Long-term exposure to wildfire smoke associated with increased risk of dementia: study
Exposure to wildfire smoke over an extended period of time has been linked to an increased risk of developing dementia, more so than exposure to other sources of air pollution, according to a recent study published in the journal JAMA Neurology.
The study examined a cohort of over 1.2 million individuals aged 60 and above living in Southern California between 2008 and 2019. Researchers tracked the incidence of dementia among the cohort and compared it to the average concentration of fine particulate matter, specifically PM2.5, in the air due to wildfires in the region. The findings revealed that a one microgram per cubic meter increase in the three-year average concentration of wildfire PM2.5 was associated with an 18% increase in the odds of receiving a dementia diagnosis. In contrast, the same increase in non-wildfire PM2.5 was only linked to a three per cent rise in the odds of dementia diagnosis.
While previous studies have established a connection between long-term exposure to air pollution and an elevated risk of developing dementia, this research sheds light on the specific impact of wildfire smoke on the brain. Fine particulate matter, such as PM2.5, can penetrate deep into the lungs when inhaled, posing a significant health risk. Wildfire smoke contains a mix of chemicals from burned materials, including residences, vehicles, and plastics. Unlike steady sources of air pollution like smog, wildfires bring abrupt spikes of PM2.5 concentration in the air, affecting not only the respiratory system but the entire body.
The body’s response to foreign particles can trigger inflammation in the lungs, potentially spreading to other organs through inflammatory cells in the bloodstream. This heightened state of inflammation may impact the cardiovascular system, affecting blood flow to the brain and contributing to the development of dementia.
To minimize exposure to wildfire smoke, individuals can utilize air filtration systems like HEPA filters and wear KN95 or N95 masks when outdoors on poor air quality days. However, the study highlighted that individuals in high-poverty areas may face challenges in accessing these protective measures, emphasizing the need for broader societal investments in climate infrastructure.
The research also found that the increased risk of dementia associated with wildfire PM2.5 was more pronounced in individuals aged 60 to 75, potentially due to greater outdoor exposure to smoke. As wildfires continue to worsen due to climate change, the long-term health impacts of wildfire smoke are a growing concern. Canada has experienced escalating wildfire activity, with larger and more intense fires occurring in recent years.
In response to the escalating wildfire threat, institutions like McGill University have established initiatives like the McGill Centre for Climate Change and Health to address the health challenges posed by climate change. As wildfires are projected to intensify over time, proactive measures to reduce exposure and mitigate risks are crucial in safeguarding public health.
