Health Risk Assessment on Drinking Water in Shenzhen, China

Objectives: To conduct health risk assessment on drinking water in 2012 in Shenzhen of China. Methods: The water quality monitoring data on product water and pipe water in 2012 were collected and analyzed, and the risk evaluation models recommended by the U.S. environmental protection agency (US EPA) were employed, to perform adults and children’s health risk assessments on the three kinds of genetic toxic substances such as hexavalent chromium, cadmium and arsenic and the 12 non-carcinogenic materials such as iron, manganese, lead, fluoride, volatile phenol, cyanide, mercury, ammonia nitrogen, nitrate, copper, zinc and selenium. Results: The results about water quality from the 150 factory samples and 207 peripheral water samples showed that the measured indicators in other water samples were accord with the National Health Standards (GB5749-2006) released by Ministry of Health of the People’s Republic of China, except manganese level in one factory sample and the same index in one peripheral sample, and nitrate concentration in another water sample were out of limit, respectively. Namely, the total of 3 samples was disqualification. The adults and children’s health risks (HI) on the 12 non-carcinogenic materials were 178.04 × 10-8 and 249.96 × 10-8 in the factor water samples, and 363.02 × 10-8 and 509.66 × 10-8 in the pipe samples, respectively. Lead in factory water and fluoride in peripheral water samples were the most serious harm in the all measured non-carcinogenic indicators. The adults and children’s cancer risks (R) on the 3 genetic toxic substances were 25.60 × 10-6 and 28.51 × 10-6 in the factor water samples, and 23.47 × 10-6 and 26.08 × 10-6 in the pipe samples, respectively. Hexavalent chromium was the most damage among the three detected carcinogenic indicators. Therefore, the total adults and children’s health hazard risks including the 3 carcinogenic and 12 non-carcinogenic substances were 27.38 × 10-6 and 31.00 × 10-6 in the factor water samples, and 27.10 × 10-6 and 31.17 × 10-6 in the pipe samples, respectively. Genetic toxic matters in drinking water are the main hazard and more children’s health risk than adults’ risk. Conclusions: The health risk (R) on the 15 kinds of chemicals in Shenzhen’s municipal water supply was in the range of maximum acceptable risk levels (5.0 × 10-5/a) recommended by the International Commission of Radiation Protection (ICRP). The results in this study indicate that the carcinogenic substances are greater risk comparing with the non-carcinogenic substances, and hexavalent chromium is the biggest carcinogenic risk, and lead and fluoride are the most non-carcinogenic risk, and the rather risk of children than adults.