A few summers ago, during British Columbia’s worst-ever wildfire season, Dr. Sarah Henderson began to receive worried messages from the families and friends of people with dementia.
“They were telling us, ‘My dad has Alzheimer’s, and he seems more confused than usual,’” she recalls. “The stories were coming from all over. At first, we weren’t sure what to make of them.”
A professor at the UBC School of Population and Public Health (SPPH) and Scientific Director of Environmental Health at the B.C. Centre for Disease Control (BCCDC), Dr. Henderson is a leading expert on the health effects of air pollution, extreme heat and other climate-sensitive hazards in the province.
But this was something new. Could wildfire smoke affect cognitive function?
She reached out to Dr. Chris Carlsten, the director of UBC’s Air Pollution Exposure Laboratory (APEL) and a close colleague, for his opinion. Dr. Carlsten agreed it was possible, and not just in people with dementia.
“The thing about air pollution — whether it’s wildfire smoke or ozone pollution emitted by vehicles and factories — is that it affects basically every organ system in the body,” he explains.
“Climate change forces us to confront existing health inequities and think very hard and very creatively about how we can build a healthier and more equitable future for everyone.”
– Dr. Michael Brauer
As global temperatures rise, and climate hazards intensify, so does their toll on our physical and mental health. We experience more severe respiratory illnesses, worse cardiovascular disease, and increased anxiety and distress from the uncertainty that comes with disruption — as well as other issues we’re only just beginning to understand. These effects are further compounded by where we live, how much money we make, whether we belong to a marginalized community and other factors.
“The fact is, we can’t separate our health from the social and physical spaces we inhabit,” says UBC’s Dr. Michael Brauer, a leading global expert on environmental health and frequent collaborator with Drs. Henderson and Carlsten.
“That’s what makes climate change such a multi-faceted threat — one that requires far-reaching, even radical solutions.”
Together, Faculty of Medicine researchers are investigating how everything from our genes, to the design of our cities, to the geography of extreme weather events can interact to make us more vulnerable to the effects of climate change. Working in close collaboration with B.C. health authorities and colleagues around the world, they are translating this work into new tools and strategies to help protect our health, today and in the future.
It’s within this larger program of action-oriented research that Drs. Henderson and Carlsten set out to solve the puzzle of air pollution and brain health.
From DNA to demographics
Working with researchers from the University of Victoria, Dr. Carlsten designed a study that would map the neurological effects of air pollution. The team exposed 25 healthy adults to diesel exhaust for brief intervals in APEL’s state-of-the-art exposure booth, measuring brain activity before and after with functional magnetic resonance imaging (fMRI).
They discovered that even brief exposure — equivalent to a commuter sitting in busy traffic for a couple of hours on a high-pollution day — causes a temporary dip in the brain’s default mode network, the circuit of interconnected brain regions which plays an important role in memory and thinking.