Résumé
Objective@#To assess the health risk associated with drinking water in Hangzhou from 2016 to 2017,and to provide evidence for the safety of drinking water .@*Methods@#The monitoring data of 5 genetic toxic substances（arsenic,hexavalent chromium,cadmium,chloroform,tetrachloromethane）and 13 body toxic substances（lead,mercury,selenium,cyanide,fluoride,nitrate,iron,ammonia nitrogen,manganese,copper,zinc,aluminum,volatile phenol）from 36 source water samples,36 finished water samples and 288 tap water samples in the main urban areas of Hangzhou were collected from 2016 to 2017. The health risk of drinking water containing the chemical pollutants mentioned above were assessed based on the evaluation models recommended by United States Environmental Protection Agency .@*Results@#The concentrations of 5 genetic toxic substances and 13 body toxic substances in source water,finished water and tap water were all within the reference limits issued by Standards for Drinking Water Quality（GB 5749—2006）. The carcinogenic risk,non-carcinogenic risk and total health risk caused by the chemical pollutants in the source water were 2.18×10-5/a,7.75×10-9/a and 2.18×10-5/a. The carcinogenic risk,non-carcinogenic risk and the total health risk caused by the chemical pollutants in the finished water were 1.08×10-5/a,3.70×10-9/a and 1.08×10-5/a. The carcinogenic risk,non-carcinogenic risk and total health risk caused by the chemical pollutants in the tap water were 1.96×10-5/a,3.61×10-9/a and 1.96×10-5/a. The carcinogenic risk and total health risk caused by chemical pollutants ranged from high to low in the source water,tap water and finished water. The non-carcinogenic risks ranged from high to low in the source water,finished water and tap water .@*Conclusion@#The health risks of 18 chemical pollutants in drinking water in Hangzhou were at a low level,with the greater carcinogenic risk than the non-carcinogenic risk. Hexavalent chromium had the highest carcinogenic risk,while fluoride and aluminum had the highest non-carcinogenic risk.
Résumé
Objective To analyze the concentration of heavy metal elements, C, N and H in PM2.5 in the atmosphere in Hangzhou. Methods Midflow samplers were used to collect the samples in Hangzhou city, the element analyzer and microwave digestion ICP-MS were applied to test the samples. Results The average concentrations of N, C, H were 13.9-14.7, 30.3-30.8 and 7.9-8.9 ?g/m3 respectively in the central and northern east areas. The average mass percent values for the three elements(N、C、H) in the city were 12.8%, 27.8% and 8.1% respectively. The average ratios of total inorganic nitrogen to total organic nitrogen (IN/ON) and total organic hydrogen to total inorganic hydrogen (OH/IH) varied in the range of 2.2-3.5 and 3.5-3.6. Eleven elements showed a higher concentration in PM2.5, in which the values of Zn, Pb, Cu and Mn were all more than 200-11 500 mg/kg and the values of Cr, Ni, Se, Mo, Cd and Sb were 17-108 mg/kg, and that was only 6-8 mg/kg for Ag. The levels of average mass percent of all the metal elements were 1.7%-2.0%. Conclusion Carbon is one of important components in PM2.5 in Hangzhou. N and H exist mainly in the form of inorganic and organic compounds respectively. Zn, Pb, Cu, Mn are major heavy metal elements in PM2.5.