Air pollution-related asthma profiles among children/adolescents: A multi-group latent class analysis

Background: This study aimed to investigate the asthma profile among children/adolescents and the relationship of the prevalence of air pollution profiles using latent class analysis (LCA). Objectives: In this cross-sectional study, a case rural community was selected in an industrial area, and two rural control communities were selected in unexposed areas. Methods: Hourly concentrations of PM₁₀, SO₂, NO_2, and total volatile organic compounds were obtained from the records of a fixed air quality monitoring station, and the concentrations of benzene, toluene, xylenes styrene were measured during six campaigns. Asthma data was collected using the International Study of Asthma and Allergies in Childhood in 7–18 years old children/adolescents. The modeling was conducted using LCA. Results: A higher amount of air pollution indices were observed in the case than both control communities. LCA divided the participants into three clusters; “healthy” (92.8%), “moderate” (2.8%), and “severe” (4.4%). A higher probability of severe asthma (6.8%) was observed in the case than control communities (2.6% and 1.8%). Additionally, after adjusting for possible confounders, the odds of asthma was lower in the control communities than the case in both moderate and sever classes (Odds Ratios in the range of 0.135–0.697). Conclusions: This study indicates asthma profiles of children/adolescents and the higher prevalence of severe class in the area, explaining the possible effect of air pollution.