Mortality in a cohort of pesticide applicators in an urban setting: Sixty years of follow-up
The study is a further follow-up of a cohort of 168 urban pesticide applicators of the municipality of Rome who were first employed in 1946. An earlier analysis of the mortality of this group concerned the deaths observed up to 1987, and showed a significant excess in mortality from liver cancer. In this report we present an updated follow up of the mortality of the cohort, which comprises the total of 85 deaths for the entire period of observation, corresponding to 5227 person/years. The living status of each member of the cohort was ascertained through the official records up to 2005. For the 85 deceased individuals, the primary cause of death was coded according to the 9th Revision of the ICD. Standardized mortality ratios (SMR) were calculated on the basis of the age, sex, and cause specific mortality rates prevailing during the same calendar years in the province of Rome. The SMR from all causes for the whole cohort was 103.8 (90 %CI 86 124). The SMR for all cancers was 106.0 ( 90 % CI 75-146). An increased risk was observed for the exposed for cancer of the gallbladder (SMR 723.8 90% CI 129-2279), of the liver (SMR 596.3, 90 % CI 204-1365) and for cancer of the nervous system (SMR 529.2, 90 % CI 144-1368). All increases were statistically significant, but no association was found between the increased risk of these cancers and the longer duration of exposure. The increase in risk of the three cancers mentioned above (liver, nervous system and gallbladder), was further increased, when the analysis was restricted to the workers exposed prior to the 1978 ban of DDT and products containing arsenic.