Air pollution hits women harder than men, according to a new study. Researchers say diesel exhaust fumes change components of blood affected by inflammation and infection — but these changes were greater among women.

Scientists at the University of Manitoba say levels of 90 proteins in the body were distinctly different in men and women following exposure to the fumes. Some of these proteins are known to play a role in inflammation, damage repair, blood clotting, heart disease and the immune system. The differences became clearer when volunteers were exposed to the higher levels of diesel exhaust.

Earlier research found sex differences in how air pollution affects lung diseases, such as asthma and respiratory infections.

For this latest study, the Canadian team recruited five men and five women, who were all healthy non-smokers. Each of them spent hours breathing filtered air and air containing diesel exhaust fumes at three different concentrations: 20, 50 and 150 micrograms of fine particulate matter per cubic meter. Participants were given a one hour break between each exposure.

Volunteers donated blood samples 24 hours after each exposure and the researchers made detailed examinations of the volunteers’ blood plasma. Plasma is the liquid component of blood that carries blood cells, as well as hundreds of proteins and other molecules around the body. Using a well-established analysis technology called liquid chromatography–mass spectrometry, the team looked for changes in the levels of different proteins after exposure to diesel exhaust and compared the changes in females and males.

“These are preliminary findings, however they show that exposure to diesel exhaust has different effects in female bodies compared to male and that could indicate that air pollution is more dangerous for females than males,” says study co-author Neeloffer Mookherjee, of the University of Manitoba in Canada, in a statement. “This is important as respiratory diseases such as asthma are known to affect females and males differently, with females more likely to suffer severe asthma that does not respond to treatments. Therefore, we need to know a lot more about how females and males respond to air pollution and what this means for preventing, diagnosing and treating their respiratory disease.”

The findings were presented at the European Respiratory Society’s (ERS) 2022 International Congress in Barcelona, Spain.

Zorana Andersen, from the University of Copenhagen in Denmark, is chair of the ERS Environment and Health Committee. She was not involved in the study, but notes that the work reveals valuable insights into how diesel exhaust affects men and women differently. “We know that exposure to air pollution, especially diesel exhaust, is a major risk factor in diseases such as asthma and chronic obstructive pulmonary disease,” she says. “There is very little we can do as individuals to avoid breathing polluted air, so we need governments to set and enforce limits on air pollutants. We also need to understand how and why air pollution contributes to poor health.”

Report by South West News Service writer Gwyn Wright.