Arsenic-laden groundwater used for cooking and drinking could pose a risk to the health of almost 20 million people across China. This is shown by a study carried out by Eawag scientists in collaboration with Chinese colleagues . The estimates are based on a risk model incorporating geological and hydrological data, as well as measurements of arsenic in wells. The study is being adopted by the authorities in the national groundwater monitoring program. Since the 1960s, it has been known that groundwater resources in certain provinces of China are contaminated with arsenic. Given the sheer size of China and the time and expense involved in testing for arsenic contamination, several more decades would probably be required to screen all of the millions of groundwater wells. Accordingly, a group of researchers from Eawag and the China Medical University in Shenyang developed a statistical risk model making use of existing data on geology, soil characteristics and topographic features. This model was calibrated using available arsenic measurements. The predictions of unsafe or safe areas showed a high level of agreement, both for known high-risk areas and for areas where elevated arsenic levels had been ruled out by sampling campaigns.
Land and Water use- Freshwater