BEIJING (KRT) - A toxic cloud of smog over China's cities caused by exhaust from millions of new cars and belching coal-fired power plants is exacting a major public health toll, experts said Monday.

"About one-fifth of urban Chinese now breathe heavily polluted air," said Zhang Lijun, vice minister of the State Environmental Protection Administration.

Zhang said improving air quality in 210 medium and large cities across China from "polluted" to "good" levels could save 178,000 lives a year.

China has given rapid economic growth priority over environmental protection during several decades of industrialization and now pays a severe price for its heavy air pollution, experts said at a conference sponsored by Chinese, U.S. and European Union environmental agencies.

Fine particles and other pollutants spewed into the air from China's 2,300 or so coal-fired power plants aggravate respiratory ailments and "are extremely poisonous to children's lung functions," Zhang told several hundred delegates at the conference.

While China is slowing the rate of its air quality deterioration by curbing industrial pollution, a car craze is retarding chances for further improvement.

Twenty-seven million vehicles clog China's roads, and each year 4 million to 5 million new cars and trucks join the fleet, said Li Xinmin, deputy director of the state administration's pollution control department.

China has chalked up average economic growth of 9.4 percent a year over the past two decades, requiring a steady increase in coal to produce electricity. Coal provides 67 percent of China's energy. To keep pace, producers are extracting dirtier coal, Li said.

"The quality of coal is deteriorating," Li said. "The sulfur content has reached 1 percent. More sulfur is being released into the air."

Sulfur dioxide is a major pollutant and contributor to greenhouse gases blamed for global warming. The United States surpasses China as a greenhouse gas producer, but if current trends continue, China will rise to No. 1 by 2025.