About 90 percent of ancient relic sites along the Chinese section of the Silk Road have lost their original looks, and some are even on the brink of extinction, an expert warned on Wednesday.

Most of the approximately 1,200 ancient cultural relic sites along the 4,000-kilometer section are grottoes and earth buildings, including the World Heritage Dunhuang Grottoes and up to 100 sites placed on the state protection lists, according to Li Zuixiong, deputy director of Dunhuang Academy.

The expert blamed wind and rain erosion and desertification for the destruction of these valuable ancient sites, warning that the weathering may even lead to the collapse of some rock sites and fatal damage of frescoes.

Insufficient management and human activities, particularly undisciplined tourist actions, have also badly wrecked some relics, Liu pointed out at the ongoing international grottoes seminar held at the Yungang Grottoes, a 1,500-year-old World Heritage site in north China's Shanxi Province.

China has stepped up its efforts over the past years in rescuing and protecting the endangered ancient sites.

Stretching over 7,000 kilometers, the 2000-year-old Silk Road, widely acclaimed as a symbol of communications between China and Europe, snakes from Xi'an, capital of northwest China's Shaanxi Province, through central Asia and ends in Rome.

Another expert attending the grottoes forum also warned that air pollution will become a fatal threat to China's archeological sites, particularly some World Heritage sites.

A major part of China's World Heritage sites are ancient buildings, grottoes and tombs that have been exposed to the air for a long time. Some air pollutants will lead to erosion, collapse or gradually will eat off these brittle sites, said Zhou Baozhong, member of the State Bureau of Cultural Relics.

About half of China's World Heritage sites are located in the regions labeled with higher air pollutants, Zhou cited his research as saying, appealing for more substantial efforts in environment protection and cultural relics preservation.

(Xinhua News Agency July 28, 2005)