Air pollution — the evidence is mounting
While most people know air pollution is linked to lung problems few realise its devastating impact on the heart and circulation — otherwise known as our cardiovascular system. Alarmingly, almost six in ten deaths related to air pollution worldwide are due to heart disease or stroke.
This month, the Committee on the Medical Effects of Air Pollutants (COMEAP) released a landmark report — the most extensive review of the research into the impact of air pollution on cardiovascular health to date.
The report was put together by a group of experts who were determined to uncover just how unacceptable levels of air pollution are damaging the world’s heart and circulatory health.
So what did they find?
The report pointed to a well-known culprit; fine particle pollution, also known as particulate matter, as the primary pollutant affecting the heart and circulation. Particulate matter is a pollutant made up of tiny particles that can get into the bloodstream and affect the whole body. BHF-funded research shows that one of the smallest of these, PM2.5, which is around 1/20th the width of a human hair, can carry many toxic chemicals on their surface.
We know from BHF research that these fine particles can enter the bloodstream via the lungs. Once there, dangerous chemicals on their surface have a perfect path to the body’s most vital organs.
The report showed that air pollution does not damage the heart and circulation in just one or two ways. It’s likely many processes work together ‘in concert’ to produce the wide ranging effects of air pollution throughout the cardiovascular system.
These toxic chemicals in air pollution cause widespread inflammation in blood vessels. Scientists believe this contributes to the build-up of plaques which eventually lead to a heart attack or stroke.
Air pollution also raises blood pressure. Blood pressure is the pressure of blood in arteries. When someone’s blood pressure is too high, for a long period of time, it can damage blood vessels throughout their body, and put them at increased risk of a heart attack or stroke. The report authors said that even small increases in blood pressure sustained over time in a large group of people is enough to lead to a significant increase in the number of heart attacks and strokes.
The report also found that air pollution makes blood more likely to clot. Blood clots are vital. They stop us from losing too much blood from cuts and wounds. But when they happen inside the blood vessels, they can have devastating effects, causing heart attacks, strokes and even vascular dementia.
And it’s not just about the blood; air pollution also changes the ‘electrical circuit’ in the heart, and alters the heart’s natural rhythm. This can lead to abnormal heart rhythms known as arrhythmias — where the heart beats too fast, too slow, or with an irregular pattern.
Individually these changes may be relatively small, but together they paint a worrying picture. And this comes as WHO figures reveal that 9 in 10 children worldwide are being exposed to toxic levels of air pollution. We are at breaking point.
We want to see the UK government commit to WHO guideline limits for particulate air pollution. Right now, the the UK’s legal limits are more than double those recommended by WHO. If we’re to protect the nation's health, we need urgent action and changes to law.
Having these targets in law will also help to improve the lives of those currently living with heart and circulatory diseases, and prevent thousands of premature deaths every year.