Expert-based assessment of chemical and physical exposures, and organizational factors, in past agricultural jobs.

Abstract

Background: Limited data document the spectrum of exposures in the agricultural environment. We describe here the wide range of chemical and physical agents, and organizational factors, encountered in agricultural jobs held in the past in Canada and abroad.

Methods: We used data from a population-based case-control study of prostate cancer including 3,925 male participants residing in Montreal, Canada in 2005-2012. Lifetime occupational histories and detailed job descriptions were collected in-person. Industrial hygienists and an agronomist conducted semi-quantitative evaluations of exposure, including intensity and reliability, to some 300 chemical and physical agents in each job held. Analyses focused on the 156 agricultural jobs ever held in the study population. Clusters of agricultural co-exposures were derived.

Results: Agricultural jobs had taken place in 1946-2012, 53% ending in 1970 or after. Jobs were often (43%) held in Quebec, Canada; 22% in Italy, Portugal or Greece, and 10% in Haiti. Jobs entailed exposure to an average of 10 chemical agents (± 7) and most were characterized by long working hours, high physical activity levels, and did not provoke stress or anxiety. Few involved early morning shifts. Exposure to 78 agents was assigned with probable or definite certainty. The most common definite or probable carcinogens were ultraviolet radiation (92% of jobs), environmental tobacco smoke (39%), diesel engine exhaust (23%), wood dust (20%), lubricating oils and greases (20%) and lead (15%). Pesticide exposure (as a group) occurred in 31% of jobs. Fifty-four percent of jobs entailed exposure to ≥ 2 recognized carcinogens. Exposure clusters varied according to countries and type of agricultural activities (general, animal, crops, horticulture, vineyards, etc.).

Conclusions: Findings highlight the heterogeneity of exposure patterns in past agricultural environments based on their setting and activities involved. Studies on health-related effects of farming should account for numerous potential exposures, beyond their typical focus on pesticides.