Exposure to Air Pollution Tied to New Asthma in Children

FRIDAY, Aug. 21, 2020 (HealthDay News) — Fine particulate matter contributes to the development of asthma and persistent wheezing in children, according to a study published online Aug. 19 in The BMJ.

Gitte J. Holst, from Aarhus University in Denmark, and colleagues sought to identify risk factors (air pollution and family-related) for the onset of asthma and persistent wheezing in children. The analysis included 3,192,785 Danish children born between 1997 and 2014 with follow-up to 15 years of age.

The researchers observed a higher incidence of asthma in children of parents with asthma (adjusted hazard ratio [aHR], 2.29) and mothers who smoked during pregnancy (aHR, 1.20). There was a lower incidence of asthma noted among children of parents with high educational attainment (aHR, 0.72) and high incomes (aHR, 0.85). There was an increased risk for asthma and persistent wheezing seen among children with exposure to particulate matter ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀) and nitrate, with hazard ratios per 5-µg/m³ increase in pollutant concentrations of 1.05 for PM_2.5, 1.04 for PM₁₀, and 1.04 for nitrogen dioxide. In a sensitivity analysis, only the positive association between PM_2.5 and asthma and persistent wheezing remained.

“The results suggest that further reductions in PM_2.5 might help to reduce the number of children who develop asthma and persistent wheezing in highly exposed populations,” the authors write.

Abstract/Full Text