Air pollution linked to increased risk of stress and depression

Air pollution linked to increased risk of stress and depression

Breathing polluted air could affect mental health, and by extension increase the risk of death from cardiovascular disease. This is what a new study carried out by American researchers reveals, covering no less than 300 million people living in the United States.

Is there still a place in the world where people breathe healthy air, free of pollution? Not sure, according to the World Health Organization (WHO), according to which 99% of men, women and children in the world “breathe air whose values ​​exceed (its) recommendations and which contains high levels of pollutants“. The health authority estimates 4.2 million premature deaths linked to outdoor air pollution worldwide in 2019, and 6.7 million premature deaths linked to outdoor air pollution. indoor and outdoor air. The majority of these deaths are associated with cardiovascular diseases.

Is particle pollution bad for our mental health?

American researchers have worked on the subject, carrying out a study on more than 3,000 counties in the United States, or 315 million inhabitants. Published by the European Society of Cardiology (ESC) on the occasion of its scientific congress, ESC Preventive Cardiology 2024, this work establishes a link between air pollution and the risk of stress and depression, which would increase significantly increased the risk of death from cardiovascular disease in people aged under 65. “Our study indicates that the air we breathe affects our mental well-being, which in turn impacts heart health“, immediately explains Dr Shady Abohashem, professor at Harvard Medical School, in Boston, in the United States.

While most scientific studies attempt to assess the impact of air pollution on physical health, this one initially focused on a potential association between pollution and mental health. Then, secondly, on the influence that this could have on the risk of cardiovascular diseases. To do this, the researchers focused on particles with a diameter of less than 2.5 micrometers, fine particles, whether they come from vehicle exhaust gases or the combustion of power plants, considered harmful to respiratory and cardiovascular health.

Harmful to mental health

The scientists collected several data from the Centers for Disease Control and Prevention (CDC) concerning 3,047 American counties: the annual levels of fine particles, which were classified according to WHO recommendations, as well as the average number of days during which the residents concerned suffered from mental health problems. As a result, the counties most affected by ambient air pollution are also those which report the most days during which the population suffers from mental health disorders (+10%).

The researchers also specify that the link between poor mental health and premature cardiovascular mortality was higher in the most polluted counties. In detail, higher levels of mental health disorders were linked to three times more premature cardiovascular mortality in counties with the most polluted air. An observation which encourages scientists to call for the implementation of strategies concerning outdoor air pollution but also the mental health of populations.

Our results reveal a double threat linked to air pollution: not only does it deteriorate mental health, but it also significantly amplifies the risk of cardiac death associated with poor mental health. There is an urgent need for public health strategies addressing both air quality and mental well-being to preserve cardiovascular health“, concludes Dr Shady Abohashem, main author of this work.