Even young, healthy adults can suffer blood vessel damage from air pollution, a new study finds.
Periodic exposure to fine particulate matter -- tiny pollutants from cars, factories, power plants and fires -- isn't a health risk only for the ill and the elderly, the researchers concluded.
Tiny particles of air pollution can damage the inner lining of veins and arteries in young and healthy people, putting them at greater risk of heart disease, stroke and high blood pressure, according to new research.
Air pollution is thought to cause the premature deaths of about 40,000 people a year in the UK, with children and older people with medical conditions thought to be the most at risk.
But the new study suggests that healthy people in their twenties are also being harmed by the particles.
The study revealed how air pollution actually affects the blood vessels to increase the risk of disease, which was previously unknown.
The researchers found that periodic exposure to fine particulate matter was associated with several abnormal changes in the blood that are markers for cardiovascular disease.
As air pollution rose, they found small, micro-particles indicating cell injury and death significantly increased in number, levels of proteins that inhibit blood vessel growth increased, and proteins that signify blood-vessel inflammation also showed significant increases.
"Although we have known for some time that air pollution can trigger heart attacks or strokes in susceptible, high-risk individuals, the finding that it could also affect even seemingly healthy individuals suggests that increased levels of air pollution are of concern to all of us, not just the sick or the elderly," said Aruni Bhatnagar, Professor at the University of Louisville in Kentucky, US.
Research into the effects of air pollution on human health is often done by comparing air quality with the health of the local population.
But in the new study, published in the journal Circulation Research, a group of 72 people with an average age of 23, from the city of Provo in Utah, provided blood samples during the winters of 2013, 2014 and 2015.
When air pollution rose, the scientists found that the number of fragments of dead cells in their bloodstream increased.
Scientists are uncertain whether the PM2.5 particles, as they are known, are able to get into the bloodstream themselves or whether they damage the lungs, which then has a knock-on effect.
The study was published in the journal Circulation Research.