Each year 3.3 million people die prematurely from the effects of air pollution worldwide – a figure that could double by 2050 if emissions continue to rise at the current rate. Elke Bunge reports on the sobering results of a new study.
Lung cancer, heart attacks and even changes to the human brain – these are some of the harmful consequences of inhaling airborne particulate matter into the human body. But while the deadly effects of air pollution have long been known, the number of people worldwide who fall ill and die prematurely from this insidious fine particulate matter or smog is less known.
Until now. In a study recently published in the journal Nature, a team of researchers led by the Dutch atmospheric chemist Jos Lelieveld from the Max Planck Institute for Chemistry in Mainz, Germany have presented their sobering results on air pollution fatalities and how mortality rates are affected by various emission sources.
Highest fatalities in Asia
Outdoor air pollution causes more than 3.3 million premature deaths per year worldwide, which means that five people in 100,000 die prematurely each year from the effects of smog. These deaths are in addition to the estimated 3.54 million deaths per year associated with indoor air pollution in people’s homes or workplaces, write the researchers.
Exposure to air pollution is particularly acute in Asia, especially China and India, where three-quarters of the world’s pollution-related deaths occur: 1.4 million people in China and 650,000 people in India die every year as a consequence of air pollution.
Lelieveld’s team found that fine particulate pollution in Asia is mainly attributable to emissions from diesel generators used for cooking and heating. In China these emissions make up one-third of particulate pollution, while in Indonesia and India that number jumps reaches 50 to 60 per cent.
“We were very surprised, but in the end it makes sense,” says Lelieveld. He said that the scientists had assumed that traffic and power plants would be the biggest cause of deadly soot and smog.
Agriculture to blame in Europe
The situation in Europe is very different, where agriculture is the largest contributor of fine particulate pollution. Ammonia from fertilisers and animal waste undergoes a number of reactions to form ammonium sulphate and ammonium nitrate, which are a major factor in the formation of small airborne particles. Agriculture is the cause of one-fifth of all deaths due to air pollution and is as high as 40 per cent in countries such as the Ukraine, Russia and Germany. Other major sources are fossil-fuel fired power plants, industry, biomass combustion and motor vehicles.
In the European Union, exposure to fine particulate pollution is responsible for around 180,000 deaths per year, with 35,000 deaths in Germany alone. Lelieveld believes that this high number is due chiefly to the country’s central location in Europe: “Germans also have to breathe the polluted air from other countries.” But the densely populated country also causes a considerable amount of air pollution itself. According to the study, traffic accounts for 20 per cent of deaths in Germany, or about 7,000 lives a year. This means that twice as many people die from the effects of vehicle emissions than from road accidents.
Pollution continues to rise
Fine particulate pollution is on the rise worldwide. And no one is spared: already today smog from China makes its way across the Pacific to reach California. And the researchers have a warning: if nothing is done to curb air pollution, the situation will worsen significantly all over the planet. The annual death toll worldwide from outdoor air pollution could double to around 6.6 million by 2050.
Asian countries would be hit hardest, particularly in urban areas. “If this growing premature mortality by air pollution is to be avoided, intensive air-quality-control measures will be needed, particularly in South and East Asia,” says Lelieveld and his colleagues.
Outsourcing worsens the problem
But the solution to this global problem is not to force the Asian countries to shoulder all the blame on their own.
“We’ve outsourced our manufacturing and much of our pollution, but some of it is blowing back across the Pacific to haunt us,” says Steve Davis of UC Irvine, adding that there’s plenty of blame to go around when it comes to how Chinese air pollution is corruption other countries’ air.