Diesel pollution 'clogs arteries'

Diesel fumes appear to combine with artery-clogging fats to raise the risk of heart disease, research published in the online journal Genome Biology suggests.

UCLA scientists found the two act in concert to switch on genes that cause potentially dangerous inflammation of the blood vessels.

The results suggest that government incentives - such as cheaper road tax - to encourage people to buy diesel cars in order to reduce carbon emissions is likely to be having a directly adverse effect on human health.

Yet it's far from proven that reducing human carbon emissions will have any effect whatsoever on the planet's climate.

Lead researcher Dr André Nel, an expert in nanomedicine, said the impact of diesel particles and cholesterol fats combined was much greater than the impact of each in isolation.

He said: "Their combination creates a dangerous synergy that wreaks cardiovascular havoc far beyond what's caused by the diesel or cholesterol alone."

Both are sources of molecules called free radicals which cause cell and tissue damage, and can trigger the inflammation that leads to artery disease.

The researchers combined the pollutants and fats and cultured them with cells taken from the inner lining of human blood vessels.

A few hours later, they extracted DNA from the cells for genetic analysis. They showed that the genes that promote cellular inflammation had been activated.

Then they exposed mice with high cholesterol to the diesel particles, and saw that some of the same genes were activated in the animals' tissue.

Dr Nel said: "Exactly how air pollutants cause cardiovascular injury is poorly understood.

"But we do know that these particles are coated with chemicals that damage tissue and cause inflammation of the nose and lungs.

"Vascular inflammation in turn leads to cholesterol deposits and clogged arteries, which can give rise to blood clots that trigger heart attack or stroke."

If the government turns out to be wrong about the cause of climate change, and global warming is not related to man-made carbon emissions, then they will have to take responsibility for pursuing policies likely to have caused thousands of people major health problems.

This study certainly destroys any claim by London mayor Ken Livingstone - in seeking to reduce the number of petrol cars on the road through congestion charging, yet needlessly packing the roads with diesel buses - to be motivated by a desire to improve air quality or human health.