Document 5LaDK5XqpZkb6QD38YkrVqRqD

FILE NAME: Exxon (EXX) DATE: 1991 Sept DOC#: EXX041 DOCUMENT DESCRIPTION: Letters to the Editor - Journal of Occupational Medicine also Heforenceii icer, 1. Lin HS, Diechinger PC, Condo J, Farrell methodology was so vague as to be un repeatable. Thus the bases of USSR val injected cornea. Clearly, then, neuro logic effects were noted at 60 ppm, which iwur K. Occupational exposure to electromagnotio utic lloldo and the occurrence of bruin tumors. J ues have never been confirmed by other scientists. At about the same time this increased with higher exposure levels. Qerarde quoted the authors of the 1942 duo Occup Med 1986;27:413-110. 2. Preston-Murtln S, Mack W, Henderson p u 11E. Risk factors for gliomas and meningiomas committee was in the USSR, a prominent Soviot industrial physician was touring paper as warning that exposure to 200 ppm as an 8-hour limit impaired coordi tho mi i1n98m9u;4le9s:8i1n3L7-o6s1A43n.geles county. Concur He*. the US and, on direct questioning, ad mitted their MACs were only recommen nation and reaction time, potentially rendering the workers "dangerous to iiieroring al. 3B. rTuihnomtuams Tor, SmtooliretayliPtyD,rSistekmahmugoenng Am,eent with electrical and electronic Jobs: a coso- dations and were ignored in practice. In fact, he seemed to think it rather quaint their own safety and to safety of the operation." He recommended a limit of .tain- eontroi study. J Natl Cancer In*t 1987; that anyone would think of observing a 100 ppm.4'" ubles lova- 79:233-238. 4. Milham S Jr. Mortality in workers ex MAICt Iis to be hoped that Ziem and Castle- Esso physician Robert Eckardt wrote Stokinger 8 years later, attaching a copy jgon- culur Hpoesaeldth tPoorsepleecottr.o1m98ag6n;6e2ti:2c97f-i3e0ld0s.. Environ nian will proceed with an open-minded 6. Speers M, Dobbins J, Miller V. Occu study of TLVs and realize that, although of Qerarde's letter and repeating the view of the Esso doctors that toiuene's 1, the with pational exposures and brain cancer mortal ity: a preliminary study of East Texas resi not perfect, they certainly are better than nothing at all and have made im TLV, still 200 ppm, was too high, again recommending 100 ppm." Although both dents. Am J Ind Med. 1988;13:629-638. none Occ6u. pMaticoLnaaulgrhislikns Jf,orMinaltkraecrrHan, iBallogtlWiom, eatsuiln. portant contributions to the control of potentially toxic exposures of workers in dToLcVto, rsthuerygerdecaomlomweenridnegdoafntheextpooluseunree .rical thin Sweden. J Natl Cancer Inst. 1987;78:263-267. the US over the past 60 years and even in some Third World countries. level double that shown to cause brain effects in short-term human trials. Not 1 not u for In Delense ol TLVs Robert E. Eckardt, MD eurnetdil t1o971300wpapsmth, eonTLthVe fboarsitsoloufenfuertlohwer .none To the Editor: The statement about C67o2n0suEl.taKntolitnonToLxaincaology Scottsdale, AZ 86264 reports of adverse effects on human vol unteers and experimental animals at 200 It is threshold limit values (TLV) by Ziem unon and Castleman (J Ocoup Med November ppmIn.7'.h8is 1960 text, Gerarde criticized y are with 1989) displayed a lack of familiarity with the past 60-year history of occupational The Author Replies the TLVs of two of eight aromatic com pounds he described. He was also con s, al- modicine in the US. The TLVs were pro 3 U S - posed as a guideline for the profession, Although TLVs were presented as guidelines in industry, their main effect cerned that xylene's 200 ppm TLV was too high for comfort and work perform noig:upa- with the understanding they could either be reduced or increased with the pres on practice has been to tend to legitimize workers'exposures up to the TLVs.1'" It ance. Such high exposures, he said, could cause "severe eye irritation" and "im o but entation of data that might so warrant. -ality Over the years many TLVs were altered, is wrong to conclude that the only alter native to the TLVs was "nothing ut ail." pairment of reaction time." Gerarde rec ommended 100 ppm for xylene, a limit udles usually downward, as the result of data collected on carefully studied groups of For industry to function, some standards would have been necessary, and if indus adopted by the American Conference of Governmental Industrial Hygienists in ueasisure employees subjected to a knowledgeable periodic examination p, ugram by com try did not have the TLV Committee, there still would have been exposure 1967." Wore these high TLVs serving a use js. In to be petent occupational physicians. In the absence of such submissions or new ani limits. It is well known that many com panies have had internal corporate ex ful purpose? Or did they provide false reassurance, especially to non-health loncy icucy mal data, the presumption was made by the TLV Committee that the existing posure limits for many years," despite their reluctance to publish lists of these professionals (such as piant managers) and workers? risk TLV was serving a useful purpose. If Ziem and Castleman have reliable limEitxsp. erience with toluene is illustra The example of toluene also raises the issue of corporate responsibility. Neuro this io be data, and not merely opinions that war rant a change in a TLV, I am sure the tive. At Esso, Dr Horace Qerarde criti cized the toluene TLV of ZOO ppm as behavioral impairment can occur below 100 ppm (eg, Table, reference 2). Why lling s oc- TLV Committee would be more than will ing to consider them. In the absence of excessive in 1966. Qerarde wrote to tox icologist Herbert Stokinger of the TLV did the oil and chemical companies not do more, earlier, to document the haz such data, the condemnation of TLVs hardly warrants attention, and I am sur Committee that a 1942 report on three human volunteers had shown mild drow ards of this product, now used in quan tities exceeding 6 billion pounds per year prised the editors of J Ocoup Med chose to publish it. siness, headache, and impaired accom modation to light at 60 ppm; and mod in the US?10Did tbey not have a respon sibility to do more than merely prevent Furthermore, because Ziem and Custleman laud the approach of the USSR, erate fatigue, sleepiness, and headache at 100 ppm. At 200 ppm, all three felt exposures whose acute toxicity would constitute imminent threats to the safety they should be aware that many years ago au expert committee of toxicologists fatigued, two experienced muscular weakness, confusion, and parusthesias; of their operations? Defenders of the TLVs who criticize n o tify was sent to the USSR to develop an wy understanding of the scientific basis on one complained in addition of headache, and another felt nausea. Two showed the Soviet MACs may rind it hard to admit that the pre-1960 Soviot limit of which USSR MACs were established. On E6 their return they agreed that the USSR impaired coordination, and moderate pu pillary changes were noted, as well as 26 ppm was more consistent than was the TLV with the historic literature on nine/Volume 33 No. 9 September 1991 Journal of Occupational Medicine/Volume 33 No. 9 September 1991 toluene; Lehman and Flury had recom mended 60 ppm for toluene (and 45 ppm for xylene) In the 1930s.*,n The more recent finding cited In our paper and the current 40 ppm limit In Norway come too late to help the laet two (feneration* oftoluene-exposed workers.*'" Had such relatively strict limits been observed here, It would have required a major change from `'business as usual" (eg, the use of more water-based paints Instead of paints using toluene as a diluent)--In contrast to the TLVs. Roach and Rappaport1* found no re lationship between the TLVs and the concentrations associated with adverse human health effects In the literature cited in the 1986 TLV Documentation as the basis for the TLVs. They did, how ever, find a "surprisingly strong corre lation" between the TLVs and the pre vailing level* of exposure In Industry reported In the cited articles. They con cluded that the TLVs strongly favored practical Industrial considerations over health concerns." Risk estimates for carcinogens Indicate that substances millions of workers are exposed to carry lifetime risks at the TLVs of 1 In 100 and higher." Tarlau," In an editorial In the Am Induat Hyg Asaoc J, critically examined the lack of chronic toxicity data and the extent of corporate Influence on the TLV development process, and wrote: "This scandal leads to the Inescapable conclu sainodn utnhraetlitahbeleA."CGIH TLVs are tainted The view that the TLV Committee Is wthialltinwg atorracnotnscidhearngdiantga TanLdVslithearsatunroet been consistent with our experience (or thhaast osfutbhmeiEttsesdo dmocattoerrsia).l Oonne onfuums e(rGoZus) chemicals over the past 6 years, In some cases because ofthe same Inconsistencies described by Roach and Rappaport. This exchange arose from clinical experience and years of reviewing literature to write government fact sheets on hundreds of chemicals. The substances addressed In these letters to the ACOIH Included: methyl Isopropyl ketone, cyclo hexene, 1,8-dlchloroethylene, chlorodlfluoromethane, carbon tetrabromlde, sulfuric acid, sliver, zirconium, stoddard solvent, sodium bisulfite, hydrogen cya nide, plclorara, trlmothylamlne, aldrln, dleldrln, and others. These submissions did not result In any reductions In the TLVs, to the best of our knowledge, al though they brought many studies show ing health effects below the TLVs to the attention of the TLV Committee. Like It or not, hundreds of TLVs are now permissible exposure limits as a result of the Occupational Safety and Health Administration (OSHA) air con taminants standard Issued In 1989. This presents us In occupational health with new problems not contemplated by those who think any TLV Is better than none. OSHA's standard Included adoption of permissible exposure limits for 184 pre viously unlisted substancos. Some em ployers may think they can control down to theso limits and go no further, even when a doctor tells them their workors are nonetheless exposed to a hazard. In this regard, It Is relevant that the DC Circuit Court of Appeals has ruled, "If an employer [who] knows fi specific standard will not protect his workers against a particular hazard, his duty under (the OSHA General Duty Clause) will not be discharged no matter how faithfully he observes that standard.""1 Given the Inadequacy and regulatory status oftho TLVs, It Is the responsibility of the Industrial physician to bring to the employer's attention any evtdenco of potential harm that could occur at pre vailing "legal" exposure levels at a worksite. Indeed, It could bo considered malpractice for an industrial physician to "prescribe" an exposure near or at a level known or suspectod of causing harm. Because physiologic alteration from xenoblotlc exposure Is unlikely to be a biological "Improvement," changes associated with chemical (or other) ex posures should be considered harmful until proved otherwise. We put this information before the Journal readers because the TLV book lets continue to be published and the TLVs continue to bo relied upon (we think excessively) by some occupational health professionals. Grace E. Zlem, MD, DrPH Barry I. Castleman, ScD Occupations! and Environments! Health Research Office 1788 Linden Avenue Baltimore, MD 81817 References I. Castleman BI, Zlem GE. Corporate In fluence on threshold limit values. Am J Ind Med8. .19Z8le8m:13G:6E3,1-6C8a9s.tleman BI. Threshold limit values: historical perspectives and cur rent3p.raPcatuicsete. nJbOacchcuDp,ALfeadn.g1n9e8r9R;3.1C:9o1r0p-o9r1aRte occupational exposure limits: the current state of affairs. Am Ind Hyg Assoc J. 1080;49:809-818. 4. von Oottlngen WP, Neal PA, Donahue DD. The toxicity and potential dangers nf toluene. JAMA 1948;118:679-684. 6. Gerardo HW (Esso Research and En gineering Co, Medical Research Dlv.) letter to HE Sloklnger, Fob 89, 1968. 8. Eckardt RE, letter to HE Stoklnger. Feb 6, 1904. 7. TLVs Threahold Limit Values for Chemical Substances and Phyalcal Agenta In the Workroom Environment with Intended Changea for 1973. Cincinnati, Ohio: American Conference of Governmental Industrial Hy gienists; 1973. Valu8e.a,D4otchumede.ntCatiinocninnoafti, TOhrheioa:hoAldmeLriicmaint Conference of Governmental Industrial Hy gienists; 1980:400-401. chem9.laGtreyraorfdeAroHmWa.tleToHxyicdorolocgayrboannsd. ABlmn- ster1d0a.m: ERlseelvsieehr;M1B90. 0T.op 60 chemicals produc tion reaches record high. Chem Eng Hen's. 198I9I;. ALperh1m0a:1n0n-K14B., Flury F. Toxicology and Hygiene of Induatrlal Solvents. Baltimore Williams ft Wilkins: 386. Originally published by J18S. pAridnmgeinr,isBtreartliinv,e 19H38o.rmer for Forurenanlng I Arheldsatmoafnere, Oslo: Dlrectnrntet for Arboldstllsynet; 1980. are13n.otRotharcehshBoAld,s:Raapcpraiptiocratl BreMv.ieBwutofthtehye documentation for TLVs. Am J Ind Med. 199104;.17A:7la8v7a-n7j6a3.MCR, Brown 0, Bplrtas R. GcoommpeazriMso. nRiosfkaapspsreosascmheenst offorthcearAciCnGogIHensa:nda the EPA. Appl Ocrup Environ Hyg 199106;.6:T6a1r0l-a6u17E.S. Industrial hygiene with no limits. Am Ind Hyg Aaaoo J. 1990;61:A-9,10. 18. International Union of United Auto mobile, Aeroapace, and Agricultural Imple- . . ment Workers of America v. OeneraI Dynam Dic.sOL. aCnidrcSuyitstCemousrDt oivfiAsipopne. aIlnsc,.A81p6rilF184d, 11967807. 948 Letter to the Editor