(HealthDay News) — Long-term exposure to wildfires may be associated with a slightly increased risk for lung cancer and brain tumors, according to a study published in the May issue of The Lancet Planetary Health.
Jill Korsiak, from McGill University in Montreal, and colleagues conducted a population-based observational cohort study of participants in the 1996 Canadian Census Health and Environment Cohort who were followed for cancer incidence and mortality from 1996 to 2015.
The relationship between exposure to wildfires and specific cancers associated with carcinogenic compounds released by wildfires was examined, adjusted for many personal and neighborhood-level covariates.
More than 2 million people were followed for a median of 20 years in the analyses, for a total of 34 million person-years. The researchers found that the incidence rates of lung cancer and brain tumors were slightly increased in association with wildfire exposure.
Cohort members exposed to a wildfire within 50 km of residential locations in the previous 10 years had a relatively higher incidence of lung cancer and brain tumors than unexposed populations (adjusted hazard ratios, 1.049 and 1.100, respectively). Associations were similar for the 20-km buffer size. No association was seen between wildfires and hematological cancers in this study.
“In light of the study limitations, and because this is the first epidemiological study investigating associations between wildfires and cancer risk, we emphasize that a causal effect cannot be ascertained from this single study,” the authors write.