06Carcinogenic nitrosamines into invisible killer, water quality standards to be introduced, people.co|Carcinogenic nitrosamines into invisible killer, water quality standards to be introduced, people.co3

Carcinogenic nitrosamines into "invisible killer", water quality standards to be introduced, people.com.cn Health Channel – people.com.cn original title: carcinogenic nitrosamines into "invisible killer", water quality standards to be introduced because of the high carcinogenicity, high detection rate and in China may be incorporated into water quality testing standards, obtained the unprecedented attention of the domestic researchers of nitrosamines in drinking water. "We collected 164 water samples from all over the country, including 23 provinces, 44 large and medium cities and towns, including a total of 155 water samples. Study on testing of disinfection by-products currently known all 9 nitrosamines, which NDMA (two of the highest concentration of nitroso methylamine)." School of environment Tsinghua University State Key Laboratory of environmental simulation and pollution control researcher Chen Chao, 12, told Technology Daily reporter, the research group of a key research work this year is about the national drinking water disinfection by-products of N-nitrosamines in census system. The results have been the municipal and environmental field of the top journals "published research on water", "nitrosamines in drinking water problem is urgent, need to study and engineering as soon as possible!" Chen Chao appeal. Drinking water nitrosamine detection rate can not be ignored in the past three years, Chen Chao and his team tested 44 nitrosamines in the city’s water system of DBPs and their precursors. In all the water samples have been detected in NDMA, the average concentration of water and water were 11ng L and 13ng L, NDMA formation potential source water was 66ng L. He said, compared with the United States Environmental Protection Agency in a large-scale survey data released in 2012, nitrosamines in water and water Chinese detection rate is 3.6 times that of the United states. Western European countries have lower concentrations of nitrosamines in drinking water than in the United states. Nearly 10 water supply systems in the research group detected in the Yangtze River Delta region, the average NDMA concentration of water and water were 27ng L and 28.5ng L, NDMA formation potential source water for 204ng L. Chen Chao said that in the identification of more than 700 kinds of disinfection by-products, nitrosamines is one of the largest health risk disinfection by-products category, especially NDMA. Closely related to the digestive tract cancer in the medical community in 50s found that nitrosamines are a class of strong carcinogens, when the main study of food, tobacco and industrial pollution of nitrosamines. Nitrosamines in drinking water disinfection by-products research began in the late twentieth Century. "Previous epidemiological studies have shown that nitrosamines are closely related to digestive tract cancers in some areas of china." Chen Chao said that their monitoring of these areas of tap water from industrial waste water pollution of nitrosamines. At the same time, this year, a group of Nanjing University in East China’s Jiangsu Province, a number of cities in the water source has also found serious nitrosamines pollution. According to reports, according to the toxicological test results, risk concentration millionth NDMA lifetime is 0.7ng L drinking carcinogenic, it is reported that the U.S. Environmental Protection Agency is trying to formulate the nitrosamine concentration standard, the limits of possible carcinogenic risk in ppm to 1/10000)