Document ybxb14Rgw8K3X1Xow80rjNg3D

ATTENTION: Nr Niton Frolfold ITEM 2 4/22/76 A Mortality Study of Worker* Exposed to Vinyl Chlorldo April 22* 1976 This Is o report of o study of mortality rates in e population of lO *173 workers' Uio at soma time In the past wore engaged In the manufac ture of vinyl chi or Ida or Its polymers. An earlier report on o portion of tills population showed that these workers experienced an increased risk of tlustli from eoneor of the Hver (already found by other investi gators) and cancers of the lung* brain and lymphatic system. The larger group represented In this study has permlttad a more detailed analysis of the relation between the risk of death from these causes and dura tion and level of exposures. The study population was Idantlfled by an examination of past end present personnel records in 37 plants which produced either vinyl chloride or polyvinyl chloride. Cvery man who had bean In an exposed Job for more then one year was Identified and his work history obtained. Mon who had worked in the past and had quit or been laid off wars traced to determine whathar they were still alive as of December 31. 1972* the date chosen as the "closing data" of the study. Of the 10*273 men selected for study. 9b percent wane successfully traced* and 707 deaths were found. The study population Included man hired as far baek as the late 1930's and included 2.006 man who had worked 15 years or more. The number of deaths which occurred was compared with the number which would have been expected In a compare!)la population of United States males for each esuso. RSV 001^376 Tha fiettl number of dtttht mi About 16 ptfcent Un thin expected, no the total number of cancer deethi mi about equal to whet would bo xpoetad. a Soma cancers occurred at a lower rata than expected. and thaaa did not appear to l># related to tha leneth or level of exposure. Cancer of the urinary organa and tha lymphatic eyiten thOMd tone exeeit daaths (22 pareant and 12 percent) but want not related In any eyttaoetlC way to exposure. Thare was a 44 pareant excess In leukemia dasths. alao not l raiatad to tha circumstances of exposure. Lung cancar showed an 8 pareant excess In tha total study group, but In men who had worked for 15 years or more and had begun work at least 20 years before tha closing data of tha study, thara was a 52 par- cant excess. Cancars classed as "Other and Unspecified" showed a 44 pareant ex cess In tha study population as a whole, but a 230 percent excess in tha older group mentioned above. This excess was largely due to an excess of>bra1n cancer, since 38 pereent of these caneers wore brain, comparad with 20 pareant for the general population. There was a slight excess of digestive cancer in man with high ex posure. and In man with other than low exposure who had worked at least 15 years beginning at least 20 years before the study data. In these Older man 50 percent of the digestive cancers were liver cancer com pared with about 9 percent for the general population. RSV 0012377 ATTENTIONS Nr. .Iton Fretfe10 In another analysis* the study population mm scored according to th# estimated total amount or vinyl chloride to which they were exposed; man ware given a score of 1 for each month of low level exposure* I for oath month at medium exposure* and 3 for eaeh month at high exposure. There was a somewhat irregular Increase in mortality from dlgastlve cancer, respiratory cancer and cancer of othar and unspecified sites with increasing score. For man with scores of 4DO or more (equivalent to 11 years of high exposure or 33 year* of low exposure, for eaampio) the excess mortality was 83 porcont for dlgastlve cancer* 64 percent for respiratory eancer* and 1B3 percent for caneers of other and un- specified sites. Tha study ganmrally confirms tha findings of oorllor Investigators* hut provides additional data for man with long service whose employment began many years ago. by Dr. w R. Gaffey RSV 0012376