Evaluation of evidence for interaction between PM2.5 and aeroallergens on childhood asthma exacerbation in Philadelphia, PA, 2011 to 2016

Wanyu Huang; Leah H Schinasi; Chén C Kenyon; Amy H Auchincloss; Kari Moore; Steven Melly; Lucy F Robinson; Christopher B Forrest; Anneclaire J De Roos

doi:10.1016/j.envres.2023.116395

Evaluation of evidence for interaction between PM2.5 and aeroallergens on childhood asthma exacerbation in Philadelphia, PA, 2011 to 2016

Environ Res. 2023 Oct 1:234:116395. doi: 10.1016/j.envres.2023.116395. Epub 2023 Jun 28.

Authors

Wanyu Huang¹, Leah H Schinasi², Chén C Kenyon³, Amy H Auchincloss⁴, Kari Moore⁵, Steven Melly⁵, Lucy F Robinson⁶, Christopher B Forrest⁷, Anneclaire J De Roos²

Affiliations

¹ Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA. Electronic address: wh397@drexel.edu.
² Department of Environmental and Occupational Health, Dornsife School of Public Health, Drexel University, PA, USA; Urban Health Collaborative, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA.
³ PolicyLab, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
⁴ Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA; Urban Health Collaborative, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA.
⁵ Urban Health Collaborative, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA.
⁶ Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA.
⁷ The Applied Clinical Research Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA.

PMID: 37390950
DOI: 10.1016/j.envres.2023.116395

Abstract

Fine particulate matter (PM_2.5) and aeroallergens (i.e., pollen, molds) are known triggers of asthma exacerbation. Despite mechanistic evidence suggesting synergistic effects between PM_2.5 and asthma exacerbation, little epidemiologic work has been performed in children, which has exhibited inconsistency. We conducted a time-series study to explore their interactions using electronic health records (EHR) data in Philadelphia, PA, for asthma diagnoses in outpatient, emergency department [ED], and inpatient settings. Daily asthma exacerbation cases (28,540 asthma exacerbation case encounters) were linked to daily ambient PM_2.5 and daily aeroallergen levels during the aeroallergen season of a six-year period (mid-March to October 2011-2016). Asthma exacerbation counts were modeled using quasi-Poisson regression, where PM_2.5 and aeroallergens were fitted with distributed lag non-linear functions (lagged from 0 to 14-days), respectively, when modeled as the primary exposure variables. Regression models were adjusted for mean daily temperature/relative humidity, long-term and seasonal trends, day-of-week, and major U.S. holidays. Increasing gradient of RR estimates were observed for only a few primary exposure risk factors [PM_2.5 (90th vs. 5th percentile)/aeroallergens (90th percentile vs. 0)], across different levels of effect modifiers. For example, RRs for the association between late-season grass pollen (lag1) and asthma exacerbation were higher at higher levels of PM_2.5, 5-days preceding the exacerbation event (low PM_2.5: RR = 1.01, 95% CI: 0.93-1.09; medium PM_2.5: 1.04, 95% CI: 0.96-1.12; high PM_2.5: 1.09, 95% CI: 1.01-1.19). However, most of the highest RRs for aeroallergens were instead observed for days with low- or medium- PM_2.5 levels; likewise, when PM_2.5 was modeled as the primary exposure with aeroallergens as the effect modifier. Most of the RR estimates did not exhibit gradients that suggested synergism, and were of relatively high imprecision. Overall, our study suggested no evidence for interactions between PM_2.5 and aeroallergens in their relationships with childhood asthma exacerbation.

Keywords: Aeroallergen; Asthma exacerbation; Children; Interaction; PM(2.5).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / toxicity
Air Pollution* / analysis
Allergens / toxicity
Asthma* / chemically induced
Child
Environmental Exposure / analysis
Humans
Particulate Matter / analysis
Philadelphia

Substances

Air Pollutants
Particulate Matter
Allergens