Document mqQaERbVkQ1YQwyM56OROgky4

. EfMcnioloiiul Studio MORTALITY EXPERIENCE OF A COHORT OF VINYL CHLORIDE-POLYVINYL CHLORIDE WORKERS* William J. Nicholson. E. Cuyler Hammond. Herbert Seidman, and Irving J. Sclikoff Mount Sinai School of Medicine of the City University of New York; and the American Cancer SocietyNew York, New York Since the publication on January 24th, in the Wall Street Journal, of three deaths from bemangiosaxcoma of the liver in polyvinyl chloride (PVC) produc tion workers at the B. F. Goodrich facility in Louisville, considerable data of , scientific interest have been forthcoming. The data include the results of ongoing animal experimentation,' some clinical results on working populations,** and rei pom of other cases or deaths from liver hemangiosarcoma in vinyl chloride exposed workers* A remarkable amount has been accomplished in a short 3*/imonth period. However, to define fully the extent of the health problem associated with vinyl chloride (VC) exposure, it is clear that epidemiological apr proaches must be extended to include many individuals observed over sufficiently long periods of time to allow the full scope of any excess disease to be manifest. While studies on the causes of death of exposed individuals offer the possi bility of obtaining much more useful information, one must recognize the ex istence of several limitations. First, they are difficult and time-consuming to ac complish; one must trace and determine the status of all individuals having a defined exposure. This presents no difficulty for those workers still employed or retired and receiving company pensions. However, many individuals will have left the employ of a company prior to retirement and must be traced in order to obtain complete data. Second, sufficiently long follow-ups of exposed individuals must be completed. In other circumstances, it has been shown that occupational)} induced cancers may take 20, 30, ever. 40 years before appearing in populations at risk. Thus, studies conducted over a short follow-up period may be misleading in that they are dominated by causes of death unrelated to the worker's exposures. Third, sufficiently large numbers of workers must be included in such studies to allow meaningful statistical considerations to be applied, particularly in causes of death that are found relatively frequently in the general population. Fourth, in such studies it is most desirable to have accurate information on vinyl chloride levels to which individuals in the cohort were exposed. At this time, unfortunately, the relatively recent use of vinyl chloride does not allow us the luxury of having each, or even any. of the preceding four criteria satisfactorily fulfilled Nevertheless, the urgency of the health problem resulting from past vinyl chloride exposures requires that all available preliminary data be scrutinized. Thus, tn initial cohort study of vinyl chloride-polyvinyl chloride This study was supported by Grant ES-00928 from the National Institute of Environmental Health Soences of the Department of Health, Education, and Wel fare. 22! BFG24175 23189001 ., Ait iW 226 Annals New York Academy of Sciences Table 1 Majok Work Activitv or 255 Individuals During First 10 Years or VC Exposure Type at Voik No. PVC production (reactor operation, reactor cleaning, PVC resin bagging) Maintenance Shipping Laboratory 151 60 26 18 Total 255 workers was undertaken at a major production facility in western New York Slate. By utilizing Union and Company records, a cohort of 257 individuals hu been established, each of whom had been occupational!) exposed to vinyl ch.:ride for at least 5 yean subsequent to 1946 in a polyvinyl chloride polvmtnzi tion facility, having begun employment in the period 1946-1963.1 This include: all individuals to employed in this plant during this time. We have determine f the mortality status of these individuals from the tenth annivenary of onset :: exposure through April 1974. The 5-year exposure criterion was establish:: ic: this preliminary study to establish the effects of significant exposures Th: cri terion that observations would begin only after 10 yean from onset was seitc::: so that one might focus on the long-term effects of vinyl chloride exposure Although the exposures began in 1946, only a relatively few individuals were em ployed prior to 1951, when a significant increase in the work force took place Thus, the majority of the cohort had a bare 20 years or less from onset of ex posure. The initial production facility consisted of six vinyl chloride monomer traction vessels, a polymerization complex of four reactors, and a building for dry ing and bagging operations. From 1946 through 1950, seven men and on; super visor per shift handled the operations in all three areas. Thus, tht product!*: work force was approximately 30 men. In 1951, a significant expansion toe. place in the production facility; 16 additional polymerization reaction vessel: and 12 monomer reactors were installed. The work force at this time expand:: to approximately 150 hourly employees in the vinyl chloride and polys::;.: chloride operations. The only other significant change in this manufacturing com plex came in 1960, when the production of vinyl chloride monomer ceased, du: to the local unavailability of raw materials. From that poini on, th: vinyl chloric: was received in tank cars from Texas. Little change occurred in the work fore: however. Of the 257 individuals exposed since 1946. 255 have been traced and thecurrent health status established. Of the 255 so traced, work histories and, tc a large extent, medical histories, have been documented. Table 1 shows a summam. of their work activity during their first 10 years of employmen: in the PVC preduction facility. The majority of the 255 were employed directly in product:.*: Typically, the first job of a newly hired individual would be the bagging of th: , | , t We are grateful to the Goodyear Tire and Rubber Company and to Local 8-2" of the Oil, Chemical and Atomic Workers for tbeir cooperation ir. presiding lie information _ BFG24176 -6s- 00 O 8 Nicholson et of.: Mortality Experience 227 is for shipment. During the count of this work, be would be periodically iped to reactor cleaning or drying machine operation duty. Sucb cleaning iperations were required weekly for each polymerization reactor and were rou ndly done without benefit of respiratory protection As a man gained seniority be :ould be transferred to the reactor operations. In this job, he would be concerned iib the operation and control of the polymerization process. On overtime, howver, be might also be asked to engage in reactor cleaning operations! Addi- lonally, whenever leaks or accidental releases of vinyl chloride occun-ed in the eactor area, the possibility of high exposures existed. Nearly one-quarter of the individuals were employed predominantly in ibe aintenancc department. Here, individuals would be assigned to correct rnechan- :a! problems anywhere in the plant. During times of mechanical breakdown in ie reactor facility, their exposure to vinyl chloride could be significant. In gen eral, however, this group would not experience extremely high exposures as often as those who would have engaged periodically its reactor cleaning. Parenthet ically, one should note that a portion of the work experience of maintenance personnel may have been as production operators, but, in these cases, it would otal less than 5 years. A third group with lesser exposure was that of 26 men in the shipping depart ment. Here, exposures were to gases that may evolve from the dried resin and from vinyl chloride released in other areas of the plant. A fourth group of IE individuals, also with a lower exposure, was composed of laboratory personnel, testing the quality of both incoming chemicals and outgoing products. Because of ihe small number of individuals in the latter two groups, it was not practical to analyze separately their experience. They are thus included as part of a total co hort of individuals exposed to vinyl chloride in this one plant. although they may dilute somewhat the experiences of individuals with high exposures. We have excluded from consideration in this cohort individuals who were employed ex clusively as plant guards or who worked outside the reactor and dryer buildings No data exist as to the levels to which these individuals may have been ex posed in past years. Generally, measurements that were made prior to 1972 were to assure that the explosive limit of vinyl chloride was not exceeded in plant operations. As this limit exceeds 30,000 ppm, it has little relevance to current consideration of health effects. In reviewing work practices and clinical symptoms experienced by individuals in the plant, it is clear that vinyl chloride concentrations could have been ex tremely high. Although reactors were purged at 20 in of vacuum for up to 20 min prior to opening, a considerable amount of unreacted monomer could re main in the vessels. This was removed by insertion of an exhaust host through the manhole cover to the bottom of the reactor vessel. The air pumped from the vessel was usually vented into the reactor room. The highest exposures occurred during cleaning when a man entered into the reactor to scrape the polyvinyl !t chloride resin from the walls and agitator, and unreacted monomer was released Some data on the degree of exposure can be obtained from information provided by the current and past employees during physical examinations conducted in March 1974. Over 50% of a group of current and past employees experienced symptoms of dizziness, headache, or euphoria during work periods, and 14 out of 354 experienced concentrations sufficient to have caused loss of consciousness/ Thus, peak exposures may often have exceeded 1,000 ppm and. during acute epi sodes. may have approached 10.000 ppm in the production facility . Table 2 shows the age distribution of individuals in this cohort as they entered BFG24177 228 Annals New York Academy of Sciences Table 2 Age at Entry WTO Study Cohort (at 10 Vum from First Employment) A/f Ko 25-29.9 30-34.9 35-39.9 40-44.9 45-49.9 50-54,9 55-59.9 60-64 9 65-69.9 42 64 60 29 32 15 9 2 2 Table 3 Status* of 257 Individuals Exposed to VC tor 5 or Mori Years Startinc between 7/1/1946 AND 12.'31/1963 lAtmirvad leteniwtd PCR*Rd Working *t PVC produc tion facility Working elsewhere Retired Deceased Untrtctd Total 139 10 -- 18 43 -- 13 8 -- 24 ---- 170 61 24 * Status recorded as of April 30.1974. Ubtriced - -- -- -- 2 2 Tea! 149 6i 21 24 2 25* the period of observation, that is, on the tenth anniversary of their emplaymer in the production facility. As one can set, it was a relatively young group and on: is w-hicb little disease and few deaths would be expected to occur. Over 50 percer of the men were under age 37 as they entered the cohort. Information on the current status of the 257 individuals in the cohort is shovt in Table 3. Over half are presently employed in the polyvinyl chloride prodcction facility, although not all in areas with vinyl chloride exposure. Eighty-r: individuals working elsewhere or retired were interviewed as to their current a-i past employment, current health, smoking habits, and alcoholic consumpbcc This was done to verify exposure history and obtain information required icr future prospective observation. One hundred seventy individuals in the total prccr were examined.* Twenty-four individuals were found to have died and 2 art as yet untraced.2 Table 4 shows the expected and observed total mortality frc~> cancc c I Contact was made with individuals in Florida, California, Louisiana. Colo-td: and many other stales and Canada; all I0ld, 24 of the 82 individuals traced were fr-"-` alive in states other than New York. In accomplishing the tracing of over 99 pe"" of the cohort in less than 2 months, we owe an enormous debt to the members o: TM Oil. Chemical and Atomic Workers, Local 8-277, as all individuals were traced d:-rr. through persona! information obtained from Union members. In particular, we see.: like to acknowledge the considerable time and effort put into this tracing b; V' fcr Critelli. formerly of Local 8-277, and Mr. Frank Damon, of tbe Environments' Sc ene*! Laboratory-. ' A*0 w BFG24178 Nicholson tt <*!.: Mortality Experience 229 |f!erem periods of time since first exposure to vinyl chloride for the group of individuals traced for the study. Although observations are limited, the Less in total mortality and in deaths from cancer is unusual, considering the Latively short period of foitow-up in this study. Tbg IpCCific Causes of death are ^ttd in Table 5. O] the 24 deaths. 3 were due to hemangiosarcoma / the liver. seti has been examined and characterized by Dr. Hans Popper and Dr. Louis B. homas of the National Cancer Institute' and is included among other tabulac>ns of hemangiosarcoma presented at this conference.* Additionally, 1 death , due to bleeding esophageal varices consequent upon cirrhosis of the liver. Tasle 4 fitKCTED* and Observed Deaths from Various Causes Among J3J Workers Eerosed to VC Eor S OR Mon Years Starting between 7/1/1946 and 12/31/196? P ClU [ Dutb 16-14 9 (1196)1 Er? ot 15-19 9 TO4) Etp ow 10-34.9 (374) *p ou 15-39.9 <991 Cap Ota Tout tip ou ptl! Causes x!i Cancer 6.1 1.2 10 3 6.6 14 7 3 s.o 1.1 7 3 1.3 0.3 0 0 19 0 3.9 24 9 * Expected deaths arc based cm mortality in Ne York Sute (other than New York :i:> t in appropriate calendar years 1 Years since first exposure with person years at risk in parentheses I Table S Causes or Death among 24 Workers Exrosed to VC for 5 or Mori Years I Cancer of all sites 9 Hemangtosarcoma of liver 3 Ntoplasms of lymphatic and hematopoietic tissues 2 Bratn (glioblastoma) 1 I Pancreas Colon 1 1 Bone 3 Cirrhosis (with esophageal varices) 1 Postoperative bleeding (cholelithiasis) 1 I Cardiovascular diseases 13 Table 6 I Work Histories of Individuals Dving or Selected Causes C*k of D*ie of OfiMl Yitrt t)*tc c! A|e eYle&a>n- Sierr firr. Dtiih poture Expo- ure DeptruneQt Hemangiosarcome 10-46 03-70 60 23 23 PVC production Hemangiosarcoma 10-47 08-61 41 14 14 PVC production Hemsngiosarcoma 06-31 05-68 54 17 17 PVC production Bleeding esophageal 06-54 11-65 39 11 11 PVC production vtrices Glioblastoma 11-52 04-68 68 12 IS Maintenance Reticulum cell nr- 08-52 03-68 34 2 16 PVC production coma 5 Maintenance Lymphosarcoma 05-5* 04-70 32 12 12 PVC production tt 006: &FG24179