Number One Toxic Environmental Contaminant Element

Abstract

Arsenic is a ubiquitous metalloid element ranks as the number one toxic environmental contaminant. Inorganic Arseic is considered the most potential human carcinogen in ground water . It is generally present as dissolved Arsenite As^­3+ or Arsenate⁵⁺ besides the organic form. Arsenites are much more soluble, mobile and toxic than Arsenates in aquatic and soil environments. Pronlonged drinking of arsenites rich water leads to  arsenicosis and  result in various pathophysiological   condition like  alteration of skin  colour ,hard   patches on  palms and soles of feet , cancer of the skin bladder,  kidney  ,lung  & vascular  disesses  in humans. WHO has recommended provisional guideline value of total arsenic concentration in  drinking water is 0.01mg/L. Since 1993 however the national standard for maximum acceptable concentration in drinking water is 0.05mg/L. The  occurence of  As in ground water was first  reported in 1980 in West Bengal   in  India  and  the first case of  Arsenic  poisoning  in  Human   was diagnosed  at the school of Tropical Medicine Calcutta  in 1983.

Although human exposure to arsenic is caused mainly through arsenic contaminated  underground drinking water. Recent studies have shown that Besides drinking water food chain is a major contributor to arsenicosis.  Thus contaminated water for irrigation  result in possibility  of  arsenic uptake  into crop plant. Arsenic content in straw grain  and  husk  of rice  is  especially  important since paddy fields are extensively  irrigated  with  underground water  having high level of arsenic concentration. Straw, husk are widely used as animal feed. So arsenic gets  deposited  into the animal body through feed  ,rice , straw & husk as well as from drinking water which inturn finds a route into the human body through food  chain  that is through the consumption of   animal  products  like beef ,mutton, pork ,chicken, egg ,milk & fish.

As rice and fish are the staple food in Bengal hence the Deltaic region is  worst  affected by  arsenicosis. It is important to know the Accumulation of arsenic  in fish  and  its contribution  for  human  exposure through food chain and the consequent effect of arsenic  load on fish health as it could have significant implications on aquaculture. Accumulation of arsenic in different tissue  and   organs  of fishes  in contaminated  water has been reported. Recent  studies have shown  that arsenic is carcinogenic to other animal also.

KEY WORDS:- Arsenicosis, Carcinogen, Pathophysiological, Arsenite.