SOS! Summer of Smoke: An Examination of the Health Effects of a Record Wildfire Season in Canada's High-Subarctic

Abstract

Background: The high-subarctic in Canada’s Northwest Territories (NWT) has warmed by 2- 2.5°C since the 1950’s. In 2014 it experienced extreme wildfires. We examined the epidemiologic health impacts of smoke, with interpretation informed by community-member interviews. Methods: Poisson regression was used to examine the relationship of 24-hour mean PM2·5 levels with 2014’s cardiorespiratory ER visits. A comparison of salbutamol dispensations, clinic visits for respiratory symptoms, cardiorespiratory ER visits and hospital admissions in 2014 with non- years (2012-2013) was also completed. Findings: Median PM2·5 peaked at 320·3 μg/m3 49 in 2014, and was five-fold higher in 2014 compared to 2012, 2013 and 2015. In 2014, a 10 μg/m3 50 increase in PM2·5 was associated with an increase in ER visits of 11% for asthma and 6% for pneumonia. Compared to 2012/13, there was a 48% increase in dispensed salbutamol; significantly more clinic visits for asthma, pneumonia and cough; double the ER visits for asthma; and 45% more ER visits for pneumonia. Interpretation: The impact of PM2·5 on respiratory health was high, possibly because prolonged smoke impacted indoor air quality or led to difficulty complying with stay inside when smoky messaging, which qualitative analysis found to be associated with isolation, decreased physical activity, disruptions to land-based activities, and Indigenous food security impacts. At-home air filtration, air shelters with recreation opportunities, attention to eco-anxiety, and go outside when not smoky messaging could improve wellness during wildfires. Funding Statement: Health Canada's Climate Change and Health Adaptation Program for First Nations and Inuit Communities. Declaration of Interests: No conflicts of interest exist. Ethics Approval Statement: This project was reviewed and approved by the Stanton Territorial and Wilfrid Laurier University Research Ethics Boards, as well as the Aurora Research Institute.