Work

Early-Life Exposure to PM2.5 and Risk of Acute Asthma Clinical Encounters among Children in Massachusetts: A Case-Crossover Analysis

Year: 2018

Type: conference-abstract

Abstract: Background/Aim: Associations between ambient particulate matter<2.5µm (PM2.5) and asthma morbidity have been suggested in previous epidemiologic studies. We estimated the associations between early-life short-term PM2.5 exposure and the risk of asthma clinical encounters among Massachusetts children in the novel Pregnancy to Early Life Longitudinal (PELL) cohort data linkage system. Methods: We used a semi-bidirectional case-crossover study design with short-term exposure lags for asthma exacerbation using information from the PELL data system. Cases included children up to 9 years of age who had a hospitalization, observational stay, or emergency department visit for asthma or wheeze between January 2001 and September 2009 (n=33,387). Daily PM2.5 concentrations were estimated at a 4-km resolution using satellite remote sensing, land use, and meteorological data. We applied conditional logistic regression models to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI). We stratified asthma clinical encounters by potential effect modifiers. Results: Overall, associations between PM2.5 exposure and asthma clinical encounters among children at lags 0, 1 and 2 were close to the null value of OR=1.0. Evidence of effect modification was observed by birthweight for lags 0, 1 and 2 (p<0.05), and season of clinical encounter for lags 0 and 1 (p<0.05). Children with low birthweight (<2500g) had increased odds of having an asthma clinical encounter due to higher PM2.5 exposure for lag 1 (OR: 1.14 per 10-µg/m3 increase in PM2.5; 95% CI: 1.01, 1.27). Conclusions: Asthma or wheeze exacerbations among low birthweight children were associated with short-term increases in PM2.5 concentrations.

Source: ISEE Conference Abstracts

DOI: 10.1289/isee.2017.2017-382