Arsenic is a poisonous metalloid that can be found in three forms; yellow, grey and black arsenic. Arsenic compounds are used as pesticides and in various alloys. It is not only toxic to insects and some plants, but also to humans. Its toxicity stems from the similarity of the chemical structure to phosphorus, causing it to partly substitute phosphorus in chemical reactions.
Bangladesh, Asia (see picture) has had major drinking water problems for many decades. Most people used to drink surface water, which led to the spread of pathogens such as cholera and dysentery. International organizations started promoting groundwater welling for drinking water production. It was however not known that groundwater in Bangladesh contained significant amounts of arsenic. The arsenic present in the groundwater is of natural origin, being released from subsurface sediment layers under anoxic conditions. Many other Asian countries, such as Vietnam, Cambodia and Tibet are thought to have similar geological environments as Bangladesh. These countries may also have high-arsenic groundwater.
When drinking water wells were installed in Bangladesh, approximately 57 million Bangladeshi people started drinking groundwater with arsenic concentrations far above the legal limit of 0,05 mg/L. After several years of applying groundwater as drinking water over a quarter of the Bangladeshi population exhibited symptoms of arsenic poisoning (arsenicosis).
Arsenic poisoning kills people by disrupting the digestive system. Symptoms include changes in skin colour, formation of skin patches (see picture), stomach pains, vomiting, delirium and gangrene. Chronic low level arsenic poisoning in Bangladesh also results in cancers, such as lung cancer, skin cancer, kidney cancer and bladder cancer.
The arsenic problem was first discovered in the early 1980s, but public awareness of the arsenic crisis did not emerge until the mid-1990s. The World Health Organisation has described the naturally occurring arsenic as the largest mass poisoning of a population in history. Today, more than 85 million Bangladeshi people are drinking the arsenic-rich groundwater. It is very probable at least 80 million people now suffer from arsenic poisoning. The exact number is uncertain because it may sometimes take up to 10 years before arsenic poisoning can be diagnosed.
Bangladesh, Asia (see picture) has had major drinking water problems for many decades. Most people used to drink surface water, which led to the spread of pathogens such as cholera and dysentery. International organizations started promoting groundwater welling for drinking water production. It was however not known that groundwater in Bangladesh contained significant amounts of arsenic. The arsenic present in the groundwater is of natural origin, being released from subsurface sediment layers under anoxic conditions. Many other Asian countries, such as Vietnam, Cambodia and Tibet are thought to have similar geological environments as Bangladesh. These countries may also have high-arsenic groundwater.When drinking water wells were installed in Bangladesh, approximately 57 million Bangladeshi people started drinking groundwater with arsenic concentrations far above the legal limit of 0,05 mg/L. After several years of applying groundwater as drinking water over a quarter of the Bangladeshi population exhibited symptoms of arsenic poisoning (arsenicosis).
Arsenic poisoning kills people by disrupting the digestive system. Symptoms include changes in skin colour, formation of skin patches (see picture), stomach pains, vomiting, delirium and gangrene. Chronic low level arsenic poisoning in Bangladesh also results in cancers, such as lung cancer, skin cancer, kidney cancer and bladder cancer.
The arsenic problem was first discovered in the early 1980s, but public awareness of the arsenic crisis did not emerge until the mid-1990s. The World Health Organisation has described the naturally occurring arsenic as the largest mass poisoning of a population in history. Today, more than 85 million Bangladeshi people are drinking the arsenic-rich groundwater. It is very probable at least 80 million people now suffer from arsenic poisoning. The exact number is uncertain because it may sometimes take up to 10 years before arsenic poisoning can be diagnosed.Legal proceedings began in London in 2003 to determine whether the British Geological Survey was negligent in failing to detect arsenic in Bangladeshi water supplies. The organization conducted research on behalf of the Bangladesh government in 1992, but did not test the groundwater for arsenic. The organization pleas 'not guilty' and argues that at the time of its report little was known about the geological origins of arsenic poisoning.
No comments:
Post a Comment