If you live in a city how can you protect yourself against air pollution?

Wear a cycle mask, avoid exercising in polluted areas and restrict car use in the city

Avoiding increasing levels of air pollution in Irish cities and towns is far from easy, given ever increasing volumes of traffic that dominate the urban landscape. The main threats are in the form nitrogen oxides; particulate matter, ozone and carbon monoxide.

The pollutants damage the physical landscape and can give rise to smog, but when levels peak – often coinciding with high traffic volumes – they pose a health risk to those who are vulnerable to asthma and people with respiratory illness. They can lead to heart failure among those with a cardiac condition.

The World Health Organisation advice is:

– Limit walking on busy streets during rush hour “and if you have a young child with you, try and lift them up about the level of vehicle exhausts”;


– Limit spending time at specific hotspots of traffic such as cars stopped at traffic lights – the EPA is putting in place a network to enable real-time monitoring of peak emissions at key locations in Dublin;

– When doing physical activity outdoors, exercise in less polluted areas;

– Limit the use of cars in highly polluted areas – especially older diesel vehicles;

– Don’t burn waste in back gardens or at the back of businesses as the smoke that results damages our health.

For those in traffic – especially those who cycle – blocking out those gases contained in exhaust fumes from buses, taxis and lorries is next to impossible as the harmful elements can easily get into the lungs and into the bloodstream. The harder people cycle, the more pollutants they inhale.

Cycle masks

The use of a cycle mask can be effective but is dependent on ensuring it fits correctly and is used according to manufacturers’ instructions. It is important to replace the filter in the mask regularly, or it will not work at all.

Research on the effectiveness of masks in differing urban environments is limited. Scientists at Edinburgh's Institute for Occupational Medicine tested nine different masks bought from shops in Beijing. Generally, the filter in each mask worked well, the best stopped more than 99 per cent of particle pollution and the worst stopped 70 to 80 per cent.

Volunteers also wore the masks in a test chamber filled with diesel exhaust fumes. Pollution inside the mask was measured as they walked, nodded and talked. One mask stopped 90 per cent of the particle pollution while others offered almost no protection.

The tightness of fit was crucial. Facial hair prevents a good seal and the fit also depends on the shape of the user’s face. If it fits well, then breathing through a mask is not easy. This might explain why masks are not in common usage in the world’s major cities.


Putting Vaseline on the inside of the nostrils to pick up any pollen spores or particulates has been recommended by some health specialists – while some “drug-free allergen barrier balms” are available that promise to trap a lot of pollen before it gets into your nose, and probably bring some benefit in curbing air pollutants getting into the body.

The ideal remedy, of course, is to avoid most congested areas and stay indoors. Evidence for the effectiveness of air purifiers in reducing the health effects of air pollution in such environments is mixed, though they may be helpful for people with allergies.

If an individual wants to do something practical, then changing the path you cycle to less congested routes is most effective change to make, according to various experts, many of whom agree the health benefits offered by cycling outweigh any potential harm from pollution exposure.

There is one certainty: restricting car use reduces air pollution. The City of Madrid’s imposition of a “low-emission zone” last Christmas, caused nitrogen oxide emissions to fall by 38 per cent in the city centre during the first month, while carbon dioxide emissions dropped by 14 per cent.

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times