Ambient air pollutants increase the risk of Immunoglobulin E-mediated allergic diseases: a systematic review and meta-analysis

Abstract

Immunoglobulin E (IgE)-mediated allergic diseases, including eczema, atopic dermatitis (AD) and allergic rhinitis (AR), have increased prevalence in recent decades. Recent studies have proved that environmental pollution might have correlations with IgE-mediated allergic diseases, but existing research findings were controversial. Thus, we performed a comprehensive meta-analysis from published observational studies to evaluate the risk of long-term and short-term exposed to air pollutants on the eczema, AD and AR in the population (per 10 μg/m3 increase in PM2.5 and PM10; per 1 ppb increase in SO2, NO2, CO and O3). PubMed, Embase and Web of Science were searched to identify qualified literatures. Cochran Q test was used to assess heterogeneity and quantified with I2 statistic. Pooled effects and the 95% confidence intervals (CIs) were used to evaluate outcome effects. A total of 55 articles were included in the study. The results showed that long-term and short-term exposed to PM10 increased the risk of eczema (PM10, RRlong=1.583, 95% CI: 1.328, 1.888; RRshort=1.006, 95% CI: 1.003-1.008) and short-term exposed to NO2 (RRshort=1.009, 95% CI: 1.008-1.011) was associated with eczema. Short-term exposed to SO2 (RRshort: 1.008, 95% CI: 1.001-1.015) was associated with the risk of AD. For AR, PM2.5 (RRlong=1.058, 95% CI: 1.014-1.222) was harmful in long-term, and short-term exposed to PM10 (RRshort: 1.028, 95% CI: 1.008-1.049;) and NO2 (RRshort: 1.018, 95% CI: 1.007-1.029) were risk factors. The findings indicated that exposed to air pollutants might increase the risk of IgE-mediated allergic diseases. Further studies are warranted to illustrate potential mechanism for air pollutants and allergic diseases.