Canadian cardiologists have discovered that even moderate levels of air pollution from particulate matter and nitrogen oxides may increase the risk of plaque buildup in the coronary arteries.
The Radiological Society of North America's press office noted that doctors found that moderate levels of air pollution increase plaque formation in the coronary artery by 13% and raise the likelihood of coronary heart disease by 23%.
Professor Kate Hanneman from the University of Toronto said: "One of the largest studies we have conducted using cardiac computed tomography showed that the likelihood of developing severe forms of coronary heart disease is significantly higher in people living in areas with moderate levels of air pollution, which is common in many developed countries."
The researchers reached these conclusions after monitoring the health of 11,100 pre-retirement and retirement patients who were followed up in three major hospitals in Toronto between 2012 and 2023. All participants underwent periodic cardiac CT scans, which allowed scientists to study the effect of variations in pollution levels within a large city on cardiovascular health.
To achieve this, researchers compared the incidence of coronary artery disease and other heart complications among participants with the levels of particulate matter and nitrogen oxides (NO₂) in the neighborhoods where they lived during the study period. They found that even moderate concentrations of the pollutants, around 7.5 micrograms per cubic meter and 12 parts per billion, were associated with significant effects on disease progression.
The results showed that an increase of one microgram per cubic meter in particulate matter concentration was associated with an 11% increased risk of accelerated calcium deposition in the coronary artery walls, a 13% increased likelihood of new cholesterol plaque formation, and a 23% increased risk of coronary artery occlusion. The same increase in nitrogen dioxide concentration was also associated with a 4% increased risk of complications, particularly in men.
Scientists confirm that these effects were recorded at pollution levels lower than or close to the environmental standards adopted in Canada, indicating that even pollution levels that are supposedly safe may negatively affect the cardiovascular health of the most vulnerable groups.
