Claims made in a US report that pollution from China is crossing the Pacific Ocean and contaminating American air and soil have been slammed as unfair and unreliable.

According to a report from the Associated Press, the US Environmental Protection Agency's (EPA) estimates that on certain days nearly 25 percent of particulate matter in the skies above Los Angeles originates in China.

And some US experts even claim China could produce a third of all California's airborne pollution on certain days. But a senior Chinese environmental official poured cold water on the US EPA's claims at a press briefing in Beijing yesterday.

"Pollutant movement is a very complicated process especially when the route is across oceans and continents," said Li Xinmin, deputy director of the Pollution Control Department of the State Environmental Protection Administration (SEPA).

"And how the 25 percent was figured out is a question which needs more scientific scrutiny," said Li, a specialist in air pollution control. The "irresponsible" report was not the first to blame China for pollution in the US, he said.

When EPA administrator Stephen L. Johnson visited Beijing in April he agreed that US reports blaming China's large-scale mercury emissions for damage to air quality in America were not fair, according to Li. But China's air pollution was still a serious problem especially the nation's high sulphur dioxide (SO2) emissions, said Li.

The country discharged a total of 25.49 million tons of SO2 in 2005 which is the largest amount in the world. Of the total 21.6 million tons were produced by industry while 3.89 million tons came from domestic sources. SO2 emissions have risen 27 percent since 2000, according to SEPA figures.

Each ton of the SO2 discharged may cause up to 20,000 yuan (US$2,500) of economic losses. On that basis China could have suffered a total loss of 509 billion yuan (US$63 billion) in 2005 which is just under 3 percent of the year's 18 trillion yuan (US$2,250 billion) Gross Domestic Product.

In the 11th Five-Year Plan (2006-10) China has promised a 10 percent cut in the country's total SO2 emissions by 2010 compared with the figures at the end of 2005. To achieve this goal the country's annual SO2 discharge must be brought down to a maximum of 22.95 million tons.

The SEPA has signed a set of commitments with the six largest electric power companies and the seven highest SO2 emitting provinces which are responsible for more than 75 percent of the country's total SO2 emissions.

"Reducing emissions is a compulsory task for them," said Li. "SEPA expects the public and media to supervise them and make a joint effort to alleviate the threat from acid rain."

Most of China's SO2 emissions come from coal burning.

Li said China's coal consumption increased by more than 800 million tons during the 10th Five-Year Plan (2001-05) of which 500 million tons were consumed by the power industry.

Coal accounts for 70 percent of China's energy consumption and that figure would be difficult to reduce in the short term, commented Li.

(China Daily August 4, 2006)