[The mortality among the makers of vinyl chloride in Italy]

A mortality study was performed on 5,946 vinyl chloride (VC)-polyvinyl chloride (PVC) workers of the nine Italian plants. The aims of the study were to investigate the cause-specific mortality of workers exposed to VC in production and polymerization stages and to ascertain whether exposure is associated with a higher risk of cancers other than liver angiosarcoma. An incident cohort was enumerated in five plants, a mixed cohort in two and a cross sectional one in the remaining two facilities. Cause-specific Standardized Mortality Ratios (SMR) were calculated for the six incidence cohorts with a sufficiently long follow-up period. Both Italian and regional rates were used for the comparison. A pooled analysis of six cohorts was performed. For deceased persons, information from death certificates was used in the mortality analysis. Additional clinical and pathological data were sought for all decreased individuals (Best Evidence = BE). The results of the study confirm the carcinogenic action of vinyl chloride on the liver but not on the other suggested target organs (i.e., lung, lymphopoietic tissues, brain). A deficit for all causes of death and cardiovascular disease was evident in most cohorts and in the pooled cohort. Analysis of BE data showed a broad spectrum of carcinogenic action of VCM on the liver as demonstrated by the occurrence of both angiosarcomas and other histotypes of tumours.