Nearly 20 million people in China may be exposed to drinking water contaminated with arsenic, suggests a new simulation that uses certain environmental factors to calculate the risk of exposure in a particular area.
Arsenic can naturally occur in water pumped up from underground. Globally, about 140 million people drink groundwater with unsafe levels of the element, which can cause cancer and other health problems. Testing individual wells for the poison is time consuming, so a team led by Luis Rodríguez-Lado, now at the University of Santiago de Compostela in Spain, developed a faster way to assess an area’s arsenic risk.
The researchers identified eight environmental variables that can predict whether a region’s groundwater will have high arsenic concentrations. For example, arsenic contamination tends to happen in wet areas with salty soil and sediments younger than about 12,000 years. After using these and other factors to map the arsenic risk in China, the researchers matched it with population data to estimate that roughly 19.6 million Chinese people live near contaminated groundwater.
The same technique could be used to predict arsenic risk in other countries, too, the researchers report in the Aug. 23 Science.