RESUMO
RATIONALE: Exposure to arsenic through drinking water has been linked to respiratory symptoms, obstructive lung diseases, and mortality from respiratory diseases. Limited evidence for the deleterious effects on lung function exists among individuals exposed to a high dose of arsenic. OBJECTIVES: To determine the deleterious effects on lung function that exist among individuals exposed to a high dose of arsenic. METHODS: In 950 individuals who presented with any respiratory symptom among a population-based cohort of 20,033 adults, we evaluated the association between arsenic exposure, measured by well water and urinary arsenic concentrations measured at baseline, and post-bronchodilator-administered pulmonary function assessed during follow-up. MEASUREMENTS AND MAIN RESULTS: For every one SD increase in baseline water arsenic exposure, we observed a lower level of FEV1 (-46.5 ml; P < 0.0005) and FVC (-53.1 ml; P < 0.01) in regression models adjusted for age, sex, body mass index, smoking, socioeconomic status, betel nut use, and arsenical skin lesions status. Similar inverse relationships were observed between baseline urinary arsenic and FEV1 (-48.3 ml; P < 0.005) and FVC (-55.2 ml; P < 0.01) in adjusted models. Our analyses also demonstrated a dose-related decrease in lung function with increasing levels of baseline water and urinary arsenic. This association remained significant in never-smokers and individuals without skin lesions, and was stronger in male smokers. Among male smokers and individuals with skin lesions, every one SD increase in water arsenic was related to a significant reduction of FEV1 (-74.4 ml, P < 0.01; and -116.1 ml, P < 0.05) and FVC (-72.8 ml, P = 0.02; and -146.9 ml, P = 0.004), respectively. CONCLUSIONS: This large population-based study confirms that arsenic exposure is associated with impaired lung function and the deleterious effect is evident at low- to moderate-dose range.