7. What are the effects of arsenic on human health?
- 7.1 Can arsenic cause cancer and skin changes?
- 7.2 What other health problems can arsenic cause?
7.1 Can arsenic cause cancer and skin changes?
Long-term exposure to arsenic in drinking water can cause cancer in the skin, lungs, bladder and kidney. It can also cause other skin changes such as thickening and pigmentation. The likelihood of effects is related to the level of exposure to arsenic and in areas where drinking water is heavily contaminated, these effects can be seen in many individuals in the population. Increased risks of lung and bladder cancer and skin changes have been reported in people ingesting arsenic in drinking water at concentrations of 50 µg/litre, or even lower.
Exposure to arsenic in the workplace by inhalation can also cause lung cancer. The likelihood of cancer is related to the level and duration of exposure. Increased risks of lung cancer have been observed at exposure levels that add up to more than 750 (µg/m3).year. This figure is obtained by multiplying the average concentration in the workplace by the number of years of exposure (for example, 15 years of exposure to a workroom air concentration of 50 µg/m3 correspond to 750 (µg/m3).year). Smoking and arsenic exposure combined increase the risk of lung cancer.
As regards the possible method by which arsenic causes cancer, the evidence in humans indicates that arsenic can cause damage to whole chromosomes (clastogenic effects) but does not appear to cause damage to individual genes. More...
7.2 What other health problems can arsenic cause?
Soluble inorganic arsenic can have immediate toxic effects. Ingestion of large amounts can lead to gastrointestinal symptoms such as severe vomiting, disturbances of the blood and circulation, damage to the nervous system, and eventually death. When not deadly, such large doses may reduce blood cell production, break up red blood cells in the circulation, enlarge the liver, color the skin, produce tingling and loss of sensation in the limbs, and cause brain damage.
Long-term exposure to inorganic arsenic in drinking water in Taiwan has caused blackfoot disease, in which the blood vessels in the lower limbs are severely damaged, resulting eventually in progressive gangrene. Its occurrence in Taiwan may be influenced by factors such as poor nutrition. However, arsenic exposure has caused other forms of blood vessel disease in the limbs in several other countries.
The relationship between arsenic exposure and other health effects is less clear. The evidence is strongest for high blood pressure, heart attacks and other circulatory disease. The evidence is weaker for diabetes and reproductive effects; it is weakest for strokes, long-term neurological effects, and cancer at sites other than lung, bladder, kidney and skin. More...