Health risks of pollutants in the surface water sources of the centralized drinking water supply in Zhengzhou, China

To evaluate the potential adverse effects caused by pollutants in the surface water sources of drinking water in Zhengzhou, concentrations of 10 elements were measured and their health risks assessed. The results show that only some concentrations of iron, manganese and fluorine are higher than the corresponding environmental quality standards. Risk assessments indicate that risk quotients (all values with carcinogenic effects of arsenic, three values of worst-case of lead and one value of worst-case of fluorine) exceed the limits respectively; one hazard index of fluorine is more than 1; and all 95% of cancer-risk values of arsenic and lead are above 1.0E-6.