A smoky haze that shrouded parts of Southeast Asia this month, forcing schools and businesses to close, is just one element of an air pollution problem that kills hundreds of thousands of people in the region annually, the World Health Organization said.
Air pollution in major Southeast Asian and Chinese cities ranks among the worst in the world and contributes to the deaths of about 500,000 people each year, said Michal Krzyzanowski, an air quality specialist at the WHO’s European Center for Environment and Health in Bonn, Germany.
Drifting smoke from purposely set forest fires in Indonesia caused Malaysia to declare a state of emergency last week in two areas outside Kuala Lumpur. Parts of Thailand were also blanketed in the haze.
Malaysian health officials said hospitals reported a 150% increase in breathing problems and seven people who had a history of respiratory problems reportedly died. The government could not confirm the smoky air was to blame.
Worldwide, air pollution contributes to some 800,000 deaths each year, the WHO estimates. About 62% of those deaths are in southeast Asia.
The emergency in Malaysia was lifted after a few days. But meteorologists are predicting a new cloud will hover over parts of Malaysia and possibly Singapore next week.
The haze, blamed on illegal dry-season burning to clear land on Indonesia’s Sumatra island, is an annual problem. It peaked in 1997-98, when several countries in the region were blanketed in smoke.
Studies from that period showed most affected countries reported increased outpatient hospital visits and admissions and that Malaysia experienced a higher number of deaths on days with the worst haze, said Michael Brauer, a researcher from the University of British Columbia who studied the problem.
Malaysia’s government and others in the region have sought to play down the potential health impact of the haze, fearing it could hurt their tourism industries.
No data is available on long-term health effects from the 1997-98 episode, but based on a general understanding of air pollution, Brauer said extended health problems could be expected in some people.
“When levels increase we see increased numbers of people dying from respiratory and cardiovascular disease,” Brauer said via e-mail. “And people living in areas of higher air pollution tend to die earlier than those living in less polluted areas.”
WHO’s Krzyzanowski said fine particles, including those released from fires, are a major contributor to respiratory problems, especially in children, the elderly and people with existing illnesses. He said more cases may be reported during smoggy periods, but day-to-day pollution is a far larger concern.
“Even though it is very spectacular and acute, it will be taken under control,” Krzyzanowski said. “Traffic-related pollution, industry and criminal burning of wood and coal and solid materials is causing a permanent high pollution level.”
People with asthma are more prone to attacks on days with heavier pollution, and dirty air can also contribute to acute respiratory infections a major killer in children younger than five in developing countries, he said. People with cardiovascular problems also are at increased risk, he added.
Indoor pollution is also a problem in developing Asian countries, where 60% to 80% of households use fuels such as wood or coal for cooking and heat, according to a report by the U.S.-based Health Effects Institute.
Southeast Asian nations have been working to address the haze issue and this week announced the formation of a panel of environmental experts to fight forest fires.
The haze is “difficult to stop because fire is used and will always be used as part of land management,” said Daniel Murdiyarso, of the Center for International Forestry Research in Indonesia. “People are working very hard, but it’s just not effective.”
Krzyzanowski said a haze crisis in the 1950s in London killed about 4,000 people, and prompted officials to implement a long-term pollution strategy to address all aspects of the problem.
“Air pollution has to be looked at as a possible unwelcome result and byproduct of development,” he said. “It is something which we should learn a lesson from these years ago in Europe.”