Up to 220 million people globally may be at risk of arsenic-contaminated water
As many as 220 million people around the world may be at risk of drinking arsenic-contaminated groundwater, a new study finds. Combining climate, environmental and geologic data with machine learning, researchers made a global map, described in the May 22 Science, that predicts where groundwater arsenic concentrations are likeliest to exceed 10 micrograms per liter, a safe drinking water limit set by the World Health Organization. Arsenic is present in trace amounts in many different types of soil and rock. It becomes harmful to people when it leaches out of these soils and into groundwater, which can occur due to a variety of chemical processes. Long-term exposure can lead to skin lesions and cancer. Scientists have previously identified many hot spots of arsenic contamination in groundwater, including regions of Bangladesh, Argentina and Vietnam (SN: 11/20/02; SN: 3/5/15). But data on groundwater arsenic are lacking for many other regions. So environmental scientist Joel Podgorski and hydrologist Michael Berg, both of the Swiss Federal Institute of Aquatic...