Analysis of atmospheric and water environmental risk factors of tumor in Cixi, Zhejiang

Objective　The study was conducted to explore the carcinogenic risk factors in air and water environment through the surveillance of the air and water in Cixi city from 2002 to 2004, in order to propose corresponding countermeasures according to the actual situation. Methods　Atmospheric environment: surveillance on sulfur dioxide, nitrogen dioxide and acid rain was performed for three consecutive years; the results were evaluated in accordance with corresponding national criteria. Water environment: surveillance for ten major lakes, reservoirs and river networks in Cixi was conducted and the results were evaluated by GB 3838-2002. Results　It was found by the surveillance that sulfur dioxide and nitrogen dioxide didnt surpass the national standards in the three years as a whole, but the rate of acid rain reached above 90 percent. The main index of water qualities of lake and river met the national standards, while ammonia nitrogen and oil contamination in the water environment in river system surpassed the national standard.Conclusion　The high incidence of cancer in Cixi city is due to the particular geographical, hydrological conditions and industrial and agricultural pollution.