Harvard study reveals how pollution raises risk of heart attack or stroke

By Stephen Beech via SWNS

Air pollution raises the risk of a fatal heart attack or stroke in middle age by triggering stress, warns new research.

The worrying findings suggest that "dirty air" puts under-65s in greater danger of dying from cardiovascular disease.

Study lead author Doctor Shady Abohashem, of Harvard Medical School, said: “Our study indicates that the air we breathe affects our mental well-being, which in turn impacts heart health."

Air pollution is estimated to have caused more than four million premature deaths worldwide in 2019, According to the World Health Organization (WHO).

Mental illness has also been previously linked with premature deaths.

The new study examined whether air pollution and poor mental health are interrelated and have a joint impact on death from cardiovascular disease.

Researchers focused on particles less than 2.5 micrometers in diameter, also referred to as fine particles or PM2.

Such particles come from vehicle exhaust fumes, power plant combustion, and burning wood, and present the highest health risk.

The research team analyzed county-level data on annual PM2.5 levels from more than 3,000 locations in the United States that are home to 315 million people,

Exposure to PM2.5 was categorized as high or low, according to WHO standards.

The team gathered data on the average number of days that county residents experienced mental health issues - such as stress, depression, and emotional problems.

Each county was then categorized into three groups based on the numbers.

The team then analyzed the associations between pollution, mental health, and premature cardiovascular deaths.

Counties with dirty air - high PM2.5 concentrations - were 10 percent more likely to report high levels of PMH days compared to counties with clean air (low PM2.5 concentrations).

The risk was "markedly" greater in counties with a high prevalence of minority groups or poverty.

The link between PMH and premature cardiovascular death was strongest in counties with higher levels of air pollution.

In those counties, higher levels of PMH were associated with a three-fold increase in premature cardiovascular death compared to lower PMH levels.

A third of the pollution-related risk of premature cardiovascular deaths was explained by increased burden of PMH, according to the findings.

Dr. Abohashem said: “Our results reveal a dual threat from air pollution: it not only worsens mental health but also significantly amplifies the risk of heart-related deaths associated with poor mental health."

He added: "Public health strategies are urgently needed to address both air quality and mental well-being in order to preserve cardiovascular health.”

The findings are due to be presented at the European Society of Cardiology (ESC) congress in Athens, Greece.