This was one of the few success stories in the public health sector for it helped reduce water-borne diseases. But tubewells are now dispensing arsenic-laced water, with the result that many people are showing arsenical skin lesions in the late stages of manifestation of arsenic toxicity. This came as a shock for no one was prepared for what could be a disaster - arsenic contamination. The source of arsenic is believed to be geological and most water samples show a mixture of arsenic and arsenate. None showed any methylarsonic or dimethylarsenic acid.
Water is one of the major means of transport of arsenic in the environment.
Arsenic in the aquatic environment is predominant in places with high geo-thermal activity. Soil erosion and agricultural run-offs are also large contributors to the arsenic concentration in sediments. High arsenic levels have been reported to be associated with sediments and a potential exists that it may be released in hazardous amounts to the overlying waters. Industrial effluents are also a major source of arsenic to the environment. It finds an application in the manufacture of herbicides and pesticides.