Arsenic contaminated with water, food and air has several health effects and toxicological effects when inhaled and ingested. Acute exposure to arsenic may lead to severe nausea and vomiting, colicky, abdominal pain, and profuse diarrhoea. Capillary damage can be occurred leading to generalised vasodilation, transudation of plasma, and shock (BGS, 1999).
Melanosis, hyperkeratosis and desquamation are common effects of chronic arsenic poisoning. High level of arsenic exposure may cause skin pigmentation, vascular diseases and hyperkeratosis of the palms of the hand and soles of the feet (Gradecka, et. al., 2001). Development of multicentric basal cell and squamous cell carcinomas are long term cutaneous complications (BGS, 1999). Arsenical skin disease includes brittle nails, patchy alopecia, and facial edema and chronic arsenic exposure causes anaemia and leukopenia (BGS, 1999).
Arsenic has been identified as a class 1 carcinogen and Colognato (2007) listed mechanisms as arsenic induced oxidative stress, perturbation of important intracellular pathways involved in cell proliferation, differentiation and apoptosis, DNA damage, a direct or indirect inhibition of DNA repair enzymes by arsenic, the perturbation of DNA methylation and induced genomic instability. Arsenic increases toxic effects stimulated by other factors such as X-radiation, UV-radiation and alkylating agents and hinders the activity of DNA repairing enzymes at the stage of ligation by changing gene expression (Gradecka, 2001). Arsenic occurs in two oxidation states: Arsenide or trivalent stage (As III or) and Arsenate or pentavalent stage (As V). Arsenide has been found to be more toxic than Arsenate (Faita et. al., 2013).
Chronic exposure to arsenic may lead to oxidative stress inducing DNA damage, liquid peroxidation and decreased glutathione levels and producing cytotoxic and genotoxic effects in the cells which furthers pathogenesis of diseases such as diabetes, cardiovascular and neurological disorders (Faita et. al., 2007). Genotoxic effects of arsenic are DNA modifications such as aneuploidy, micronuclei formation, chromosomal aberrations, deletion mutations, sister chromatid exchange and DNA-protein crosslinking (Faita et. al., 2013).
British Geological Survey (BGS) (1999) Groundwater Studies for Arsenic Contamination in Bangladesh: Phase 1 Rapid Investigation Phase. Mott MacDonald Ltd (UK), Final Report, Volume S5, pp1-8.
Colognato, R., Coppede, F., Ponti, J., Sabbioni, E. and Migliore, L. (2007) Genotoxicity induced by arsenic compounds in peripheral human lymphocytes analysed by cytokinesis-block micronucleus assay. Mutagenesis, 22 (4), 255-261.
Faita, F., Cori, L., Bianchi, F. and Andreassi, M. G. (2013) Arsenic-Induced Genotoxicity and Genetic Susceptibility to Arsenic-Related Pathologies. International Journal of Environmental Research and Public Health. Vol. 10, 1527-1546.
Gradecka, D., Palus, J. and Wasowicz, W. (2001) Selected Mechanisms of Genotoxic Effects of Inorganic Arsenic Compounds. International Journal of Occupational Medicine and Environmental Health, Vol. 14, No. 4, 317—328