Cancer mortality among rice growers in Novara Province, northern Italy.

ABSTRACT

Some excess of non-Hodgkin lymphomas (NHL) and soft tissue sarcomas (STS) was reported in the literature among agricultural workers, mainly in relation to exposure to phenoxyacids and chlorophenols. In this study, information was analyzed for a cohort of rice growers that comprised 1,493 subjects, and for a follow-up that was more than 99% complete with regard to both traced subjects and known causes of deaths. A total of 960 subjects (65%) died during the observation period (1957-1992). Lower than expected standardized mortality ratios (SMRs) were found for all causes, for cardiovascular diseases (especially ischemic heart disease) and for all cancers. Slightly increased SMRs were found for some cancer sites (oral cavity, esophagus, liver, intestines, pancreas, bladder, STS, and NHL), although none of these was statistically significant in the overall analysis. An excess risk of close to statistical significance was found for NHL among workers with longer exposure during the period when phenoxyacid herbicide was in use (1950-1992). Thus, a prolonged follow-up is advisable. At present the study should be evaluated in the context of the data set suggesting a tendency toward an increased risk of NHL among farmers.