BEIJING, Oct. 24 (Xinhuanet) -- China will blacklist cities that fail to reach the national air quality standard, a senior official of the country's environmental agency said here Monday.

    "The list will be announced regularly to warn cities of deteriorating air quality," said Zhang Lijun, deputy director of the State Environmental Protection Administration (SEPA), at an international symposium on improving regional air quality.

    He said that as a penalty, SEPA will issue risk warnings to investors who consider investing in the cities that have been blacklisted for several consecutive years.

    Meanwhile, SEPA will strictly control construction in such cities of any projects that could add new air pollution, he said.

    Official statistics indicate that one-third of Chinese cities are experiencing severe air pollution.

    In 2004, the emission of SO2 in the country reached 26 million tons, ranking highest in the world, causing some 30 percent of the country's land territory to be ravaged by acid rain.

    Air pollution, including dust, smog, acid rain and suspended particles, is posing an increasingly dangerous threat to human health, said Zhang.

    He cited an unidentified report saying that if the country's air quality were at the "good" national standard, more than 178,000 people would not have died of air pollution-related diseases annually.

    The deputy director warned that if effective measures are not taken immediately to tackle environmental problems, human health in the country will be at greater risk, with its social and economic development seriously hampered.

    To improve air quality, SEPA is drafting a program to combat acid rain and the SO2 pollution in the coming five years, focusing on the control of SO2 emissions from coal power plants, a major source of SO2 pollution in the country, according to Zhang.

    SEPA will also take harsher measures to control increasingly serious car emissions, he said.

    "We shall also enhance international cooperation in air pollution control," Zhang said, adding that the symposium had provided a good platform for exchanges of ideas and experience.

    The symposium, dubbed Strategic Approaches to Regional Air Quality Management in China, attracted more than 100 government officials, experts and businessmen from China, the US and the European Union.

    During the three-day event ending on Wednesday, they will discuss ways of cooperation in improving regional air quality.

    The Symposium is jointly sponsored by SEPA, the US Environmental Protection Agency, the Environmental Directorate of the European Commission and the Italian Ministry for the Environment and Territory. Enditem