Protecting our health from air pollution

Air pollution takes an estimated six months off the average life expectancy in the UK, and is associated with up to 11,000 heart and circulatory deaths every year.

Globally, air pollution is attributed to 1 out of every 5 deaths from heart attack and stroke. We’ve been working for over a decade to understand how air pollution damages the heart and blood vessels, and using the evidence to lobby for improvement in air quality.

Showing why air pollution is a problem

BHF-funded researchers were among the first to show how exposure to air pollution damages the heart and blood vessels.

Air pollution is caused by many different things, including car exhaust fumes, dust from car brakes and tyres, burning fuels in factories or power plants, and wood or coal fires in homes. In the last 10 years, researchers have taken a particular interest in fine particulate matter known as PM2.5. These are made up of particles smaller than 2.5 micrometres across, more than 100 times thinner than a human hair. PM2.5 caused by a variety of sources, including heavy industry and road traffic, especially diesel exhaust.

In 2005, we funded BHF Professor David Newby and his team at the University of Edinburgh to work with researchers at Umea University in Sweden to investigate the effects of air pollution from diesel vehicles on the heart and blood vessels. The team found breathing in diesel fumes at the levels found in a polluted city stops blood vessels relaxing and encourages blood to clot. The team also found that exposure for as little as an hour produces these damaging effects, which remained for more than 24 hours after exposure had ended.

In 2015, the team also found strong evidence of a link between exposure to PM2.5 and poor cardiovascular health. Short-term exposure to high levels of particulate matter has been linked with an increase in the risk of having a stroke in the following week.

But researchers didn’t know how air pollution end up affecting our heart and blood vessels. For example, do inhaled pollutants enter the bloodstream to cause damage? It’s not currently possible to reliably detect small particles from exhaust fumes in blood. To work around this problem, a team of researchers at the University of Edinburgh led by Dr Mark Miller and Professor Newby asked healthy volunteers and people with fatty plaques to breathe in harmless tiny gold particles, the same size as particles created by diesel vehicles. This 2017 study found that gold had moved from the lungs into the volunteers’ blood and urine after 24 hours, and stayed in the blood for up to three months. The research team also found that nanoparticles built up in the fatty plaques of diseased arteries. These fatty plaques are part of the process that can lead to heart attacks and strokes, so this finding helps us to understand more about how air pollution leads to heart attacks and strokes.

Campaigning for clean air

The BHF has been highlighting these research findings to the Government to ensure a better understanding of the link between exposure to PM2.5 and poor heart and circulatory health. We were pleased to see that the Clean Air Strategy, published in 2019, recognised the huge health burden of air pollution and pledged to reduce the most harmful pollutants. But we believe that there is more that can be done to tackle this urgent problem.

That’s why we launched a campaign in 2020, called ‘We’re all full of it’. The campaign calls for the World Health Organization’s (WHO) guideline limits for PM2.5, which are much stricter than the limits we currently adhere to, to be adopted into law with a target of reaching these by 2030. The campaign launch coincided with the Government introducing the Environment Bill, which commits to the introduction of new limits on PM2.5, but stops short of including the WHO guidelines. We will continue to push for these limits to be introduced as soon as possible.

First published 1st June 2021