Pesticides use and impaired lung function among male agricultural farmers in rural Sindh, Pakistan

Pesticides are widely used to protect the foods and crops. However, use of pesticides may lead to many harmful health effects among the users, if precautionary measures are not taken. Even mild exposure of pesticides has led to decrement in lung function, manifested as restrictive or obstructive pattern of dysfunction or both. Although pesticides are widely used mostly unregulated by farmers in Pakistan, however its health effects have not been studied robustly. Therefore, we conducted the study to determine the association of impairment in lung function (restrictive/obstructive pattern of lung function) with pesticides use among the farmers. Methods: We used comparative cross-sectional study deign to collect data from the Union Council Karampur, Taluka Mirpur Sakro district Thatta. Using eligibility criteria, we systematically included 276 non-smoker male agricultural farmers according to their pesticide use experience, 142 who used pesticides regularly for the last five years and 136 who never used pesticides in their lifetime. We used modified American Thoracic Society Division of Lung Disease (ATSDLD- 78A) questionnaire. In addition, we collected information regarding pesticide use and conducted spirometry to measure the lung volumes of the farmers. Multinomial logistic regression was used to determine the association with pesticide use and restrictive/obstructive lung dysfunction, adjusting for potential confounders. In addition, we used independent t-test to determine the mean difference in lung volumes (forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEVi/FVC ratio) among the pesticide exposed and unexposed groups of farmers. 4 Results: The risk of restrictive lung function was increased almost twice with exposure to pesticides each year at every level of age after adjusting for number of crops per year, number of family members and use of wood to heat the house (RRR= 1.92, 95% C.I= 1.39-2.62). Similarly, the risk of obstructive lung function was increased 2 times with exposure to pesticides at every level of age after adjusting for number of crops per year, number of family members and use of wood to heat house (RRR= 1.95, 95% C.I= 1.25-3.03). Secondly, the mean decrement in FVC (0.34 liters), FEVi (0.35 liters) and FEV1/FVC ratio (4) among the exposed compared to unexposed group of farmers was highly significant. Conclusion: Pesticides impose significant harmful effects on the lungs of the farmers who use pesticides. There is a need of interventional studies where farmer should be taught regarding the usage of personal protective equipment to avoid exposure to pesticides. Key words: Agricultural pesticides, forced expiratory volume in one second, forced vital capacity, lung function, obstructive lung dysfunction, restrictive lung dysfunction, male farmers