ABSTRACT
Arsenic (As) is widely distributed in the environment and is known to be highly toxic to humans. Both natural and anthropogenic activities result in the significant input of As to the environment. Natural processes like erosion and weathering of crustal rocks lead to the breakdown and translocation of arsenic from the primary sulfide minerals, and the background concentrations of arsenic in soils are strongly related to the nature of parent rocks. An extensive range of anthropogenic sources may enhance concentration of As in the environment. Some of these activities include industrial processes that contribute to both atmospheric and terrestrial depositions, such as mining and metallurgy, wood preservation, urban and industrial wastes, and applications of sewage sludge and fertilizer (1-3). Among the two modes of As input, the environment is mostly threatened by anthropogenic activities. The fate of As accumulated in the surface environment depends essentially on its retention and mobility in the host medium, soil and groundwater, and is most vulnerable for biota.
