Association Between Wildfire Smoke Exposure and Psychometric Health Measures: Findings from the Lovelace Smokers Cohort

Rationale: Wildfire frequency and intensity increased globally due to the impacts of climate change. Evidence concerning health impacts after episodic exposure to wildfire smoke is limited. Methods: Using the Lovelace Smokers Cohort (LSC), we evaluated whether wildfire smoke exposure was associated with psychometric measures of physical and mental health and whether the associations observed were modified by individual factors.The St. George's Respiratory Questionnaire (SGRQ) and the 36-Item Short Form Survey (SF-36) were administered to assess respiratory-specific and general health-related quality of life in 4 weeks prior to questionnaire filling, respectively. Exposure to wildfire smoke was quantified using satellite-derived smoke plume imagery in combination of near ground estimates of PM2.5 and black carbon concentrations. Results: The Albuquerque metropolitan area in New Mexico, the catchment area of the LSC was frequently affected by wildfire smoke during non-winter seasons that predominantly originated from the fires in Apache and Gila National Forest around the Arizona and New Mexico borders. We identified a total of 381 smoke days from 2006 to 2016 when Albuquerque overlapped with smoke plumes. The contribution of smoke to ambient PM2.5 levels was estimated to be an average of 2.31 µg/m3 during these days which is equivalent to 57% of the average ambient PM2.5 levels during non-smoke days. Among subjects (n=747) who filled SGRQ and SF-36 health survey between 2006 and 2016, wildfire smoke exposure was associated with worse psychometric measures, with mental health more likely to be affected by recent (1-2 weeks) wildfire smoke exposure, while physical health affected by wildfire smoke exposure estimated for up to 4-8 weeks. Specifically, per 1 µg/m3 increase (90th to 95th percentile) in smoke PM2.5 in 7-, 15-, and 30-day prior to questionnaire filling is associated with an increase of 4 or more points in activity and symptom scores of SGRQ, an effects size exceeding clinical significance. Additionally, the associations were stronger among males, individuals with lower education, those with chronic mucous hypersecretion, and participants with prior residential woodsmoke exposure. Conclusions: This study suggests that episodic exposure to wildfire smoke is associated with worse SGRQ and SF-36 scores, with distinct timing differences between the impacts on mental and physical health. Additionally, individuals with lower education levels, chronic mucus hypersecretion, or prior woodsmoke exposure appear to be more vulnerable to the effects of wildfire smoke. Further research is needed to validate these findings and to explore the biological mechanisms underlying these associations.