Low levels may occur naturally in water after it has passed through various mineral deposits and rock strata. Arsenic is present in small amounts in soil and therefore is present in our food. It is also in the ocean, which transfers to seafood, especially the filtering mollusks, such as clams and oysters. Some arsenic may be present as a contaminant in meats as well.
Arsenic is also found in many fuel oils and coal, and hence it is added to the environment when these are burned. Weed killers and some insecticides (particularly lead-arsenate sprays) are the main sources of arsenic contamination. This is responsible for a twentyfold increase in the level of arsenic found in humans.
The UK maximum contaminant level for Arsenic in tap water set by DWI/DEFRA is 10µg/l.
The toxic effects of arsenic contamination can be poisonous, ingestion of arsenic can be dangerous and lead to illness and in some cases can be fatal. The possible effects of arsenic toxicity include hair loss, dermatitis, diarrhoea and other gastrointestinal symptoms, fatigue, headaches, confusion, muscle pains, red and white blood cell problems, neurological symptoms and liver and kidney damage. Acute arsenic exposure may cause a rapid series of symptoms. Arsine gas exposure is very toxic to the lungs and kidneys and is often fatal. Death from low-level, chronic arsenic exposure has the appearance of death from natural causes.