Health threats to China's drinking water are increasing because of the serious contamination of many of the country's water sources.

At a symposium on potable water safety and health, a group of Chinese experts on Monday urged the government and enterprises to introduce more high-end technologies to protect people from drinking polluted water.

The symposium is being held concurrently with a national water pollution prevention conference organized by the State Council.

The deterioration of the general water situation on the Chinese mainland means that most of the source water for Chinese waterworks is polluted to some extent.

According to E Xueli, a researcher with China Disease Prevention and Control Center, for economic and other reasons, more than 90 percent of Chinese waterworks are still using outdated technologies developed at the beginning of the 20th century.

"Those waterworks can handle physical and microbial pollution but not chemical pollution," he said.

"China's waterworks can only filter out 30 percent of the organic substances in the water treated. People drink the other 70 percent," warned Wang Zhanshen, a professor with the Tsinghua University.

China must deal with potable water problems in a scientific and pragmatic way, spreading water health knowledge and mobilizing society to promote water safety, Wang said.