July 24, 2024
Generally, when thinking of stress, the causes are often school, work, finances, or other personal challenges. But what if the air we breathe contributes to the stress our body feels?
Most of us are exposed to air pollutants everyday, both inside and outside our homes, and what is in the air we breathe has an impact on our health. In Canada, over 17,000 people die prematurely because of air pollution each year. Research shows that air pollution is linked to many health conditions including type 2 diabetes, obesity, dementia, depression, anxiety, and even stress.
While we have learned about some of the common health effects of air pollution, we need to learn more about how poor air quality can lead to conditions that go beyond effects on the lungs and heart.
Errol Thomson, a toxicologist at Heath Canada, leads the Inhalation Toxicology Lab, where he and his team are studying the underlying effects of air pollution to understand how it affects our health. He says, “Air pollution doesn’t only affect our lungs; rather, it appears likely that virtually every cell in our body is affected by air pollution.”
The link between stress and air pollution
During Errol’s research, the team found that when air pollutants are inhaled, the body responds by producing cortisol, similarly to what happens when we are stressed. While cortisol plays many important roles in the body – including being involved in the fight-or-flight response – too much or too little cortisol can be a bad thing. This stress response may be one of the ways through which air pollution is impacting human health. Just like chronic stress, chronic exposure to air pollution is not good for us.
One of the ways that Errol’s team demonstrated this stress-like impact from air pollution was through a collaborative study with University of British Columbia researchers. In the study, participants (some with respiratory conditions) inhaled clean air or polluted air for short periods of time. Every time they would come into the lab, the participants were exposed to either the clean or polluted air. However, they didn’t know what they were inhaling.
The study showed that those breathing in the pollutants had increased levels of cortisol. Participants with asthma had a greater increase in their cortisol levels, indicating that they might be more sensitive to the effects of pollutants.
Errol and his team now want to find out the effects of specific air pollutants, as well as how individual differences and stressors can affect the body’s response to exposure to air pollution.
Modeling effects of pollutants on the human body
This air-liquid interface exposure system serves as the artificial lung in Errol’s research.
A close up of the area were lung cell models sit, showing the device attached that measures the amount of pollution to which the lung-like cells are exposed.
Over the years, the team developed an innovative system to model the relationship between the environment and the lung. This artificial lung system can test the effects of air pollution, helping understand how the body responds to pollution without actually testing directly on humans.
This is done by first getting lung cells from various people, with and without health conditions. Then, the cells are placed in a machine that exposes the cells to air and pollution, in a similar environment as in the body.
In other research, Errol and his team are using data from the Canadian Health Measures Survey (CHMS) to create an index of the impact of stressors on people living in Canada. Their research looks at various factors – including air pollution - that collectively take a toll on the body. The index also recognizes certain subpopulations to understand who might be more sensitive to these stressors.
Modeling something as complex as effects of air pollutants on the human body is tough work! There are researchers around the world tackling this important work, and Errol and his team integrate those international advancements in their work to generate evidence that can be used to protect the Canadian public. After all, “we don’t get to choose the air we breathe,” says Errol.