Revealed, how diesel pollution causes heart attacks and strokes
POLLUTION from diesel engines triggers heart attacks and strokes by entering the bloodstream and inflaming damaged blood vessels, a study shows.
Nanoparticles – many times smaller than the width of a human hair – have long been associated with heart disease, but how inhaled particles affect blood vessels has remained a mystery. Now, scientists have found evidence that the nanoparticles can travel from the lungs into the bloodstream and accumulate in parts of the heart or in blood vessels already suffering from inflammation – which they may aggravate further.
By inflaming arteries and veins, the particles can contribute to fatal blockages. Air pollution, especially from traffic, is estimated to cause between 29,000 and 52,000 deaths a year in the UK.
Scientists have long suspected that fine particles travel from the lungs into the bloodstream, but evidence has been difficult to collect. Researchers at the University of Edinburgh and the National Institute for Public Health and the Environment in Holland tracked inhaled gold nanoparticles, which do not cause health problems to volunteers. Carbon nanoparticles from diesel exhaust can’t be tracked.
In the British Heart Foundation-funded study, published in the journal ACS Nano, 14 healthy volunteers and 12 surgical patients inhaled gold nanoparticles. Within just 24 hours, the nanoparticles were detected in blood and urine. The particles were still detectable three months later.
In a further study, stroke patients with blockages in their carotid arteries – the major artery in the neck – about to undergo surgery were asked to breathe in a quantity of the nanoparticles.
When the fatty ‘plaques’ blocking the artery were removed, they were found to have accumulated large numbers of nanoparticles – high-
‘Serious health consequences’
lighting how they end up in diseased areas. Lead researcher Dr Mark Miller, from the University of Edinburgh, said: ‘We show that gold nanoparticles can get into the blood and that these particles appear to preferentially accumulate at sites of disease.
‘These findings suggest that ultra-fine nanoparticles in air pollution may well do the same thing. They will enter the blood and accumulate at sites of vascular disease. It doesn’t take large amounts of these particles. If they reach these susceptible areas it can have serious health consequences.’
The UK Government will ask the High Court today for permission to delay publishing its draft plan for tackling air pollution until after the June 8 election.