[Cancer incidence among petrochemical workers in the Porto Torres industrial area, 1990-2006]

Various epidemiological studies explored cancer mortality and incidence among petrochemical workers. We followed up cancer incidence in a cohort of 5350 male petrochemical workers in the industrial area of Porto Torres (Sardinia, Italy).

The follow-up covered the period from 01/01/1990, when completeness of the cohort was certain and reference rates by the local Cancer Registry became available, up to 31/12/2006. Cohort members were subjects employed for six months or more in one of the chemical plants of the industrial area, alive as at 01/01/1990. Overall, a total of 81,392 person-years at risk were accumulated. The standardized incidence ratio (sir), as the ratio of observed to expected events, and its 95% confidence interval (CI) were calculated for all cancers and selected cancer sites, in the total cohort and in sub-cohorts of workers in plants where exposure to chemical agents evaluated in the IARC Monographs might have occurred.

An increase in risk for all cancers was observed in the total cohort (596 cases; sir = 1.09; 95% CI 1.00-1.18), and it was highest for non-Hodgkin lymphoma (NHL, 26 cases: sir = 1.78; 95% CI 1.22-2.62). Risk for haemolymphatic cancer was highest in the sub-cohort of workers employed for 10 years or more, with a latency period of 20 years or longer, and among those employed in the manufacture and polymerization of vinyl chloride (VCM; all cancers, 51 cases: sir = 1.43; 95% CI 1.08-1.88; NHL, 4 cases: sir=4.06; 95% CI 1.64-10.0). Risk of haemolymphatic cancer was not significantly elevated in the sub-cohort potentially exposed to benzene. An excess risk of bladder cancer (RR = 1.46; 95% CI 1.09-1.96), but not of pleural cancer, was observed in the sub-cohort potentially exposed to asbestos. No significant increase in cancer risk was observed among workers potentially exposed to acrylonitrile, butadiene, or styrene.

Our follow-up study of petrochemical workers showed an increase in risk for all cancers, and particularly NHL, apparently concentrated among workers potentially exposed to VCM