Document z0zk0y0v5Ve1vYxkO1bqGZqg

G. Ott 3/20/73 A MORTALITY STUDY OF TEXAS DIVISION EMPLOYEES EXPOSED TO VINYL CHLORIDE INTRODUCTION This report examines the mortality experience of workers occupationally exposed to vinyl chloride at the Texas Division. The study parallels one conducted at the Midland Division. However, the results of the two studies are not directly additive because considerably, lower exposures,wer^^xRSJE&enced by the Texas Division employees. . ... :;.r>.:037 R&s 000663 METHODOLOGY Selection of the Popular ion-at-Risk i .............. ;5i Ccmnany C:..:: - ;-3. 3J33 S{H) Westsffi District of New York The exposed-to-risk population included all employees of the Saran V1V2 Department with the exception of salaried women personnel. The interval covered in selecting the population was 1949 through 1963. January personnel lists for each of these years were examined to identify inscope employees. Through this mechanism, a total of 167 men were identified. Because the procedure for identifying employees in the exposed-to-risk population used only January lists, a few individuals with less than one year of exposure might not be included in the study. However, virtually all employees with several years of exposure would have been identified. No mortality follow-up of released employees other than retirees was undertaken. Recent industrial hygiene data (1972) have indicated that T.W.A. exposure levels to vinyl chloride for all jobs within the V1V2 area are well below 50 ppm. The exposure patterns were characterized as involving very low background levels with occasional short term excursions to higher levels (e.g. over 500 ppm). A number of other chlorinated hydrocarbons were present in the plant atmosphere, includ ing ethylene dichloride. Discussions with personnel familiar with past operations did not indicate that prior exposure levels differed greatly from recent levels. It was felt that lab assistants who collected samples from the production streams might have experienced the highest vinyl chloride exposures. Some high exposures to ethylene dichloride may have been experienced in the past years. In the analyses, exposure was quantified only in terms of years on the job within the department. No attempt was made to distinguish between different job classifications within the department. The employment and vital status of the exposed population as of January , 1973, was as follows: Employment and Vital Status Group Total Group Total Group 167 Still Working For Company 74 Retired 10 Transferred 7 Releases Other Than Retirees 66 Deceased 10 <1 Yr. Exposure 17 4 0 0 11 2 1-6 Years Exposure 72 17 5 2 44 4 6+ Years Exposure 78 53 5 5 11 4 R&S 000664 Sources of Mortality Data and Comparison Population The mortality analysis is based on copies of death certificates received by the Company Group Insurance Department as proof of death. A cohort of 4,100 hourly employees of the Texas Division followed between 1954 and 1973 served as a control population. Mortality rates by age group and year of death were multiplied by the appro priate years at risk in the exposure group to provide the expected number of deaths. Since the Texas Division mortality rates for total malignant neoplasms closely paralleled Texas white male mortality rates, these rates were used in computing the expected number of deaths due to malignant neoplasms. I.',; V- .' ;- '-^ProducedPurs RESULTS Hie observed and expected deaths by duration of exposure and interval since initial exposure are shown in Table 1. The frequencies are too small for statistical tests of significance to be meaningful. A brief summary of the exposure history for each decedent is shown below: Cause of Death 1) Cancer of lip with metastases to lung and neck Died 9/66 2) Alveolar Cell Carcinoma Died 11/71 3) Carcinoma Brain and Lungs Died 12/58 n Malignant Mediastinal Tumor Unclassified with generalized metastases Died 1/63 5) Ischemic Heart Disease Died 6/71 6) Abscess Left Frontal Lobe Died 3/58 7) Acute Myocardial Infarction Died 2/65 8) Accidental Drowning Died 5/61 9) Auto Accident Died 7/58 10) Unknown Died 9/50 . Department Work History Janitor 8/62-9/66 Operator 4/56-9/59 Lab Assistant 9/59-5/67 Operator & Shift Foreman 10/49-12/58 Operator 1/62-1/63 R&D Engineer 9/48-10/49 Welder 5/52-2/53 Operator 9/51-2/65 Operator 3/52-5/61 Clerk 10/50-3/51 Clerk 9/48-9/50 Interpreting the significance of such small numbers should be left to a physician. . i Ui SLiSlit R&S 000665 CaS2 i.2. S'.n) Western District of New York ,