A Study of Twelve Southern California Communities with Differing Levels and Types of Air Pollution

TLDR

The study aimed to investigate chronic respiratory effects of ozone, particulate matter, acids, and NO₂ in Southern California children through a 10‑year prospective cohort. Twelve demographically similar communities were selected to represent extremes of exposure, and about 150 grade‑4, 75 grade‑7, and 75 grade‑10 students per community were enrolled, with consent and detailed surveys collected. Questionnaire data from 3,676 students revealed higher respiratory illness rates among males, those with pets, pests, mildew, water damage, parental asthma, or smokers, and wheeze prevalence positively associated with acid and NO₂ levels, suggesting ambient air pollution may affect schoolchildren’s respiratory morbidity.

Abstract

To study possible chronic respiratory effects of air pollutants, we initiated a 10-yr prospective cohort study of Southern California children, with a study design focused on four pollutants: ozone, particulate matter, acids, and nitrogen dioxide (NO2). Twelve demographically similar communities were selected on the basis of historic monitoring information to represent extremes of exposure to one or more pollutants. In each community, about 150 public school students in grade 4, 75 in grade 7, and 75 in grade 10 were enrolled through their classrooms. Informed consent and written responses to surveys about students' lifetime residential histories, historic and current health status, residential characteristics, and physical activity were obtained with the help of the parents. In the first testing season, 3,676 students returned questionnaires. We confirmed associations previously reported between respiratory morbidity prevalence and the presence of personal, demographic, and residential risk factors. Rates of respiratory illness were higher for males, those living in houses with pets, pests, mildew, and water damage, those whose parents had asthma, and those living in houses with smokers. Wheeze prevalence was positively associated with levels of both acid (odds ratio [OR] = 1.45; 95% confidence interval [CI], 1.14–1.83) and NO2 (OR = 1.54; 95% CI, 1.08–2.19) in boys. We conclude, based on this cross-sectional assessment of questionnaire responses, that current levels of ambient air pollution in Southern California may be associated with effects on schoolchildren's respiratory morbidity as assessed by questionnaire.