Since water is the principal route through which As enters into the human body , the understanding of the processes of As contamination in groundwater, associated health risks, and mitigation of As problem is required.The present review summarizes possible sources of As contamination of groundwater, global overview of groundwater As contamination, toxicity, basic chemistry, associated health risks, and the best available strategies for mitigation of As pollution in groundwater.Arsenic, a well-known carcinogen, is considered as one of the world’s most hazardous chemicals .
As contamination of groundwater, poses a serious risk to human health.
Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet.
The major arsenicosis affected areas have been reported in large deltas and/or along major river basins across the world  such as in Paraiba do Sul delta, Brazil , Bengal delta [17–19], Mekong delta, Cambodia , Danube river basin, Hungry , Hetao river basin, Mongolia , Duero Cenozoic Basin, Spain , Zenne river basin, Belgium , and Tulare Lake, USA .
The transfer of As to the food chain will ultimately remain as long-term risks to human and ecological systems .
The main anthropogenic sources for contamination of groundwater with As are mining, burning of fossil fuels, use of arsenical fungicides, herbicides and insecticides in agriculture, and wood preservatives .