Short-term exposure to ambient air pollution and hospital visits for IgE-mediated allergy: A time-stratified case-crossover study in southern China from 2012 to 2019

Elsevier, eClinicalMedicine, Volume 37, July 2021
Hou X., Huang H., Hu H., Wang D., Sun B., Zhang X.D.
Background: Because of the limited epidemiological evidence on the association between acute air pollutants and allergy, there is a need to investigate this association, especially between the short-term exposure to air pollution and the serum Immunoglobulin E (IgE)-mediated allergy. Methods: A total of 39,569 IgE test results and demographic characteristics were obtained in the First Affiliated Hospital of Guangzhou Medical University between August 2012 and September 2019. Ninety-nine specific allergens were tested according to clinical diagnosis. The logistic regression was used to assess the effects of CO, NO2 and PM2.5 exposure on the risk of sensitization to specific inhalant/food allergens. Generalized additive models with multivariate adjustments were utilized to model the exposure-response relationship. Stratified analyses were performed to estimate the reliability of correlations in various subgroups. Findings: Single-pollutant models indicate that the 3-day moving average (lag2–4) of CO, PM2.5 or NO2 is associated with the increased risk for allergic diseases related to specific inhaled allergens. In multi-pollutant models, the adjusted Odds Ratio (OR) 95% (Confidence Interval, CI) increases by 8% (95% CI, 2%–15%) for per increment of 0.2 mg/m3 in CO levels, and rises by 8% (95% CI, 2%–13%) for each increase of 16.3 μg/m3 in PM2.5 concentration. The associations are stronger in youngsters (