Arsenic pollution in ground water has been envisaged as a problem of
Global concern. Chronic arsenic toxicity (arsenicosis) due to drinking of
arsenic contaminated ground water is a major environmental health
hazard throughout the world including India and Bangladesh. Chronic
exposure to arsenic in drinking water can cause increased risk of skin,
lung, kidney, bladder cancer, liver disease and chronic respiratory
problems. The exact molecular mechanism of arsenic induced
carcinogenesis is still less understood. Both arsenite and its metabolites
can have a variety of genotoxic effects, which may be mediated by
oxidants or free radical species. All of these species also have effects on
signaling pathways leading to proliferative responses. There are
interesting differences in the activities of inorganic and organic species
both in terms of target organ carcinogenicity and genotoxic and toxic
mechanisms. A scientific consensus has not yet been reached on the many
suggested modes of arsenic carcinogenesis that exist in the literature.
These include modes that are predominately genotoxic (i.e.,chromosomal
abnormalities, oxidative stress, and gene amplification) vs. more
nongenotoxic (i.e., altered growth factors, enhanced cell proliferation and
promotion of carcinogenesis, and altered DNA repair). Likewise, the doseresponse
relationship at low arsenic concentrations for any of these
suggested modes is not known.
Arsenic, Chronic exposure, Cancer.