We're used to thinking about the damage air pollution does to our lungs, but it's also bad for our hearts, even in small amounts.
People who live in areas with higher amounts of fine particles or higher amounts of nitrogen dioxide have noticeably larger hearts, British researchers found when they compared air pollution levels near people's homes to changes in the structure of their hearts. These were the results seen in people who were living in areas with air pollution levels that were on average far lower than those called for in the national guidelines.
Specifically, the study found evidence of stretching and thinning of the heart's ventricles, changes that impair its ability to pump blood. These changes increased as air pollution levels rose. An enlarged heart is usually a sign that the heart has to work harder to pump blood. It can be a sign of impending heart failure.
“Doctors and the general public all need to be aware of their exposure when they think about their heart health, just like they think about their blood pressure, their cholesterol and their weight.”
In this study, people's average annual exposure to fine particles, often called PM2.5, was 9.9 micrograms per cubic meter. This is well below the acceptable maximum of 25 micrograms per cubic meter in the UK and even below the (current) U.S. standard of 12 micrograms per cubic meter. Yet at these low levels, more fine particles in the air still meant more heart enlargement.
“We can't expect people to move home to avoid air pollution — Government and public bodies must be acting right now to make all areas safe and protect the population from these harms,” said Jeremy Pearson, Associate Director of the British Heart Foundation, in a statement. That means considering air pollution a public health issue, not just an environmental one.
The study's lead author, Nay Aung, a clinical research fellow at Queen Mary University of London's William Harvey Research Institute, adds, “Air pollution should be seen as a modifiable risk factor. Doctors and the general public all need to be aware of their exposure when they think about their heart health, just like they think about their blood pressure, their cholesterol and their weight.”
Many studies show or suggest that lowering air pollution can save lives. But clean air often takes a back seat to industrial growth, with clean air legislation a favorite target of industrial lobbyists and many elected officials.