Air pollution linked to heart attacks, strokes

Air pollution thickens the blood and boosts inflammation, increasing the risk of heart attacks and strokes, researchers have found.

The New Zealand city worst affected is Christchurch, where the city's main hospital has noted a surge in admissions for heart attacks, strokes and respiratory problems each winter, particularly after nights of high air pollution.

A 2000 mortality study estimated that up to 55 deaths in Christchurch each winter could be caused by air pollution.

Now Scottish research, published in the Occupational and Environmental Medicine journal, helps explain why pollution affects our health.

The Edinburgh University team tested the inflammatory and blood clotting responses of human immune cells and umbilical cord and lung cells, six and 24 hours after exposure to particles of the type found in smog.

Their results showed that clotting factors, which thicken the blood, were enhanced in almost all the cell types.

The rate of death in immune cells also rose, and exposure to the pollutants boosted inflammatory activity.

The authors say their findings suggest that smog particles can alter cell function so it promotes thickening or coagulation of the blood.

Canterbury Respiratory Research Group director Dr Michael Epton said it had been known for some time that air pollution was linked to increased cardiovascular and respiratory admissions to hospital.

It had been harder to explain what was happening in the body to cause this.

"This new research provides some answers for why problems may occur during times of high air pollution."

Dr Epton said the solution was to try to reduce Christchurch's air pollution.

The city's smog is expected to breach maximum levels set by the Government's compulsory National Environmental Standards, which come into effect on October 1 and get progressively tougher until 2013.

- NZPA