Sewage, usually refers to water which is certainly polluted, abandoned from life and industry. The sewage mainly includes the sanitary sewage, the industrial waste and the initial period rain water. The sewage main pollutant has the pathogen pollutant, consumes the oxygen pollutant, the plant nourishing substance, virulent pollutant and so on.The harm of sewage to our body is various, here introduces simply how the water influence human health . causes acute and chronic is poisoned carcinogenesis occur take the water as medium infectious disease the main pollutant influence: lead: To the kidney, the nervous system cause the harm, has toxic to the child, the carcinogenicity was confirmed cadmium: Has the acute injury to the kidney arsenic: To the skin, the nervous system and so on cause the harm, the carcinogenicity were confirmed mercury: To human body's wound sewageinfluence