Occupational exposure to pesticides, nicotine and mental health problems among tobacco farm workers in southern Brazil

INTRODUCTION:   Exposure to pesticides has been associated with psychiatric problems among farm workers, although there is controversy as to the type of chemicals and the forms and intensity of exposure that represents risk factors for psychological problems. Furthermore, tobacco workers are exposed to dermal absorption of nicotine, although its effect on mental health has not yet been studied. This study aims to identify the prevalence of minor psychiatric disorders (MPD) among tobacco farmers and associated factors, paying special attention to pesticide and nicotine exposure.

METHODS: Cross-sectional study with a representative sample of tobacco growers, characterizing the economic indicators of the farms, socio-demographic factors, lifestyle habits and occupational exposures. Multivariate analysis was performed using a hierarchical Poisson regression model.

RESULTS: 2,400 tobacco farmers were assessed, MPD prevalence was 12% and was higher among women (PR 1.4), among workers aged 40 or over, those that were tenants/employees (PR 1.8) and among those who reported having difficulty in paying debts (PR 2.0). Tobacco production volume was inversely associated with MPD prevalence. Tasks involving dermal exposure to pesticides showed risk varying between 40% and 80%, whereas tobacco growers on farms using organophosphates had 50% more risk of MPD than those on farms not using this kind of pesticide. The number of pesticide poisoning and green tobacco sickness episodes showed direct linear association with MPD. 

CONCLUSIONS: The study reinforces the evidence of the association between pesticide poisoning and mental health problems. It also points to increased risk from pesticide exposure through dermal contact and exposure to organophosphates, as well as indicates intense nicotine exposure as a potential risk for tobacco farmers’ mental health.