Annual SO 2 exposure, asthma, atopy, and lung function in Puerto Rican children

Background Long‐term effects of sulfur dioxide (SO 2 ) exposure on children, a vulnerable population, are largely unknown. Further, how long‐term SO 2 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 SO 2 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 SO 2 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 SO 2 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 SO 2 exposure was not significantly associated with total IgE, FEV1, or FVC. Conclusions Among Puerto Rican children in Puerto Rico, long‐term SO 2 exposure is linked to asthma and atopy. In these children, long‐term SO 2 exposure is also associated with reduced FEV1/FVC, particularly in those with asthma.