Prevalence of Asthma-Related Symptoms in Adolescents Living near Industrial Animal Feeding Operations in Eastern North Carolina (U.S.A.)

摘要

Animal feeding operations (AFOs) generate substantial air pollution; proximity has been associated with asthma-related illness in children. In North Carolina, swine and poultry AFOs are most common. We examined the relation between adolescents' home exposure to swine and poultry AFO-related air pollution and prevalence of asthma-related symptoms. The Rural Air Pollutants and Children's Health study enrolled 340 students from three eastern North Carolina middle schools in 2009. Participants self-reported demographics, health, and respiratory symptoms. We developed novel exposure indices to estimate home exposure to air pollution from swine and poultry AFOs. Home exposures were indexed by geocoded address, orthoimagery-derived size and location of barns within 2 miles, and predominant past-year wind direction. Indices were categorized (low/middle/high) for swine and poultry separately. We estimated prevalence differences (PD) for current wheeze and asthma by exposure category, using linear binomial regression with inverse-probability weights to control confounding by gender, age, school, time outside, lunch assistance, passive smoke exposure, and livestock exposure (ie, chores). Of 326 participants with complete data, 93% lived within 2 miles of at least one AFO. Prevalence of current wheeze and current asthma were 24.0% and 10.6%, respectively. In crude data, neither swine nor poultry exposure index was associated with current wheeze or current asthma. After controlling for confounding, middle and high swine exposure index categories were associated with higher prevalence for both outcomes compared to the lowest category (current wheeze PD per 100 adolescents: 11.$395% CI: 2.6, 20.0; current asthma PD: 5.9, 95% CI: -0.$111.9). Using a novel exposure metric and rich covariate data, we observed higher prevalence of current wheeze and asthma with higher swine AFO exposure. Future research should examine potential heterogeneity by sociodemographic or geographic factors.