aesenic poisoning

1. Arsenic
Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in
many minerals, usually in conjunction with sulfur and metals, and also as a pure
elemental crystal. Arsenic is a metalloid. It can exist in various allotropes, although only the gray
form has important use in industry.
The main use of metallic arsenic is for strengthening alloys of copper and especially lead (for
example, in car batteries). Arsenic is a common n-type dopant in semiconductor electronic
devices, and the optoelectronic compound gallium arsenide is the most common semiconductor
in use after doped silicon. Arsenic and its compounds, especially the trioxide, are used in the
production of pesticides, treated wood products, herbicides, and insecticides. Arsenic forms
colorless, odorless, crystalline oxides As2O3 ("white arsenic") and As2O5 which
are hygroscopic and readily soluble in water to form acidic solutions. Arsenic(V) acid is a weak
acid. Its salts are called arsenates which are the basis of arsenic contamination of groundwater, a
problem that affects many people. Synthetic arsenates include Paris Green (copper(II)
acetoarsenite), calcium arsenate, and lead hydrogen arsenate. These three have been used
as agricultural insecticides and poisons.
Arsenic Poisoning
Arsenic poisoning is a medical condition caused by elevated levels of arsenic in the body. The
dominant basis of arsenic poisoning is from ground water that naturally contains high
concentrations of arsenic. A 2007 study found that over 137 million people in more than 70
countries are probably affected by arsenic poisoning from drinking water.
Exposure to arsenic through groundwater has been a major public health problem in the USA,
Taiwan, Mexico, Mongolia, Argentina, India, Chile, and Bangladesh. More than 100 million
people worldwide have been estimated to be chronically exposed to arsenic from drinking water
containing high arsenic levels. The situation is devastating in Bangladesh that can easily be

2. reflected via the number of affected people. Among the countries’ 7-11 million hand pumped
tube-wells, approximately half have been estimated to supply groundwater with an arsenic
concentration more than 50 microgram/L, which is the maximum level of arsenic allowed in
drinking water.2 People in Bangladesh become terror-stricken when they come to know that
underground water in parts of the country is strained by deadly arsenic. The permissible level of
arsenic in water is 50 ppb (Parts per billion) according to experts. But according to the
Bangladesh Atomic Energy Commission, the level of arsenic is between 150 and 200 ppb in
tube-well water in the districts boarding West Bengal. It is estimated that nearly 80 million
people of the country are affected by arsenic and one in ten has the probability of developing
cancer from the poisoning.
In Bangladesh, arsenic contamination in groundwater was first detected in the year 1993.
According to the data provided by UNICEF in 2008, there are approximately 8.6 million tube-
wells in Bangladesh. Of these, 4.75 million tube wells (55%) have been tested for arsenic among
which 3.3 million (39%) were marked green indicating that the ground water is safe; while 1.4
million (16%) were marked red indicating that they are unsafe to use as sources of drinking
water due to the high arsenic level. Recent findings show that about 20 million people in
Bangladesh are using tube-wells contaminated with arsenic over the permissible level (>50 ppb)
Diseases ofArsenic
Chronic arsenic exposure is associated with many human health conditions, including skin
lesions and cancers of the liver, lung, bladder and skin. It is also associated with many non-
cancer health conditions, such as adverse reproductive outcomes, neurological disorders and
impaired cognitive development in children. Cardiovascular effects in human drinking arsenic-
contaminated water include black foot disease, atherosclerosis, cerebrovascular diseases and
ischemic heart disease. Moreover, maternal arsenic exposure via drinking water is associated
with fetal loss, small size at birth, infant morbidity and mortality. Also causes skin melanosis.

3. Causes
Drinking water
Chronic arsenic poisoning results from drinking contaminated well water over a long period of
time. Many aquifers contain high concentration of arsenic salts. The World Health
Organization recommends a limit of 0.01 mg/L (10ppb) of arsenic in drinking water. This
recommendation was established based on the limit of detection for most laboratories testing
equipment at the time of publication of the WHO water quality guidelines. More recent findings
show that consumption of water with levels as low as 0.00017 mg/L (0.17ppb) over long periods
of time can lead to arsenicosis.
From a 1988 study in China, the US protection agency quantified the lifetime exposure of arsenic
in drinking water at concentrations of 0.0017 mg/L, 0.00017 mg/L, and 0.000017 mg/L are
associated with a lifetime skin cancer risk of 1 in 10,000, 1 in 100,000, and 1 in 1,000,000
respectively. The World Health Organization asserts that a level of 0.01 mg/L poses a risk of 6 in
10000 chance of lifetime skin cancer risk and contends that this level of risk is acceptable.
One of the worst incidents of arsenic poisoning via well water occurred in Bangladesh, which the
World Health Organization called the "largest mass poisoning of a population in history.
Mining techniques such as hydraulic fracturing may mobilize arsenic in groundwater and
aquifers due to enhanced methane transport and resulting changes in redox conditions and inject
fluid containing additional arsenic.
Occupational exposures
Because of its high toxicity, arsenic is little used in the Western world, although in Asia is still a
popular pesticide. Arsenic is mainly encountered occupationally in the smelting of zinc and
copper ores.
Food
It has been found that rice is particularly susceptible to accumulation of arsenic from
soil.[21] Rice grown in the US has an average 260 ppb of arsenic according to a study, but U.S.
arsenic intake remains far below WHO recommended limits. China has set a standard for arsenic
limits in food (150 ppb), as levels in rice exceed those in water.

4. Arsenic is a ubiquitous element present in American drinking water.[25] In the United States,
levels of arsenic that are above natural levels, but still well below danger levels set in federal
safety standards, have been detected in commercially grown chickens.[26] The source of the
arsenic appears to be the feed additives roxarsone and nitarsone, which are used to control the
parasitic infection coccidiosis as well as to increase weight and skin coloring of the poultry.
What is arsenic poisoning? What is
arsenicosis?
Arsenic is Arsenic poisoning or arsenicosis is a condition caused by the ingestion, absorption or
inhalation of dangerous levels of arsenic. a natural semi-metallic chemical that is found all over
the world in groundwater.
In some areas of the world, natural levels of arsenic in the water are extremely dangerous and
hard to detect; arsenic typically has no flavor or odor. Arsenic can also be found in some
industries, whether it be contained within a chemical used, or the byproduct of a certain process.
Arsenic poisoning can cause major health complications if not treated, including death. Because
of the risks involved, some precautions are required to protect the populations and workers at
risk of arsenic poisoning.
Arsenic has proven to be potentially useful in cancer treatment, as some studies have shown it
can send the disease into remission and help thin the blood. This treatment is still being tested,
but could show some promise in the ongoing battle against cancer.
According to Medilexicon's medical dictionary, Arsenis (As) is:
"1. A metallic element, atomic no. 33, atomic wt. 74.92159; forms a number of poisonous
compounds, some of which are used in medicine.
2. Denoting the element arsenic or one of its compounds, especially arsenic acid."
What are the signs and symptoms of arsenic poisoning?
A symptom is felt by the sufferer and described to the doctors, such as pain or dizziness, while a
sign is noticed by other people too. Examples of signs include a rash, pallor, or swelling.
If the arsenic has been ingested orally, the first signs and symptoms of arsenic poisoning will
appear within thirty minutes, and may include some of the following:

5.  drowsiness
 headaches
 confusion
 terrible diarrhea
Please note that if the 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 (leukonychia).
The following signs and symptoms are associated in more severe cases of arsenic poisoning:
 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
 breath smells like garlic
 vomiting
 diarrhea
 Bangladesh
 77 million people (1/2 population of crowded Bangladesh) may have been
exposed to toxic levels of arsenic.
 More than 20% of deaths are caused by arsenic.
 Groundwater is contaminated with As