Scientists are now warning drivers that car fumes and braking too hard are causing a sudden spike in heart attacks.
According to a new study, fumes from vehicle exhausts caused by heavy braking increase the risk of a driver getting a heart attack.
Researchers looked at the links between air pollution from traffic, such as nitric oxide and particulates, and the number of heart attacks.
Dailymail.co.uk reports: Nitric oxide (NO) originates from combustion at high temperatures, in particular from diesel engines.
Combustion, abrasion from brakes and tires, and dust are also sources of harmful particulates.
Analysis of 18,000 Berliners revealed higher daily levels of NO increased incidence of heart attacks.
Smokers appeared unaffected by smog perhaps because they already inhale toxic fumes, experts said.
Professor Sir Nilesh Samani, of 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.’
Up to 11,000 UK deaths from heart disease and circulatory conditions, a year may be caused by air pollution.
The European Society of Cardiology will hear the findings this week.
It was also found heart attacks fell in hot weather.
Every 10C rise in temperature was associated with a 6 percent lower incidence.
The study included 17,873 patients who suffered a heart attack between 2008 and 2014.
Study author Dr Insa de Buhr-Stockburger, from the Berlin Brandenburg Myocardial Infarction Registry (B2HIR), said: ‘The correlation between air pollution and heart attacks in our study was absent in smokers.
‘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.’
She added: ‘The study indicates that dirty air is a risk factor for acute myocardial infarction [heart attacks] and more efforts are needed to lower pollution from traffic and combustion.
‘Causation cannot be established by an observational study.
‘It is plausible that air pollution is a contributing cause of myocardial infarction, given that nitric oxide and PM10 promote inflammation, atherosclerosis is partly caused by inflammatory processes, and no associations were found in smokers.’
Heart and circulatory disease cause 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 hospitals in England after a heart attack.