Effects of Inhalable Particles on Respiratory Health of Children

TLDR

The study used quality‑controlled monitoring stations to measure total suspended particulates, PM15, PM2.5, fine sulfate, SO₂, O₃, and NO₂ and linked these concentrations to health outcomes in children. Higher concentrations of particulate pollutants were associated with increased rates of chronic cough, bronchitis, chest illness, and earache, especially among children with wheeze or asthma, but no links were found with asthma, wheeze, hay fever, non‑respiratory illness, or pulmonary function, indicating that particulate exposure raises respiratory symptoms without causing permanent pulmonary impairment.

Abstract

Results are presented from a second cross-sectional assessment of the association of air pollution with chronic respiratory health of children participating in the Six Cities Study of Air Pollution and Health. Air pollution measurements collected at quality-controlled monitoring stations included total suspended particulates (TSP), particulate matter less than 15 µm (PM15) and 2.5 µm (PM2.5) aerodynamic diameter, fine fraction aerosol sulfate (FSO4), SO2, O3, and NO2 Reported rates of chronic cough, bronchitis, and chest illness during the 1980–1981 school year were positively associated with all measures of particulate pollution (TSP, PM15, PM2.5, and FSO4) and positively but less strongly associated with concentrations of two of the gases (SO2 and NO2). Frequency of earache also tended to be associated with particulate concentrations, but no associations were found with asthma, persistent wheeze, hay fever, or nonrespiratory illness. No associations were found between pollutant concentrations and any of the pulmonary function measures considered (FVC, FEV1, FEV0.75, and MMEF). Children with a history of wheeze or asthma had a much higher prevalence of respiratory symptoms, and there was some evidence that the association between air pollutant concentrations and symptom rates was stronger among children with these markers for hyperreactive airways. These data provide further evidence that rates of respiratory illnesses and symptoms are elevated among children living in cities with high particulate pollution. They also suggest that children with hyperreactive airways may be particularly susceptible to other respiratory symptoms when exposed to these pollutants. The lack of association between pollutant concentrations and measures of both pulmonary flow and volume suggests, however, that these increased rates of illness are not associated with permanent loss of pulmonary function, at least during the preadolescent years.