of a population forward into tn* future through tin* is referred to aa a groacxctive study,
jnrortunately tnia ideal cesig,-. lui a atudy oZ' fns'effect'oZ an Trns>j; on a population ftoa a purely scientific point of view la
often not faaalbl*. For example, an elaborate prospective atudy may not oe practical because of cost or time constraints.
Diseases that are very rare (i.e. the Incidence rata is small) require an unmanageably large study cohort to assure that there will be enough cases of disease for study and tnus that significant data will be provided. Diseases that have long latent periods (i.e. diseases tnat require decades or even scores of years following initial sxposure befors they become manifest) may requira irapracticaliy long follow-up periods (tim* of on-goinq observation). Because of these problems, methods of invsstigadon that utilize events that have already occurred (ratner than waitinq for future observation of the disease experience) have been developed. This general approach of loosing back at Historical evidence (in contrast to the prospective or present or future approach) is referred to as retrospective tnvti-otier.. unfortunately, one of the major problems frequently encountered in rtropctiVe investigations is incomplete, unobtsinable or questionaoly reliaole previously accumulated data. In contrast, th* mors ideal prospective study allows for *xtensive planning for data collection adequate to assure that all hypotheses of Interest
and merit can be investigated. Thus retrospective studies ars never as reliable as prospective studies frost the standpoint of the conclusions drawn therefrom.
Since the bulk of the studies providing information about the
toxicological effects of asbestos are retrospective in nature, an understanding of tne three recognized types of retrospective study
designs is mandatory. The three types are (1) retrospective-prospective, (2) case control, and (3) case study.
A retrospective-prospective investigation attempts to retrieve
information on a study cohort beginning at an earlier-point in
time (e.g. 10 or 20 years earlier), and from that date on, it then
attempts to follow the population in the manner o* a oro3occtive
study. Inherent limitations in this study approach include
variations in the quality and reliability of the data that
characterize the members of the cohorts (e.g. intensity of
sxposure, duration of exposure, work location, smoking habits,
see.), in addition the frequent inability to follow up
(individuals who drop out of signt and cannot be traced cause real
problems) interferes with accurate estimation of incidence or
Prevalence. These limiting factors in retrospective-prospective
studies have immediate application to the study of
*
asoestos-related disease, since many of tne asbestos
Conort-mortality studies ars of this type.
The case-control method identifies Individual cases of the disease
of interest and anicnti ot pairs up sacn caa* un On*
iv,(i
controls (individuals who do not havs th dissass) , catching being
in terms ot uaa aqe, saa, qanaral anvironaant. stc. Matching Is
ths K2 to retcospcctivt case-control studies, the essence of the
case-control investigation is to natch cases and controls on all
possible characteristics other than that which is the reason for
the study (in this case, asoestos exposure). Cases and controls
are tnen compared for this specific characteristic of interest (in
this case, the pattern of asbestos exposure). For exanole, if
more asbestos exposure is found in the lung cancer cases than in
their nonlung-cancer controls (here lung cancer is the disease)
asbestos exposure is the characteristic of interest) , then
asbestos exposure has been found to be associated with lung cancer
in tms study. The case-control design can be useful in the
investigation of rare [very small incidence rate) diseases.
There are wcll-xnown limitations inherent in the case-control aetnod. Inability to match the case to the control is caused commonly oy inadequate records describing both the case and the control in terms of tne features to be matched. Thus, dependency upon previously accumulated data wnich commonly is inadequate, impairs tms method in a way similar to that v.nich limits the retrospective-prospective approach.
| I
1
' '
In spite of the limitations o. tne first two retrospective designs I described above (cetrospecti*e-orospective and case control) they allow for some formal analyses of the data to identify increased risk groups. For our kinds of purposes, an increased risk group is that part of the population identified with the characteristic
that has been shown to be associated with the hiqher incidence rate of a particular disease.
The third retrospective design, namely case study, does not permit formal analysis of the data. The case-study approach aimply describes each case as completely as possible and the cases msy o* collected without adherence to specific experimental design rules, since formal comparison wit*' *Uk*r reworkets er other population! cannot be made. Obviously, cases can be collected for a case-stud',
report either retrospectively or prospectively. Retrospective case-study collection Is the most frequently used when awareness of a new problem points to the gathering of all the information that can readily be obtained. Formal risk assessments are not
possible with the case-Btuuy design, altnougn they can oe very helpful in tne early stages of the investigation of race diseassi
Many of the mesothelioma citations are case studies. .
From tne discussion of these methods it is apparent that tne onl. useful one for determining risk assessment in the establishment TLV's relatinq tne dytee of cUik to the amount of exposure (i.. the quantification of dose-response relationships) is sithec the
prospective or the retrospective-prospective study design. In such studies, the effect of exDosure on health is the parameter ' Interest. In addition, hovevtr. Information relating dose to
*
o
fr.*- c.rr::r ("vieoc i n U s i ~
Patter Tear. Sn-rific
- j- 'i `
j_r- c 7yr s_i j rl^i :n ...-J uOse- Sec nor. " e Ft. j;nnmios
_:-.ce neitner --> current r.C: pcuocsed GSHA asbesws stsndacds ifiow empieyers to average toe exposure of several worxers emaqed
different activities or to average over several dav3 or months '.t excosute, limitations innerent in averages soon as tnose on wnio.n the C5riA proposed standard is Sased reauire discussion with r-'spect to the way in. which individual exaosutei (QSHA Regulations) relate to averages .r the workplace- Furtherm---
averaging exposures far the puroose of con. p L i uc 11 ng dose-response r1 a 11 ons.n i 03 *"-di tp conceal the true oiologipai dose level . --uc ol me uiiuting effort of low exposures on the nigh individual expcsu-ep.
GSKA reference No. 19 (Nicholson [1975]) is a clear misapplication
of averaging data if it is to oe ultimately related to inci/tdual
exposures. The author states: Using the standard membrane
filter tecnnique proposed- by tne U.S. Puolic Health Service for
counting asoestos fibers, three different Laboratories m tne
United States have found that average concentrations of asoestos
dust m insulation worx oetween 1969 and 1971 ranged-from 3 to
icpjt 6 f/ml.... However. ovec naif the time of U.S. insulation
lexers during tnese years was spent using other mstr?a>....
Considering t.nis di str i bu t icn of
woix activities, the
decal! time-weighted average exposure of United States asbestos
otxers in the late i960 s was less than 3 f/ml. Nicnolson goes
n to report on an additional set of averages: 'Tne data from
fnese tnree studies would suggest that the' insulators' average
-xpes-rtrs m. the United draper during Dasr years could have raned
r' " io to l i f.'mi." (e.upnasis addedl One of tr>e references ut
;U1S Nicholson (1975) manuscript was: Nicholson, ,i.J. 1975 .
ijiacion Hygiene Progress Resorts, ''cl. 2:1. dt. Sinai. The
following is a discussion of tne reasoning and data manipulation
- f-hat at. Sinai report and the tacie below (dealing with 1
'f"yards discussed by Nicholson [13751 ) has been taxen frem it:
5
TAIL! I
SMpytrt nhrWM fiber tacMnUM by Kikmm cwmt-- IMf, INMt
mm MM.
wrer ro
I
mm Hirer cm
i lift* Mf*ff rat
< tmm
MffCf l
MflHTmF
mm (m
SlMf A cl i'll? Ns. .* .>.. va^.w-J
Vwmj atxJ fjtxtcation General room a*c
The fojlowtftf thop
Band u* culling
vemem
Scrap fnndift|
U
j (' i i i o n* : <
;!
a r1 *. : * l '
0 I \5 o
::
001 n 4 o 4
;*
--
i -6 o ;7 v 4
0 3 luh
!* o 6' ::
ii 0> 1 1
0 02 i; '
were Ji-ne m inircqoeni tmcrvilt jr*J insi4>cJ .wily me *. 4 m*tsi. two men
0 \l 4 :
3 0 106
h :9 2H
0 7 24 7
--
o: 7 Q
1 7 60
3 1 IU9
0 23 Hi
0 01
--
"i
0 47 16 6
Aboard .Ship So oi men etpoteO < \ 945i
Avg. e*poture. ail jcnt(X'
461
o o: o 7
?iJO 2 S VS
-- ibu
1I
.w
0 17 6 0
0 03 , .
Time Wfif hied Aerafc fcrpokur* i 1 90 l All fihrr 'M'lhlei
35
`
All of cue above data in taole 1 were available prior to 1972 as
ic merely presents data from fleisner et al (1946) and Muipny
(1966). Nicholson, in .1/Tih\t these data -r. the lepoct states:
"These woulu include tiDers pernaps as short as 1.5
microns,...this overestimates the number of fibers lonqer than 5
microns by a factor of 2." It should be pointed out, however,
-
Fleisher et al (1946) state: "Asbestosis results from breathing !
asbestos fibers of relatively lorn? lenqth, such as 15 to 75
i
microns. It is not caused by bceathino chopped up asbestos fibers !
of one or two microyis (1). Therefore we are concerned with the J
presence in air of asbestos fibers whicn can be easily seen as
.
such under low power of the ocdlnary microscope." fleisner et al ;
(1946) used the phrase "which can be easily seen as such
(relatively long length), it does not 'just" sav, can be seen.
The conclusion of the Mt. Sinai report and the quote from Fleishe:
et al (1946) are in evident disaoreement. Nicholson a division c:
all fioer counts by a factor of 2 is clearly arbitrary.
furthermore, Fleisher el al (1946) state: The figures liven in table 5 (of Fleisher et al) for shop average and.ship average cannot give a composite picture of the asoestos dust that a wor<i: may oteatne over a period of yrs . m* snip average referred v is also given in Table I of the at. Sinai report, wnile the snog average nas been calculated differently. Thus, the authors of mt original work took tne pro.action of specially noting tneir
judgment that the numbers could not be used as they nave been m the Mt. Sinai report.
for the sake of discussion let us assume that the time-weighted
average esposure calculated in the Mt. Sinai report does represet' a typical worker ekposure. Shipyard B in reference 1 represents 45 percent of the workers (75B out of 1645) studied in 1945.
Sven using the
i-itle fi'. tor of 2, tne tyotcal worker would
achieve a 90 floer-year/ml exposure In only two years. That
represents a 42-year exposure at tha TLV of 2 (/ml. without tha
facrnr of 2. tne typical " worker gets an antlta maximum workinq
lifetime exposure (at TLV of 2 f/ml) In only one year
Fur theritnr. -_-c numerical average establishes that some would'
achieve that exposure in iess tnan a year. Recalling that this
.ayieienti 42 percent of tha workars atudlad in 1)42. thesa
exposure levels surely cannot Da meaningfully averaged with very
low measured levels of 1.1 or 0.22 f/ml.
Shipyard C (Table 1 In tha Mt. Sinai report) was also observed by Murphy (1)68) in 1962 and 1966. Tne figures 0.27 MPPC? and 9.2 t/ml are divan for sewing and fabrication for that shipyard in Table I. This category is c. special significance in the report because of. the heavy weighting placed on it In the Mt. Sinai averaging process. Tha figure reported is only for 1962. however, wnen 1966 is included, the averages of .42 MFC? and 12.9 f/ml are ootained. In the averages given here and in the report, the authors, for reasons best known to thasiselves, have ignored one observation (Sample No. LK 3 fiom 1965) that was too numerous to count! The available figures in tact yield a weighted shop average of about 19 f/ml. Thus the all-man average of 1 h mi in
the report is far ton
The Mt. Sinai report is correct in that "a detailed analysis of
the result, however, presents difficulties.' However, Table I docs
tell us that large numbers of workers were exposed to conditions
many times over the 2 f/ml standard, even on a time-weighted
average scale. At least for shipyard C. the data suggest that
conditions were better in the mid 1960 s but still several times
the 2 f/ml standard. One very important fact must be kept in mind
concerning Table I: the observations are all for Insulation
installation while the tearing out" of Insulation. claislciny the
IusbIest~jpetatIon, ~Ti not repteiented ~at"'afI7
"........... ..... "
Similar manipulations were done <"* hg fatu from other references. For example, if a worker is engaged in activities giving 20 f/cc 10 percent of his days at work, and 0 f/cc 90 percent of his days at work, tne time-weighted average calculation
for ms total period of employment would oe 20 X .1 * "J X .9 2.0 f/cc usi.ig the Mt. Sinai calculation. This is clearly nor
'ar*sr in which compliance with one permissible limits are estaolisned pursuant to tne current or proposed OSHA asbestos standard. '
The "conclusion that the time-weighted average exposure of insulators between 1962 and 1969 was less than 2 fibers longer man five microns per milliliter," on page 2 of that report, 13 aased on what must clearly be described as much arbitrary and unjustifiable data manipulation. Those same studies show that
large numbers of insulation workers have both peak and ixe-weighted average exposures far above TLV's. The suggestion 'tnat the upper limit on insulators' exposures in the united
JOOJt IB
.tani t es t ly not
Harries <'.971, were alio presented in t-.e :-it.
rso'M riii* " T rt rrf>fr*^ m *'*o
^ C! 'J ! 1 OP. C t
* * '*''* " Dy Harries !L971 actually
-s:; Min exposures m z,m yews wnn
f/r.* standard. vir. tnouqn individual
:r ;n:-jlati"n workers 23 to
/ears
ire
tT,<fttnriat:cal .nodal ma o t a nyo-t t ne 11 o a l
sar<> Jata sources as the Mt. imji report,
1 exposure histories far out of co.floliance
:d. * fflatnenatica! ncdelim investigation to
L i.!,, - . '-ai exposures in the tca^eworx ',1 j 2
'.5 -v r In0:T.atw* than averoairvs different
wr.ion r.as oeen oone
imai
:.`.s-Ii".i:ns work' 3 ivtr
: a i n e i * - - -j*
case:
jl'lcliv. na n -
;iot calculated m tne same framework. namely individual exposures, as present and proposed standards
3 . Based on data primarily from insulation installation, having excluded the "tearing out'
operations.
The studies referenced oy the report actually provide firm evidence that the 2 f/cc standard will provide dramatic (factors of 20. SO or 10fl) decreases in finer exposures for large segments of the insulation workforce, when the exposures ace discussed in the same framework as tr.,, CCC,'.___c-,u-u u-andar 1. ir,.. detailed discussion of averages, using the Mt. Sinai report as an examole. r.as seen undertaken to:
1. Illustrate now misleading averages can he.
... Illustrate some of the extremely man exposures of past years.
Clarification of British Worker Population Studies and Their
5eI"ationini5 tu'tne Estaolisnment o"Sritisri Occupational
Simulations
"
In Section 3 of the 1975 Proposal. CSHA states: lor these reasons, NIOoH, in its evaluation of considerations relating to :
standard for occupational exposurt to asbestos (NICSH. Criteria Oocument, 1971) stated tnat tne recommendation of tne ur.tisn Occupational dygiene Society was given jteat weignt ih tne
n u
L'lfi
development o( thle etandard. ... In cm*, it I0SHA1 olaced considerable reliance on an addlciaiel facet of the Scltleh experience. Concur rently. a published report from the same factory by its medical director and racoonliad statlsttciana
Holmes. Do 11 and Hill, IRA*) Had indicated no significant increase in cancar mortality nad nen fot,"d --ng vocXecs first
employed in thia plant tuuiquan: ta 191}. wnen tna improved condition* mandated Dy tne 193V factory Regulation* earn* into
effect."
In Sac cion C of tna 19 ootainad from Great Be a difference Detween ; among worxets X-rayad
Occupational Hygiene S worxere in tna tame fa importance, new data r
the cancar ns* of wor British standard....' tha peasant D.S. tegul
from Great Britain m understanding of the a
ProDOtal. after discussing the data am in 1966, u5HA states: mere was tnus
prevalence of abnormal x-ray findings 1966 as reported to toe Sntisn iety, and evaluation of other X-rays of ory four years later...of significant " recently oeen made availaole concerning rs at the textile mill reviewed for tne
he impact of the BOHS recommendation on ion and the reliance on '.new Information'
e current OSHA proposal maxe a clear tish experience imperative.
. ne ronowir.g is a chronology of events and publications associated with the British worxforce of T.3.A. (Turner Brothers Asbestos. Ltd,). Available Britisn data follow the chronology.
1931: (December): British Asbestos Industry Regulations, 1931.
were promulgated. They were to be ohased in between Harch 1932 and March 1933. (Recent literature has indicated January 1 , 1933 a* the effective date for the regulations). Note: tne 1931 Regulations were not standards, they were regulations covering ventilation and respiratory protection.
No asbestos monitoring was required untii 1969.
19 33 : Ventilation systems were Introduced in Carding and Leaving.
1333: Damping techniques were established m tne plant s weaving
process. (It nas been reported that conditions have
remained approximately constant in neavinq since damping
' techniques ware esvablished.)
.
i?li: Inc plant's ventilation system was modified, replacing the
' settling chambers by sleeve filters (eliminating the need ' for the ha2ardous ---nation of cleaning out the chambers).
Rost wWII: Camping was extended to yarn doubling.
1351: Routine dust sampling was initiated (Casella thermal precipitator in MPPCF).
19g3-195I: The card extraction system was improved. Fibre tiling introduced at the mixing stage.
t
'pottd on i cohort (retrospective-prospective
mortality study) of all male
-..* :! w-,rd twwntv
or more yecrs in "scheduled area* li.. areas classified at
lusty oy Asbestos Industry Aegulatiwn*, 1911) up to the end
of 1951.
1959 : Open fi-or
d""* exhaust hooaa> truer blend!
replaced oy a totally enclosed system.
19 51 : Routine fiber count (rather than particle count) monitoring initiated (long-running thermal precipitatori .
1965 :
Knox and Coll (1965) updated and enlarged tne original Ooll (1955) cor.or t-Tor tal l ty study to the end of 1961 (the cohort numbered 199 at that time) ahd exoanded the study to Include ill workers vno were first employed on or after January 1. 1933 and completed at least 10 years in "scheduled areas. (347 men and 175 women r.at included before) .
1968 i
Knox et al (19 6 9) undated and enlarged the 1961 (1955/ conott-mortality study to the end of June 1466. Dust levels were reported in particles/cc for 1952 and I960 and in
fibers/cc fet 1961 and 1966. Tnis was tne first publication nr cr.vuon.ter.tal measurements.
1968:
The Sritisn Occupational Hygien Society (aOHS) Committee on" hygiene Standards published data on a cohort of 290 workers actively working on June 30, 1966 (it was a moroidlty prevalence study). This recommendation, based on using tne same dust measurements as reported in Knox et al (1968) , "* provided the actual numerical level (in f ibre-years/cc) for the British standard.
1969:
The British Asbestos Regulations 1969 were published oy km Factory Inspectorate. (The BOHS recommendations were utilized.) Asoestos monitoring (fiber counts) was renulred for the first tine in Britain with the promulgation of the
1969 regula Lie,..-.
1972i
A presentation of preliminary morbidity information bv Lewinsohn (1972) was published (discussed in detail below).
This paper precipitated a controversy and is an imoortant part of the "new information" cited by OSHA.
1973:
The BOHS Committee reviewed the 1969 recommendation, huoti.r: from the 197J reoort: "It is therefore recommended that r.o
change be made at tne pcesent time, tut tnat tr.e Standard :i Kept under review.
1973:
Berry (1973) used tne asbestos dust measurements published in 1968 as an example of the use of measurement daca'fot re setting of a standard. No new data were available in 1973. However tnis is the only'reFerence to "tne T.5.A7-dust'I<v.:
in the 1975 OSHA proposal.
10
1-0n r,
j L'
y n ft UJuu
tr nn , 5uu
1975:
The ror.o r t-rc r . 1 1 : ty studies of Doll (19551 , Knox nd Doll (1955f , Fr.cx t ai (195-f were undated and enlarged tt include all elnisle employees to the end of 19 7 4 . Tne update was repotted out nas not yet Seen puDlixhed :>o duct
exposure data ate included. Tms -e another oact of thi important "new informa11or,* cited Oy OSHA.
1976: A complete review and ucdate of all available T B.A. data is under way (beginning 19751 oy t.ne BOHS committee. .not even preliminary results are available.
In order to completely understand tr.e morbidity and mortality studies, listed in tr.e cnrcnolcqy, tr.at have seen done on t.ne Turner Brothers Asbestos workers in England, it is imperative to characterize the wore env i: oii.-e . t. In spite of tne fact tnat tne teenniques, assumptions, conversions and extrapolations employed oy British researchers .nave oeen clearly described in print, inexcusable misconceptions and m i - r epr eser. ta t i or.s persist on tms sice of the Atlantic.
Tne earliest environmental x.easurements utilized oy t.ne British
riseareners were taxen by T.3.A. in 1957. The
wij iei
"Routine Hn?f f-;!
tne various factory locations aid not
commence until 1951.'' No dramatic environmental improvements were
made in 1951 or 1953. T.B.A. simply oegan routine sampling in
1951. It is to their credit tnat routine monitoring was
instituted in the early 1950 s. The Casella thermal precioitator.
giving particle epunts, npt fiber counts, was used until I960.
Fiber counts were instituted in 1961 usinq the long-runnino
tnermal precipitator. Modern membrane filter sampling, wrticn
correlated well with the' long-running thermal precipitator, was
instituted in 1965. Environmental monitoring measurements in
fiber counts from 1961 and 1966 were used in conjunction with
particle counts from 1952 and 1960 to estimate exposure hi3tones
for tfte BOHS morbidity prevalence study (CSHA reference No. l'Ji.
Table 4 from tne BOHS (i960' report
..ic.t:.ue No. iuj is
reproduced below:
T*au 4 Den tivnj t wbious nvrnt nocuiu 1952-06
Yearly mean duit level i
Depanmem
Prncesa
TP. 'ParTicies/cm*)
lRTP and memarana ff'crtvcm*)
Fibamsni Cardin#
Seewwe
Waavwt Planwi#
Mitma Floor Openmf
Mechanical Baffin# Card*
Medium Cards Coane Cards E'ecircal Slivtr Cards Fma Sowmn# Ro*m# Frames twrsrmadiata Framas
Baamm#
Ptm Windmf CoUi Weavmf L'Miac Wcavtnf Medium Plaitw#
i95:
;ro 440
-
-
200
*10 1140
490 170 510 m ISO ?50 im !50 . 140
10*0
I'M!
19*6
--
Now touliv enclosed
110 4 5
i:o 4 :no 5 <
4 43 33
WSJ ` 3 *
4:0 1
260 -;
-3 2
110 4 150 S 5
)3 33
00 3 3 220
33 33
1 *0 )
23
140 )
2
no ;
so *
1 4
u
t*n n uu
Several, tact* jdouc the Moure* in tne aaove tab'* reouire eapiuiu:
-- The envir?nni*r*l *i>isurenti were cased upon static area sampling, not personal sampling.
--The numbers In the table ar av**nes for areas of the plan'.. H . gh-exposure jobs and/or piak-exposur* f:r individual vomers, though most certainly present, are obviously invisible to determine from these averages.
--using these iveraqes alone, it is impossible to evaluate tne T.B.A. worn environment for any period of time in the
framework of tre current or orooosed OSHA standards for exposure to ascestos.
--tven thouqh speciric expos.re ieuiis ate missino. it is unequivocll that individual tettec; of the T.3.A workforce have oeen -posed since 1951 to levels far m excess of eve*
2 f ioers/c .
--Mo attempt has ever oeen made tr.ua tar m any published data from Turner Brothers to relate individual exposures t; asoescos to specific incidences of ashes too-n'i red it:*:::
. -^ueiveo m individuals.
Dividing the work areas of the plant into two general categories
(Department and Process), the averages in tne above taole were
again averaged "according to the total number of men who are
employed on the different tasks and according to tne number of
years that tne process remained rougnly constant." If one area
had twice the numoer of workers as another area, the average fr:n '
the area with the large number of workers was given 'twice as t::-
weight" as the other area, to give a single estimate for all goes '
in Carding and Spinning (Group i) and another sinole estimate for ;
all jobs in Heaving and Plaiting (Group 1). In addition, the
f
particle counts (1952 and I960) were "converted" to fibre count: [
utilizing "the relationship bet-:e:. '.h. fid.- c-.nts in 1551 i.ed ;
T.P. particies/cra3 [or particles/ml] for I9601' in the different I
departments. Tne problem of estimating the exposures back to
j
was handled by estimating that on the averaae the concentration . I
19 3 3 was at least one and a half times`wfiat it was m 1952.
I
Ouot'-.g from "the BCHS (195?.) report: "This civc; a 1-ver lit:: * [
tne exposure tor workers with the lonqest durations." (empr.asi: j
added)
I
The following is from tne 30HS 1968 report:
I
I
<ot 2ro :o , *(
12
10 13 -- iu -
23 Jo --
UOM<
31 72 .y 44
6
M
' If ."11 -.
M'KOta'f'*'1
n> bm No**
m m <o <M0
Atom*cm* (Mb Nom n
II
II
>0 eg
ftJMMdb
1 II
>4 2
Bo Ml ni
i 1
1 1
vray enonpn
0 1
I 1
Gaouv l
S ean mployd
S lipovd
MM 4wU conhootrtuoo
a*ri*c wt-cm* ten Not* l>
fihmcm* iwtf Not! 2)
Number slfactad
RnoActii
Bom! rain
X-e*T cMn***
10-
1?202330-
12 20 10
7
163 163
TO
J 3 1 t) 0
J3 1 0 0
2 <2 0
111
* 0
30
0
?S.e 1 f : K cm' n term* of 'homti; rtc'r'ijif'f ui \C*i equaled after incintraiion. undar
Uvimmiiion 2 mm o^trciiv* and inclwjift| ill p-mectet freue* ihftit 0 3 J
Vj/# 2 Pihr. cm1 'fl inm of membrane filler umpMi A "Abet" it a pamclt longer iK*n 3 * And ruvinj rmo of icnfth to breadth fxt*ier than ) : 1.
&
ai
ill
it
li tiores/cm3 entry for the 59 employees "exposed** first category foe Group 1 (employed 10 years), is the estimated
average exposure (fiber* longer than 5 microns) for every day of employment for the 58 workers. Twenty-seven fibers/cmJ In the fifth category (employed 30 years) is the conservative estimate for the average (for every day) exposure for the nighest exposure period since 1933 for Group 1.
Berry (1973) used the aoove data to construct tne following table: Data on man am****'* c**vao'4 aaOMtoa (an** facto*
r toIt 292310-
IW< 7 10)30:t-
**
M ' 'Of 7* It It >31 M 'll
if a
II 34 10 18 0 If 10 0
' 81
8sW <%\ mm
-*4JI>IM
13* t >1 7 102 1 (I at IM H3I> 3*1 furai 41 1 (If 7)
at 0 89 0 14 9 10T * If 0) 131 0
iota tnat the entry for the 58 employees (employed 10 years) m
Jtoup 1 is the same as in the BQRS 1968 report (13.9 was rounded ts 11 in the estlier BODS report). The 15.2 entry foe individuals (employed 38 years) from Berry (1973) means that taking into
13
n in n
Li J I U
account- tinutt^
is:: levels ranging uun </
the 1931a to 18.9 in the 1964 i, tn estimated average axposuct
for every working day vat IS.2 fiDers/cmJ for cne b workers.
(E.g. working in a 38 liorai/cj1 environment for 1 yeaar and an 111 Cidcct/ca 4 tnviconatnt for 2 ytars gives an aver age exposure of
(1X28 * 2X1D/3 14 fiuiaa/cB- for tna J -/jars aand a cumulative
exposure of 1X29 * 2X11 - 42 fiore-years/cmJ .)
Tna lowaat estimated cumulative dose (keeping in mind the many averaging steps) for the 211 workers in Croup 1 was 131 fiore-years/cm^ in 1966. erne British standard is 190 f iDre-years/cm3 ) Conservative or not, the important point is
that all of the T.B.A. workers {as in virtually all asbestos manufacturing operations) in the 30HS study cohort (sometimes referred to as the Knox cohort) have worked in environments that would be far out of compliant* with the 2 fibers/cc standard promugated by OSHA in 1972 (scheduled to be in effect on July 1, 1976) , as many had very heavy exposures.
To illustrate the misrepresentation that has been given tne T.B.A.
exposures, the following is quoted from the 1972 NIOSH criteria for a recommended standard:
Knox et al.27 suggested that in one asbestos plant where environmental levels varied between 1 and a particles/cc > 5 in lenqth...
Tne uninformed reader is given the incorrect impression that tne
entire workforce has experienced exposure levels of 9 f/cc and below.
The only reference to exposure levels at T.B.A in the 1975 OSHA
proposal is the 4 to 15 fibers/ml taken from Berry (1973) (Table 1
reproduced earlier) . Since the 4 to 15 represents estimated and
actual static area sampling averaged over many jobs and years, it
is obvious that the information availabl on members of T.B.A.
cohorts cannot be interpreted in tne framework of individual
exposures. In addition, it is equally obvious that the exposures
(through 1966 at least) must have been far in excess of the
current OSHA standard of 2 f/cc. For example, elementary
knowledge of Industrial monitoring will snow tnat' measurements
ti-ditionally demonstrate large variation about the average.
Also, short- or long-term maintenance activities, often resulting
in extremely nigh peak exposures, are not captured by area
sampling.
':
In view of the great e.mpnasis placed on the British Jats and its evident misconstrual by NIOSH, OSHA and others in the U.S. a visit was made to the United Kingdom in January 1976 by a team of physicians and scientists, including J-N personnel, to elicit additional information. Through the cooperation of Turner 3rotners Asbestos, unpublished detailed aummaries of tne exposure measurements were provided. From this Information, for example.
14
tnn i i
1-0
w
it w* pmirs;
ie
nt trat
the JatJ used lor tne 1468
93HS report there *r at leasr two operations witn average fiber
count* m aiceas of 29 fibr/cc. in addirron. the new, detailed
suamacre* provided oy T-rner Brothers Asbestos contain data tnac
suqgest aoout 42 oercent of tne sair.pl inn inrint! routinely
produced sample value3 m excess of 'f-'-rs/ce. and then'' counts
""it averaged with. lower count: to arrive at the levels m tne
1569 BOHS report.
In the interval between 1966 and 1372 average counts of 4 to 6
fioers/cc persist in same places. with the exception of heaving. Thus, since these were averages sased on static sampling, it is obvious tnat levels to wnicn individuals were #xr.03ed were undoubtedly hrgner than this. 'lance, for NI05H or 05HA to interpret that the recently reported ireto |1375i) T.3.A.
worxfocce health experience sterna from asbestos rioer levels continuously in the range of 2 t.-cc and below from 1951 onward is
a gross misrepresentation of data available tb tnem in tne rublisr.ed literature and of additional data that can ae . uJe available to tnem sy a3King for it from Turner 3rotner3.
r.rt.ner, it should be noted tnat tne3e measurements were taxen
alter extensive environmental control efforts oy 7.3..*, ... Uie post
, isi pw-d.
it nas nevec been suqgesteo oy tne aritisn,
r.ar can it reasonably or responsibly oe construed by others, that
even the post 1951 Turner Brothers workforce has, in its entirety,
oeen exposed to an environment comparable to the current OSHA
asbestos standards or the British standards. Bearing in mind the
fact that some individuals in the T.8.A. workforce employed aftec
1351 at the British textile plant have demonstrably been exposed
to levels well above 2 f/cc, even though there has been a
strikingly Improved work * environment. let us review the studies
done on the plant employees, with particular reference to the
evidence available ore and post 1972.
In order to read the British publications, it it necessary to understand the classificatir. ` sch._JuI-d ...a . .tiese aie aceas classified as dusty by the 1931 British regulations. In general,
they do not include all employees with possible asbestos exposures. Only workers assigned full-time in the scheduled areas nave been considered in most of the publications. Studies done on
tne Jcit'sh workforce fall mtc tve distinct caiejvi .n. w* i'. f f orer.t principal investigators. Classifying tne studies by
mortality and morbidity, let us consider tr.e mortality investigations first.
It is important to xeep m mind that the mortality studies slaved t-tly o suooorting role in the britisn or OSHA standard setting m 1969 and 1972.
further comments are pertinent to tne mortality data published from Great Britain and referred to by OSHA. Tr.e mortality data nave never been analyzed using individual reconstructed exposure . ^stories, thus failing to supply individual 'dosa- response"
tnn *uu
n inn u Juu
information. i.cconorti have been defined unmi .mniaum yeare experience, sax, and broad tlaa period* of entrance 'nto the workforce, not "exposure cateqor lea. " General tin* from onset of exposure categories nave only been identified.
me first mortality -"ydy. a retrospective-prospective design, wa*
puol.ined by Sir Richard Doll in 1955. Comparison c; tne
mortality experience of all workers, some employed prior to 1931,
with at least 20 years in tne scheduled areas witn tne rates
derived toe all men in England and males, revealed excesses in
lung cancer (obaerved-11, Expected*.8) and excesses in other
respiratory diseases and cardiovascular diseases (observed-20,
Exptcted-7.61, but not in neoplasms other tnan lung cancer
iobserved-4, Expected-2.3) and all other diseases (observed-4,
Expected-4.7). Subsequently, the conort was expanded to include
workers witn at least id years in scheduled areas, and was uodated
tnrougn 1961 (published in 1965) and through June 1966 (published
in 1963). To summarize briefly the second and third publications,
the conort was divided into pre and post 1933 initial exposure,
and the pre 1933 experience was consistent with the first report,
while the post 1933 experience was good. The cohort has been
updated and enlarged to include all eligible employees to the e-d
of 197 4. This study has he reported, but ha: r.ct yet ii,T
published. In the presentation m 1975 (to the end of 1974), the
post 1933 lung cancer experience was reported as "excessive wn-'n
compared with all of England and Hales. For all workers with ten
or more years experience in scheduled areas whose work commenced
In the post 1933 period, althouqh the ratio of observed to ,
expected was less tr.an previously (reflecting improved work r" '
environment), 35 observed lung cancer deaths were reootted.
compared with 19.3 .expected, about double instead of tha tenfold '
reported previously. There were 33 observed nonmalignant
respiratory disease deaths, whereas 25.4 were expected. There
not been an excess of observed over expected of malianant
'
digestive tract deaths. Considering the xnown exposures
experienced by members of the cohort, the continued though lower .
excess uf lung
exce.icriwad
ts be excec&ed. It is
,
additional evidence confirming that'hIgn~asbestoi'exposure resul- :
in an increased risk.
`
tn particular, the experience in the post 1951 ubcohort nas cat' j singled out as cause for concern by OSHA in the Procosal. Si< ; lung cancer deaths were reported from the cohort made uo of workers who were first exposed on or after January 1. 19sl. contrasted with an expected estimated to be 3.2 from the Ep.o'.ic: and Hales experience. There are a few facts that sr.ould be in mind when considering these findings. First of all, dust levels were still very high for some workers in the 1958 t. = " worker exposures continued hign well into the 1968 s. as sent:: oafort. Quoting from the nandout of the most recent study presented in September 1975 at Brighton. England: "The six eta this group who died of lung cancer were all smokers. five wo:,. in araas where dust levels were high in 1951. and one may ha> been exposed to asbestos dust from 1925 to 1938 in a oravioui
occupation.
Secondly, the numbsrs observed and espected In tha poat 1951 aubcobort ere vary email. Responsible scientists do not draw lira conclualona from acanty data, for axaapla. jellkoff at al (OSSA rtferenc* Bo. 5) rapoctad, 'Tba nuabar ot daatha froa thaaa rausss ware to aaall tbit we atlll rafcain froa drawing any conclualon at thla tlaa. whan thay war# discussing two studlaa of
cancar ot tba atoaach, colon and ractua. in tha atudiaa cafarrad to by Salikoff, tha firat study bad 9.4 aapactad vs. 29 obsarvad. wblla tha sacond had 1.8 aapactad and 8 obsarvad. Our parsonal discussion with tha British authors of tha Pa to (197S) praaantatlon confiraad that thay baliava that It la vary praaatura to quaatlon tba currant standard at this tins, particularly on tha
basis of svldonea froa tbs cohort they reported on and which obviously axparlanead heavy aaposuras. Only recently have individual estlnated exposure histories beeoae available to these
Investigators. Subsequent follow-up nay provide new Information! however, none Is now available. It bears rapaatlnq that tha paper oy Peto at al (1975), upon which such qraat walqht la being placed
by OSHA. contains not a single aeasurenent of dust exposure.
Consider now tha Morbidity studies on tha T.9.A. textile plant
workforce. Tha so-caIIS3 Knox cohort formed the basis for the
British standard which was published in I32S. 1c snould be
c;.phaalxaii again that tha cohort was not one that was uniformly
exposed to low levels of asbestos fiber. Rather, It was a cohort
exposed to a broad spectrua of asbestos concentrations. That
morbidity study, usinq a 1-year prevalence design, was done
Independently of tba mortality studies reported by Coll. However,
there would be soaa aaabers of tha cohorts common to both. In the
October 9, 1975 Notice of Proposed Rulemaking, OSHA statesi 'In
1972, results of evaluation of new x-rays that had been taken In
1972, of tha workforce then employed in the same factory, were
reported as showing tnat many now had abnormal findings either in
tha lung or in tha coverings of the lung pleurae (Lewinsohn.
1972). Thera was thus a difference between the prevalence of
abnormal x-ray findings among workers x-rayed In I9fi* * reno-ted
to the Bntlsn Occupational Hygiene Society, and evaluation of
other x-rays of workers in the same factory four years later."
This statement is a misleading oversimplification of a highly
publiclxed controversy. "
"
"
To discuss and document all the communications and events connected with the controversy would require more effort and time thanis warranted by the study. Perhaps more enlightening than anything that' night be said is the fact tnat the suocommittee of
the British Occupational Hygiene Society (BOBS) met and reported in 1973, aubeequent to the availability of the data in question. Ho action has been taker by the BOBS toward recommending chanqes in the British standard <n the basis of those findings, in fact, quits to the contrary, their 1973 report recommended no change.
However, It may be helpful to bring out xome facta In connaction
17
0
X
with me Knox (1968 readings) and the Liniohr. article: r.ot only
were tne conocts and x-ray readers d'"ferent (Knox and Eewinsohnl
ut I
Ln'.tni were oitrerenc -- the rln msult* were
preliminary first reading attempts using tne ILO/'JC classification
without tne Oenerit of a set of standard tiim3 and the Knox
rescinds were not Dy tne ILO/UC classification at all. To lend
empnasis to tne inconclusive nature of the 1972 Lewmsonn reoort.
tne eiJHb suocomm 11 tee is onlv now undertaxing a complete review,
coasting, eniaro*ment, validation and reanalysis of the available
information on T.B.A. employees. Not even preliminary findings cr
recommendations are available at this time. To sum up the
i-oortmt poi-m on me morbidity information actually available
from tne cohort studied by tne fiOHS, not only has there been no
"now ir.ftrta
av a 11 acl e 3ince 19_72, t Re~3uoccmmTt tee " Is only
n ow'goner sting tr.e'flist information they consider aporoptiate
circs lr,t3, md wr.icn nav cp "new' when available
i n ^a ii w J^ ^ n a a e q C
: liability of new
information" m tn area of asbes tos-r e la ted disease as a major
factor in support of its ocomulgation. In attempting to clarlfv
tr.e scope of tne "new" evidence, we nave analysed the data
available since 1972. me date of tne oromulqation of the current
standard, to determine whether a.nv new principles of
acoestos-related disease nave evolved which would permit the
_
revxam; nation and reinterpretation of tne data
prior .o
mm .-.j c.-.ic.". -v-lti leao to tne proposed rule changes, we nave
oven unaole to identity any new information tnat would justify tne
conclusions that have seen dcawn oy OSHA in the Proposal.
The "New" Evidence on Asbestosis
'
Referring to tne BOrfS (1968) report, the 1975 OSHA proposal
states: "The data from Creat Britain obtained in 1966 indicated tnat little clinical disease, including x-ray evidence of asbestosis, nad occurred among worxets first employed in that
factory at some time after 1933, when important improvements in work practices had been achieved." The data from Great Britain ir 1966 were on the Knox cohort of 29a men 'who had worxed at the factory for 10 years or TMne* sm- lt Janvcry 1933." Asbestosis in any cohort from the T.B.A. workforce certainly does not per se invalidate the current OSHA asbestos standard. As proven earlio: heavy exposures for many members of the cohorts is documentable. Indeed, medical findings related to asbestosis and a spectrum cf neavy exposures were used to derive the laa fihen-yar/co "OHS recommendation. la othei wuids, not only were tnere heavily exposed workers in the Knox cohort, but cases of asbestosis as
well.
In 1972, Lewi-sbhn reported on 1297 employees (978 males and 31` females) estimated to be in scheduled areas by tne medical
department at T.B.A. in November 1970. (years since first exposure ranged from 0 to 49.) Any gross comparison of the 19v 1 data on the cohort of 290 and the 1970 preliminary data on the cohprt of 1287, even though there are certainly employees common
18
n jnn u Juu
i>.jC uno0
SffSiSf
co Doth cohort*. t s-e-----s
(aiom already discussed. In
addition, it anouia s* ceempnasned chic th 30HS suocomml ttee i*
only r.ow tevitvinq tn* morbidity experience in tne updated cohort,
accordinq to their long-standing olan*.
In addition to the r_ew tnschn ;197;i presen tat ion. t.ie 1TS JSHA proposal cited a manocri?t by Anaerson t al. currently ir. ore**, 'n* study by Anderson *t al is purported by OiitA to have tound
x-ray changa* characteristic of asbestos exposure in a cohort of nousehold contacts of asbestos worxers. Several qualifications must be made concerning tnis study, first of all, tne study vis a
prevalence study done an the household contact cohort, and it we not possible to assess changes by looxing at a series of films for eacn suoject. Due to veil-documented intra- and inter ealer
variability, it la veil xr.ovn tnat any sound cpi Jemoloj iu investigation using tnls system must topic use of sucropriate controls. Consistent interooserver variation nas oeen veil
documented i some times refecred to as observer oiasi . For example, Sossiter (British Journal of Industrial rtedicme, 197u. 19 ) presented -n results of 12 readers reading the same lJd iilma using tne I LG/DC classification. Table 7 of tnat paper presents categories of small irregular opacities for that study and is reproduced below.
TA DLfc 7 C*rroo>iJk r Sxixit Imiuu Orxrirm
1 <"
II - 0 0 <! t 1 ll
/2J
HB .. o
LB . PC OF -
o J
7
MJ it | 4t
:o
;i 9
jx l) j t.i
i*
U |7 1 art
IM
'
t
1
!
.fnilm jnJ ,i'i
!> I uni <|>I
'll
.i
rim .i ii, > r >' 1 .xi-
hi i*'i, i\ itial X JiiiMiti i ilk/fli ll f,lii* i it
.. a J in < i ts iXxli itiHinel Mix % 11
19
Referring to Tide 7 aDove. on* reader (IS) classified 79 of the
101 films in category 1/0 ot ioovi, wmle lot the 12 teadera the
average Ferc.-. sage
- catcgcr; \/l " - "**. i-'mi' 7
percent. Again [or tne 12 readers, tne extremes assigned to
category 2/1 or above (columns 2 and 3 in Table 7) *r* 8 ot 102
toe tna low to JJ ot I0e rot tn* high. Recall that theie are
dit;*r*nc*i in intatprctation oy 12 expart read*rt where tn* 12
readers eacn read the
! films.
Tn* following taol* nas oeen derived from Anderson et al:
ItO/TXT classification Irregular Opacities
i '
Cl4tlflcitlon
0
1
2
3
No. in cohost 261 60 2 0
From the above taole It can be seen that 62 out of 3 26 ( 199) have J
oeen classified 1/0 or above. Since Rossiter (1972) has 3hown that I
disagreements between readers can easily account for as much as 82 |
nor/-oor
:e 1/3 and above, the reported 15
1/2 i
and above tn the Anderson et al (In press) study cannot be
|
interpreted without proper controls. In addition to reader
differences in tne classification of irregular opacities, readers I
differ in the classification of pleural thickening. Figure 2 fror *
Rossiter (1972) is also given below:
|
i- --
III .*<# .h>iv<r
) > ? '.'is" ..kr.w <"?
iiiii'io^K.i! ch.in^t.
*
VO II
rr**i*<M* **
1
'
It can be seen from Figure 2 above that pleural thickening was classified as "abnormal' in approximately 20 percent to 50 orcen: of the films by the 12 readers, with 11 of the 12 readers classifying between 20 percent and 40 percent aonormal. Anderson
et al (in presa) reported the following:
20
< - Ka / Ab.not.T.a; 11 e a Amonj i 2 6 Houiho!'< Members of
wnrx-r-
:<-My Fi-di.-.qi
Number of Household Verrers
Pleural m: : < e r. i n g and/or
P-e-,ral fa___f
icn
52 1 * t
Wur. a ::roit.s:r of me Rossiter (1971! fmd.-.gs ii.e.
:;fler^,-:: oev-ee- :eam:s ranging ub to 10 re: :en: of me films
mt i-e..-il
and the Anderson et si i .n press)
1 f p-emil abnormalities) reveals that differences
between mi-lecs Tin easily account for me maqnituoe of me
' >^r -- a 1 fins: or 3 resorted ry Anderoon et ai .
Als). me A no e r son r si ree dings oheuld oe criticised uecause
m.ey we.-'.- consensus readings. It is impoaslble to assess the
influence oi a single "more influential or more experienced
reader' m a consensus reading witr.Out a great deal of additional
.ulorraation. A numoer of authors nave considered me advantages
of and '-U/S to nandle individual independent readmqs, rather than
me consensus readings reported Dy Anaemon et al. For example, _
Hossitvr (1372) and Fox (British Journal of ''`itir.il
1975. if '
pair or t.nese problems and gave pertinent
i e 1 v r erices .
over and aoove t.he deficiencies in the studies already cited, is tne erroneous assumption enat .household exposures to asoestos have
oeen minimal in tne dose-relationsmp concept. The osverse is more likely tne truth. As recognized hy Seiikoff and others, the impregnation of drapes, rugs, furniture, etc. with asbestos fioers and their constant resuspen3lon of fibers m the respiraole range creates an exaggerated hazard for the following reasons:
fa) 24-hour, 7 days a week exposure. :o) Absence of any environmental eno inhering controls, m) Potential exoosure of the o-rir- *specm .s, C.s.c. ..-.fancy
througn senescence. 11 An exaggerated opportunity for cofactors to oe oceratin
(smoking and .household oulmonary irritants).
'e|An opportunity for repetitive high, short peax exposures (snaxi.og out work clothes!
Tcjs. it is patently obvious mat me 'new information' on asoestosi: -.led o> OduA is not new and provides no evidence mas a 2 ficers/cc stanoard will nave any adverse imoact on morbiditv or mortality.
Let us now look at tr.e references in t.he 1975 OSH.A proposal which deal wish lung cancer.
The "New' Evidence on Lung Cancer
Suaflirv of Information or. Lung Cancer Oeatns* from Cohort! In 7" \ * s f a'fi # t
Ffcftrtnco ! lO.
Type of -crk
No. in cohort
Pubiicatiai
Data Pre-'72 Othmr
0
E
1
factory
1175
1963
n 6.13
2,5
insulation
632
1964(68)
72 8.9
16
** 1972
12
2.5
4
factor/
21,735
1967
02 67.27
13 factor/ i:o 1068
17 2.75
20
197 (?) 8
1.88
13 factory 730 1968
10 3.10
30
197(7** 25
11.21
26 insulation 165 1971
26 1 4
16 factory
03 3
1972
73
11.41
16
insulation
17,800
19
1972 213 197(7)* 62
44.42 11.45
17 factory 1464
19 factory
fir:?
1972 197(7)
59 35
23.7 8.4
`Dependent on availaole data , the entries may represent lur.g cancer alone, or lunq cancer combined itn other respiratory
malignant deaths. ``Updated information for preceding cohort.
The table for lung cancer given above summarizes lung cancer info-matron from the cohort-mortality studies i *or .iave ceer.
retrospective-prospective cohort-mortality designs) referenced :* the OSHA 1975 proposal.
hile not all cohort-mortality studies have been mentioned m th;
proposal, a review of the available information confirms that
was well documented in 1972 that some occupational qroups have
been at high risk of lung cancer. Subsequent studies and updated
of ongoing studies have continued to support this very same
conclusion .
" ""
22
i n tt tuu
n inn u Juu
1-0
It II (tc more important. nc"ve, -c cmp.-.asliw ui^i an jvjildo.e
information naa net been aiscussed oy OSHA in tha Pcoooaal witn ralation to now it upporta or doesn't aupport a 2 f/cc standard. In all ot tna studlss, information or. exposure Ii limited -- only a very tew atudle* have attempted to reconstruct individual exposures. Resorting to the use of svacayea over workers, goos a..! locations or simple estimates of r<n. ot employment without consider**1-- of Individual or claasea of gob eaposurea con be
vary misleading aa already discussed at lsngth.
Reports on a conort followed by McDonald at al (Archives of
environmental Health. 1971 , 22 . and Proceedings of the IV
International Pneumoconioses Conference, 1971) have not been
cited by OSHA. Those etudies. while not belnq directly
interpretable in taros of f/cc exposures, were structured oy
cumulative individual exposures and do snow a clear dose-response
relationship7`"?urtnermore, it can only be assumed tnat OSHA
concurs witn tnose studies' support of tne 2 f/cc standard since
tr.ey were available and cited oy NICSH in 197s m tneir Criteria
document.
.
Che only other mortality study published to date and providing dose-response information was publisned by Enterline (1972)
cnile increasing risk with increasin'; cupowuie is aiso evidenced in tne a'-"'*;/ hy C,,canine, it is not possible to determine a dose response in f/cc because tne estimated exposures in /PPCF represent varied mixtures of many air contaminants, no additional dose-cesponse/moctality information is available.
Nicholson (1975) presented some mortality information (Table 5 of tnat paper) by general categories derived from the dubious worker self-estimation of exposure scheme. (All workers had been
employed for at least 20 years in 1959.) Unfortunately only percent of deaths due to a given cause are presented, which can be very misleading (i.e. a percent due tb a given cause can be high because of "excess* deaths due to that cause, or also because deaths due to other causes are "low') , and thus r i-poss;1-!; tintstoret. In any event, the asbestos exposures ore 1939 and between 1939 and 1959 were very extreme in many locations. Tne minimum exposure category (self-assessed) obviously had extreme exposures for many workers.
The "New* Evidence on aesothel ium*
'
It is quire clear that an excess risk of bronchogenic or gastrointestinal cancer occurs only ir. thoj,, wr.o have been heavily exposed, surely well above a 2 f/cc level for a working lifetime. An excess ri3k of mesothelioma on tne other hand, though dose
related, is said to occur at levels less than required to cause an excess ot tne above-mentioned cancers or to cause asbestosis.
unfortunately, the epidemiology of pleural and peritoneal mesothelioma haa not been clarified in the period 3ince 1972. Since it is a rare cauae of death in tne general population.
reliable oopuiarion rates are not available. Evidence lugaests
.-.at-----................... l .j
.......... . .
3"j
-jf. ronor.-'d .n oc.ers. Increased awareness m copulations
containin': r..;n-::cx. heavily asbeaLoa-exocsed ' wirxforces causes
rti3'.5flu,j and compounds tne problems
associated o t.n an understanding o tne etiology o *t so tnel loni.
H j,
First. c'.'.jLvti i:.e teuutt o tne case reoort studier (see page i
this nscussim an. mesot.nelioma among r.ousenold contact* o ascectos-exccsed wurx-:s. Tne numcer of tries* is shown oy Aide: ajn et ai : a: * i according to tne fallowing tacie:
Household Asbestos Exposure Mesothelicra Case Reports
Pro-1972
Date of Pubiicatd.cn
1972
Pcst-1972
For obvious r easons. such studies do not provide any dose-respo| information, bevels of past exposures (for example, from shaxir. out clothing) can only oe conjectured about for household member
Moreover, it is impossiole to determine even approximate pcofcaoi1iries for the chance of at least some naturally occur nr. mesothelioma cases among household contacts. Community exposure
levels o the past must Oe conjectuced. as much so as household levels. Repo rted cases of mesothelioma in pooulations residing near commecci al asbestos operations present a nixed and confusi* picture today -- gust as in 1972. They add nothing to out
understanding of dose-resoonse relationships.
Two CSHA refe rences have presented the results o repotted meso thelioma cases. A mesothelioma reqi u.ale? era See tldhd, under the control ami Jnect
Insoectorate, was reported for 1967-68 by Greer.S (1974) . A se ties of 232 confirmed mesothelioma
Ar.._i, evalu ateC >:i laige part because of Act3 dealing with occupational diseases, were reporte (1973). Whil e tnese useful contributions give a into mesothel loma etiology, they have been colle occupational awareness conditions and hence do n eauivalent ra te of presumptive diagnoses in the
large. For t hat reason, comparison of mesotheli factories usi nq asbestos to that of the general
arge sene r for Enqi
of ,i.A rac
and Davie es in Sout Pari iame.ni y vieoster
tional ins 3 under reoresent ulation n
incidence lie is sue
24
n 3nn ujuu
.,n additional important possioilicy related to increased awareness of meuotnelloma snould oe Kept ;n mind when uonsldermg
neighborhood exposures. This factoc has seen evidenced in several studies. For example, the following information has oeen taken from Taels If in the McDonald and McOoriald study (i ?, 5} i
distribution of repor ted oases of mesothelloma by province:
:to of
l ii |
jreported oases
(19G0-1770) O---n--t-a--r-i-o
GO
r-'-u-r-:-<--?-c102
otlier Provinces
65
"^viewed ty | 7'it-TuC *.Ou7V r4Tu2l |
80 47
accepted as j rcSC. wsbuk^vwttia | 711 42%
57%
me study by McDonald and McDonald (197 3) was based on a formal
national survey of all pathologists in Canada. The differences in
percentages accepted as mesothelioma (42%, 71%, 57%) were
_
statistically significant (P < .01). The lower percentage
*
accepted in Quebec (42%) supports the falsely higher reporting
with increased awareness, in that geographic area.
It is unreasonable that CSHA has failed to cite the only report of a formal national survey of all pathologists, conducted In Canada and published by McDonald and McDonald (1973) . On community exposure, quoting from tne summary of that oaoer: "No case other tom tnose occupationally or domestically exposed had lived witnin 23 miles of asbestos mines or mills. ' Neighborhood exposures (asbestos factories and shipyards) were reported for 9 of 234 mesotheliomas regarded as "definite* in the article oy Dceenburq ir.d Lloyd Davies ( 1974). However, possible past exposures, local awareness and lack of rii*ole baseline ratco render o formal
evaluation impossible.
The di.c--mission by v:cbster (1973) points out the difficulties in interpreting the South Africa mesothelioma experience. Another
complete pathological survey was reported for Scotland foe the period from 1950 to 1967 (30 cases) period. The 3tudv was
designea and carried out as a retrospective matched case-control I two sets of controls were selected). Of the 51 esses who had residential exposure, all out one also had some evidence of
occupational exposure to asbestos. (There were 5 females with
25
nn uu
i inn (J J u u
1-0
te'identiai
without octupafionai axpoaure.)
Thus. considering tr.e nunbsi of studies tnat have been compieteu. there is little evidence that past residential espotjtes have appreciably increased the risx. Snne cases would oe expected neat asbestos operations due to the sx.all but accepted natural rate,
and the increased jwjrcr.ias o the d !* near asbestos operations. besot hel i orc> deaths - or: pationally esnosed cohorts nave been well documented. Inis docu,mentation wao available before 19 7 2 . Long latent periods tor tne disease are evidenced -- meaning tr.at current cases were exposed long ago at a time when
tne levels were undoubtedly hijner. In addition, nign wartime exposures due to factors such as snippuildinq and lung wor< days
undouDtedly conttiDute to recent cases
It should oe reiterated that none o tne mesothelloxa studies tnua tar referred, to nave been accompanied by numerical estimates of actual exposures, and nence are not of practical nelp in arciving at a numerical standard.
Tne only recent publication giving some new insight' cited by QSKA was a paper presented, but not yet in print, by Newhouse and Berry. While it is not believed that the Protections of mesothelioma deaths m a workforce exposed*'5etoe~T59, usinq the Weibull distribution, nelp in any way *0 tablieh 3 TLV, ore basic assumption ot that paper is: "Both the degree and length of
exposure are of importance." Evidence was presented to suoport a dose-response relationship. Even though some mesotnellomas nave been reported with short exposures, the intensities and peak levels 29 to 40 years ago can only be conjectured. The autnot3 note: "It should be stressed that the population we are considering were all first exposed to asbestos prior to 1964. and most of them before 1991. Therefore, the conditions responsible are not those which should be achieved today. The evidence of a dose response relationship snows that improved factory environments at the present and in the future should markedly reduce risks...." Thus, the new evidence cited by 05HA comes free a manuscript supporting a dose-response foe aessthalisma and reporting "markedly reduced naxs aw w..u p-cue.it time. In addition, this article is refreshi-.a in its criticism of its own
data -- statements apparently igno. sd by OSHA.
In tne rtoposal, OSHA states: "mesothelioma deaths have occurred among tne specific group ot 29u workers wheue axocr'ence prior f*
1JC6 had led to the development of tne current standard' (tms refers to the Knox cohort reported by tne 30HS (19681), suggestis-tnat tnis would invalidate the ?tandro. As discussed in detail earlier, the cohort of 290 include? a spectrum of past exposures
(3ome extremely high lifetime exposures even as late as 1966', many far in excess of the current GSHA standard. Based on tne knowledge from other cohorts, mesothelioma deaths would oe expected In the Knox cohort.
when efforts to relate doee to the risk of excess mesothelioma 1:
15
n u
iSSSSffii
conaueced, tneae ace mere l:*eiy to oe success *! in an
occupational setting inr# * - rrnr* fct developing u*cle
exposure dat* is virtually nonexistent m r.ousenold ano
community- cases and in tnese env i z: -.ten ts tnere is a large cnance
ot indeterminable
ta.net-3 occurrence of mesothelioma.
-*- ^.vKi^ncrj Ca31roir. tesf na: ^ncer
Tne availucle information on gastrointestinal cancer m tn* GSHA
references ace summarised m tne following taoLe.
-
Summary Tao^e of Information on Gastrointestinal* Cancer Deaths in JuMocts s.n"Cltc3 StuTTelT ~ ~
1963 1964(68)
a.i
1967
13 639
1971 1972 1972 1972
_____ 1971?)
26 50 59 13
12.81 23.42 15.9
5.0
Generally ICD's 150-159 or suDsets. varying with the study.
'pdsted information for or acceding cohot* -- obi-S'-ned hv s j. tr ad i c ion .
"'.stained by personal ----"unication.
Reviewing the data availaole on gastrointestinal cancer presents a
sued picture. There is a two- to three-fold increase in cis snown in sone studies, while other studies nave snown little or no increase in observed over expected. The consistency of an excess in observed over expected, as is snown in lung cancer, is not
27
n ynn u juu
present with r*ip#rt pc g a sp r o: n Pe a Pi na 1 In Any event, there
-joes nop accear to he mv 'new' evidence it"e 1972 which
"
JITt^ries "tH'e itt 1*22 5 ic.pdl? Increased ceqionei ilij reTTected In increasid regional rates ay account for some of the
leer m nne of the studiea. All ot the cited data
taken together suggest mat iny increase in risk is somewhat less
-in-, tne two to three times mentioned In the procosal and also
mdicmes t.nap the excess risk occurs only in tne most heavily
ekooued category : (IcEcnald et si' . No evidence to ::ggest that a
1 t/cc standard is unsafe for g as t r o i n te ot inai canc-.r has oeen
oresentel by 25iiA.
Tne 'New" Evidence for Ktner Neoplasms
Following a oriel ; i:-r. o l o- of ecocide mcte>5"d risk ct canc^' of tne larynx, or opnai yr.k and esophagus, t.ne CKIA pi uposal states: 'However, acta concerning pr.eue neoplasms arc Iocs extensive t.nj.o i. r lung cancer, mesothelioma and gastrointestinal cancer and : .rone: experiences ace awaited. in. any case, Pn.ey are not very condor, tuner: ;.o general and any increase does nop weigh heavilv on ohe overall cancer risk of ascestos workers. ' IP may he conjectured mat it is unlikely that any possible increased r:3< of tnese tumors will ever be fully documented. If tne large cohort-mortality studies or. t.n neavilv exoosed vo-ker of rt uuso nave oeen tnaDle to document an increased risk, tnese otter neoplasms certainly cannot support tne contention mat the far lower level of a 2 f/cc standard will .nave any adverse impact mortality from these tumors.
The ''New" Evidence on Pleural plaques
The study by Fletcher (19721 , recocted on a 19 year follow-uo :: j
439 men (selected from 15,524 available for study) with pleura-
plaques and 404 controls (without plaques selected from the sa' =
workforce). Tne controls were matened for age (within 5 years
but not for onset of -exposure or smokmg habits. * matened-ca.'
analysis was not ppssibl., cc
-p'-~-c recncn-?o-l mat
controls were definitely younger than the cases. The increase
risk, within a 5 year age group, of some diseases, notacl/
j
cancer, is well known. Tne data were analyzed as two
I
retrospective-prospective mortality studies (cases and centra.- j
separa.eiy), using local rates tor comparison. 3eciu.su of fa." j
such as the small percentage of t.ne workforce rcliowea, un j
exposure times or times from onset of exposure, uc actual
j
numerical estimates of exoosure to asbestos fiber it is .r:.;-
now tne results of mat stuuy support the contention mat i -
standard will nave any adverse impact on morbidity or .ncraJ--
The draft of t.ne paper by Edge (1975) describes another re'---"' period for a conort witn pleural plaques and a matched con::'
study foe part of tne cohort, as in the discussion of me by Fletcher (1972), no information is available to support :
contention that the i t/cc standard will nava any adverse impact on aoioiiity
.na New- Evidence on Underground natal Miners
*e have elected to comment ori tula paper in great detail oecaufie ~>t tne obvious importance ittacneo to it oy OSBa and because of me major impltcatione inherent in uncritically accepting tne iubstanca of this study and its conclusions.
as previously indicated, the OSHA proposal la premised on "new information* about the toxic effects of asbestos. Tne study by Gillam et al (197S), OSHA reference MO. 41, appears to be the one reference most relied upon by OSHA.
Before discussing this mtosh study in depth, a discussion of the problems Inherent in small samples, mentioned several times previously, is appropriate. To clarify some of the problems associated with analyzing the results of small samples, consider the following:
Testing a 1-tailed alternation of interest, the observed level of significance (so-called P-value, or just P) represents the chance *.f obserui-n i viigo zz iai-je or laiget it m tact tne worxfotce happened to be a random sample (representative of or similar in health characteristics) from the general population. For example, for an expected () of 2, the cnance of observing exactly 5 deaths from a sample of the general population is approximated by the Poisson distribution as .036. The chanca of obsatving 5 or mora (o, 6, 7, 8, ate.) is approximated to be 8.853 and is tha P-valua for a one-sided alternative of interest (that it, if tha study population differs from, the standard population, wa ara only interested if tnere are more deaths). While opinion differs in the `seriousness* of a P of .05 or .01, etc., it la true m any event that, the smaller P is, the more it casts doubt on tha possibility thit the `study* population is similar to the "standard" population. (In other words, if the two copulations ore truly the same, the differences otseeved were '`unliXely. )
Cfeaerved
3 3 3 3
18 18 16
.
2 2.2 2.4 2.6
10.0 11.0 13.0
2.5 .051 2.3 .072 2.1 .096 1.9 .122
1.8 .014 1.6 .032 1.4 .115
For many possible outcomes, a relatively small change in the 'expected' can result in a relatively large change in the "P.` For example, an ooserved of 5 with expected of 2 gives a p of it.153. Increasing the expected 10 percent to 2.6, increases P 132 percent to 0.123. The other example in the above table is even more 'dramatic' -- an E*10.0 and n nn.erved !C) of 13 .cuIl. ir.
increasing E 30 percent to 13. increases P 686 percent to 0.110. It should be noted that m tne two examples cited above, the observed was still larger than the expected after a 30 percent increase. In the absolute sense, the modest increase in E did not 'explain* the fact that the observed was in 'excess' of the expected. However, the data are generally not investigated by simply asking) Is 0 larger than E? The observed will be larqer than the expected approximately 50 percent of the time if the null hypothesis is true (i.e. the two populations are the same). The data are analyzed statistically to sea if the findings are 'consistent* with the null hypothesis ("larger' P-values). As car be seen from these examples, modest increases in E can (not necessarily will) result in a dramatic iuuiease in P.
The type of analysis discussed above is based on a number of assumptions. For example, it is known that the risk of death depends upon age, sex and many other factors. Some factors ace adjusted in the analysis, others may not be. Larger sample sizei alleviate concern for gome unaccounted for fucLLcs. To ili-strit:
tne possible problems, suppose a standard population had 50 percent smokers and 50 percent nonsmoxers, wnile a study population had 65 percent smokers and 35 percent nonsmokers. Suppose further that nonsmokers and smokers had ' risks' of 1 and 3 respectively, in both populations. On the averaqe then, the standard population risk is (.5) l+(.5)9*5.3, while the study population is (.4)l+(.6)9>6.8. Although the populations differ only in proportion of smokers, the averaqe ti5k~5~f~the"study population is 14 percent higfiet, and tnetefote~tKe expected rate would be~7< percent higher If smoking is correctly accounted lot.
30
Ttr.er posaioie lectori that toy inf 1 uenc# the accuracy of the
]'j;y3L, a.e v,t J . - r-.. -1 n-3 laltnouqn aq* is taxer, into
rcotv, d.fferences m age distributions aidu.i o___
. -v
account fur ?rt::s of percent or 13 percent) , approDrlateness of
me standard pocuia--.ur, and differences in regional and/or level
of urbanization commonly considered. Of cour3e, not all factors
render tn* estimate of to" `tw. It is generally accepted that
t.tc teneral nealtn of a om--- -`-`ined Cron onset of employment,
will ce tetter man tne general population, at least for a few
years. Uncertainty of tne standard peculation estimate say also
oe a factor. (For example, two National Center for riealtt
statistics puD1 ica11ons. aeries 2, Nos. 21 and 33. consider
aspects of mis problem, i Considerations of factors such as
dynamic peculation rates and natural variation may oe magnified
ur.en : r j i cnu! rates are used.
Toe r.a,:, point m oe made from this discussion is that variation ' doc ciis an acco _n t eiT tor* m t He ~Po isst-ri ini! y s l s ' snou Id oe an ~c n t a n t cons Hieratic r, in lti.vii.ij small samples.
T.oe acove discussion of t:.e problems mnerent m studying a small
. :r,oit 13 essential to appreciate the fatal flaws in tne Ciilsra et
a; (NICiH) paper. Keeping tne aoove discussion in mind, tr.e
cti'ique of tne study of Gillsm et al (1975) orepared oy Paul
'm.
srd Ce'*'d ?. '* . Ph.D. . of J ohns-ldanv 11 le is
ascended. Their critique concludes that the claim of excessive
rates in tne aoestos-related malignant and no.nmal .gnant disease
categories is clearly oased on poor ar.d incomplete data analyses.
Even, if tne claim were based on valid analyses, data to
incriminate asbestos rather than one or a combination of other
coexisting materials in tne causation of cancer are entirely
lacxing. To ascribe the excess of nonmalignant respiratory
disease to asbestos and iqnore tr.e Known exposure to hiqh levels
of free crystalline silica m the past, confirmed Pv the frequent
diagnosis of silicosis on tne death certificates, borders on
irresponsibility. To iqnore the potential for carcinoqemc and
cocarcmoqenic effects resultinq from the mixed exposure to silica
dust, arsenic fumes and particles, blasting powder fumes and
possibly radon daughters a>u .. -gUitrcrly ascribe all of their
excess ol cancer to asoestos particles is manifestly irresponsible
ana nas no justification in the metnodology of science.
Tr.e claim by OSHA that "since tr.e promulgation of the T.S. permanent asoctos standard, cnnsideraole new information has been forthcoming on the toxic effects of asbestos' is clearly oased cr. sn incomplete and unscientific review and assessment of available data. In its 42 references C3HA nas not otesented valid evidence to support a need for further reduction of tne airborne asbestos standard from 2.0 f/cc longer tnan 5 microns to i.5 f/cc longer tnan 5 microns.
31
Replication of the finding* and diacutsion* of risk already known
in 1972 **. nor '-nrsr l tut* ' c^rri? :. . Is fu : -,f
on. 1 Ai
was true in 1972, it i* known that heavily expoaed cohort* now
dating back It to 70 year* ago have experienced excea* morbidity
and mortality, but that i* not "considerable new information."
The `new evidence* cited by OSSA less British atudie* i* a pciae example of uninformed selective reporting. While lgnorlnq a 30H3 subcommittee report (1973) specifically recommendinq no change, OSHA has misrepresented the available information on the TBA workforce. The available information has been detailed in this report, when the facta are reviewed, it 1* obvious that there la no evidence available on the TBA workforce that supports a need for further reduction in the asbestos standard now scheduled for July 1976. Indeed, the documented high exposure levels extending into the recent past, olus the fact that such exposures were derived from static, not personal, sambllnq, whan coupled with tr.e
recently published health studies, demonstrate tnat the lessened adverse health effects noted were related to lower out still substantial exposures and provides confidence for maintaining tr.e 2.0 f/cc airborne asbestos standard.
Selective use of preliminary, unpublished ind nonoeer-reviewed
manuscripts and studies have been used by OSHA as important segments of the "new forma tier.. * Tii* most notable example is the morbidity and mortality study by NIOSH (Gillsm et al 11979!
Since the OSHA citation, the drafts of the study have undergone substantive revisions, including tne removal of the entice
morbidity portion. The conclusions of that paper are of such questionable scientific quality that it cannot be considered "nvw information* of the scientific competency and accuracy required for use in decision making.
In reference after reference, detailed review has shown that OS<A has cited information that was already known in 1972, non* of
which supports a reduction in the standard.
Omission of references, such as a national mesothelioma survey is
Canada, is ii.excusable, awiectiv* reference to oarts of other
reports is lust as inexcusable. The very report that was cited
(Newhouse and Berry 119751) as providing evidence for a continue!
increase in mesothelioma among known heavily asbestos exposed
workers was based on a dose-response relationship for
mesothelioma. Further, tne limitations
that itudy. sc r.icelv
given by the authors, have been ignored by OSHA.
we nave the right and the obligation to insist that all regulate?
agencies aaiiere to the nignest requirements of scientific competency and accuracy in reviewing avallaol* information for v standard. This was not don* for the October 9, 1975 Notice of Proposed Rulemaking on Occupational exposure to Aaoeato*.
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