Exposure to Particulate Matter From Wildfire Smoke Leads to Adverse Respiratory Events

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 (PM_2.5), 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 PM_2.5 in Colorado. Associations were estimated using a novel exposure model that isolated smoke PM_2.5 from surrounding ambient PM_2.5 levels.

Increases in fire smoke PM_2.5 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 PM_2.5 was not significant.

Positive age-specific relationships between smoke PM_2.5 and asthma and combined respiratory disease were observed in children. Positive age-specific relationships in adults were observed between smoke PM_2.5 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 PM_2.5,” which did not link toxicologic effects to exposure metrics.

“Our findings point to potential toxic differences between smoke and non-smoke PM_2.5 exposure; suggesting that PM_2.5 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.

Reference
Stowell JD, Geng G, Saikawa E, et al. Associations of wildfire smoke and PM_2.5 exposure with cardiorespiratory events in Colorado 2011-2014. [published online September 11, 2019]. Environ Int. doi:10.1016/j.envint.2019.105151