Posted: Tuesday, June 21, 2022
Scott Weichenthal, PhD, of McGill University, Quebec, Canada, and colleagues evaluated the potential correlation between long-term exposure to wildfires and various cancers—particularly lung cancer. Published in The Lancet Planetary Health, this study ultimately determined that further work is necessary to develop long-term estimates of wildfire exposure that are more representative of the environmental carcinogens they release.
“Wildfires tend to happen in the same locations each year, but we know very little about the long-term health effects of these events,” stated Dr. Weichenthal in a McGill University press release. “Our study shows that living in close proximity to wildfires may increase the risk of certain cancers.”
This population-based observational cohort study focused on more than 2 million people from the 1996 Canadian Consensus Health and Environment Cohort. Participants were followed for cancer incidence and mortality until 2015. Wildfire exposure was assigned based on the area burned within a 20-km or 50-km radius of residential locations and was updated for annual residential mobility.
Of note, exposure to wildfires appeared to correlate with a slightly increased incidence of lung cancer and brain tumors, attributing to 43,000 and 3,900 cases, respectively. More important, individuals who were exposed to a wildfire within 50 km of a residential location in the past 10 years had a 4.9% higher rate of lung cancer (hazard ratio [HR] = 1.049) than those who were unexposed, as well as a 10% higher incidence of brain tumors (HR = 1.100); individuals in the 20-km buffer–sized group experienced similar rates of lung and brain cancers.
“Exposure to harmful environmental pollutants might continue beyond the period of active burning through several routes of exposure,” added Dr. Weichenthal. “With the changing climate, wildfires are predicted to become more prevalent, severe, and longer in duration in the future—and they are increasingly recognized as a global health problem.”
Disclosure: The study authors reported no conflicts of interest.