The Detection And Health Risk Assessment Of Different Kinds Of Drinking Water

Water is the material basis of human survival and social development.However,in recent years,there are"triple"problems of the drinking water safety in domestic,namely,pollution of drinking water sources and water shortages because of water pollution,the unadvanced technologies of drinking water treatment,water supply network pollution.With the acceleration of the economic development and urbanization in our country,the demand for high-quality drinking water is increasing.Therefore,,to investigate the safety of different types of drinking water in residential household and analyze their risk level to human health,different types of drinking water were tested,and the risk relationship between exposure to drinking water and the risk of human health was assessed utilizing health risk assessment model proposed by the United States Environmental Protection Agency.The research is of great significance for raising residents'awareness of drinking water health.A six-month monitoring of tap water which take the upper Huangpu River as the water source was conducted.The indicators include five categories,namely organic indicators,inorganic indicators,microbial indicators,metal indicators and disinfection by-products indicators.The results showed that,the average concentrations of COD_Mnn and TOC are2.3mg/L and 3.7mg/L respectively.Organic pollution remains the main concern of drinking water pollution projects.For metal indicators,the maximum concentration of Pb is 10.7?g/L,exceeding the limit of national drinking water standard at 10?g/L,the other metal concentrations are within the standard range.For the indicators of disinfection by-products,CCL₄ once exceeded the standard value at 2.5?g/L,other indicators of disinfection by-products are within the standard range.The water quality of two kinds of terminal water treatment equipment whose main water purification process are activated carbon and hollow fiber ultrafiltration membrane respectively was monitored.The results showed that,different water purification process on the removal of organic pollutants than inorganic pollutants removal rate above more than 5 times.Both types equipment on the removal of disinfection by-products have a very high efficiency.Besides,the activated carbon-based water purifier has a100%removal rate for the five kinds of disinfection by-products selected.Different equipment have different removal efficiency on the selected seven kinds of metals,while the removal rate of activated carbon-based equipment was significantly higher than the ultrafiltration-based equipment on Zn?Pb?Cr,but not much difference on Al.The health risk model proposed by the United States Environmental Protection Agency was applied to examine the influence on human health of metal elements and disinfection by-products in drinking water.The results showed that,the total health risk values for different types of drinking water are below the maximum acceptable risk level(1×10^-61×10^-4)set by ICRP and the US EPA;the magnitude of the health risk value of residents exposed by mouth is about 5 times than skin.The risk to human health of drinking water focused on the route of mouth exposure;while children's health risk value is a little higher than that adults,so more attention should be put on the health risks of the sensitive groups;the carcinogenic risk in different types of drinking water accounts for about98%⁹9%of the total health risk,and the non-carcinogenic risk of residents exposed to water pollutants is low,so its impacts on people are negligible.