Air pollution linked to more severe heart disease in women

Long-term air pollution exposure is linked to more advanced heart disease, with notable differences between women and men, a large-scale study has found.

The findings show that even levels of pollution below or near regulatory standards are associated with early signs of disease, often before symptoms appear.

Felipe Castillo Aravena, study lead author and cardiothoracic imaging fellow at the University of Toronto, said: “Even at low exposure levels, air pollution is associated with more plaque in the coronary arteries.

“Overall, higher long-term exposure to air pollution was associated with more coronary artery disease on cardiac CT in both women and men.

“In women, long-term exposure to fine particulate matter was linked to higher calcium scores and more severe narrowing of the arteries.

“In men, higher long-term exposure to fine particulate matter was associated with higher calcium scores and higher plaque burden.”

Researchers analysed data from more than 11,000 adults who had undergone cardiac CT exams from 2012 through 2023 across three major hospitals in Toronto.

They linked patients’ residential postal codes with air quality data to estimate each person’s average exposure over the 10-year period prior to CT.

The study examined exposure to two common pollutants: fine particulate matter (PM2.5), tiny particles from vehicle exhaust, industrial emissions and wildfire smoke that can penetrate deep into the lungs and bloodstream, and nitrogen dioxide (NO2), a harmful gas produced mainly by burning fossil fuels.

For each increase in long-term PM2.5 of 1 microgram per cubic metre, there was an 11 per cent increase in calcium build-up in the coronary arteries, 13 per cent greater odds of more plaque and 23 per cent greater odds of obstructive disease.

Exposure to nitrogen dioxide showed similar trends, though with smaller effect sizes for every 1 part per billion increase.

Kate Hanneman, study senior author and cardiac radiologist at the University of Toronto, said: “Heart disease is the number one cause of death globally.

“The results of this study add to the growing body of evidence that air pollution is a modifiable cardiovascular risk factor and reinforce the need for further research to understand why these associations differ between men and women.”