Arsenic is present in more than 200 mineral species, the most common of which is arsenopyrite. It has been estimated that about one-third of the atmospheric flux of arsenic is of natural origin. Volcanic action is the most important natural source of arsenic, followed by low-temperature volatilization. Inorganic arsenic of geological origin is found in groundwater used as drinking-water in several parts of the world.

It has been estimated that 70% of the world arsenic production is used in timber treatment as copper chrome arsenate (CCA), 22% in agricultural chemicals, and the remainder in glass, pharmaceuticals and non-ferrous alloys.

Mining, smelting of non-ferrous metals and burning of fossil fuels are the major industrial processes that contribute to anthropogenic arsenic contamination of air, water and soil. Historically, use of arsenic-containing pesticides has left large tracts of agricultural land contaminated. The use of arsenic in the preservation of timber has also led to contamination of the environment.

Arsenic poisoning or arsenicosis is a condition caused by the ingestion, absorption or inhalation of dangerous levels of arsenic. Arsenic causes or increases the risk of numerous illnesses. Examples are skin damage including keratosis and skin cancer, internal cancers such as lung and bladder, and diseases of the vascular system. Other health problems, such as diabetes, cancers of the other organs and adverse reproductive outcomes have been observed, but the evidence is not yet conclusive, although it keeps increasing.

First signs of arsenic poisoning will appear within thirty minutes, and may include some of the following:

• Drowsiness
• Headache
• Confusion
• Terrible Diarrhoea

Note that if arsenic has been inhaled or a less concentrated amount has been ingested, symptoms may take longer to emerge. As the arsenic poisoning develops, the patient may start suffering convulsions and their fingernail pigmentation may change.

In more severe cases of arsenic poisoning, the following symptoms may be observed:

• Metallic taste in the mouth
• Mouth produces excess saliva
• Problems swallowing
• Blood in the urine
• Cramping muscles
• Loss of hair
• Stomach cramps
• Convulsions
• Excessive sweating
• Garlicy breadth
• Vomiting
• Diarrhoea

However, intra and interfamily variations may be observed in visible signs and symptoms.

WHO (World Health Organization) has set a provisional guideline value or maximum contaminant level (MCL) for arsenic in drinking water as 10 ppb (parts per billion). This value is followed by most of the countries now. This value though is a practical quantification limit, that is, it is acknowledged that even this limit may not be entirely free of health risks, but there are practical problems in many areas of the world in reducing levels below this limit.

Field experiences show that usually people drinking arsenic contaminated water for couple of years may show arsenical skin lesions. However, inter and intra family variations have been observed in the degree of impact of arsenic contamination.

These sources can be used for drinking water purposes after proper treatment against bacteriological contamination and other toxins.

No. Arsenic cannot be removed by boiling as it is not a volatile substance. In fact, its concentration increases as water evaporates during boiling.

Arsenic has no distinctive taste, colour or odour. After proper collection and preservation, the water sample has to be analyzed for presence of arsenic in an authorized laboratory. Certified field kits can also serve the purpose, but results from these kits are only indicative in nature and need to be verified from laboratories.

In areas and occupations where there is a risk of arsenic poisoning, it is important to monitor the levels of arsenic in the people at risk. Levels of arsenic can be measured by taking blood, hair, urine, and fingernail samples.

Urine tests would have to be carried out within 1-2 days of the initial exposure, making it an accurate indicator of when the arsenic poisoning occurred. These tests can also be used to help diagnose cases where symptoms of arsenic poisoning are apparent.

To determine the level of arsenic exposure over a period of up to 12 months, tests on hair and fingernails can be performed. Although these tests can give an accurate indication of arsenic exposure levels, they do not indicate what effects they will have on the patient’s health.

Although there isn’t substantial evidence yet to show that arsenic can harm the foetuses of pregnant women, studies in animals have shown that doses of arsenic that are large enough to cause illness in pregnant females may cause low birth weight, foetal malformations, ore even foetal death.

No. Absolutely not!