Environmental arsenic contamination and its health effects in a historic gold mining area of the Mangalur greenstone belt of Northeastern Karnataka, India

► First report of chronic human arsenic toxicity in any historic gold mining area. ► Highly elevated arsenic in topsoil as well as groundwater used for drinking. ► Prevalence of arsenical skin lesions comparable to other severe areas in South Asia. ► Integration of clinical, analytical chemical, and environmental research.