“We already know that there are sex differences in lung diseases such as asthma and respiratory infections,” said lead researcher Hemshekhar Mahadevappa, from the University of Manitoba in Winnipeg.
“Our previous research showed that breathing diesel exhaust creates inflammation in the lungs and has an impact on how the body deals with respiratory infections,” he said. “In this study, we wanted to look for any effects in the blood and how these differ in females and males.”
To study the issue, the researchers recruited five women and five men, all of whom were healthy nonsmokers. They were then asked to spend four hours breathing filtered air and another four hours breathing air containing diesel fumes.
They did this three times, each four weeks apart, with different concentrations of fine particulate matter (PM2.5). The concentrations were 20, 50 and 150 micrograms per cubic meter. While the European Union limits PM2.5 emissions to 25 micrograms per cubic meter, cities commonly have more.
After each breathing experience, the volunteers donated blood samples 24 hours later.
Researchers examined the volunteers’ blood plasma — the liquid component of blood that carries blood cells, proteins and other molecules throughout the body. Using a technology called liquid chromatography–mass spectrometry, the researchers looked for changes in the levels of different proteins following exposure to diesel exhaust. They then compared the changes in men and women.
The team found levels of 90 proteins that were distinctly different between female and male volunteers after exposure to diesel exhaust, with more changes seen in females.
Some of those differing proteins are known to be involved in inflammation, damage repair, clotting, heart disease and the immune system. Some of these differences were clearer with higher levels of diesel exhaust.
The findings were presented at the European Respiratory Society annual meeting, in Barcelona. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
“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,” said researcher Neeloffer Mookherjee, of the University of Manitoba.
“This is important as respiratory diseases such as asthma are known to effect females and males differently, with females more likely to suffer severe asthma that does not respond to treatments,” Mookherjee explained in a meeting news release. “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.”
“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. 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,” said Zorana Andersen, from the University of Copenhagen. She is chair of the European Respiratory Society Environment and Health Committee.
The U.S. Environmental Protection Agency has more on particulate matter pollution.
SOURCE: European Respiratory Society, news release, Sept. 1, 2022