Arsenic in Gley-Soils, Occurrence and Human Exposure

In some gley-soils (Haplaquepts) in the pleistocene part of the Netherlands high concentrations of arsenic are found. In these gley-soils iron and arsenic have accumulated, presumably by weathering and mobilization in higher grounds, e.g. ice pushed sands, and the subsequent transportation by groundwater (reducing conditions) to lower areas. By oxidation of ferrous iron and arsenite near the surface of the gley-soils a coprecipitate has been formed, also containing some manganese.