Environmental Arsenic Exposure, Biomarkers and Lung Function in Children from Yaqui Communities in Sonora, Mexico.

Arsenic exposure in children and adults has been associated with respiratory symptoms, respiratory infections, and decreased lung function. The goal of this study was to evaluate the relationship between environmental arsenic exposure and serum pneumoproteins and lung function. A cross-sectional study was conducted including 175 children exposed to arsenic by drinking water (range: 7.4 to 91 µg/L) and soil (range: 4.76 to 35.93 mg/kg), from some Yaqui villages. Arsenic was analyzed in dust and urine using field-portable X-ray fluorescence spectrometry and ICP/OES, respectively. Serum was analyzed for Clara Cell protein (CC16) and Matrix Metalloproteinase-9 (MMP-9) using immunoassays, and lung function was evaluated by spirometry. The results showed that increased arsenic in drinking water was associated with reduced forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) ratio (β = -0.027, p = 0.0000) whereas, contrary to expectations, arsenic in dust was associated with increased FEV₁/FVC (β = 0.004, p = 0.0076). Increased urinary arsenic was associated with reduced % predicted FEV₁ (β = -0.723, p = 0.0152) and reduced FEV₁/FVC ratio (β = -0.022, p = 0.0222). Increased serum MMP-9 was associated with reduced FEV₁/FVC ratio (β = -0.017, p = 0.0167). Children with % predicted FEV₁ values less than 80 had the lowest levels of CC16 (Median 29.0 ng/mL, IQR 21.3, 37.4, p = 0.0148). As a conclusion, our study evidenced an impairment in lung function in children exposed to low arsenic levels.