Children play near a power plant in Taiyuan, Shanxi Province, China. The coal-fired plants spew emissions that cause environmental damage as far away as the United States.

Taiyuan, China ? Editor’s note: This is part of an occasional series on the growing use of coal and its effects worldwide.

It takes five to 10 days for the pollution from China’s coal-fired plants to make its way to the United States, like a slow-moving storm.

It shows up as mercury in the bass and trout caught in Oregon’s Willamette River. It increases cloud cover and raises ozone levels. And along the way, it contributes to acid rain in Japan and South Korea and health problems everywhere from Taiyuan to the United States.

This is the dark side of the world’s growing use of coal.

Cheap and abundant, coal has become the fuel of choice in much of the world, powering economic booms in China and India that have lifted millions of people out of poverty. Worldwide demand is projected to rise by about 60 percent through 2030 to 6.9 billion tons a year, most of it going to electrical power plants.

But the growth of coal-burning is also contributing to global warming and is linked to environmental and health issues ranging from acid rain to asthma. Air pollution kills more than 2 million people prematurely, according to the World Health Organization.

“Hands down, coal is by far the dirtiest pollutant,” said Dan Jaffe, an atmospheric scientist at the University of Washington who has detected pollutants from Asia at monitoring sites on Mount Bachelor in Oregon and Cheeka Peak in Washington state. “It is a pretty bad fuel on all scores.”

‘Can’t live’ without it

To understand the conflict over coal, look at Taiyuan and the surrounding Shanxi Province, the country’s top coal-producing region – and one of its most polluted.

Almost overnight, coal has turned poor farmers in this city of 3 million people into Mercedes-driving millionaires, known derisively as “baofahu” or the quick rich. Flashy hotels display chunks of coal in the lobby, and sprawling malls advertise designer goods from Versace and Karl Lagerfeld. Real estate prices have doubled, residents say, and construction cranes fill the skyline.

A museum in Taiyuan celebrates all things coal. Amid photos of smiling miners, coal is presented as the foundation of the country’s economic development, credited with making possible everything from the railroad to skin care products.

“Today, coal has penetrated into every aspect of people’s lives,” the museum says in one of many cheery pronouncements. “We can’t live comfortably without coal.”

Yet the cornstalks lining a highway outside the city 254 miles southwest of Beijing are covered in soot. The same soot settles on vegetables sold at the roadside, and the thick, acrid smoke blots out the morning sun. At its worst, the haze forces highway closures and flight delays.

With pressure to clean up major cities such as Shanghai and Beijing, particularly in the run-up to next year’s Beijing Olympics, the central government is turning increasingly to provinces such as Shanxi to meet the country’s power demands.

“They look at polluted places like Taiyuan and say it’s so polluted there so it doesn’t matter if they have another five power plants,” said Ramanan Laxminarayan, a senior fellow at Resources For the Future, an American think tank that found links between air pollution and rising hospital admissions in Taiyuan.

“I visited these power plants and there is no concept of pollution control,” he said. “They sort of had a laugh and asked, ‘Why would you expect us to install pollution-control equipment?'”

Paying heavy price

China is home to 20 of the world’s 30 most polluted cities, according to a World Bank report.

Health costs related to air pollution total $68 billion a year, nearly 4 percent of the country’s economic output, the report said. And acid rain has contaminated a third of the country, Sheng Huaren, a senior Chinese parliamentary official, said last year. It is said to destroy some $4 billion worth of crops every year.

“What we are facing in China is enormous economic growth, and … China is paying a price for it,” said Henk Bekedam, the country representative for the World Health Organization. “Their growth is not sustainable from an environmental perspective. The good news is that they realize it. The bad news is they’re dependent on coal as an energy source.”

But the costs go far beyond China. The soot from power plants boosts global warming because coal emits almost twice as much carbon dioxide as natural gas. And researchers from Texas A&M University found that air pollution from China and India has increased in cloud cover and major Pacific Ocean storms by 20 percent to 50 percent over the past 20 years.

“We know dust from factories in China, India, Mexico and Africa does not simply disappear; the wind brings it here,” said the U.S. Chamber of Commerce’s Bill Kovacs.

Kovacs said overseas dust is adding to the number of counties that do not qualify for federal transportation funds because they are out of compliance with ozone standards.

More than 100 counties do not meet the limit of 84 parts per billion. China alone contributes 3 to 5 parts per billion, estimates Daniel J. Jacob, professor of atmospheric chemistry and environmental engineering at Harvard University.

Mercury, a byproduct of some coal-mining, is another major concern. The potent toxin falls into waterways and shows up in fish. Asia’s contribution to U.S. mercury levels has shot up over the past 20 years. Jacob estimated half of the mercury in the United States comes from overseas, especially China.

“It’s a global problem and right now China is a source on the rise,” he said. “If we want to bring down mercury levels in fish, then we have to go after emissions in East Asia.”