Air pollution is bad for your heart

People who live in heavily polluted areas have a higher-than-average risk of developing cardiovascular disease, and smog can worsen symptoms in people with heart and circulatory disease. Here's what you need to know about air pollution and how it's bad for your heart.

Pollution raises blood pressure and can trigger heart attacks and strokes, especially in people who are already vulnerable.

Exhaust fumes are a major contaminating factor, according to epidemiologists. In fact, studies suggest that these fumes can adversely affect arteries and reduce oxygen supply to the heart.

To corroborate these findings, hospital admissions among patients with heart disease often increase during periods of high air pollution.

How pollution is absorbed

It's the minute particles in polluted air, that vehicles, factories, and electricity generators emit, which seem to do the most damage. These can penetrate deep into the lungs, causing inflammation.

This kind of reaction can occur because a high proportion of the particles is retained in the lungs, and a tiny amount gets absorbed into the body.

Narrowing blood vessels

Air pollution causes blood vessels to narrow, even in healthy people, which may explain why high pollution levels increase the rate of heart attacks and other cardiovascular problems in people with cardiovascular disease.

Researchers found that after breathing air polluted with fine particles and ozone for just two hours, the blood vessels of 25 healthy volunteers narrowed by between two and four per cent.

A danger to exercise

Being exposed to diesel exhaust fumes reduces the amount of oxygen that reaches the heart during exercise.

When a group of men who had each recovered from a heart attack exercised for an hour in a room polluted with low levels of diesel fumes, tests revealed a three-fold leap in the amount of stress on the heart — enough to increase the risk of a heart attack.

The concentration of diesel fumes in the room the men exercised in was kept to just 10 per cent of the typical pollution levels in city centres, suggesting that real-life exercise in urban environments may be even more hazardous.

Clean air benefits

People who live in cities with clean-air policies may add an extra five months to their lifespan, compared with those living in more polluted places.

One study found that those who had more exposure to traffic-related pollution were 20 per cent more likely to die at any time than those with less exposure, and 40 per cent more likely to die from heart disease.

Avoid traffic

Doctors frequently recommend that people recovering from a heart attack should not drive in heavy traffic for a few weeks because of the stress this creates. But this is good advice for everyone and another reason for everyone to avoid heavy traffic congestion whenever possible.

It is not always possible to avoid air pollution, but you can take steps to reduce your exposure.

• You can check your local air quality-pollution index along with daily weather forecasts.
• In the car, drive with your windows closed on major roads or downtown, especially on smoggy days.
• If you can, plan a route away from heavily congested areas.

You are especially at risk from the effects of pollution when doing exercise because you breathe more often and more deeply, inhaling more pollutants and sucking them further down into your lungs.

Athletes also tend to breathe through the mouth more than normal, bypassing the effective filters against particles that hair and mucus in the nose provide. So, when possible, try to breathe through your nose.

However, it's important not to abandon exercise. Just try to avoid the rush hour, or exercise in green open spaces away from heavy traffic, especially on days when the pollution index is high. Keep away from roads and, whenever possible, walk, run or cycle in a park or the countryside.

Keep this information in mind and use it to plan out your trips and exercise so that you can avoid as much air pollution as possible.