Dirty air triggers more heart attacks than cocaine

LONDON Thu Feb 24, 2011 8:19am EST

Thick pollution can be seen as a man rides his bicycle across the main road running through Beijing's Tiananmen Square February 21, 2011. REUTERS/David Gray

Thick pollution can be seen as a man rides his bicycle across the main road running through Beijing's Tiananmen Square February 21, 2011.

Credit: Reuters/David Gray

LONDON (Reuters) - Air pollution triggers more heart attacks than using cocaine and poses as high a risk of sparking a heart attack as alcohol, coffee and physical exertion, scientists said on Thursday.

Sex, anger, marijuana use and chest or respiratory infections and can also trigger heart attacks to different extents, the researchers said, but air pollution, particularly in heavy traffic, is the major culprit.

The findings, published in The Lancet journal, suggest population-wide factors like polluted air should be taken more seriously when looking at heart risks, and should be put into context beside higher but relatively rarer risks like drug use.

Tim Nawrot of Hasselt University in Belgium, who led the study, said he hoped his findings would also encourage doctors to think more often about population level risks.

"Physicians are always looking at individual patients -- and low risk factors might not look important at an individual level, but if they are prevalent in the population then they have a greater public health relevance," he said in a telephone interview.

The World Health Organization (WHO) describes air pollution as "a major environmental risk to health" and estimates that it causes around 2 million premature deaths worldwide every year.

Nawrot's team combined data from 36 separate studies and calculated the relative risk posed by a series of heart attack triggers and their population-attributable fraction (PAF) -- in other words the proportion of total heart attacks estimated to have been caused by each trigger.

The highest risk PAF was exposure to traffic, followed by physical exertion, alcohol, coffee, air pollution, and then things like anger, sex, cocaine use, smoking marijuana and respiratory infections.

"Of the triggers for heart attack studied, cocaine is the most likely to trigger an event in an individual, but traffic has the greatest population effect as more people are exposed to (it)," the researchers wrote. "PAFs give a measure of how much disease would be avoided if the risk was no longer present."

A report published late last year found that air pollution in many major cities in Asia exceeds the WHO's air quality guidelines and that toxic cocktails of pollutants results in more than 530,000 premature deaths a year.

While passive smoking was not included in this study, Nawrot said the effects of second-hand smoke were likely to be similar to that of outdoor air pollution, and noted previous research which found that bans on smoking in public places have significantly reduced heart attack rates.

British researchers said last year that a ban on smoking in public places in England led to a swift and significant drop in the number of heart attacks, saving the health service 8.4 million pounds ($13 million) in the first year.

Tim Chico, a heart specialist at the University of Sheffield who was not involved in this research, said it would help health authorities focus on which are the most important triggers.

"However, what triggers the heart attack should be considered the "last straw." The foundations of heart disease that lead to a heart attack are laid down over many years," he said in an emailed comment. "If someone wants to avoid a heart attack they should focus on not smoking, exercising, eating a healthy diet and maintaining their ideal weight."

(Editing by Paul Casciato)

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Comments (15)
mrwr92 wrote:
It’s clear that we have a problem with this air polution however it would make me feel much better if I thought that there was a way we could end this problem. As far as I understand the most significant help would be to find a different way than cars to get around as they cause the most emissions.

Feb 24, 2011 9:01am EST  --  Report as abuse
130riosinagua wrote:
Even if you don’t believe in “man made climate change” let’s reduce air pollution for this! Just does not make sense to breath dirty air, and now the Tea Party/Republicans want to eliminate the EPA. How stupid is that!! AZ WI Ed

Feb 24, 2011 11:00am EST  --  Report as abuse
jrj90620 wrote:
I have to agree with 130riosinagua.I’m a Ron Paul conservative/libertarian and really upset with Republicans’ constant pro pollution stand.The govt is doing all kinds of things it shouldn’t, but one responsibility of govt is protecting citizens from being harmed by other citizens.That should mean protecting common resources like air from being polluted by anyone.New York just passed laws preventing people from smoking in many outdoor areas.Outdoor air pollution by people smoking is millions of times less than air pollution from internal combustion engine vehicles.I guess it’s a lot easier to come down on a non-favored group,like smokers,than the average driver.Hopefully oil and gasoline prices keep going up,batteries get better and this causes a move to electric vehicles.Way to go Nissan with your Leaf.Hope it’s a great success.

Feb 24, 2011 12:26pm EST  --  Report as abuse
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