Diesel fumes raise risk of strokes and heart attacks

DIESEL fumes increase the risk of heart attacks and strokes by damaging the body’s protective cholesterol, research suggests.

Breathing in black carbon – the tiny, sooty particles particularly linked to diesel exhaust – reduces levels of ‘good’ HDL cholesterol thought to protect the heart and arteries, experts said.

A US study found that three months of exposure to high air pollution was enough to see HDL levels fall.

Medical experts are increasingly aware of the impact of diesel air pollution fumes on human health, including the risk of asthma. The new study explains why they might also raise the risk of heart disease.

Study leader Dr Griffith Bell, from the University of Washington in Seattle, said the damage can happen at comparatively low levels of air pollution. Dr Bell, whose work is published in the journal Arteriosclerosis, Thrombosis and Vascular Biology, suspects black carbon attacks HDL.

This results in higher quantities of harmful fat forming in vessels and raising the risk of a clot, blocking off blood supply to the heart or brain.

In a study of 6,654 middleaged and elderly Americans, those living in areas with high levels of traffic-related air pollution tended to have lower HDL levels.

Higher exposure to black carbon over a year was significantly associated with less HDL. More exposure to other particulate matter for three months was also linked with a lower HDL particle number.

Air pollution is linked to 40,000 UK deaths every year. Ministers are due to publish new air quality plans later this month.

‘Damage at low levels of pollution’