Document dQGKbJneMKLXXm2Gnq5m2Mj95

VCM Epidemiological Study - Individual Work History Instructions Work History List all job titles which involve some exposure to vinyl chloride, starting with the earliest job. If these jobs are interspersed with jobs involving no exposure, simply omit the latter. We will understand that gaps in the job history mean jobs with no exposure. If a man leaves a vinyl chloride unit but continues to work in a different part of the plant, his job history on the form will end as of his last job In the vinyl chloride unit, but we will know from the data at the top of the form how long he worked in other parts of the plant. Estimated Exposure "Estimated exposure" means a time weighted average. For example, if a job involves a 200 ppm exposure for of the time, a 50 ppm exposure for % of the time, and a 25 ppm exposure for If of the time, the estimated exposure will be 200 50 25 - 50 + 12.5 + 12.5 * 75 ppm. 4 ^ 4+ 2 We realize that these estimated exposures will be educated guesses in many instances, and that no such precise calculation as the above may be practical. An industrial hygienist's estimate of 200 may be a best guess at a value which he feels may in fact be as small as 50 or as large as 500. We expect that on the average those whose estimated exposures are high will probably have true exposures which are high, even though the estimates may be imprecise. However, please note the hazards of consistently overestimating or consistently underestimating exposure. If it is overestimated, men with low exposure will be erroneously classified as high, diluting whatever effects may be occurring among those whose true exposure is high. Underestimating exposure will place men with high exposure, who may be experiencing some effects of that exposure, in a low exposure group, and the effects may then be attributed to low level exposure. Confidentiality In Follow-up On Form B we request the worker's name if no death certificate is available. We will then obtain the death certificate, which Is a public document, from the appropriate health department. No contact with the worker's family or physician is necessary nor will any be attempted. On Form C we request the worker's name and last known address. We-will not contact the worker, but will contract with a retail credit bureau to find out by the usual indirect means (purchases, driver's license violations, etc.) If the man was alive on December 31, 1972. UCC 095713