Arsenic toxicity exacerbates China’s groundwater and health crisis

Arsenic (As) contamination is considered a major threat to groundwater quality and human health. The uneven distribution of arsenic contributes to regional variations, creating discrimination related to arsenic enrichment and carcinogenic risk. Here, we have analyzed 2,737 groundwater samples across China, which spans a broad range of geo-environments, climates and land use types. We find that regional inequality of groundwater arsenic concentration is caused by ontology environment. By mapping the groundwater arsenic distribution across China and conducting a global meta-analysis, the spatial response of arsenic concentration to different cancer risks was revealed, and neglected As(V) should be given attention. A random forest analysis identified chemical properties (including oxidation-reduction potential, pH, total manganese ion, total iron ion, total dissolved solids, and sulfate ion) as the most influential drivers, contributing 56% to the model's explanatory power, followed by geographical factors at 28%, climatic factors at 10%, and human activities at 6%. Additionally, reducing the proportion of groundwater supply with high arsenic concentration in drinking water in regions without water treatment may help lower the potential carcinogenic risk. This study emphasizes the potential health risk associated with high arsenic groundwater, making it particularly important to roll out efficient water purification technologies given the natural enrichment of arsenic, especially rural regions.