What are the causes of air pollution?

Every year 7 million people worldwide fall ill and die as a consequence of air pollution. Yet it’s only recently that governments have started addressing the cause of air pollution by, for example, regulating emissions. Similarly, it seems that the public is only just realising the dangers.

Take London. I used to like living there when I was young. But now I don’t think it would be a healthy place for me and my kids. Recent research has revealed that 7.9 million Londoners, that’s nearly 95% of the population, live in zones where air quality falls short of World Health Organisation stipulations. No wonder that some people want to leave.

A global threat

If we all stopped to think more about our lifestyle – and tried to reduce the causes of air pollution – then the world around us would become a better place.

As it is, we’re in deep trouble because air pollution could well be described as a global pandemic. After all, if a virus killed 7 million people worldwide, it would be top news. Yet without understanding the causes of air pollution, we can do nothing to improve things.

Burning fossil fuels

If there’s one activity responsible for polluting our air the most – for filling it with the highest quantity of Particulate Matter (PM) – it’s the burning of fossil fuels. Of course, fossil fuels provide most of the energy that supports so many activities. (For example, the United States derives 81% of its total energy from oil, coal, and natural gas.) These fossil fuels are vital to heat homes, run cars, power industry and manufacturing, and supply electricity.

Unfortunately, though, burning fossil fuels is not an environmentally-friendly activity. Coal and oil, in particular, release sulfur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain.

Too much industry

Air pollution, you see, is overwhelmingly man-made, produced by factories (or other industrial plants) emitting harmful by-products and waste into the environment. Airborne nitrogen pollution is also one of the most damaging effects of all these industrial activities. Nitrogen is the most commonplace element in the air and essential to plant and animal life. But the natural balance of nitrogen in the environment can be disturbed when man-made nitrogen – whether it’s through agriculture, transport or electric power generation – upsets the normal equilibrium.

Most of the nitrogen oxides released in America, for example, stem from burning fossil fuels. This, in turn, contributes to smog and acid rain. Among the major sources of nitrogen oxide emissions are cars and trucks, coal-fired power plants, large industrial operations, ships, and airplanes.

Pollution from cars

Our love affair with private transport also does us few favours. When I was a kid in London I remember reading graffiti along the lines of ‘let’s throw away our cars and learn to love our environment’. If commuters were to travel more by bus and train, our cities would be much cleaner. To that extent commuting in our own vehicles – often just because we don’t wish to rub shoulders with other human beings on public transport(!) – is a major cause of air pollution.

Sadly, diesel engines can be just as bad as petrol engines, if not worse. Diesel engines produce higher levels of particulates, microscopic bits of soot left over from the combustion process. These find their way deep into our lungs, causing irritation and asthma. A recent survey showed that over half of diesel cars recently approved for sale in Europe – and supposedly ‘environmentally-friendly’ – are emitting pollutants far above current legal air pollution limits. It was established that dozens of these cars were approved for sale during a “monitoring period” in which their emissions were not evaluated. In other words, they’re as dirty as hell!

Unusual causes of air pollution

Some European cities still suffer from smog but it’s nothing compared to how things were a century ago – or even less. For example, the Great Smog of 1952 killed some 4,000 people in London. Such was the scale of deaths that it led to the government introducing the Clean Air of 1956 whereby only smokeless fuels could be burned in certain towns and cities.

Yet sometimes do not look to the usual culprits – by which I mean cars and industrial plants – when you seek the causes of air pollution. In Britain, fairly recently, dust blew in from the Sahara Desert more than 3000 kilometres away, ushered in by strong northern winds. Then it combined with local pollutants. The dust was brought down to earth by rain, and when that water evaporated, it left behind layers of dust.

Dust-related smog can envelop other areas too. In East Asia, sand from the Gobi Desert is blown east every spring. The so-called Asian Dust passes over parts of China, North and South Korea and Japan. It is sometimes so heavy that residents can feel the dust in their eyes and their teeth. The dust can even be carried thousands of miles across the Pacific to North America. That is an example of a natural phenomenon in which man – perhaps for once (!) – is not responsible for exacerbating the causes of air pollution.

Governments need to take steps

Air pollution causes terrible damage everywhere. Long-term exposure to filthy air causes illnesses, especially asthma and bronchitis. It also destroys our vegetation and wildlife: almost two-thirds of Europe’s ecosystems are threatened by its effects.

So what can be done? Most of the time, the causes of air pollution are rooted in man’s behaviour. It depends on governments and individuals all playing their part. And there are measures that can be taken. For example, a recent study says that premature deaths from air pollution could be cut drastically if governments agreed to cut carbon emissions. The study, conducted by Duke University, found that if the policy-makers act to reduce emissions by 180 gigatonnes of carbon this century, up to 153 million premature deaths could be avoided.