Document Xw3doNqM91KnRQMpzzBVEeQy
Medical Department
Charles H.Hine.M.D.
Medical Director
ic'ZC'xQ
; FWM. M.Q.VKW
! Cufliea 'at: JPSimaM
MOV
pdp ;; n
OAR .. Q
LOW
26 June 1980
Messrs. KWNelson MOVarner
Re: Mortality Experience in Asbestos-Exposed Persons
I recently saw a case of pharyngeal cancer in a person who had relatively low exposures to asbestos fibers. He was a warehouseman and his exposures occurred while unloading boxcars in which the shipped asbestos .had broken loose from their containers. As I was not aware of any data indicating a relationship between pharyngeal cancer and asbestos exposure, I requested a review by the Institute of Occupational & Environmental Health (which ASARCO helps support). They sent me the enclosed paper by Selikoff. I think that you will find the statistics interesting.
CHHine
CHH:cab
Enclosure
CC =- DHSoutar MJMessel
ASARCO Incorporated 7604 Rincon Annex, Sail Francisco.California yqizu 357 Tehama Street (415) 777-2210
ASARCO ALV 0002076
330: 91-116, 1979.
ici-sinc*
MORTALITY EXPERIENCE OF INSULATION WORKERS IN THE UNITED STATES AND CANADA. 1943-1976*
i-
..
.... .
- Irving J. Selikoff
Environmental Sciences Laboratory Mount Sinai School ofMedicine The City University ofNew York
New York. New York 10029
'
Cuyler Hammond and Herbert Seidman
........ .......... ................................
' \
Code
T ^ bJ
10 36 37 38 63 70 80
81
'iT'Vir.'-i-er.r'';''
asbestos, insulation workers in the New York-New Jersey metropolitan area 1943--
1962.' Significant increases in deaths of lung cancer, mesothelioma, gastrointestinal
~--jZk&z:cancer and asbestosis.were found. Findings-were limited to observation of only-632
L-$figS&si. men, however:. Oil January.-1, 1967,'a larger cohort was enrolled for 'prospective '-"F.tfS^St^observation and Included ail-17,800 men on the rolls of the-insulation workers' union
(International Association of.Heat and Frost Insulators aitd Asbestos Workers,
."dj^^hr-AFLtCIO, CLC) in the United States and Canada on that day. This second cohort
. `JStSnT^i included- the survivors of the original 632 New York-New jersey men. Observation
-has been maintained and an interval report of deaths in this group since January 1,
1967 has been made.1 The present analysis details findings among these men through
December31, 1976"'--
Asbestos Insulation in the United States
Asbestos, as a mixture of fiber and sodium silicate, was first used as an insulation material in 1866 and as asbestos cement about 1870. Magnesia with asbestos as a binder soon followed and air-cell covering, using corregated asbestos paper, was introduced in 1898.
The first union of insulation workers in the United States was formed in New York City in 1883 under a charter issued by the Knights of Labor (predecessor of the American Federation of Labor), as "The Salamander Association of Boiler and Pipe Fellers." The present union of insulation workers in this country as chartered by the AFL in 1910, as the International Association of Heat and Frost Insulators and Asbestos Workers, by the amalgamation of the Salamanders Association of New York with other independent locals throughout the country. Members of this union are insulation workers, primarily employed in the building trades doing construction insulation work but also employed as insulation workers in refineries, industrial plants,
This study was supported by grams from the American Cancer Society (R-53), the National
Institute for Occupational Safety and Health (0H00320) and the National Institute of Environ mental Health Sciences (ES0O928) of the U.S. Department of Health, Education and Welfare, and the Health Research Council of the City of New York (UI272).
. 91
.
0077-J92J/79/0330-0091 SI.7J/0O I97J.NYAS
I
ASARCO ALV 0002077
92 Annals New York Academy of Sciences
shipyards and powerhouse construction and repair. Much of their work is in the open
but sometimes, as in shipyards, in rather tight quarters. The men generally work in all
parts of the trade, with few specialists at one or another part of it. Conditions at work
vary from job to job and from company to company, with fewer than 10% of the men
remaining with one company during their working lifetimes.1 Data published concern
ing work practices in other countries suggest that asbestos exposure in insulation work
has been approximately the same the world over.4 - ' *
_ Asbestos exposure to which insulation workers are subject has been limited, varied
and intermittent. Some of the materials used have contained no asbestos. In the early
part of the century, magnesia pipe coverings used shredded rope as a binder, with no
asbestos. Somewhat later, wool-felt, cork and rock wool.were used. Starting during
World War II, fibrous glass products came into increasing use and, during the 1970s,
their utilization was greatly expanded, as asbestos content of insulation materials
sharply .decreased- Magnesia block insulation, including molded pipe coverings,
usually contained approximately 15% asbestos, while asbestos cement generally had
T5-20% or less of asbestos. Asbestos paper products contained a higher asbestos
content, but. were used in much smaller quantities.
r Until approximately the early 1940a, chrysotilc alone was utilized in the manufac
ture of the asbestos insulation products used by these men.'Amosite began to be used
in the mid-1950s in small quantities but became more widely utilized during World
.War II and subsequently.1.;:. .
; r--. . .
Few dusfeounts were made in insulation work until the mid-1960s. However,
analysis of available data, including reconstruction of work situations and extrapola
tion to the past of observations made more recently, suggest that insulation workers
would have been exposed to dust levels of 4-12 fibers/mi (as time weighted
Table 1A
' Membership of New York and New Jersey Insulation Workers' Union* January I, 1943. Classified by Ace and Years from First Exposure to Asbestos Dust
Tout
.Number
Age,
of
Number of Years Since First Exposure to Asbestos
Years Members 0-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50+
15-19
22
20-24 25-29
14 ; 14 38 19
19 *- -
30-34 i22 ."2 . 94
26
3S-39
76 ' I
21 - 47 - 6
40-44 .. 74 . I . 4 ... 28 : 30
45-49 -i- -77 c -rzTtjU.
r. 19' :-29
50-54 - 82 - 1 ; 2
9 24
55-59 . 65
1 4
9
60-64
41
258
65-69
23
1 22
70-74
13
75-79
3
80-84
2
Total
632 40 145 140 108
; -* v-- -
. ..
'J-' 1 1 ' * '**** 10 t 24 ' 4
18 :-2*-II 20 3 13
I3 22
4
19 6 8 2
1 70 67 40
* ' ""T`
*
i
4 42 22 3 I 15 4
.
3 3
'Locals 12 and 32 of the International Association of Heal and Frost Insulators and Asbestos
Workers, AFL-CIO.
*
ASARCO ALV 0002078
SelikofF el air Mortality of Insulation Workers
93
Table IB Man-vea Of Observation. January 1. 1943-December 31. 1962. or January 1.
1943 MEMBERSHIP OF NEW YORK AND NEW JERSEY INSULATION WORKERS' UNION*
Classified by Attained Ace and Years from First Exposure to Asbestos Dust
Attained-. . Age, Years
Total v. = Man-years
.<20
Years from Onset 20-34
35+
.
15-19 . 20-24 -.-
--. ... 4 . = 44
25-29 ' - ' - ------ '.165
-
4 * 44 *
' ' 165
-+ ;
--
30-34
542 -- - ' 542
--
35-39
1.068
773 ... ' . 295
- -- 40-44:
. - . - - U39
45-49-57=:-- .-..El-vC- - 1,588
253 -
1086
74 --1510 -
50-54.IV. _.
U62.
__ 39 ~.-.-a^l368 .
55-59-p-
1 -544
... 28- sKi'se- 782
'' 22
361
1 65-69 -
849 17 ; . 175
70-74 ' . v ...-- rL. -513.- -..u
9 4 :-4d 72
75-79 '
242 -- .... 33
80-84 .85+
84 ' - 29- 1
--
' ---- .*" 2 ' - *.*
1' -
Total
' 10.515
1970
5683
--^4:
'Yl-
;4
j55 era 534
- . 759- =657 ' !+' 432
209
. *3 -'29
2862
*-*
International Association of Heat and Frojt Insulators and Asbestos Workers, AFL-CIO."
averages).1 While there might have been periods of little or no exposure. Jhere could also have been times of peak exposures much higher than the calculated averages.
Mortality Experience of New York-New Jersey -. Insulation Workers 1943-1976 -
On January 1, 1943, there were 632 men registered as members of the two locals or the International Association of Heat and Frost Insulators and Asbestos Workers in :he New York-New Jersey metropolitan area (Locals 12 and 32). Their age distribu tion according to years from onset is contained in Table 1A and man-years of observation 1943-1962 areshown in Table IB. .
Each of these men was traced to December 31, 1962; expected and observed deaths are found in Table 2. Nine men died before reaching 20 years from first employment, and they are excluded from -Table 2, which is limited to the 623 men who achieved that point. While deaths related to asbestos exposure of the kind experienced by insulation workers may sometimes occur in less than 20 years from onset of employment (lung cancer, asbestosis and, occasionally, mesothelioma) these are not common and we consider that analyses of experiences beyond the 20-year point more clearly define the influence of such exposure. It was of interest, parenthetically, that there was no excess in total deaths of all causes during the first 10 years of observation, 1943-1952, in the post 20 years from onset experience-(although art excess was seen for lung cancer specifically), as example of the "healthy worker effect."'
Observation of the survivors of the original cohort has continued prospectively and by December 31,1976,478 of the original 632 men had died. The same overall pattern of causes of death has continued, although distribution of deaths by cause ha- changed
r
ASARCO ALV 0002079
94 Annals New York Academy of Sciences
"Table 2
Expected and Observed Deaths Among 623 Asbestos Insulation Workers New York-New Jersey, 20 or More Years after Onset of Work January I. 1943-December 31. 1962 (8545 Man-years of Observation)
Underlying Cause of Death
. Expected*
Observed
Totaldeaths-allcauses
_.
195.4
253 ' -
Total cancer-all sites --- - r
-------- 32.1 ------r...........95
. Ca'nceroflung
s: ec. ; _.
-
6.0
42... sA.
Pleural mesothelioma ,--
(
t - 3 a*
. Peritoneal mesothelioma------------------- ---------- --------------- t-------------- -------- 4-------- --
. Cancer of esophagus, stomach, colon-rectum 9.7 29 ;.
Cancer of larynx, pharynx, buccal cavity
1.7 . .
2.,, .
Cancer of kidney
0.7 - -
0
All other cancer '
14.0 15
-Noninfectious pulmonary diseases, total
. ----- ; 4.0 ; -
14
. . Asbestosis - ___ -
.- - -
t--
12--____:
All other causes
159.3
144
'Expected deaths are based upon white male age-specific US. death rales of the US..
Nauonal Center for Health Statistics, 1949-19o2. Rales for specific causes of death for
1943-1948 were extrapolated from rates for 1949-1935.
:
tRates are not available, but these have been rare causes of death in the general population.
somewhat, reflecting a number of epidemiological influences. Thus, pleural and peritoneal mesothelioma, which tend to occur somewhat later than bronchogenic carcinoma, became proportionately more common (Table 3). This change in preponderance also reflects the smaller proportions of older men who ever smoked cigarettes, and also a "survivor effect." Since the cigarette smokers in the original group had
'
Table 3
Expected and Observed Deaths Among 632 New York-New Jersey Asbestos Insulation Workers January I. 1943-December 31, 1976
(13.925 Man-years of Observation)
Underlying Cause of Death
Total deaths, all causes ......
Total cancer, all sites
Cancer of lung . .
- ` -
Pleural mesothelioma
Peritoneal mesothelioma -
Cancer of esophagus
.......
.
Cancer of stomach '
Cancer of colon-rectum
-- ' '
Cancer oflarynx, pharynx, buccal cavity
Cancer of kidney
;
AU other cancer
-
Noninfectious pulmonary diseases, total
Asbestosis
All other causes
Expected*
Observed
328.9 57.0
478 210 ! `
KS. . 13J -. .- t
. - t. ...
93 - . a.-?- :
. 11 - "
?
27 *--.r t-n
1.4 .. - -
-
' 5.4 ' .
. 19 .. . ......
i. *".
8.3 2.8-'.;
. .2-3g
- * '
1.3 " -5%24.5 -
" .28
. ...
9.3
t 262.6
45 41 i
223 i
'Expected deaths are based upon white male age-specific U.S. death rales of the U.S. National Center for Health Statistics, 1949-1976. Rates for specific cauie of death for 1943-1948 were extrapolated from rates for 1949-1955.
tRates are not available, but these have been rare causes of death in the general population. |
* .4
(
I
6
ASARCO ALV 0002080
Selikoff er al;. Mortality of Insulation Workers
95
increased mortality risk (especially from lung cancer and cardiovascular disease)
there would likely have been comparatively fewer men with a history of cigarette
smoking and still fewer who continued smoking at least the same amount, among the
cohort survivors, as the years went by. Except as influenced by other factors associated
with advancing lapsed time since onset of asbestos work, this would make for fewer
deaths of lung cancer,* with more men at risk of dying of other asbestos-associated
disease.
Lung caacer remained the most important cause of excess deaths, with 93 such
deaths observed vs.,13J expected. Thirty-eight deaths occurred of mesothelioma, 11
pleural and 27 peritoneaL The increase in gastrointestinal cancer originally reported
in 1964 was again seen, with 43 deaths observed.. 15.1 expected. There were 41 deaths
of asbestosis. In addition, 4 deaths were observed of other noninfectious pulmonary
diseases. Apart from cancer, asbestosis. and other noninfectious pulmonary diseases,
observed deaths ;were fewer than expected of all other causes; only 223 seen,
approximately 40 fewer than anticipated. : '
This experience, with 19% of deaths due to lung cancer, 8% the result of
mesothelioma. 9% of gastrointestinal cancer and 9% of asbestosis and other noninfec
tious pulmonary diseases, begins to provide a broad outline of the total mortality
experience of insulation workers employed under conditions of the past (much less
asbestos insulation was used in new construction after 1972. although variable and
intermittent asbestos exposuie would be expected to h~ve continued to occur during
repair work).-76%of the original cohort enrolled in 1943 had died by the end of 1976.
Variations in distribution of deaths by cause over lime may be seen in Table 4.
Among the 9 deaths listed before 20 years from onset of exposure, there was none of
lung cancer,, mesothelioma. gastrointestinal cancer, or asbestosis and other noninfec
tious pulmonary diseases. Variations are also evident in the two periods, 20-34 years
and 35 or more years from onset. Although the proportion of deaths due to cancer of
all sites was virtually identical in the two periods (44.5% and 44.3%). the specific
neoplasms were quite different in proportional distribution. Lung cancer accounted for
49% of the cancer deaths in the shorter period but only 43% later. There were 7 deaths
of mesothelioma in the 6263 man-years of observation during the 20-34 year span but
31 such deaths in the 5692 man-years later on. It is of interest, too, that the proportion
of mesotheliomas that were pleural in location also changed over time; 4 of the 7 were
pleural in the earlier period, against only 7 or 31 in the second period. It is clear that
unless opportunity for prolonged observation is available, it will be difficult to fully
evaluate the distribution of deaths by cause among asbestos-exposed groups. Concomi
tantly. such analysis will be enhanced by considering deaths in each period of duration
from onset, separately.
Not unexpectedly, deaths of asbestosis were again largely concentrated in the 35
or more years from onset period; 38 of the 41 such deaths were found at this time.
It has been of interest to inquire concerning the experience of those insulation
workers whose exposure began after 1943, since this would reflect postwar conditions.
Eight hundred and ninety men joined the New York-New Jersey metropolitan area',
locals of the union during the period January 1, 1943-December 31. 1962. Most (833)
had had no prior asbestos employment before entering the union. These men have been
observed prospectively from the time of admission to the union to December 31,1976
(Tables 5A and 58). Our experience with their pre-1943 predecessors had demon
strated that we were to expect relitively few deaths before 20 years from onset of their
work. Still, because of the importance of evaluating postwar experience among men
not exposed in earlier years, we undertook this study. Table 6 details their mortality
experience from first employment to December 31, 1976. In the 15,520 matt-years of
observation during the less than 20-year period, there was no unusual mortality
experience. AltoIgether, there were fewer deaths than expected (again, the "healthy
I
ASARCO ALV 0002081
t Rales arc nol available, but these have been rare causes o f death in Ihe gcneral'populalion.,
96 Annals New York Academy of Sciences
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ASARCO ALV 0002082
Table 5A
New York and New Jersey Insulation Workers Observed January l. 1943-- December 31. 1962. and Subsequently to December- 31, 1976 (Number of Men Attaining Category)
Period
1943-1952 1953-1962 1963-1969 1970-1976
Uaion Members Jan. 1. 19*3 . Vears from Onset
Men Joining Union 1943-1962 ' Years from Onset
Taul
<20 20-34 J5 --
Total . <20 20-34 35 +
632 325 523
190 412 -- 412
542 40 393 321 833 833
370 : - ---- ' : - 154 .. - 328 - 828 - 828 -
234 - ' --' r- ' 32 a- -.224- - 811 - : * 561
---
258 515 -
-----
; --
. .f. - r .-yiv;
*'. vfp
- .
y>
' _ --`
j:.r.iC r?:!' Table 5B -
x-Tri Tz~rr\ -.v
Man-years of Observation of New York and New Jersey ' " Insulation Workers, 1943-1976 'i
(Number of Maa-years) ~ "
Union Members Jan. 1. 1943 ' Years from Onset ;
Period
Total
<20 20-34 - 35 +
1943-1952 1953-1962 1963-1969 1970-1976
5928 4587 ' 2088 1322
. 1682
283 --
3253 , 993
' 2430
1869
418 1670
162 ' 1160
. Men Joining Union 1943-1962 . ..- Years from Onset. - -.t -
' Total
<20 20-34 ---35 +
1658 1658. 5906 ' "5906 5752 5156 5485 2800
-- ' '___ --- * -- 596
2685 '- --
; i:a; '
- " . i.
Table 6
Expected and Observed Deaths Among 833 New York-New Jersey Asbestos Insulation Workers First Employed January I. 1943-December 31, 1962, and Observed from First E.mploy.ment-December 31. 1976 (Duration from Onset of Employment)
Number or Men Attaining Category Man-years of Observation
Underlying Cause of Death
Tore! deaths, all causes
Tot?!, cancer, all sites
.' ' ' '
Cancer of lung
Pleural mesothelioma
Peritoneal mesothelioma .'''
Cancer of esophagus, stomach.:;
colon-rectum-.
Cancer of larynx, pharynx, buccal cavity
Cancer of kidney .
...
All other cancer
Noninfeclious pulmonary diseases, total
Asbestosis
All other causes
Less than 20 Years
20-34 Years
833 15.520
523 - ' 3281
Expected* Observed Expected* Observed
39.8 5.1 1.1
"t t
.....- 0.7 . 0.2 0.1 3.0 0.5 t 34.2
23 -. ' 24.8
39 '
5. r' 5.0
15
2 1.8 8
0 ' t -: -- - 2 .
0 .-' .- t-
: i 1
-
1 -- .... 0.8
2
1.
0.3
.1
0.
0.1
1
1 2.0 0
0 0.6 7
0t
6
18 19.2 17
'Expected deaths are based upon white male age-specific U-S. death rates of the U-S. National Center for Health Statistics, 1949-1976. Rates for specific causes of death for 1943-1948 were extrapolated from rates for 1949-1955.
tRates are not available, but these have been rare causes of death in the general population.
t ASARCO ALV 0002083
98 Annals New York Ac'ademv of Sciences
worker effect") and there was no increase in cancer deaths. No mesotheliomas were
seen, nor deaths of 2sbestosis. There was no significant increase of either lung cancer or gastrointestinal cancer. Since the 20-year point, we have begun to see the changes
predicted by our earlier studies. In the 3281 men-years of observation 20-34 years
from onset.'there were approximately three times as many cancer deaths as expected,
primarily due to lung cancer. Mesotheliomas were now first seen and some deaths of .
asbestosis occurred. These had occurred primarily during the period 1970-1976 '
(Table7)._ -- '
-
When the post-1943 workers were compared with those first exposed before that -
. time; and evaluation was limited to observations less than 20 years from first exposure, -
it was found that neither group had unusual lung cancer, mesothelioma or asbestosis :
experience. Table 8 demonstrates that among 325 pre-World War II men who had not reached 20 years from onset of exposure- during their period of observation,
covering 1970 man-years, no excess of these diseases was seen. Similarly, among the
833 post-war men, with 15,520 man-years of observation during the shorter than
20-year from onset point, and with exposures starting 1943-1962, neither mesothe
lioma nor asbestosis deaths.occurred and there were not significant excess deaths of!.*
lung cancer* This is of interest in that, by and large, only chrysotile exposure had
occurred before 1943 for the first group, while amosite was added to chrysotile in
terms of potential exposure, from 1943 on. The after-1943 group was potentially _
exposed to both types of asbestos throughout their work experience. These data-
indicate that amosite did not Wten
p--/-tt-->-.! in--<-v
.'
associatctLdtiSSc m these insulation workers. Further, taken together with the data in :
Tables 6 and 7. these observations suggest that the mortality experience of insulators exposed to both chrysotile ano aifio^ite win oe in tlie same direction as tftosc onginally
cxccsaLonlv to chrysotile and later to insulation dusts also containing amosite. i able 9, reviewing deaths of selected causes 20-34 years from onset in the post-1943 group,
and comparing the findings with observations in the pre-1943 group for the same time
span, suggests that this will be the case.
Mortality Experience of Insulators in the - United States and Canada 1967-1976
There were 17,800 men on the rolls of the asbestos workers union in the United
States and Canada on January 1, 1967t. A good deal of information concerning these
men was available, including date of birth, date of first insulation work, employment
status on January 1, 1967. Additional information was obtained by questionnaire from
a majority of the men concerning current symptoms, respirator use. smoking habits,
work practices.
. .
We have maintained observation of this cohort since 1967, with the. valuable
assistance of the local and international officers of the union. Tne men are registered in approximately 120 local unions in the various parts of the United States and
Canada, including Alaska and Hawaii. Whenever an insulation worker associated
with the union dies, we are notified. In most instances, a death certificate is forwarded;
if not, it is obtained. As with the New York-New Jersey group, information is then
sought concerning the details of the circumstances of death,u including clinical data,
roentgenograms, histological material obtained at surgery or autopsy. The clinical and
tlniernational Association of Heat and Frost Insulators and Asbestos Workers. AFL-CIO,
CLC
%
I
ASARCO ALV 0002084
Selikoff st at.: Mortality of Insulation Workers
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99
t ASARCO ALV 0002085
100 Annals New York Academy of Sciences
I
I I Ik
fA m o tiic insulation materials were first introduced shortly before and during W orld W ar II.
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ASARCO ALV 0002086
Selikoff et air Mortality of Insulation Workers
101
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nNvnomT--/< rNt >vo-t
LJ s8K 3S 8
"ij
-I
111
- .1*
|1|
^ ^wr* --** rw*-> ||
e4*
5r^t
,2
u
Hi
sii 315
Si's
rTi PrWv i(O?n> c-oO>* oHa
N
<s CN
*nC0N
evO3N
Poo*
^IaISJ2 aaa a J 53J -- owi oc% ro- h n1 -0r aw- oo a H | --. S ---
isi
&2 2 i5A `5^
: .v;^;:sv: . siS -- :'
~ .'. i'll .
.= -.--rr=~ I
ASARCO ALV 0002087
102 Annals New York Academy of Sciences
Table 10
Membership op Asbestos Insulation Workers' Union". January 1, 1967, Classified by Age and by Years from First Exposure to Asbestos Dust
Total . ..
''
r~
*~
~
- Number^--Number of Years Sinca First Exposure to Asbestos
' - -. 1
--'"A
Years Members 0-9 10-14 15-19 20-24 25-29 30-34 35-39 40-49 50+
- 15-19 + 244 _ . 244 . r
' rZ ;
20-24
1.695 1695 * - .1
--
' r-' --
25-29 30-34 35-39
2,412. 2066-
2,762 * 1065
2,988
313
345 1356 1141
-1 341
1342
. 192
'T-'.'.Vj - A
r.
V .. A__
J.-,--W -- - - - - - -
40--*4^ 7lZ2&0^-=
-- 424A-'1026 ""591"
4^--4^' . ^nr.589^ --49 --131 433 -* 442' -- 487-- -47-
-
50-54
1,297
27 88 214 332 - 377 182 . 77
_-,v>+.35-59.!: 984 . 13 - 49 12 206 176 146 - 193
72 ' - -...... '
60-64+ -- '`703 - - 1
21
59 131 126 ' 87 T 59 179
- 65-69- ' L4I9 .. --
6 . 18 41 58 45 29 201 2i
' - 70-74. 255 --
--
6
14 22 21
16 .105
71
- 75-79 - em
--
1--
.4
8 : 4 . ~ 7 37 50
. 80-84 --
52 . --
--
--
--- . ,
2
\ .`2 16 31
85 +
29
2 7 20
Total 17.800 5552 3562 3569 1953 1395 534 425 617 193
"Membership in the United States and Canada of the International Association of Heal and Frost Insulators and Asbestos Workers, AFL-CIO, CLC.
roentgenological data arc reviewed and the pathological material examined. Most of the presentation for this cohort is in terms of underlying cause of death categorized according to best evidence available (BE). Further details are also given in the tables for underlying cause assigned on the basis of death certificate information only (DC).
.At the outset of the study, a majority of the men were below the age of 40 (10,101 of 17,800). The majority, too, had yet to achieve 20 years from first exposure (12,683 of 17,800) (Table 10).
During the period January 1. 1967-December31, 1976, the cohort changed its age and duration from onset distribution with the passage of time. Many of the men who started in the less than 20 year from onset group achieved 20+ years from onset during the decade or observation (Table 11). Altogether, 12,683 men, with 89,462 man-years of experience, suffered 325 deaths in the period before 20 years. There
.
Table 11
Observation of 17,800 Asbestos Insulation Workers in the United States and Canada January I. 1967-December 31. 1976
Number of men
- *. Man-yearsof '*
observation
Deaths
'
Average age
(luring observation
`
Total 17,800
166.853 2.271
44.4
<20 Years from Onset
12,683
89.462 325
36.3
20-!- Years from Onset . J2.051 . . .
77,391 1.946
53.8 - .
______ , _, ;
I
ASARCO ALV 0002088
Sslikoff ei a!.: Mortality of Insulation Workers
103
occurred 19-to deaths among 12.051 men who had achieved 20-t- years from onset,
with 77.391 man-years of observation. The average age during observation was 36.3
years for the shorter group and 53.S years for those with longer duration from onset.
During the decide of observation 2271 deaths occurred (Table 12). whereas only
1658.9 deaths were expected (based upon white male age specific mortality data of the '
U.S. National Ceater for Health Statistics). The excess deaths were primarily the
'result of an increased number.of instances of cancer of several sites. Investigation of `
the deaths found 486 due. to bronchogenic carcinoma, between 4 and 5 times the .
;`number anticipatesL-There were 175 deaths of mesothelioma, 62 pleural in location
* - ..
\
ii'.'TZ/TTiz.'ZFJiiyyi'T:
: f; ..
.. y~*;TAli '12 -J
?v. Deaths. A>*o*oc 17.800-asbestos Insulation Workers in the United STATES_j.,-^'^,i2;f?
everCanaoa..Janlaxv-^TJ 1967-ipEcz.uaex
. .. u.number of Men 17.800 , ........... ' "
" irMan-years of- Observation- 166,353
-J
... ''<-r7'"
. Observed -: r\ Ratioo/e - r-
' Underlying Cause of Death Expected*
(BE)
(DC) - . (BE) (DC)
: .. --w-Toul deaths, all auses `-u-Vi.v u 1658.9 u .2271--a 2271 -- -1.37 -V--/U7
Total cancer, all sites-'Lcr -r
' : 319.7 - 995-^r 922
3.11
2.88
Tr.-r--!-\ Canceroflung -Bstrs-*s.-v-'
- 105.6- . - 486-- . 429 -- 4.60
4.06
> ! Pleural mesothelioma -...
t.
63 . . . -25 .. . --- ,- a ---- . ' -
Peritoneal mesothelioma . .
... t
. 112
24 . . ---- .
---
- Mesothelioma, D.Q.S-
' t'
0 . 55
--
--
Cancer of esophagus Cancer of stomach
' 7.1 . 18 18 2.53 2.53
14.2
22
18 1.54
1.26
Cancer of colon-rectum Cancer of larynx
38.1 4.7
59 58 1.55 1.52 11 9 2.34 .1.91
" Cancer of pharynx, buccal Cancer of kidney
10.1 21 : 16 2.08 .. 1.59 8.1 19- 18 2.36 2.23
All other cancer
131.8
184 252 1.40 1.91
Noninfectious pulmonary
diseases, total Asbestosis All other causes
-
. 59.0 t
1280.2
212 168 i064
188 . 3.59
78 --
1161
0.83
3.19 --
0.91
,r ' V `
-gyj vcA* - tx y*.
rVyC--L -
tT't
- 'Expected deaths are based upon white male Bge-specific U.S. death rates of the XJS.
1 - National Center for Health Statistics. 1967-1976.
4 ? * : - * / * ; *;; _ ..
, '.`.tRales are not available, but (hoe have been rare causes of death in the general population. ..
(BE): Best evidence. Number of deaths categorired after review of best available information
(autopsy,surgical.diaical).-`i.
.. .
(DC): Number of deaths as recorded from death eertifieateinformation only.
'
CO.
"and 112 peritoneal. There was a modest increase in deaths of gastrointestinal cancer
(esophagus, stomach, colon-rectum).:'
-'
Cancers of several other sites were also significantly increased over the number
expected. There were 11 deaths of cancer of the larynx, 21' of the buccal cavity and
oro-pharynx, as well as 19 deaths of cancer of the kidney. In each instance, this was
^twice-the- number-anticipated. Comment had previously been made1 conceming-
interest in these sites but, at the time, there were inadequate data for evaluation.
Additional experience has indicated that the early hints were predictive...
Review of information concerning the deaths allowed a distinction to be made
between deaths caused by asbestosis and those of other noninfectious pulmonary
I
ASARCO ALV 0002089
104 Annals New York Academy of Sciences
diseases, including emphysema and cor pulmonale. Thereby. 163 deaths were assigned to asbestosis and 44 were attributed to other noninfectious pulmonary diseases, compared with a total expectation of 53.0 in the general population. The question oi whether noninfectious pulmonary diseases, other than asbestosis, are or are' not increased in asbestos workers is a complex problem. Continuing questions of nomen clature of "chronic obstructive lung disease" in general; and uncertainties of designa tion and pathological categorization were recently well reviewed by C, M. Fletcher.'
Chronic nonspecific lung disease, particularly that due to cigarette smoking, may r have an influence on the course of the asbestosis, providing an added burden to
damaged lungs. We have evidence that there is such influence.* On the other hand, diffuse interstitial parenchymal fibrosis or diffuse pleural fibrosis would be disadvan- " tagecus for individuals with extensive chronic obstructive lung disease, particularly with superimposed pulmonary infections or other physiological stress. Such disadvan tageous additional contributions, in individual cases, may play important roles in t ;^determjning.the adequacy:of arpatientls.xespiratory. reserve. Categorizing deaths.hr ' Terms ofa single underlying cause, however, does not allow for inclusion of nuances.of. interaction among the several factors, nor to depict, the full spectrum of such "'interacting disear.% from cases in which little other than asbestotic pulmonary fibrosis may be-involved to those in which all evidence indicates that cigarette smoking and _chronic obstructive lung disease were the principal factors.
For causes other than cancer and asbestosis and other noninfectious diseases, there were fewer deaths than expected, 1064 against 1280.2. In particular, there were fewer deaths of arteriosclerotic cardiovascular disease and its consequences. This is further considered elsewhere,* and it may well be that the active physical work associated with employment as insulation workers is advantageous in preventing or delaying death of " cardiovascular disease, although the influence of initial selection upon admission to the trade cannot be disregarded.
It is evident that most excess deaths in this cohort were due to cancer (675) rather than to asbestosis and other noninfectious pulmonary diseases (153). This is notewor thy, since the present United States Standard for occupational exposure to asbestos is in large part derived from reported recommendations designed to prevent asbestosis.*
.. . Deaths of Less Common Malignant Neoplasms
Apart from lung cancer, mesothelioma, gastrointestinal cancer, cancer of the larynx, pharynx and oral cavity and cancer of the kidney, there was still as excess of cancer of other-sites, with 184 observed, compared with 131.8 expected. Table 13 provides information concerning expected and observed deaths fora number of other sites. For some, there was no evidence of increased incidence, as with leukemia, -- ...lymphoma, primary cancer of the liver, testes, bladder. Relatively small increases were suggested for brain, skin, pancreas, prostate. The overall increase is of some - interest, especially in view of the known possibility of asbestos fibrils being dissemi nated to virtually all organs following inhalation or ingestion.1'1'" We have long been properly accustomed to seeking verification of increases beyond chance expectation - ("statistically significant") in incidence of cancers of defined sites. This perspective does not contradict the potential importance of more general increases in cancer ..^--incidence of a large variety of sites, perhaps not reaching levels of statistical significance in any one' location but still yielding definite increases 'of the overall cancer burden of the groups investigated. . ,
ASARCO ALV 0002090
SelikofT et al.: Mortality of Insulation Workers
105
-.1 " Multiple Cancers
From a purely statistical point of view, in view of the increased incidence of cancer of several sites among asbestos insulation workers, we would expect that a proportion of these men would suffer multiple cancers simultaneously, even beyond the tendency of such findings to be made among individuals with cancer, in general.'1 Again, this ' would not be reflected in tabulations of causes of death by single underlying cause, as \ is the usual practice. Analysis of our experience demonstrated one hundred malignant i.i-V'neoplasms present-bur noL causing.death (Table 14). Sometimes these additional neoplasms were.;mentioned on the death certificate but as an ."other significant condition,1;not in the section on the underlying cause of death. Forty, were present '' 'among the 1064 cases-where death was due to causes other than cancer or asbestosis
TTi. `-'-Table U--~ *=
^^^^DtAT>g2Ai4ftNcnr30tt:!^Eaitoig^5gti(TtONCWdRS~ci:THg'U<CTE&.-STATtS*iU-fa-^agiULL-Iv
A.NO XMMDA-jANUARyv ] ~ 1967-DCCEMiiR 31, 1976 fr
:'--52AS!?.vii','NUMEJl OF. ME:*' 17.800
S??.?';Man-years of Observation 166.833
--
-SSST-iTiwT
....... Observed
Underlying Oum of Death 1-*: Expected*' . "(BE) . (DC)
' - Total deaths, all causes
:* 1658.9 .
" Cancer, ill siics
: . 319.7-
;' Deaths of less common-
. .-
- malignant neoplasms......... .
Pancreas
17.5 "
Liver, biliary passages
7.2
Bladder
9.1
Testes -- - -
1.9
' - Prosute
- *
.20.4-'
Leukemia
13.1 -
Lymphoma
20.1
Skin
6.6
Brain
10.4
2271 ,. 2271 995.~ 922
23 "
5 9
2 30 15 19 12 14
<9 19 7
I 28 15 16
8 17
Ratio o/e
(BE) (DC) "
-1J7 3.11
1.37 .. .2.88
1.32 0.70 0.99
--
1.47 1.15 . 0.95 1.82 1.35
2.81 2.65 0.77
--
1.37 US 0.80 1.22 1.63
"Expected deaths are based upon white male age-specific U.S. death rates of the U.S.
National Center for Health Statistics. 1967-1976.
* (BE): Best evidence. Number of deaths categorized after review of best available information
(autopsy,surgical,clinical).,
.. .
.
(DC): Number of deaths as recorded from dealh.certificate information only. .
......
.. . -(Table 15).: Among the.168 deaths of asbestosis, cancer was also present in 7, 6 of ' these being bronchogenic carcinoma. Analysis of the circumstances leading to death,. however, indicated that the underlying cause was asbestotic pulmonary insufficiency, and that the lung cancers were present but with no decisive influence at the time of ' death. Nineteen other cancers were present among the 486 deaths of lung cancer and 10 other cancers accompanied the 175 deaths of mesothelioma. There were 9 "incidental" neoplasms among the 99 deaths of gastrointestinal cancer. Although experiences are so far limited, it may not be wholly unexpected that there were proportionately more incidental-neoplasms accompanying deaths of colon-rectum.__ cancer, compared to those oflung cancer (3.5% vs. 3.9%). One may speculate-that this ~
I
ASARCO ALV 0002091
106 Annals New York Academy of Sciences
Table 14-
-
Mortality Experience Among 17.800 Asbestos Insolation Workers in the United States and Canada 1967-1976: Observations in 2271 Consecutive Deaths
j j
. . Miiigrunl Neoplasms Present, but not Causing Death*
Site
Number
, - .-. Lung . tr.-i-
.
'.-id;'. .
Pleural mesothelioma -
irsu Peritoneal mesothelioma.
Ephap- l-._.
Stomach
...
tt- * v~--. --1"-"v'Colon I."--'-*"-i"--'-
.... ''t - Oropharynx -----
'
?*,3ser,s i~'~* Larynx
>- 2
Kidney--:-":t.y+r; ... i
Olher - - i
- '______ v-________
42t
Too;__________ /-"
--^TwcnlyrOfte'.oTilheie- neoplasms wirt.cisnuoned-.on_the death- certificate (but were. not. -T-jV-' irii
ategorized is underlying cause of deathh^
./Including leulcemia 5. lymphoma 3. bladder 5. prostate 13. thyroid, etc.
Jin 92 i-dividuals; total includes multiple cancers in eight cases. .
. - ^...................... ..
J.. -- -.'-N could be due to the longer clinical course of many patients with colon-rectum cancer,
compared to lung cancer,.with greater opportunity, simply in terms of time, to develop
additional disease.
- '
Multiple cancers were present, overall, in 2.1% of deaths among these asbestos
insulation workers (48 of 2271). It is perhaps to be expected that this was more likely
to be the case among those for whom cancer was the primary cause of death (4.5%)
while only 3 of the 1276 other deaths had this finding.
From a clinical point of view, in the management of patients with asbestos-
associated disease, the potential for incidental or multiple cancers is of some
importance, and awareness of the possibility may assist in both the diagnostic
investigation and long-term surveillance of individuals with history of significant
asbestos exposure.
. . ,T
Lapsed Period
" "
':
- It is now well appreciated that most asbestos associated disease is first seen after considerable periods from onset of exposure In both occupational and environmental circumstances. This is true both for the presence and extent of parenchymal fibrosis and pleural fibrosis and/or calcification/11 and for asbestos-associated neoplasms.14
Data obtained in this investigation now provide a more complete overview of this question. Broadly, we saw some limited excess disease in less than 20 years from onset of exposure (Table 16). Among 12,683 men. with such experience; covering 89,462 man-years of observation, the number of cancer deaths was about doubled, with 42.6 deaths expected and 83 observed. There were no excess deaths of gastrointestinal cancer and only 5 deaths of mesothelioma, with these in the 15-19 years from onset category. Age, year and sex specific mortality data of the U.S. National Cancer for Health Statistics indicated that 11.9 deaths of lung cancer were to be expected. Thirty-six occurred. There were 8 deaths of asbestosis.
-
ASARCO ALV 0002092
Selikoff et al.: Mortality of Insulation Workers
107
On the other hand, extensive disease was seen among the 12.051 men who had
reached 20 or more years from onset during the decade of study. Here, 1376.0 deaths
>ere anticipated: 1946 occurred. There were 160 deaths of asoestosis and 912 of
cancer. It was al this time that bronchogenic carcinoma made its heaviest contribu
tion, with 93.7 such deaths expected and 450 observed. One hundred and seventy
deaths of mesothelioma were then seen and the increase in gastrointestinal cancer
found. Ta3L 17 depicts these data in some detail, in five-year periods from onset of j-.-
empIoymenL Lung cancer data are given as both expected and observed numbers of .
death. This practice cannot be followed for mesothelioma, where expected deaths'
cannot be computed for the general population. Instead, we have provided data in both
. number of deaths of pleural and peritoneal mesothelioma, as well as in terms of
- ! number of deaths of these causes per thousand persons years at risk. The latter does - Tf' -
v. not take into account variations in achieved age, but this may have less influence than '
achieved duration from onset of employment. It will be seen that very major increases .
in numbers of deaths of lung cancer are first seen at 15-24 years from onset of work.
-- with continued further increases. The extraordinary increase in deaths of mesothe-
js-ljotnaiJxsthiof'the.pleura anctthe-.periioneumc^ribrobservecf unnl somewhat laTer/--1^3^
r reachihg'2.78 deaths per thousand person-years al risk for pleural mesothelioma at..
35-39 years from onset of work, and 5.47 deaths of peritoneal mesothelioma per "7^1?;
"iDousand person-years at 45-t-years from onset-
i; . 'r '
V.L, In another reflection of the clinical concerns among these workers. Table 18
indicates that'approximately one-third of all deaths were due to lung cancer at 30-34 .
years from onset, while mesothelioma accounted for 13% of all deaths at 35-39 years.,
*."
Table 15
' ' r "
Mortality Experience Among 17,800 asbestos Insulation Workers in the United States and Canada 1967-1976: Observations in 2271 Consecutive Deaths
Number of Incidental Malignant Neoplasms (not Causing Death) in Relation to Underlying Cause of Death as Established by Best Evioence (BE)
.. *
- - *. *.* `
Underlying Cause of Death
Number of Deaths of Underlying Cause
Incidental Malignant Neoplasms
No. of .. Total
Deaths
Cancers
Oncer all sites
995 45 -
Oncer oflung
486 17 -
Pleural mesothelioma -
63 .
4-
Peritoneal mesothelioma
112 ' 5 - '
Oncer of esophagus ... Oncer of stomach
18 i . - 22 ---- -
i; 3.
-- Oncer of colon-rectum - . e'. -. ;
59 i
i. 5 i-'
Cancer of larynx .. ri. :
- i
it
r_' o
Oncer ofpharynx, buccal cavity -- : .
21 .. :
2v
Oncerofkidney
' - ' i 19
All other cancers ?*. 1. .r-- i. v- i : 184
' - 0 i. - . %-r:
Noninfeetious pulmonary ~. T " .
-
diseases, total
..
212 .
10
- Asbestosis .
168 7
All other causes ' ' - . - -
1064
37
Total
227!
92
50 19 4
6 1
3
-5 -
o 3 :: o
9
107* 40 1Q0
" :rr '. - " .. ...a.'i
*
- oC these wcrelung cancer..-----
I
ASARCO ALV 0002093
108 Annals New York Academy of Sciences
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ASARCO ALV 0002094
Seiikoff et a!.: Mortality of Insulation Work:rs
109
>ONC9Nv5r fOco. d" c9-'n^'X9'XY
a
'JL'
v
* **
- in -- -- rt ,, _
55
"oja
' t^Os'-*noaar"r*rcn^: Tv
41
OOOOdo<N-^r<
sc .*r-
a9u
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f
J;-* .>-. -
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>rv^-
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u
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' rtr>'Ofl9p*M*
*n n rr o n ri
^11=----- --- ---r==^c -V
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\ y-;: k :' - j-.-" '-
-. -
---
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-
.--vrv--f `V.'.-s-
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1 pr<* vp>* eo* o --^ nw
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-
S A
no. rOt rn^onor..<--=->oto -- 30r.|j 2i-
3?n= X.- ';
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yf: :- r i " --
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1
ASARCO ALV 0002095
110 Annals New York Academy of Sciences
Table.18
Deaths Among 17.800 Asbestos Insulation Workers in the United States and Canada, January 1, 1967-DECEM8ER 31, 1976.
Analysis by Duration from Onset of Employment
j
I j
Percent of All Deaths Mesothelioma
Years from Onset of
Employment
Total Deaths
Lung Cancer
(BE) (DC)
Pleural (BE) (DC)
Peritoneal (BE) (DC)
Total (BE) (DC)
<10`
10-14
15--19 - "
20-24
51 0- . 0 . 0 0 85 sa 5.9 0 ,, .0 . 189 15J 14.3 1.1 l.l 320 - 18.4 17.8 1.9 -,1J
o.. 0 . 0
0.
00 0 o !
1.6 0
2.7 - 1.6 . - -
0.9 0.6 - 18 2S -
25-29 30-34
35-39
388 ; 27.t 24.7" 340 32.9 30.3253 - 25.7 22.5
3.4 - - 1.3 2.7 - 0.95.9 1.6
4.9 -.0.8 .. 8.3 . 5.2 . ..v -
6.8 1.8 9.4 6.5
7.5 2.0 13.4
7.9
40--44
203 19.7 15.3 2.0 1J 7.9 IS 9.9 6.4 --
45+ ;
442 - 15.6 12.0 ' 3.2 0.9 6.6 1.1 9.7 4.1
- . Totali.-----5--- 2271 -- - 21.4 18.9 " 2.8.V-ZI3', 7~4.9^--r,i~.."7.7.-TT- 4.s
`Total includes mesothelioma not specified as either pleural or peritoneal.
. . ------- -
(BE): Beil evidence. Number of death catc.-rizcd after review z~ oesi available ir.formatios
(autopsy, surgical,clinical).
; -.j'
(DC): Number of deaths as recorded from death certificate information only.
' T~-r-
--
Altogether, lung cancer was responsible for 21% of all deaths observed by us in this cohort and mesothelioma for 8%. - '
Investigation and Categorization of Causes of Death
It is widely known that causes of death as recorded on death certificates may be ia error and that, even when accurate, these may be coded with considerable variation among different agencies, despite the existence of agreed upon international rules and rccommentations.15 Yet death rates based upon large series of causes of death as recorded on death certificates are nevertheless useful, and are widely utilized. This distinction, however, leads to the understanding that comparisons between observed causes of death and those expected from national or local "death rates" should not be considered in rigid exact terms, especially when considering the mortality experience of very specific groups. For these, there are no perfect "controls" that would lake into account their age distribution, ethnic derivation, smoking habits, economic circum stances, prior personal and social history, and so on.
The matter is further- complicated by the fact that deaths in the general population, which provide the basis for established comparison death rates, are not verified by investigation or examination of available data concerning the circum stances associated with the deaths. Of course, one may elect to treat the deaths in the study population in exactly the same way, with no attempt to review data other than that recorded on the death certificate, explicitly accepting whatever errors might exist in causes of death recorded and implicitly hoping that whatever errors exist are very much the same in the two sets of data, deaths in the general population and those in the group under investigation. Certainly this latter method is simpler, cheaper, much less time consuming.1*
*
ASARCO ALV 0002096
Selikoff et atMortality of Insulation Workers
1)1
But this approach has a number of drawbacks. Firsts where the distribution of causes of death in the group being studied is different than that found in the general population, one may expect that, the distribution of inherent error might also be. different. Second, data may be available which can shed much light on the causes of death under investigation and not including such information permits the risk of reporting results which are simply inaccurate. It is perhaps inadequate comfort to skirt this difficulty by dearly stating that only death certificate diagnoses are reported; this only gives, the reason for potential inaccuracy..There are also technical issues, and these are of particular concern among asbestos-exposed groups.in the sixth, seventh ': and eighth revisions of the International Classification of causes of death. There have . 4 been no dear-categories for the diffuse-malignant mesotheliomas of the pleura and ..." peritoneum which occurs and while some, improvements have been made in the ninth ?-' A revision now being introduced,we feat that these will still not resolve the problem. . ^ . ..'.As -lust as there are no perfect controls, there is also no single-perfect solution, and it... ' is unlikely that there-wilt be such in.the foreseeable future, especially since d3ia-available for ascertainment of cause of death, even when investigations during life and - at autopsy have been undertaken, are not always complete and are surely not uniform. -:I
^.vSrm Mo*T*Lmf'Ex?wiMCEdA>ONCrL7^00 Asbesto*- Insulation Workers in the .States ano Canada. 1967-1977: Observations in 2271 Consecutive .,
Death*with Underlying Cause.of Death Cooeo>-Accoroing to Death'.- -
-^Ihisd'C'CER-nncAtE-Information- Only-and According to Best Evidence--:
;i'-v-' :..T Underlying Cause of Death
Death ; - Best ,,t.
* - r--.**;Ce(rDtifCic)ate -
Evidence (BE)
Expected* No. o/e No.- o/e
. / Of . Best
Evidence
Cancer all sites
-- '- -
319.7
922 2.88 995 3.11
93
Cancer oflung
105.6
429 4.06 : 486 4.60
88
Pleural mesotheUoma>.""- .- .t, ...
25 ' tv--. . 63 . ---
- - Peritoneal mesothelioma ..
t ____ . 24 ---
.112 --
Mesothelioma. n-o.s. .... ., t. ..
55 --
' 0 '--- `
. 40 .. 21 . ` --- *
Cancer of esophagus
' " 7.1'
18 2.53 .. ' 18 ' 2-53
100
Cancer of stomach
14.2 18 1.26 - 22 1.54
82
Cancer of coion-rectum "* - Cancer of larynx, pharynx. ""
': 38.1 `
58 1.52 ' 59 1.55 .*
' 98 '
buccal cavity '
-
14.8 - :v 25 1.69. >- 32 2.16 u 78
" Cancer of kidney
. 8.1 -- < 18 203
19 2.36
95
Cancer of prostate .
: - : 20.4 -. . .28 - 137 . 30 1.47
93 ...:
Cancer of bladder ...-j-,:-....... -- 9.1 .., - .7. 0.77 .... 9 0.99
- 78
Cancer of pancreas
.' - 17.5
. Cancer of liver _
' Cancer of brain
'T*V ' 10.4
Noninfectious pulmonary1
v - S+* _ .
diseases, total--------
------- 59.0
,, . 49 2-SI ... -.25. 1J2 . 213
;j9. 2.65 V ''5 . 0.70 ` 380
' -17' 1.63 ~ 'ri4~ 1.35 ' - 121
--
--
- * * v;
'' ''tV _; .
-188 3.19 -*? 212. 3.59 89 =-:. . ....C- .
.
Asbestosis --
3,'r' - .t
: 78 :
168 -- * * 46
. C.
All other causes
`........ 1280.2-r- 1161 0.9V 1064- 0.83 a '109
:
'Expected deaths based on white male age-specific U.S. death rates of the U.S. National
Center for Health Statistics. 1967-1976.
tRaies not available, but these have been rare causes of death in the general population.
(BE): Best evidence. Number of deaths categorized after review of best available information.
(DC): Number of deaths as recorded from death certificate information only.
" "
I -
ASARCO ALV 0002097
f
112 Annals New York Academy of Sciences
We have elected to approach this problem by providing data in more than one way,
including causes of death as recorded on the death certificate in our cases, for
comparison with'"expected'' deaths based upon the data of the U.S. National Center
for Health Statistics, as well as causes of death established after detailed review of all
available information. Such data were retrieved in 1961 of the 2271 deaths. However,
detailed information was not equally available for .all categories of causes of death.
This was to be expected, in the nature of things. As a rule, the best .available
information for establishing the cause of death was considered to be autopsy findings,
with pathological information derivtd from surgical intervention next, and, in their*
absence, clinical and roentgenological observations made during life, particularly in
the period before death. Where no such details were available, the cause of death as
recorded from death certificate information was then utilized. Among the 995 cases of.
cancer, we were required to depend upon the death certificate alone in only 23, with
other information available in 967 cases (97%). In all 175 cases of mesothetioma,.
surgical and/or autopsy findings were utilized. We depended upon death certificate .
information alone irtlOof the 486 cases of lung cancerc^TM:
i=sISirni!arIy. in 166 of 168 deaths of asbestosis, information was available irr addition'.....
to the death certificate, leaving dependence of the latter in only 1%. In contrast, for
causes other than cancer and asbestosis. additional information was available in only-
three-q'^arters of the cases. Analysis of the distribution of de-ihs within this category
showed that this was by no means unexpected. Sudden death attributed to myocardial
infarction or cerebrovascular accident is often not further investigated nor need
clinical abnormalities have preexisted. It was therefore no surprise that in 156 cases
the medical attendant or the medical examiner warranted such death certificate '
diagnosis without other information being available. It would seem difficult to avoid
differences in quality of ascertainment, under such varied circumstances.
Analysis of our data suggests that, by and large, death certificate diagnoses were
not far off the mark. This speaks highly for the'diagnostic acumen and quality of care
provided to these men by their medical attendants. Cancer as the underlying cause of
death was indicated by the death certificate in 922 instances compared with 955 so
categorized after considering all available information (Table 19). The specific
diagnosis of cancer of the lung and cancer of the several sites of gastrointestinal
cancer, as well as cancer of the larynx, oro-pharynx and kidney was also generally well
predicted by the death certificate diagnosis.
... . . .
In a number of instances, however, there was important disparity between causes
of death as recorded on the death certificate and those judged to be the case after
review of available clinical and pathological material. This was true for pleural and
peritoneal mesothelioma, asbestosis, cancer of the pancreas, primary cancer of the
liver, cancer of the brain and chronic obstructive lung disease.
--. --
In 49 cases, cancer of the pancreas was listed on the death certificate as cause of
death. Only 17_5 such deaths were expected (Table 14). If we were to accept cause of
death as listed on the death certificate to establish the "observed" number of deaths
for this disease, we would have to conclude that cancer of the pancreas is significantly '
increased as a cause of death among asbestos insulation workers. But this is not the
case; when all.available material was reviewed, it was found that only 23 deaths
compared with the 49 so categorized on the death certificate were due to cancer of the
pancreas. Four were the result of metastatic lung cancer, 15 were found on review of
histological material to be cases of peritoneal mesothelioma and 5 were best categor- j
ized as abdominal carcinoma, primary site not established. Two were due to cancer of
the colon. This is not to say that we have established that there 1s no increased -
incidence of cancer.of the pancreas among asbestos workers: It is possible there is'- "
some limited increase and we are cognizant of the uncertainties inherent in the
ASARCO ALV 0002098
SelikofT et a!Mortality of Insulation Workers
113
computation of "expected" rates forcancer of the pancreas since it may well be that
j some of the cases so categorized in the general population from which the expected
i rates were derived, might really be instances of lung cancer, colon cancer and even,
perhaps, peritoneal mesothelioma. Since these deaths in the general population have
' not been investigated to verify death certificate cause of death, it is not possible to
| imow whether such inaccuracy exists,.nor its degree.
- ...7
- i> .--Asbestosis. was another example where categorization by death certificate would
i,.` be misleading since only 78 deaths or this disease were so categorized compared with
V^-ssb 168 after review. A. variety of other diagnoses were offered in the discrepant cases,
rlvir! - primarily those of "chronic obstructive lung disease," orother noninfectious respira-
%5&*:t0ry disease.- acute infections, and..fn two cases, cancer of the lung. It was of interest
that in 16af the 97 cases called asbestosis after review,-but in which asbestosis was not
7r_ listed as the underlying-cause of dcalh.it was mentioned on the death certificate under
the rubric of "other significant conditions." In 129 other cases, asbestosis was again
mentioned on the death certificate, but-not as underlying causeof death. Altogether,'
asbestosis was mentioned in. 230 of the 2271 death certificates: ''
77' -' ' ' ' :r
In-7 cases,, asbestosis so categorized, by death certificate designation was
^.--.'reassigned to other categories after review, with death found due to lung cancer in 5,.
peritoneal mesothelioma in one and myocardial iniarction in another..-' -
-
"'ftiiyiM--Accuracy of diagnosis of mesothelioma, and its being recorded on death certifi-
-wtz^cates, is a special problemi-First; there are the difficulties and subtleties of patholog-
V^T.-.tr.ical diagnosis, of^ particular- importance- when cases of this neoplasm are seen
throughout the United.Stales and Canada by pathologists with varied.experience.
- : Sometimes, there is the added difficulty of extending the pathological diagnosis to the
death certificate, not infrequently completed by a physician who may or may not have
.. been the regular medical attendant and fully cognizant of pathological findings; to this
could be added the problem occasioned by the fact that the death certificate must
often be completed before there has been full consideration of postmortem findings.
. When these differ with the death certificate diagnosis, an amended certificate is
... - expected to be filed. In our experience, this is rarely done. When to these are added the
. . administrative uncertainties and insecurities of classification, it is not surprising that
only about one-quarter of the deaths of mesothelioma in this series were correctly
- : recorded on death certificates as pleural or peritoneal, although 104 of the 175 cases
were recorded as`'mesothelioma." even if not with full details.
We are presently analyzing the 175 deaths of pleural and peritoneal mesothelio*
.' ma, and the results will be reported. In 108 of the 112 cases of peritoneal mesothelio*
. irra, surgical and pathological material was submitted to us for review and this was the
- case as well as 61 of the 63 pleural mesotheliomas (96.5% and 96.8%).
The association of pleural and peritoneal mesothelioma with prior asbestos
exposure is so striking" that it is not surprising that overdiagnosis might now
* sometimes occurs .We found such to be the case in this study. In 8 cases in which
mesothelioma was recorded as underlying cause of death on the death certificate,
.i.. review of the histological material showed the diagnosis to be other than mesothelioma
.:(cancer of the lung in 5 cases, metastatic carcinoma in 1 and Wegener's granulomato- .
'sis involving the pleura in another). In the eighth case, pleural mesothelioma was
present but was not the cause of death, which was better attributed to concurrent
j cancer of the stomach.
.........
.....
j Where mesothelioma appeared as the diagnosis on the death certificate, depending
upon the exact phrasing used, this might be coded in the eighth revision of the
International List'fri'categories 158.9 (malignant neoplasm of peritoneum), 163.0
(malignant neoplasm of pleura), 197.0 (secondary malignant neoplasm of lung). 195.0
(malignant neoplasm of abdomen), 198.9 (secondary malignant neoplasm, specified as
.:-V
'A'
I
ASARCO ALV 0002099
114 Annals New York Academy of Sciences
secondary). 199.0 (multiple malignant neoplasm [carcinomatosis, disseminated
cancer]), 199.1 (malignant neoplasm without specification of site) and. not infre
quently. 228 (benign neoplasm of other and unspecified organs and tissues). There is
at the moment no reliable way to extract the numbers of pleural and peritoneal
mesotheliomas from death certificate data categorized and recorded by health
statistics agencies in the past, using the several revisions of the International
Classification of causes of death.
.
V/e might add that, overall, pathologists' diagnoses were much more accurate than
' death certificate characterization of causes of death would lead one-to believe. This
'^""again bespeaks a high degree of competence on the part of pathologists in the United
States and-Canada, (we are aware, of-course,-that diagnostic suspicion may be
` `^increased in those instances in which it is. known that asbestos exposure had occurred,
-"i;'as with individuals among whom occupational history indicated such exposure; this
'.tc-tilcould perhaps have accounted for some of the over-diagnosis). However this might be,
'-jxiiit is clear that a problem, exists in translating the information obtained in pathological
-vr jtudyto the death certificate diagnosis, as well as a problem of subsequent coding of
-i-lhe stated cause of death.'-
~ .r vjr-
-HO '-.rrc'.*-
w'tiy ItCONCLUSIONS. *7, .'jA'SZiLJizz*.* - *--v -f
C* V ^ v*~r .
Asbestos insulation workers inthe Uniteu States and Canada suffer an extraordlnaiy increased risk of death of cancer and asbestosis, associated with their employj^'ment. This includes-increases in death of lung cancer, pleural mesothelioma, peritoneal mesothelioma, cancer of the esophagus, colon and rectum, cancer of the larynx, - oro-pharynx, kidney and perhaps stomach. Some increases were seen in cancer of ... o-several other sites, as well, but data are inadequate at this time to permit characteriza- tion of their significance, although attention is called to such wider increase. .,
Littljjjmgseii^cancerdeaihSjjjj^jtiiiisSiUBjS^SaUilJSBSiilUfiSUilSiLliii^
^ea^Tro^jjijij^rtj^SSSSfcTn^eneral. l^e Period of latency betweenonseToT
exposure and death was 2, 3, 4. or more decades. Large increases in lung cancer occurred at 15-35 years from onset while pleural and peritoneal mesothelioma showed -- ; : their greatest incidence somewhat later. Under the conditions of exposure which ' obtained, the period of clinical latency for asbestosis was also prolonged and in many cases was 30-40 years or more from onset of employment. It would appear that in ..... studies of the effects of such asbestos exposure it would be advantageous to analyze . the experience of exposed individuals in duration-from-onset exposure categories, with particular reference to durations of more than 30 years. If this is not done, the risk is run of obscuring the neoplastic effects of asbestos exposure by the co-mingling oflater -" deaths with those which may have occurred much earlier and which would be much less likely to have been influenced by asbestos exposure. In the same way, studies -'--- should include, whenever possible, the opportunity for observation of the mortality experience of the individuals at risk at least 30--35 and. preferably 40 or more years from onset of their exposure. Again, unless this is possible, only the very limited early ' effects will be identified and the full import of the exposures may not be appreciated. - Our experiences demonstrate the advantages of review of all available information ^concerning the-circumstances associated with the deaths that occur. Depending entirely upon death certificate diagnosis can lead to erroneous reports of causes of death, a problem that can be mitigated by characterizing causes of death according to the best available, information. Using this approach, we found that the apparent increased incidence of cancer of the pancreas among asbestos insulation workers. - iindicated "by death certificate diagnosis, did not really exist, and that many so
*:
ASARCO ALV 0002100
Selikofi* et al.: Mortality of Insulation Workers
115
designated were due to other causes. The same was found for primary cancer of the liver and cancer of the brain, both of which would have been considered of increased incidence using solely death certificate diagnosis, but were not so established following review of histological material. This, of course, could well be anticipated with exDOsures to agents which increase the risk of neoplasms known to metastasize to these sites (bronchogenic carcinoma, gastrointestinal cancer).
Our experiences do not indicate that the addition of amosite asbestos exposure during and after World War II to the chrysolite asbestos exposure which existed before then, and which continued, demonstrably altered the nature of the asbestos* : induced diseases which resulted, nor their extent. Further, limited experiences suggest : that asbestos insulation, employment begun 1943-1962 carried the same type of long-term risk as that begun before that lime. We have no information concerning the nature or extent of risk: among insulation workers whose employment began after
fi -
?'. zVj: ULferwm# hsa:si:-.f.-u -- / =.;: _."7
.Y -Vit's; .
- 7 :/L
We are grateful , for the extraordinarily valuable assistance of Ms. Janet S. KiiTenburgh and Ms. F;-ar..ej Pere^. in the tracing-.and acquisitioi. of material concerning the insulation workers in these cohorts." Clearly, the completeness of the -. prolonged serial observations could not have been accomplished without their dedi- . cated and skillful help-.At.lhe same time, the leaders of the asbestos workers' union equally share our gratitude;- Mr: Andrew T. Haas,, and Mr. William C. Bernard, , International President.and International Secretary of the union, Mr. Roy J. Steinfurth, coordinator of the Insulators Health Hazard Program and the many union officers throughout the United States and Canada whose dedication and concern have permeated their work with us. Special mention should be made of officials of the New York-New Jersey metropolitan locals of the union, Mr. Jack Novak, Mr. Harry Ahrens, Mr. Terence McConnell, Mr. Jerome Market, Mr. Thomas Viscovich, Mr. William D. Fitzgerald, Mr. James Grogan, Mr. James F. Dwyer, Jr. and Mr. Howard
Barnett.*' Our warm thanks are due, too, to the staff of the Department of Epidemiology and
Statistics of the American Cancer Society, including Mr. David A. Newman, Mr. Ashley Bodden, Mr. Edwin Silverberg. Ms. Marie Corbo, who have with competence and dedication, assisted in the extensive processing and computation of the statistical data that were obtained. As so often nowadays, this epidemiological study could not Jtave been completed without the integrated cooperation of many. .
Equally warm and strongly held gratitude is due to our colleagues. Dr. Jacob Churg, Dr. Yasunosuke Suzuki and Dr. Milton Kannerstein for their help in reviewing the many anatomical and histological specimens that were made available to us. Their skills, knowledge and competence form a qualitative bedrock for the study. Equally, we are appreciative of the generous help given to us by clinicians, pathologists, medical examiners and others in medical facilities in all parts of the United Slates and Canada, providing detailed information, records, roentgenograms. We obtained as much pleasure and satisfaction from our experiences with the kindliness and generos ity of medical and scientific colleagues as with the observations these enabled us to make.
These acknowledgements would be sadly incomplete if they did not include our
appreciation for the many at the Environmental Sciences Laboratory whose patient day-to-day help assisted the rest of us and assured the collection of the very large amount of information inherent in our data; warm thanks are extended to Selma - -
7I
ASARCO ALV 0002101
116 Annals New York Academy of Sciences
Anncnberg. Richard Ashley. Doris Fleisher. Rupert Fuller, Judith Marmor. Maria Martinez. Diane Monahan, Vera Reitman, Julia Roberts. Albert Rodriguez and. Sidney Sibcl. Their work was the warp and woof of the fabric of the investigation.
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^ ;`
`
7=^3" iT.y
ASARCO ALV 0002102