Annual SO2 exposure, asthma, atopy, and lung function in Puerto Rican children

Background Long‐term effects of sulfur dioxide (SO2) exposure on children, a vulnerable population, are largely unknown. Further, how long‐term SO2 affects Puerto Rican children living in the island of Puerto Rico, a group with high asthma prevalence, is unclear. We evaluated the effects of annual average 1‐hour daily maximum SO2 average on asthma, atopy, total immunoglobulin E (IgE), and lung function in Puerto Rican children. Methods A cohort of 678 children (351 with asthma, 327 without asthma) was recruited in Puerto Rico from 2009 to 2010. Annual average 1‐hour daily maximum SO2 exposure was interpolated utilizing publicly available monitoring data. Multivariable logistic and linear regression was used for the analysis of asthma, atopy (defined as an IgE ≥0.35 IU/mL to at least one of five common aero‐allergens), total IgE, and lung function measures (forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], and FEV1/FVC ratio). Results Annual SO2 exposure (per 1 ppb) was significantly associated with asthma (odds ratio [OR] = 1.42; 95% confidence interval [CI] = 1.05‐1.91) and atopy (OR = 1.35; 95% CI = 1.02‐1.78). Such exposure was also significantly associated with lower FEV1/FVC in all children (β = −1.42; 95% CI = −2.78 to −0.08) and in children with asthma (β = −2.39; 95% CI= −4.31 to −0.46). Annual SO2 exposure was not significantly associated with total IgE, FEV1, or FVC. Conclusions Among Puerto Rican children in Puerto Rico, long‐term SO2 exposure is linked to asthma and atopy. In these children, long‐term SO2 exposure is also associated with reduced FEV1/FVC, particularly in those with asthma.