Fumes from exhausts and harsh braking may 'significantly increase heart attack risk'

Fumes from exhausts and harsh braking may significantly increase the risk of heart attacks, a major study suggests.

German research on almost 18,000 people found close links between increases in nitric oxide, a common pollutant caused by traffic, and the chance of suffering an attack.

Every 10 μg increase in daily levels of air pollution increased incidence of heart attacks by one per cent, while a three day spell of high levels of pollution raised the risk by four per cent.

Researchers said smokers did not appear to be affected by smog, which was probably because they were already continuously inhaling toxic fumes.

It follows warnings that up to 11,000 deaths from heart disease and circulatory conditions in the UK may be caused by air pollution annually.

The findings, which will be presented to the European Society of Cardiology’s annual congress in Barcelona this weekend, also found heart attacks fell in hot weather.

Every 10C rise in temperature was also associated with a 6 per cent lower incidence in heart attacks.

The study included 17,873 patients who suffered a heart attack between 2008 and 2014.

'Dirty air is a risk factor'

Dr Insa de Buhr-Stockburger, the study author from the Berlin-Brandenburg Myocardial Infarction Registry, said the research indicated that "dirty air is a risk factor" for heart attacks.

"More efforts are needed to lower pollution from traffic and combustion," she said.

While the study was observational and could not prove a causal relationship, she said it was plausible that the pollutants increased the risk of heart attacks by promoting inflammation in the body.

"The correlation between air pollution and heart attacks in our study was absent in smokers," she said.

"This may indicate that bad air can actually cause heart attacks since smokers, who are continuously self-intoxicating with air pollutants, seem less affected by additional external pollutants."

The study examined levels of nitric oxide and particular matter.

Experts recorded one per cent more events for every 10 μg per m3 increase in daily nitric oxide levels. And there was a four per cent jump for every 10 μg per m3 jump in PM10 [air pollutant] concentrations over the preceding three days.

80,000 admitted a year to English hospitals after heart attacks

Heart and circulatory disease causes one in four deaths in the UK, with one in eight men and one in 14 women dying from this cause. Every year, 80,000 people are admitted to hospital in England after a heart attack.

Diesel is a particular source of such pollutants, along with abrasion from brakes, tyres and dust.

Professor Sir Nilesh Samani, the medical director at the British Heart Foundation, said: "These findings add to evidence that dirty air is linked to a higher risk of heart attacks in non-smokers.

"The association is not seen in smokers, and it’s suggested this could be because smokers already breathe in pollutants regularly.

"However, this study can’t prove causation, and other factors could be at play.

"Up to 11,000 heart and circulatory deaths in the UK are attributable to air pollution each year, so we need more research to further understand the link between dangerous polluting particles and an increased risk of heart attacks in non-smokers.”