Arsenic poisoning

Arsenic is an element that raises much concern from the both environmental and human health standpoints. Arsenic is one of the most toxic metals derived from the natural environment.

In industry, arsenic is used to manufacture paints, fungicides, insecticides, pesticides, herbicides, wood preservatives, and cotton desiccants. As it is an essential trace element for some animals, arsenic is an additive in animal feed.

Most arsenic gets into the body through ingestion of food or water. Arsenic in drinking water is a problem in many countries around the world, including Bangladesh, Chile, China, Vietnam, Taiwan, India, and the United States. Humans may encounter arsenic in water from wells drilled into arsenic-rich ground strata or in water contaminated by industrial or agrochemical waste. They may come in contact with arsenic in contaminated dusts, fumes, or mists. They may eat food contaminated with arsenical pesticides or grown with arsenic-contaminated water or in arsenic-rich soil.

Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial processes.

Arsenic poisoning interferes with cellular longevity by allosteric inhibition of an essential metabolicenzyme pyruvate dehydrogenase (PDH) complex which catalyzes the reaction Pyruvate + CoA-SH +NAD+ PDH Acetyl-Co-A + NADH + CO. With the enzyme inhibited, the energy system of the cell isdisrupted resulting in a cellular apoptosis episode. Symptoms of acute intoxication usually occur within 30 minutes of ingestion but may be delayed if arsenic is taken with the food. Initially, a patient may have a metallic taste or notice a slight garlicky odor to the breath associated with a dry mouth and difficulty in swallowing. Early clinical symptoms at acute arsenic intoxication may be muscular pain, weakness with flusking skin. Severe nausea and vomiting, colicky abdominal pain, and profuse diarrhoea with rice-water stools abruptly ensure. Capillary damage leads to generalized vasodilation, transudation of plasma, and vasagenice shock.

The working group of International Agency for Research on Cancer evaluated data from ecological studies, cohort studies and case-control studies from many countries and observed that arsenic was potentially carcinogenic for skin cancer. Malignant arsenical skin lesions may be Bowen’s disease (intraepithelial carcinoma, or carcinoma in situ), basal cell carcinoma, or squamous cell carcinoma.
Arsenic poisoning 

Note: The maximum level of inorganic arsenic permitted in U.S. drinking water is 10 parts per billion (ppb). This standard was set by the U.S. Environmental Protection Agency (EPA).