Millions of Britons face increased stroke risk due to dirty air, study suggests
Millions of Britons face a higher risk of stroke or heart failure because of air pollution, with those in the worst-affected areas 7 per cent more likely to suffer strokes.
People living in the most polluted areas also faced a 27 per cent greater risk of developing heart failure compared with those in areas with the cleanest air, new research revealed.
The findings come from a decade-long study of 299,323 people between 2010 and 2020, presented at the European Society of Cardiology conference in Madrid.
Ghita Housni, the study’s lead author, said: “We know cleaner air means healthier hearts, and this research lays bare the impact of air pollution on public health.
“Reducing your exposure to air pollution is a crucial part of preventing heart conditions in the modern age and lowering your risk of heart failure and stroke.
“We need to improve air quality by introducing public health strategies which strongly prioritise cardiovascular protection.”
Researchers analysed UK Biobank data, measuring average levels of PM2.5 – fine particles from vehicles, industry and heating systems that are around 30 times smaller than the width of a human hair.
These particles are small enough to pass into the bloodstream after being inhaled, causing inflammation in blood vessels which can raise blood pressure and increase stroke risk.
The study found that for every extra microgram of PM2.5 in an area, the risk of developing heart failure rose by 7 per cent and stroke risk by 3 per cent.
Those living in the worst 10 per cent of areas for PM2.5 pollution faced markedly higher risks after researchers adjusted for factors including age, sex, ethnicity, residential setting, deprivation, education, smoking and alcohol use.
The team reported one additional stroke case per 100 people in the most polluted areas compared with the cleanest, and two additional cases of heart failure per 100 people in the dirtiest areas.
There was also a slight increase in the risk of heart attack with higher PM2.5 levels, though the link was not statistically significant.
When PM2.5 particles are inhaled, the immune system overreacts, causing inflammation that stiffens blood vessels and increases fatty build-up.
This forces the heart to pump harder through inflamed vessels, which over time can weaken the heart and lead to failure.
The findings are significant because the increased risks of stroke and heart failure were recorded even after researchers adjusted for a wide range of factors.
The team analysed the data without identifying specific locations, so the results do not show which areas of the UK may pose the greatest health risks.
Despite a 30 per cent reduction in PM2.5 levels since 2015, UK safety limits are still breached, with an average of 22 days each year when levels exceed World Health Organization targets.
Dr Sonya Babu-Narayan, clinical director at the British Heart Foundation, said: “We know there are no safe levels of air pollution.
“These early findings linking high PM2.5 levels to heart failure add to a growing body of evidence that poor air quality is damaging to our hearts.
“It’s good to know that the kind of PM2.5 levels experienced by the people in this study have already improved since the introduction of government targets in 2021.
“Nevertheless, these levels still exceed World Health Organization guidelines.
“Going further to reduce air pollution could help the UK to prevent premature cardiovascular disease, and save and improve lives for current and future generations.”
