Asia's cities have some of the highest levels of air pollution in the world. The poor air quality is not only causing health problems, it is also putting a strain on finances and clouding economic prospects. But, as Claudia Blume reports from VOA's Asia News Center in Hong Kong, some governments in the region are trying to help their citizens breathe more easily.
In Asia, hundreds of thousands of people in urban areas get sick just by breathing the air that surrounds them. Air pollution in cities such as Beijing, New Delhi and Jakarta has reached alarming levels. This is due to the cumulative effects of rapid population growth, industrialization and increased use of vehicles. China alone is home to 16 of the world's 20 most polluted cities.
Hisashi Ogawa, environmental adviser for the World Health Organization's regional office in Manila, says exposure to polluted air is associated with a range of both acute and chronic health problems.
"For children under five years, for instance, pneumonia is a major problem in children," Ogawa explained. "In the Asia-Pacific region, probably the largest killer of children is pneumonia. And pneumonia is aggravated by air pollution, particularly for children. For the older generation, they have chronic lung - respiratory symptom problems - bronchitis, asthma, even lung cancer in certain cases."
Asiairnet, an organization co-founded by the WHO, says up to 30 percent of all respiratory diseases are caused by air pollution. The WHO estimates that dirty air kills more than half a million people in Asia each year. Ogawa says this burden falls heaviest on the poor.
"Overall we estimate that 97 percent of these deaths occur in developing countries, urban air particularly, and only three or four percent occur in developed countries," Ogawa said. "Developed countries of course have better control of air pollution through regulations, also the public awareness as well."
The air in cities such as Singapore and Tokyo is relatively clean. But one of the region's other financial centers, Hong Kong, suffers from severe air pollution. Much of it is blowing in from neighboring Guangdong province, one of China's main industrial centers.
A local air pollution concern group says Hong Kong's bad air is responsible for up to 1600 deaths a year. David Hui, head of respiratory medicine at the Chinese University of Hong Kong, says there is a clear link between the city's worsening air quality and an increase in health problems.
"From a number of epidemiological studies we have seen that an increase in pollutants such as oxides of nitrogen, PM 10 and ozone actually led to [an] increase in GP consultations in Hong Kong for upper respiratory infection," Hui said.
The worsening pollution also has severe economic implications. The WHO estimates that health care costs for illnesses caused by air pollution amount to about $200 million per city. And bad air can be bad for business, too. Global investment bank Merrill Lynch recently warned that Hong Kong's worsening air quality could drive out foreign professionals, threatening the city's competitiveness.
The outlook for Asia's cities is not all hazy. Cornie Huizenga heads the secretariat of the "Clean Air Initiative for Asian Cities" at the Asian Development Bank in Manila. He says the levels of some pollutants have actually decreased.
"If we look at air quality now in Asian cities - this is a good news, bad news story," Huizenga said. "The bad news is that the air pollution levels are still high. The good news is that even though we have added all these vehicles, all these people, all this energy use - the fact is, for example for particulate matter - for example SO 2 [sulfur dioxide] - the levels are either flat or slowly improving. That is what we would say is the good news - it means that we are not fighting a losing battle."
Huizenga says governments in the region have begun to take air quality management more seriously. Most Asian countries have made progress in phasing out lead in petrol, reducing vehicle emissions. The introduction of light rail and mass transport systems in some cities, such as Bangkok, has also helped clean up the air.
Countries from the region regularly meet for "Better Air Quality" workshops, the next of which will be held in Indonesia in the middle of December.
But Huizenga says many challenges remain. These include setting up consistent air quality monitoring systems and increasing funding for air quality management. He also says local objectives should reflect the air quality guidelines the WHO released in October, which set uniform targets for clean air.