Document 9L4oDo4EeJ5D2w32mZjNNdjd6

Mortality Among Employees of PVC Fabricators Leonard Chiazze, )r,, Sc.D.; William E. Nichols, Ph.D.; and Olio Wong, Sc.D. A cross-sectional mortality study of 4,341 deaths occurring among current and former employees of 17 PVC fabricators during 1964-1973 is presented. The objectives are: (1) to iden tify any angiosarcoma deaths among the employees of these fabricators, and 12) to examine the distribution of deaths by cause. No angiosarcoma deaths were found among the study group. Sex-race-cause-specific Proportionate Mortality Ratios (PMR's) were computed, using the corresponding U.S. mor tality as the standard. Among white employees, there appears to be an excess in total cancer mortality, particularly that of the digestive system. Observed deaths were found to exceed (he expected in cancers of the breast and urinary organs among white females. Deficit mortality was observed in cirrhosis of liver among both male and female white em ployees. Xhe lanuarv 1974 disclosure of three deaths from angio sarcoma of the liver m a single vinyl chloride polymerization plant and the attention tocused on this new occupational disease are well knon, A significant amount of information from animal ex perimentation and observation on humans engaged in the produc tion of vmvl chloride followed ' However, there was no informa tion regarding the possible adverse effects on employees engaged in polwrnvi chloride tPVO fabrication, where potential exposures were thought to be low and to result from the release of unreact ed monomer trapped in the resin. This issue was considered of great import because of the very large number of workers believed to be engaged in fabrication In March 1974, representatives of PVC producers, who are members pi the Organization Resources Counselors (ORCk Oc cupational Safety and Health Standards Group, contacted ORC about the ieasibilitv of a study of health risks to employees work ing with vmvl chloride and polwinvl chloride Since the National Institute for Occupational Satetv and Health IN'IOSH) was con ducting a study of vmvl chloride and resin producing employees, the scope of the proposed ORC study was limned to employees of from i*e D*v*ton o' Bo*.:amiici A^d fpfemto*oev DeoArimenj o* Commons M*a*ine Hiein#tionAl HfAhh CeO'geiOwn Schoo' o' Medtone \v*hncin DC 2000" (Dis Chi*ue Wong* irxi O'gAmjAiton ftevouce* Coun* *eie*f* *nc Ws*h*gion DC 20006 (O' \ichoV Journal of Occupational MetiicineA'ol. 19, No. 9/September 5977 companies engaged in the fabrication of PVC resin into finished products, A number o; alternative study designs was considered and it was decided that a proportional mortality stud'' would best meet the urgent need for information. The studv concentrated on deaths occurring during the ten-vear petiod 1964-1973 among ac tive fabricating employees plus retirees Smce it was not possible to identify those employees with onlv vmvl chloride exposure, the study focused on deceased employees who worked anvwhere in those plants where PVC tabncanon was earned on The primary objective of the study was to determine whether or not any angiosa-coma deaths had occurred among employees of the faoricators under studv, A secondary objective was to examine the distribu tion of all deaths bv cause. The relatively iew producers of vmvl chloride monomer and of PVC resin are generally medium to large companies. PVC fabncators. however, range from large plants of ma|or companies to very small job shops. Even in a large plant, there mav be few em ployees vvho are in the vicmitv of PVC resins The range of com pany plant size and number of exposed employees help to explain the wide range of estimates of total employment dependent upon PVC resins. Fabrication is geographical disbursed, with at least some operation in almost every state Typical fabrication orooucts include coated wire, upholstery tahnrt floor and wall coverings, pipe and other construction materials, toys, recreational equip ment, phonograoh records containers and container lining and a myriad of novelty items Smce the fabrication of PVC resin into finished products is often a part of diversified product lines in a plant, raw materials other than resm are utilized Thus, employees may be exposed to toxic agents other than vinyl chloride Conse quently, in the current study, it is not possible to isolate only the effect of vmvl chloride Some departures from expectation mav be due to exposures to vinyl chloride, to one or more Other agents, to some combination, or to employee characteristics other than occupation. Materials and Methods The decision to focus on a cross-sectional mortality studv rather than on an historical cohort study derived from several con siderations. First, the primary studv objective was to determine relatively quickly whether or not anv angiosarcoma deaths could be identified among the study group, and this was best ac complished by examining causes of death among relatively recent 623 VC5958 (i.e.. past ten years' decedents The desirability of identifying an historical cohort for iolloiv-up was recognized, but it was deter mined that it would not be possible to identify clearly and com pletely the necessary cohort of workers within a reasonable period of time, if at all. As a consequence, this study is based upon 4,341 deaths which occurred during the period 196--1973 among current or former employees of 17 companies engaged in PVC fabrication A total of 55 plants supplied data on all identifiable deaths since, as was mentioned earlier, it was not possible to iden tity those employees with only vinvl chloride exposure tor the study. In order to be included in this study, a deceased employee fell into one of the tollowing categories: Hi employee died while ac tively employed. (21 employee died after retiring from the company with retirement benefits, and ;3> employee died after ter minating employment but with vesting in a company-sponsored life insurance plan Deaths occurring among former employees with less than the number o' years necessary for insurance vesting were not included m plant records and were tneretore not available for this study An attempt was made to compensate for at least some of the "leakage'' due to employees leaving the industry prior to the time they were vested in anv insurance program bv using the ioliowing procedures Once death records for a given company wete iden tified. death certificates were obtained and separated into two groups as follows: n: all deaths with cancer (ICDa 140-205 up to 1967; ICDA 140-209 for 1966 on!, or liver disease (ICDA 580-586 Up to 1967: ICDA 570-576 for 1966 on), or suspected liver con dition mentioned on the death certificate; and (2) all deaths from causes other than cancer or liver disease. Death records men tioning cancer or liver disease and giving a hospital as place of death were segregated and sorted by hospital. Where there were several death records for a single hospital or several hospitals in the same area, arrangements were made for a Registered Records Administrator (RRAI to visit the hospitals, review medical records, contact the hospital pathologist and review pathology records to determine whether there were anv angiosarcoma cases in the hospital's pathology records. If so. an attempt was made to deter mine whether or not the angiosarcoma possibly could be related to vinyl chloride exposure This procedure enabled us to identify whether anv employees, who had left the industry prior to vesting in an insurance program and remained in the local area, had died from angiosarcoma of the liver. The hospital inquiry procedures turned up five deaths from angiosarcoma of the liver; according to company employment records, none were employed at anv time in PVC fabricating plants These deaths were reported to OSHA, NIOSH, and CDC for inclusion in the nationwide angiosarcoma survey Death certificates not mentioning a hospital as a place of death required an additional step to determine whether death occurred in a hospital or if a recent hospitalization had occurred prior to death The certifying physician was queried by mail for in formation on recent hospitalization of the decedent and whether there was anv indication that he or she had cancer or liver disease. Additionally identified hospitals were contacted as above. Originally, it was planned that death certificates would be ob tained from life insurance carriers. In practice, both company and life insurance records were used because of record retention prac tices and retrieval problems in the insurance carriers. All available death certificates were examined by a trained nosologist for men tion of angiosarcoma anywhere on the certificate, and no angio sarcomas were found on the death certificates. Underlying cause 0< death was classmed according to the eighth revision ot the In ternational Classmcation of Diseases-' Over the ten-vear period under study, plant size was found to have changed drastically in many cases In one instance, a plant employing 300 employees in 1973 employed fewer than 10 in 1964 At the other extreme, one plant employing 5,000 people in 1964 had only 2.000 in 1973, Some companies had gone out o( business. Such developments shots no: only the rapid changes taking place ouf also the ditncuitv oi oeterminmg as'erage inoustrv employment ine i/ companies coveiec in this report ranged irom single plant small companies tone with 70 employees' to multiplant large companies tone with over 7,000 employees' Average number oi employees clustered between 300 and 500 Although total employment is difficult to determine precisely. it is estimated to have been between 65.000 and 70,000 at the end O' 1973. Since the population at risk could not be determined mortality rates as measures of risk could not be calculated Rathe;, results were summarized in terms of Proportionate Mortality Ratios IPMR adjusted for the age distribution of the study group Tne PMR uses relative frequencies ot soecmc causes o' death by age m a com parison population to obtain expected numbers of deaths from that cause in the study population Selection oi an appropriate comparison population poses some difficulties since it would pe desirable to nave a cause ot death distribution for a similar group of workers dying during the same period, but no: subiected to the factor under studv. But such a comparison population was not available, and the study used mortality ior the United States specific fpi coior and sex. tor comparative purposes.1 Despite recognized deficiencies, the PmR can provide clues on unusual distributions oi causes of death where true rates cannot be calculated. Results Table 1 gives the distribution of deaths among the employees of the 17 PVC fabricators within each of the ten years. An increase in the proportion oi deaths taking place in later years of the decade may reflect a variety of factors, such as an increasing employee population, less complete availability of records for earlier vears (e.g., in one company, there were no records for the first four of the ten years', increase In duration of exposure, etc. However, there is no teason to believe that anv unavailable death records for earlier years would be concentrated in a iew causes and thereov bias the distribution of deaths <of loose vears Table 1. -- Distribution of Death* Among Employees of 17 PVC Fabricators by Year of Death, 1964.1973, Year of Death >964 196b ms m> 1968 1959 1970 19?) 1972 '1973 Total: No 3ZS Hi 400 429 499 4<? s <71 SZ8 30 4341 \ 7S to 93 99 If S 10.3 107 109 133 99 100 624 Mortality Among Employees of PVC Fabricators/Chiazze, Nichols, and Wong VC5959 2 17Table . --- Distribution ot Deaths Amont Employees oi 186 1973PVC Fibricators by Color nnf! *x. * face lota' hpftartwte Total Mtte SOIMll , UnkMwn *3(1 xn 663 36*5 3?* 60' 20* tat 7i m 36 7 L c i The distribution of deaths in the study group by face and spv is given in Table 2. Most deaths (8-5 2%i occurred among males The vast maiontv (86 2%) of decedents were white and there were 288 (6.6V tor whom race could not be determined Table 3 shows this distribution or deaths bv age For both white male and white female emplovees, more than hair or the deaths occurred among those aged 65 and over (58.1 V and 51.9% tor white men and white women, respectively!. The corresponding proportions ot deaths which occurred after age 65 in the United States population in 1966 were 39% and T2% respectively' The higher proportion ot deaths among white women over 65 m the U S. population compared to the emplovee population mav indicate that relatively fewer women work to retirement age than do men. While the numbers or deaths among nonwhite employees are too small ior any definite conclusions, the distribution of deaths bv age among nonwhite men is roughlv comparable to mat tor the total United States. Tables -s Bnd 5 show the distribution or deaths tor selected causes by sex for whites and nonwhites, respectively Among white men. nearly 60% or the deaths are from diseases or the cir culatorv svstem UCDa 390*456* and 20% are deaths from cancer (ICDa 140-209', The corresponding percentages ior the total U.5 population or white males in 1968 (midpoint or the studv period' were 54% (or diseases or the circulatory system and 16% tor can cer Digestive and respiratory cancers account (or somewhat less than two-thirds or all cancer deaths among the white males in the studs- group as compared to about 59% or all cancer deaths among U.S white males in 1966, For white women, over 46% ot the deaths are from diseases oi the circulatory system (compared to 52% (or all U.S. white women in 1968i. and 30% were (torn can cer (compared to 16% (or all U.S. white women in 1968'. Somewhat over hal< or the cancer deaths among white women in the studv were rrom cancers oi the breast and digestive system. about the same proportion as ior all U.S white women in 1968 About two-thirds o( the deaths (or both nonwhite men and women were (rom diseases of the circulatory system and (rom cancer. The numbers of deaths (or most causes among nonwhnes. however, are quite small making interpretation difficult and ate presented matnlv (or completeness. Age-adrusted 9MRs for white male and white female employees of the 12 PVC fabricators are presented in Table 6 ior selected causes oi death There were no similar analyses ior nonwhnes because ior nearly all causes the numbers oi deaths were too small to produce stable PmRs. Expected numbers oi deaths have been calculated on the basis oi the sex-cause-ace specific distiibuuon oi deaths among U.S whites in 1968 applied to the total number oi deaths bv age among white men or white w omen in the studv group The midpoint oi the studv period (1966' was selected tor the standard since n is representative oi the studv period and provides U.S mortality data coded according to the eighth revision oi the international Classification oi Diseases. fvpecic>d numbers ate deaths ior individual causes to be expected in the studv group ri the proportion oi total deaths ascribed to a given cause were the same as tor the corresponding U.S race-sex group, while accounting ior difierences between the age distributions oi deaths in the studv groups and deaths ior the United States A PMR larger than unity would indicate that the relative proportion of mortality from that particular cause in the study population is higher than would be expected based on the 1968 U.S mortality experience. Due to the nature oi the data, formal significance tests and interpretation m probabilistic terms are deemed inappropriate. In addition to the numerical value oi the PMR itself, the ob served number oi deaths is also oi interest The larger the number of deaths observed, the more reliable the PMR, There were two deaths oi unknown age among the white males, one a digestive cancer (ICDA 153' and one an unspecified cancer (ICDA 199> These were included in the age groups with the lowest relative irequencv for those causes, that is. less than 35 years for total can cer and digestive cancer and 65 and over for other and un specified cancer. Such an assignment has a trivial effect on the ex pectation but is the most conservative wav of handling these unknowns, since it serves to increase the expectation (and hence lower the PMR) by the least amount. Based upon both the number of deaths and the value of the PmR, there seems to be an important excess in total cancer mor tality among the white males in the study group The distribution by specific cancer site suggests that any excess appears to be con- Color, Stk WNIt Milt fern* It Honwtate Mile fomile Unknown Milt female Unknown V 3 17 1964 1973Toblt . -- Distribution of Dostbs Amonj Employers of PVC Fsbricotors by A*. Color. Sex. -. Alt At** No. \ 37*1 100 601 100 ISO too 100 7*6 IDO 36 100 2 100 36Undtr Ho X 107 33 4?< P 7Zl n 2J0 20 11 76 1 50 0 35-44 Ho. \ 136 <2 *7 7.0 2t 133 t 63 i 70 b 73.7 00 45 54 N. % 365 712 100 156 76 IS 6 5 70S 37 12.9 4 105 00 55-64 ho. * 757 732 173 70 5 35 21 7 6 250 4E 19* E 71 1 00 55 1 OV*f He. X 1866 56! 3)7 519 66 37.6 5 70 6 13) 52 8 16 47 4 00 Unknown Ho* s 2 01 00 00 00 12 IE 7 5.3 1 500 Journal oi Occupational Medicine/Vot. !9. No. 9/September 1977 VC5960 625 Tibtt 4. -- Distribution of Doithi front Stitcttd CouMt Antoni Employ*** of 17 PVC Ftbricilon by Stx. Whitt Only, 1964*1972 Como l Duth ICDA tth AkV At) Cues Alt taneri wore Buccal twir art Anaryru Difestn* Svsteir Stemacti truest mt Akimt* Lw Resattr> System Uflf Soot Connect** Ttlwc. $*r, frets'. frets' Gemiif Offers Dimarv 0*f*m fram i On* Nervous Svsterr Owr ( Unspetihec Lyntfhomai LttAeimas DltMItS Douses e the CircuttiV) System Ccrtfrovesojla' DrsetM Cxrhom <r li*e ChotfifttkOSlS. Cholecystitis and Choianfitts Atttoenis Fooenm;, rtf Violence Attaint! StHCier AH Dtnr Couses IftestfuiD 140 M9 isoiss 151 153 IW 155 160-163 162 mvt m 1S0-1E7 ieeie? 191-152 190. 253-199 700703 20E-7DS 20* 707 25C 39D45E <30^38 571 574-575 C600-E99E EBOO-E945 E950-E959 AUta fern#It No % No. K 3?4f 666 100 00 SOI 100 DO 20iC 111 30.17 15 048 2 050 709 54- 53 m: 41 tit i 125 72 225 7* 3.95 25 0.77 e 125 8 Oil 0 0 205 631 17 7DG 192 5 9* 12 200 ?* 0.7* 51 t 49 c -- a* 737 u 131 19 3.1f 31 i :i 1] 1 n 0 49 4 0.67 a 177 n 5 DO 4; 125 9 120 IF 056 1 0.17 42 1.79 11 113 1931 59 <5 7S1 46.78 269 7.90 66 10.96 42 129 5 050 7 027 3 020 m 5 7? 47 755 13< 4,13 3E 637 40 125 2 033 377 1145 U 1731 Tobit 5, -- Dittrfbutioti of Doitht -from t*itcud Comet Antoni Employe*! ol 17 PVC Fobricotort by Sti. Nonwhht Only, 1964*1973. C*vu *t Duth ICDA th Ate. 1FvnaN Nt. * Ns. % All CWHS All Conors 140*705 iet 100.00 ?4 100DO 39 7166 l 35.35 frxsl Cavity itf Pnrym Ditnior Si*iw, Stamen intestine Reaum Lwe< Attpmion Snim lvn( Bone. Cmeawe Tiisoe. 54m fresst frust Genital Off*m Unary dtim frtffl 1 Othr Nervtus System Dthr i UnsoecilmC twiphomes trjtimui Dabetes Diseases oJ the Cneuiaton System CerebrovttQJfct Disuse Crimn e> Lm Cwttiithuis Ciwfenmitn. 1 ChottnritB AccatnU. Pwunnc. 6 VaOno Accidents Suctoe All Oita Causes (Restful) 140-149 150-159 151 155 15* 155 16016:* 12 170-17* 174 1IG1S7 166*115 191-192 190 153*195 700-705. 20E 209 704-707 250 390456 130-438 571 57<*5?5 [100*6995 [800WF [950E955 0 0 00 15 722 * 1667 5 1 67 0 C 2 in 1 4)6 j 056 0 0 1 056 c 0 7 3.tS 0 0 7 319 0 0 0 0 i 125C c c 3 1230 * 72? 0 0 \ 1.67 0 C 1 055 0 0 6 335 0 0 < 222 0 0 2 Ml 1 4.16 2 l.li 0 0 61 45.00 6 33 33 IS 10.56 3 17.50 1.67 i <16 0 0 00 33 1635 3 1350 17 9 4* 1 436 7 111 0 0 77 1327 * 16.67 centrated in digestive system cancer, given the large number of deaths (31% of all cancer deaths). For each of the sues within the digestive system, observed numbers of deaths are greater than ex pected Although, except for intestinal cancer, the observed num bers of deaths are small. The PMR for liver cancer is rather high, out a definite conclusion is difficult with only six observed deaths. On the other hand, the PMR for cirrhosis of the liver suggests a deficit in mortality from that cause. For white women, the PMR for total cancer appears high, as it did for white men. with cancer of the digestive system and. perhaps, cancer of the breast contributing a fair amount to the ex cess. The PMRs for individual sites within the digestive system are based upon small numbers but suggest an increase in intestinal cancer. The PMR ior urinary cancer, though based upon only 11 deaths, seems strikingly high and may be an indication for further investigation. On the other hand, in contrast to the observation in white men, the PMR for respiratory cancer among white women is very close to unity. Similar to the observation in white men, mor tality from cirrhosis of the liver seems to be in deficit, but the corresponding observed number of deaths is quite small. Among both white male and female employees, diseases of the circulatory system account for a large percentage of total deaths. In each case, observed numbers of deaths are close to expected. There appears to be a somewhat different pattern among men and women for deaths due to accidents, poisonings, violence with the number of deaths somewhat low among men and high among women. There were 39 cancer deaths among nonwhite men. somewhat greater than expectation, although the numbers by site are too small for meaningful analysis. Mortality from cerebrovascular disease appeared high (PMR 2.11) but the finding was based upon only 19 deaths Discussion The present study was designed with two objectives. The first was to determine whether or not any angiosarcoma deaths had 626 Mortality Among Employees of PVC Fabricators/Chiazze. Nichols, and Wong VC5961 Tabic . -- Observed and Expected DaatM ter Selected Ceinet Mnonz Employ**! e( 17 PVC Fabriceten by Sex. White Only. 1964-1973. C*uu cl Dutti AN Ctntt't ICDA llh Htv nozos Oawnva 6SE Matt Ekpacitti 561.997 w 1 19 Obttrvatf )] fMlt tiwettf 137,699 HMC 13! P7jrvrt3 Dtfttiwt Svfttir. Simief. tnitstim iiff1 fiesafftipy Sptttr. bene Conntaivt Tttwc Sfcf tan: Gtnrti' Offim Ottneiv Drg*" L Dlhr fcetvous Svittr, Oihtf i Un$&ei>l>K Ivm&taRu* Lftfttmit! ClWlt! Chimts the Circutaiery Sytwn Cfrtftrawait*fttvuit Lmhctu ! In* Cwfelittans Ctotoctttitts tv Chottflfftfj Accttemi fQtiontftf, ntf Vtofenct mown SuiOQt HMH 15015S Jtl j 53 15* jtt ISC-leS 36? 170-1?* )7i 180-1 S' 1BE-189 1SM57 190 193)99 700-703 70S-70S 70S 707 ISO 390-1SE 430-S38 573 554-MS 8004999 4004919 9504959 IS 16 MS 049 109 162.143 3.25 C] 31407 130 73 57579 13$ 29 19.63! 135 i 4.190 u:- ?K 176657 i it Iftb 165469 1 17 ?l 15117 159 D-- a 57 879 083 39 33 III 109 It 13485 1 15 59 34 405 1.63 t? 3230 130 IS 73361 041 i? 49600 0E5 193! 1837515 105 2** IS! 074 0,9? 67 621 0 6/ ? 110 188 265 548 0.71 IJi 185368 0,51 to 52325 0 78 * 9M.R IS if* rjlit t|*rvf to noene: ***** irw npent: rumdfr rs cttcuUiec c*> ine fits* ot it* oism&uuon 4 otiifts tv 3 1496 148 53 25 342 1 bt 8 1,98! 1 6! ?i 149 E 3 677 2.06 C 0.613 a- 12 11888 1.00 n 1147< Itf 5] 3666! 143 it 32 397 139 ;t 23 797 043 31 1.537 212 i nt 18 9 622 IV e 7.63! 1.18 1 6 009 0.20 n 15138 0.71 78! 309.237 091 71.985 0.97 l 12313 D,?i 3 1783 188 48 40455 1.17 38 27.931 1.3E 2 9.171 042 toi*l Ui m 19E ttrtvrfi: to* tot* sn, oust rtf ift occurred among employees oi the PVC fabricators under study. Since no angiosarcoma deaths were found among the employees Studied, the first question has an unequivocal answer. A secondary objective was that or examining the distribution of deaths by cause among the emplovees under study. Implicit in that obiective is the question of whether or not that distribution is. m some sense, unusual. There is no unequivocal answer to the latter question. Whether or not an observed distribution of causes of death is unusual clearly relates to the standard or comparison population as well as the analvtic methodology.'' On the basis of a proportionate mortality analysis, there appear to be excesses in total cancer mortality among both white men and white women m the studv, when compared to the distributions of deaths for the total United States specific for color and sex and adfusted for age. Excesses in cancer mortality appear concentrated in cancers of the digestive system and. in particular, in cancers of the intestine for both men and women. In addition, there is a suggestion that mortality from cancer of the breast and urinary organs among white women employees is higher than that for the total U.S. There are. however, several reasons why Journal o' Occupational Medipne/Vol. 19, No. 9/September 1977 definitive interpretation is difficult. It has, for example, been suggested that a Proportionate Mortality Ratio based on an exter nal population may not be sufficiently discriminating in screening for potential hazards.5 In addition, an analysis using PMRs fails to take account of the absolute risk of dying in the population under study.' Further, a number of studies have suggested an overall favorable mortality for industrial working populations, even in those where well-defined hazards increase risk for a specific cause/ * Factors such as these are meant to suggest that proportionate mortalitv analysis must be interpreted cautiously, with the intention of providing leads for further investigation. Results consistent with those of previously published studies would be of particular interest With no comparable working populations in the fabrication industry, potential contrasts may be found in studies of vinyl chloride workers. Monson. et al, provided a proportionate mortality analysis ot 161 deceased workers (all presumably white males) in two plants, one where vinyl chloride monomer is produced and one where it is polymerized into polyvinyl chloride * Results of that study suggest a possible excess in total cancer mortality, primarily cancer of the 627 VC5962 Ik ' f* liver. However, there was a suggestion that cancers ol the lung and brain also appeared with excess frequency. The current studv. while suggesting an excess in total cancer, particularly digestive cancer, does not clearly point to marked excesses for cancers of the liver. lung, and brain among white men. although the PMRs tor these cancers are greater than one. The observed-to-expected PMRs reported by Monson for vascular lesions affecting the cen tral nervous system, circulatory diseases, and external causes are similar to those reported here. Tabershaw and Catfev. in a studv of workers engaged in the manufacture of vinyl chloride and its polymers, conclude that no specific cause of death was statistically signiiitantlv greaier than expectations based upon Standardized Mortality Ratios (SMRs) using the U.S male population as the standard.* Bs' other criteria, however, the authors conclude there mav be an excess risk ior mortality from digestive cancer, respiratory cancer, cancer of other and unspecified sites, and Ivmphomas. At lower exposure levels, they suggest some excess for cancers of the buccal cavitv and cancers of the other and unspecified sites The current study would seem to indicate that excesses of mor tality from cancer of the digestive system are not sex-specific and are not limited to liver cancer. The majority of the PMRs for cancer among both white men and white women ate in excess of unitv Such results must be interpreted with caution but. since thev ap pear to be consistent with previously studied workers, they suggest the need for continued investigation. Summary Results of a study of -5.341 deaths occurring among current and former employees of IT PVC fabricators during the period 19641973 are presented. The study was carried out to determine whether anv angiosarcoma deaths had occurred among em ployees of these fabricators and to examine the distribution of deaths bv cause. No angiosarcoma deaths were found among the study population. Distributions bv cause of death among white male and white female employees were compared with those for the entire US., specific for color and sex and adiusted for age bv means of Proportionate Mortality Ratios There appears to be an important excess m total cancer mortality among both white male and white female employees with digestive cancer, particularly that of the intestine, contributing to the excess Among the women employees, cancers of the breast and urinary organs may also be in excess. No excesses were found for diseases of the cir culatory system. There were deficits in mortality from cirrhosis oi the liver among both male and female emplovees and a deficit in accidents, poisonings, and violence among men. The use of the Proportionate Mortalttv Ratio based on an external standard requires caution in interpreting these results, but the need tor iurther investigations is indicated. Tfttt jiuqv wt% pori*0rtd bi orgafttfaitpo* tmenctn Can Com&im i f, Cooduch Cwticunv. Diamond Shamrock Cotpouiwt Th* am ftubwi toHn* Manvtite mow Vehicle Mnui*etu?A4 -mmxuuoci Suvh*r CnemiCAl Companv union Carbide Corporation Urwoval incorporated References I.Selikoii II and Hammond EC Eds': Tovicm oi vinvl chloride -- polwinvl chlonde 4nn \ \ Acad Sfi 246 10"5 2 Manual of the imemaiienal Classification of Diseases Adapted lo' Use m the United States. Eighth Revision Washington D C . U S. Govt. Punting Ohice 1967. Vol 1 3 vattonal Center fo' Health Stanstics Vital Statistics oi the united States. 1966 Volume li - Mottalitv Pan a Washington. D C.. U S Covt. Printing Ofuce. 1972 pp. 140-205. - Chiazze L: Problems of studv design and interpretation of industrial mortality experience. SOM 18:169-1*0, 1976 S. Redmond CK and Breslm PP: Comparison o' methods for assessing oc cupational hazards. IOM 17:313-317. 19*5. 6 Monspn RR. Peters I.M. and lohnson MV: Proportional monalitv among vinvl-chloride workers lancer 2:397-398 1974 7. Uovd IW and Crocco A. long term morialitv studv O' steelworkers I Methodologv. IOM 11:299-310. 1969. 8 Redmond CK. C'occo A. Uovd |W and Rush HW; long term mortality studv oi steelworkers IV. Mortality from malignant neoplasms among coke oven worke'S (O'! 14:621-629 1972 9. Tabershaw )R and Cartev WR: Mortality study of workers in the manufacture o' vinyl chloride and its polvmers /OM 16:509-516, 1974 628 Mortality Among Employees of PVC Fabricators/Chiazze. Nichols, and Wong VC5963