Mortalita per tumori e altre cause tra i lavoratori del cemento-amianto a Casale Monferrato

The present report updates a mortality cohort study of workers in the largest Italian asbestos cement plant. The plant had been active in Casale Monferrato in 1907-1986 and produced boards, corrugated sheets, tubes and high-pressure pipes. Raw material included both chrysotile and crocidolite but not amosite. Airborne asbestos concentrations were measured for the first time in 1971 (over 20 ff/cc in most areas). Regular monitoring started in 1978, when the concentration measured in most samples was below 1 ff/cc. The cohort included 3367 blue-collar workers (2605 men and 762 women) employed at the plant at any time between 1950 and 1980. At the end of the follow-up in 1993, 57% were alive, 41% were dead and 2% were either lost or had moved abroad. Mortality in the cohort was compared to mortality rates in Piedmont; local rates have been available only since 1969 and mortality analyses were limited to the period since 1965. Both sexes showed a statistically significant increase in mortality for all causes: lung cancer (males: 162 obs. vs. 65.4 exp.; females 9 vs. 3.2), malignant neoplasm (MN) of the pleura (males 53 vs. 1.7; females 21 vs. 0.4), MN of the peritoneum (males 23 vs. 1.2; females 8 vs. 0.5) and asbestosis (males 118 vs. 0.2; females 14 vs. 0.1). No excesses were observed for MN of the larynx or of the digestive tract. Women show a statistically significant increase in MN of the ovary (7 vs. 2.7) and of the uterus (14 vs. 4.3). Mortality from MN of the lung increased with latency but, in men, showed a curvilinear trend with the highest SMR for those with between 10 and 19 years of employment. The curve could be related to workers with the highest seniority employed in better jobs. The study includes a review of epidemiological studies on mortality among asbestos cement workers.