Beijing (AsiaNews/SCMP) – Controlling air and water pollution in China's main cities will be a tough job for the government, this according to the government's own latest environmental study: the 2004 State Environmental Protection Administration (SEPA) report.

SEPA's deputy director Wang Yuqing said during a press conference that the overall air quality in urban cities was poor, with more than half the mainland cities surveyed being affected by acid rain and high concentrations of breathable particles.

Mr Wang said that although great emphasis was put on improving air quality in Beijing ahead of the 2008 Olympic Games, the capital remained one of the worst-polluted cities, fifth on SEPA'S list of 47 main centres, surpassed only by Chongqing, Urumqi, Taiyuan and Lanzhou.

The report notes that 66.9 per cent of those living in urban areas were exposed to poor-quality air. "From 1994 to 2003, emissions of air pollutants from industrial sources in China increased dramatically each year. This is closely related to the steady growth of the national economy," it said.

The water quality of the most important rivers did not improve much last year, with the Haihe—a main source of fresh water for Beijing and Tianjin—remaining the most polluted.

"The East China Sea and the Bohai Sea remain heavily polluted and last year we saw a trend of further degradation," Mr Wang said.

What is worse is that last year things got worse. The maritime area affected by red tides—which pose severe threats to fish and to the aquatic industries—increased by 83 per cent last year, mostly in the East China Sea.

Wang Jirong, another SEPA deputy director, said: "I know the public is not satisfied with the quality of our water environment. I am not happy with it either. But the improvement of the water quality remains an arduous task."

Ms Wang blamed rampant local foot-dragging for obstructing environmental watchdogs. "Local protectionism has been very troublesome for SEPA," she said.

Many local governments focus too much on economic growth and fail to follow Beijing's line on sustainable development.

Last year SEPA and six other ministries teamed up to scrap 208 local regulations allegedly violating environmental laws.

"Under pressure from upper-level environmental authorities, local government interference and public complaints, some local environmental chiefs even wrote anonymous complaints to SEPA reporting issues which should have been dealt with by themselves," Ms Wang said.

Of the mainland's seven biggest rivers, only the Pearl and Yangtze were rated good in terms of water quality. The Liaohe, Huaihe, Yellow and Songhuajiang were rated relatively poor, with the Haihe rated poor.

Of the 412 sections of the seven main rivers monitored for water quality last year, 58.2 per cent were deemed unfit for human consumption.