RESPIRATORY SYMPTOMS, SPIROMETRY AND CHRONIC OCCUPATIONAL PARAQUAT EXPOSURE

Objectives A cross-sectional study was conducted to evaluate the relat ionship between respiratory health and paraquat exposure. Methods The study population was selected from among workers at 15 Nicaraguan bana na plantations which relied on paraquat for the control of weeds. All the workers were interviewed after they received their job assignment for the day of the survey, and all who reported never having applied p araquat and all who reported more than 2 years of cumulative exposure as applicators of paraquat with knapsack sprayers were invited for med ical evaluation. One hundred and thirty-four exposed workers and 152 u nexposed workers were administered a questionnaire interview asking ab out exposure and respiratory symptoms, and they underwent spirometric testing of forced expiratory volume in 1 s (FEV1.0) and forced vital c apacity (FVC). Results In the exposed group 53% reported having experi enced a skin rash or burn resulting from paraquat exposure, 25% report ed epistaxis, 58% nail damage, and 42% paraquat splashed in the eyes. There was a consistent dose-response relationship between intensity of exposure (as indicated by a history of skin rash or burn) and the pre valence of dyspnea. This relationship was more marked for more severe dyspnea. There was a 3-fold increase in episodic wheezing accompanied by shortness of breath among the more intensely exposed workers. There was no relationship between exposure and FEV1.0 or FVC. Conclusions T he high prevalence of respiratory symptoms associated with exposure, i n the absence of spirometric abnormalities associated with exposure, c ould be a result of unmeasured gas exchange abnormalities among worker s with long-term exposure to paraquat.