Acute respiratory events are significantly associated with Colorado wildfire smoke exposure, despite the lack of association with total concentrations of fine particulate matter < 2.5µm in aerodynamic diameter (PM2.5), according to study results published in Environment International.
A team of investigators conducted a study using data from emergency department visits and hospitalizations for acute cardiorespiratory outcomes to determine the link between cardiorespiratory events and exposure to smoke PM2.5 in Colorado. Associations were estimated using a novel exposure model that isolated smoke PM2.5 from surrounding ambient PM2.5 levels.
Increases in fire smoke PM2.5 per 1µg/m3 were significantly associated with asthma and combined respiratory disease (odds ratio [OR], 1.081 and 1.021, respectively); however, the relationship between cardiovascular disease and smoke PM2.5 was not significant.
Positive age-specific relationships between smoke PM2.5 and asthma and combined respiratory disease were observed in children. Positive age-specific relationships in adults were observed between smoke PM2.5 and asthma, bronchitis, combined respiratory disease, and chronic obstructive pulmonary disease.
The investigators noted limitations to the study, including that the “…analyses lacked the ability to differentiate chemical compositions of PM2.5,” which did not link toxicologic effects to exposure metrics.
“Our findings point to potential toxic differences between smoke and non-smoke PM2.5 exposure; suggesting that PM2.5 from wildfire smoke could pose a significant threat to public health,” the investigators noted.
“It is, therefore, important to derive more accurate concentration-response relationships specific to wildfire smoke in order to develop a better understanding of future potential health risks based on increased wildfire activity,” continued the researchers.
“This information may be a key element in evaluating and enhancing current preparations aimed at wildfire-event response readiness,” they concluded.
Stowell JD, Geng G, Saikawa E, et al. Associations of wildfire smoke and PM2.5 exposure with cardiorespiratory events in Colorado 2011-2014. [published online September 11, 2019]. Environ Int. doi:10.1016/j.envint.2019.105151