Poor air quality is the largest environmental risk to public health in the UK. But while the effects of air pollution on the lungs have been known for more than half a century, researchers are now seeing the range of its impact on heart health.
Dr Mark Miller, a research scientist funded by the British Heart Foundation, explains the impact that air pollution has on the heart, as well as our blood and blood vessels.
Mark Miller
“Scientists knew that air pollution had an impact on the lungs, but there was increasing evidence that diseases of the heart, the blood vessels and the blood are associated with air pollution” says Dr Miller, who began exploring the impact of air pollution at the University of Edinburgh almost 20 years ago.
How air pollution affects our hearts
Cars and vans queueing in heavy traffic on a busy London road
“A lot of people think that what comes out of a vehicle exhaust is just soot, but it is not, it is actually hundreds of thousands of different chemicals, many of which are likely to be harmful to the body,” he says.
We now know that some of the smallest particles, called ultra-fine particles, can enter the bloodstream and travel around the body: “That is perhaps why we are starting to see that air pollution has effects all over the body: in the brain, the kidneys, on unborn babies, and more.
“These particles not only reach the different organs of the body, but they seem to build up in inflamed blood vessels where they are going to cause the most harm.” Thanks to funding from the British Heart Foundation, Dr Miller has focused on how breathed-in particles contribute to cardiovascular disease.
“We were rather surprised; when we first started this, we thought maybe we would see some effects on the heart and circulation because of the similarities to smoking. What we found is that air pollutants had so many detrimental effects throughout the cardiovascular system,” he says.
The effects of air pollution include stopping blood vessels relaxing and contracting, as well as increasing blood pressure, which affects the flow of blood around the body. Air pollution also increases the risk of blood clots (as well as preventing the body from getting rid of clots), alters the rhythm of the heart and makes the heart more susceptible to damage from blocked arteries.
Dr Miller stresses that even short exposure to air pollution can cause these to happen in healthy people. “They will make you more likely to get cardiovascular disease or heart disease. And if you are somebody who already has heart disease, the chances are you are more likely to get a heart attack or stroke.”
Nitrogen dioxide, another pollutant from vehicle emissions, tends to affect the lungs, he adds, but “long-term exposure to nitrogen dioxide is linked to cardiovascular disease and diseases of other parts of the body.”
So what can be done?
According to Dr Miller, there are ways to limit your exposure to air pollution: if you’re walking or cycling, alter your journey to avoid busy roads or travel at quieter times if you can, for example.
But the measures individuals can take to avoid polluted air are limited which make reducing the amount of air pollution so important – and that is why the British Heart Foundation supports the expansion of London’s Ultra Low Emission Zone (ULEZ).
What is the ULEZ?
From 29 August 2023, the ULEZ will be expanded to create one single zone across all London boroughs, to help clear London’s air and improve health.
9 out of 10 cars seen driving in Outer London on an average day meet the ULEZ standards, so their drivers will not need to pay the charge. But, if you drive a petrol vehicle over 16 years old or a diesel vehicle over 6 years old you need to check if you’re affected. The easiest way to check is to use TfL’s simple vehicle checker:tfl.gov.uk/check-your-vehicle
Londoners on certain low income or disability benefits may be eligible to receive a payment to scrap their vehicle through the Mayor of London’s £110m scrappage scheme. London-based sole traders, businesses with up to 10 employees and registered charities can also apply to scrap or retrofit their van or minibus. Scrappage scheme funds are limited, and payments will be awarded on a first come first served basis, so we encourage eligible Londoners to apply now. Some disabled drivers and vehicle types may also qualify for a grace period (temporary exemption) from the ULEZ.
For more information on the ULEZ expansion, including an interactive map to check your postcode, click here
