Outdoor air pollution and the risk of asthma exacerbations in single lag0 and lag1 exposure patterns: A systematic review and meta-analysis

Abstract

Background: Asthma exacerbations accelerate the disease progression, as well as increases the incidence of hospitalizations and deaths. There have been studies on the effects of outdoor air pollution and asthma exacerbations; however, evidence regarding single lag0 and lag1 exposure patterns is inconclusive. Objective To synthesize evidence regarding the relationship between outdoor air pollution and the asthma exacerbation risk in single lag0 and lag1 exposure patterns. Methods We performed a systematic literature search using PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials, China National Knowledge Internet, Chinese BioMedical, and Wanfang databases until August 1st, 2020. Additionally, we reviewed the reference lists of the relevant articles. Two authors independently evaluated the eligible articles and performed structured extraction of relevant information. Pooled relative risks (RRs) and 95% confidence intervals (CIs) of lag0 and lag1 exposure patterns were estimated using the random-effect models. Results: Eighty-four studies met the eligibility criteria and provided sufficient information for meta-analysis. Outdoor air pollutants were associated with significantly increased risks of asthma exacerbations in both single lag0 and lag1 exposure patterns [lag0: RR (95%CI) (pollutants), 1.057(1.011, 1.103) (air quality index; AQI), 1.007(1.005, 1.010) (PM2.5), 1.009(1.005, 1.012) (PM10), 1.010(1.006, 1.014) (NO2), 1.030(1.011, 1.048) (CO), 1.005(1.002, 1.009) (O3); lag1: RR (95%CI) (pollutants), 1.064(1.022, 1.106) (AQI), 1.005(1.002, 1.008) (PM2.5), 1.007(1.004, 1.011) (PM10), 1.008(1.004, 1.012) (NO2), 1.025(1.007, 1.042) (CO), 1.010(1.006, 1.013) (O3)], except SO2 [lag0: RR (95%CI), 1.004(1.000, 1.007); lag1: RR (95%CI), 1.003(0.999, 1.006)]. Subgroup analyses revealed stronger effects in children and asthma exacerbations associated with other events (including symptoms, lung function changes, and medication use as required). Conclusion These findings demonstrate that outdoor air pollution significantly increases the asthma exacerbation risk in single lag0 and lag1 exposure patterns.

Rhinovirus persistence during the COVID‐19 pandemic—Impact on pediatric acute wheezing presentations

“…Another well‐recognized characteristic of rhinoviruses is their ability to cause acute wheezing and exacerbations of asthma in children—a common winter season healthcare presentation in pediatric emergency departments (PEDs) 11–13 . Such clinical wheezing can also be exacerbated by the inhalation of airborne particulate material in the ≤2.5 and ≤10 µm diameter range (PM 2.5 , PM 10 ) 13–15 …”