Effects of exposure to vinyl chloride. An assessment of the evidence.

Abstract

An assessment of the evidenceby Sir Richard Doll, FRS' DOLL R. Effects of exposure to vinyl chloride: An assessment of the evidence. Scand J Work En viron Health 14 ( 1988) 61-78. This paper reviews the possible effects of vinyl chloride on the mortality of occupationally exposed men and the carcinogenic effects that might be observed in the general population as a result of environmental pollution with vinyl chloride. The results of four studies fulfilling the criteria of providing substantial numbers of observations more than 25 years after first exposure and covering a period long enough for more than 10 0J0 of the workers to have been expected to die constitute the basis for the assessment of the occupational hazards. Other studies provide only supplementary information. The data permit two conclusions. First, men occupationally exposed to vinyl chloride have experienced a specific hazard of angiosarcoma of the liver. Second, any other occupational hazards that may have existed have been small. No positive evidence of a hazard of any nonmalignant disease or any type of cancer other than angiosarcoma of the liver has been found except possibly for a small hazard of lung cancer when exposure was heavy. More definite conclusions might be reached if those who have studied exposed employees could present their results in appropriate and comparable ways. A very small risk of angiosarcoma may have occurred as a result of vinyl chloride escaping into the environment around plants handling vinyl chloride in the past, but the evidence indicates that the current risk to the general public (if any) must be negligible.

Meta-analysis of studies of occupational exposure to vinyl chloride in relation to cancer mortality

“…In figure 4, we have summarized the accumulating evidence on an association between lung cancer and vinyl chloride exposure by presenting the results of repeated meta-analyses conducted on the data reported up to each year between 1974 and 2002. Using the SMR available before 1987-1990, as well as the suggestion of a higher risk in some groups with longer durations of exposure and latency, one would have concluded that vinyl chloride workers may be at increased risk of lung cancer (2). Results published subsequently, mainly from the two multicenter studies (14,26), did not confirm these findings.…”

“…However, the early results were not confirmed by subsequent investigations, which had greater statistical power and better exposure information. Credible reviews conducted in the 1980s concluded, on the basis of the evidence available at that time, that a causal association was plausible in the case of lung cancer (1,2). These examples speak for the need to confirm reports of small excesses of common cancers.…”

“…To date, the only cancer that has clearly been associated with vinyl chloride exposure is angiosarcoma of the liver. In addition, neoplasms of the liver other than angiosarcoma, malignancies of the lung, brain and skin, and neoplasms of the lymphatic and hematopoietic system have been reported in excess in studies of vinyl chloride exposure (1)(2)(3).…”

A collaborative study of cancer incidence and mortality among vinyl chloride workers.

“…la r level (4) renewed the interest in this substance. In addition the ep idemiologic data have recently been updated (5-7) and reevaluated in a review (8).…”

Tales of Occupational Cancer

“…Doll published his own analysis, agreeing that angiosarcoma was associated with vinyl chloride but disputing its links with more common cancers (Doll, 1988). Although he found more cases of brain cancer than expected, he argued this was statistically insignificant (Doll, 1988). However, Doll failed to declare his highly paid consultancy (Doll, 2000) for the Chemical Manufacturer's Association (Sass et al, 2005).…”