What is Arsenic

Arsenic is naturally occurring element. Its atomic number – 33, atomic weight is 74.92;. Chemically, arsenic is always present as compounds with oxygen, chlorine, sulpher, carbon and hydrogen on one hand and with lead, gold and iron on the other. Organic arsenic is generally fewer toxins than inorganic arsenic. Arsenic in element from is insoluble in water. It is soluble in oxidize from.
 

History

Inorganic arsenic has been recognized as a human poison since a long times. Oral intake of arsenic has proved to be deadly on many occasions. But it had been used to treat skin ailments, worms and syphilis in the past. A century ago, incidence of skin cancer were observed due to use of arsenic medicine. It is still used in cattle fodder to enhance physical growth.
 

Occurrence

Arsenic contamination is a global problem now. It virtually appears on all continents. It occurs as results of geological processes and actives by man which include agriculture, manufacturing, mining, smelting etc. Contamination from food and beverage is also extensive.
 

In Bangladesh, high arsenic concentrations are suspected to exist so far in 53 districts out of the total 64 and people of 34 districts have been found to be suffering from various affections caused by arsenic pollution. The physiographic regions vulnerable to arsenic contamination are Ganges floodplain, the Atrai flood plain, the tidal regions, the coastal plain and the Meghna floodplain. The high probability zone, moderate probability and low probability areas of contamination together cover almost 60% of the total country area.
 

Source of Contamination

The Bangladesh arsenic contamination is possibly the largest mass poisoning case in the world now. The ‘Green Revolution’ has been identified theoretical to be the recent cause of the problem which has involved large-scale unplanned withdrawal of ground-water, gradually denuding the arsenic deposited under the fertile delta of Bangladesh millions of years ago by the rivers from the Himalayas or some other source.  The arsenic affected areas of West Bengal are lying on a sediment of Younger Deltaic Deposition (YDD) which extends east-ward towards Bangladesh covering the approximate area of the aforesaid 41 districts which lie mostly in the Atrai, Meghna and Genetics flood plains and the tidal regions.
 

Investigation

The Dhaka Community Hospital (DCH) and the School of environmental Studies (SOES), Jadavpur University, Calcutta, India scientists and support personnel conducted a number of surveys, collecting water samples from 1 lac tube-wells covering 64 Districts including the 53 district suspected to be arsenic contaminated. The samples ware then laboratory -tested and the results of 53 districts show concentration of arsenic in ground-water to be above the maximum permissible limit, which is 0.05mg/l. So far, the collected from 53 districts contained arsenic above 0.05mg/l. While comparing the West Bengal arsenic scenario with the available data of Bangladesh, it appears that Bangladesh’s arsenic contamination disaster ma be more severe and jeopardizing in nature and extent. An updated status report on West Bengal situation shows that 8 districts, 58 blocks and 830 villages are affected; the total area and population of these districts being 38,000km² and 38 million respectively. On the other hand, the area and population of the affected regions of Bangladesh are 87,000km²  and 65 million respectively.
 

Health Effects for Arsenic

Toxicity for arsenic in human body is manifested in three manners:

a)   Arsenic in urine (for recent exposure) 
 
b)   Arsenic in blood (for instant exposure)
 
c)   Arsenic in skin, hair and fingernails (for chronic exposure)
 
1.   Large doses for arsenic can produce human deaths.
 
2.   Lower levels impact many different body tissues or systems: result in ‘systemic’
      effects.
 
3.   Oral intake has greater harmful effects than dermal or inhalation exposure.
 
4.   Following effects may be observed when arsenic is taken orally:

• Skin abnormalities (dark/light spots on skin, ‘crons’ on palms and soles) may progress to skin cancer.

• Increase cancer risk, especially in liver, bladder, kidney and lung

• Irritation of digestive tract, leading to pain, nausea, vomiting, diarrhea

• Aggravated malnutrition affectations

• Decreased production of red and white bloods cells

• Abnormal heart function

• Blood vessel damage

• Liver and/ or Kidney damage

• Impaired nerve functioning pins and needles feeling in feet and hands, hot feeling etc.      

• Fetus damage during pregnancy

Toxicity of Arsenic

1)   Arsenic and certain arsenic compounds are known carcinogens.

2)   Amounts of arsenic intake required to cause harmful effect depends on the chemical and physical form of arsenic.

3)   Inorganic from of arsenic is more toxins than organic forms.

4)   Water-soluble forms are more toxins.

5)   Humans are most sensitive to arsenic than animals.

6)   Studies in humans indicate considerable variation among individuals

• Some humans can ingest over 150mg/kg/ day without apparent ill-effects (1000-1500 mg/kg/day for adults)

• Sensitive individuals affected at 20mg/kg/day  (1000-1500 mg/kg/day for adults)

7)   Doses of 600 - 700 ug/kg/day (around 50,000 mg/kg/day for adults; 3,000 mg/kg/day for infants) have caused death in some cases.   

9.   Maximum Concentration of Arsenic in Drinking Water

The US Environmental Protection Agency (USEPA) has Maximum Concentration Level (MCL) of arsenic set as 20 mg/L.

Many scientists view this is above the threshold or reasonable risk to human health and there is a consideration to lower this to-10 mg/L which is equal to the WHO approved limit.

10.   The Fist Patient Identification: the role of DCH

While conducting a health camp at Paksi, Pabna on 3^rd July 1996 the Dhaka Community Hospital (DCH) dermatologist Dr. Saiful Kabir identified the first cases of Arsenic poisoned patients and referred them to The Pabna Civil Surgeon. The local journalists were also notified of the situation.

The DCH then launched its ‘Arsenic Pollution’ Identification Program’, marked by 4 day survey during 12-15 October 1996 at Pabna town, Ishwardi, Bera and Kushtia. Drinking water samples and specimens of suspected skin diseases patients’ skin fingernails, urine and hair were collected for laboratory tests which subsequently confirmed occurrence of arsenic poisoning in most cases, varying in degrees. Water samples tests revealed that 66% of them contained abnormally high proportions of arsenic. The samples were double tested in the laboratories of Bangladesh Council for Scientific and industrial Research (BCSIR) and School of Environmental Studies (SOES) Jadavpur University, West Bengal, India.

The immediate next step adopted by the DCH was to send a 4- member DCH team to SOES, India for exchanging experience on the subject. Another DCH team of 8 health professionals attended an NIPSOM training on the syndrome. 

The Second DCH survey was participated by Dr. Dipankar Chakraborti of SOES during 20^th December 1996- 5^th January 1997 when 14 examining patients and collection of specimens for tests.

On 6^th January 1997 the DCH and Disaster Forum - Bangladesh hosted a day -long seminar on ‘Arsenic Disaster in Bangladesh’ Where two scientific papers were presented by Dr. Gulshan Ara (DCH) and Dr. Dipankar Chakraborti (SOES) and a number of emergent resolutions were adopted to forestall the spreading menace. DCH also formed an Arsenic Action Group (AAG) to combat the public health disaster on a war footing.

The DCH has also been closely watching the Development of Arsenic Pollution related activities launched by the government and other agencies and joining hands with all activities on any platform. In the DCH newsletters, it has been publishing the day-to-day events on the campaign, highlight of, which are presented here.
 

Highlights of Bangladesh Campaign to Ward off Arsenic Disaster

The Smatter Case Study: A special study was jointly conducted by the DCH and the SOES on the arsenic contamination of groundwater in Smatter village under Shirt Police station in Jester. The test results showed that 91% of the Existing tube-wells in the village were unsuitable for human uses.

International conference on the subject is being jointly organized by DCH and SOES to be during 8-12 February 1998,  in which connection ‘the second international call for scientific papers on arsenic pollution’ has been published widely.

Public Notice on Basic Facts

The DCH publicized NIPSOM -approved public notices on arsenic pollution with a view to informing the public of the situation and advising them on the must to do in this regard.

Indo- Bangladesh Consultation

Recognizing that both the governments India and Bangladesh are facing the challenge of arsenic contamination of drinking water, the WHO regional office in Delhi invited the DCH Chairperson Professor Quazi Quamruzzaman and Dr. Shibtosh Roy to attend a workshop during 29 April 97 - 1 May 97 in Delhi where activities from both countries met and exchanged experience, views and findings for developing a joint program.

DCH (AAG) of DCH has been organizing a countrywide networking, coalition building and sensitizing campaign on the disaster, raising considerable enthusiasm and supportive activities involving important national and international agencies working in the related field viz. GoB agencies, the World Bank, Disaster Forum, Oxfam, NIPSOM, ANN, SOES, CIDA, WHO, UNICEF, CARITAS, Grameen Bank, NGO Forum, BRAC etc.
 

Usual Symptoms of Arsenicosis

The symptoms of arsenic toxicity may take 8 - 14 years to be manifested in a person’s body after the patient starts drinking arsenic contaminated water. This period differs from patient to patient, depending on the quantity/volume of arsenic ingested, nutritional status of the person, immunity level of the individual and the total time -period of arsenic ingestion.

The apparent symptoms of arsenicosis may be said to have manifested themselves as melanosis and keratosis mainly.

Melanosis: Change of complexions towards blackishness/duskiness. The limbs are first affected, then the rest of the body which shows gradual complexion change which is ‘diffuse melanosis’. When the body is marked by black white spots, it is known as ‘spotted melanosis’.

Keratosis: - The palms of the hands and foot-soles become hardened by onslaught of Keratosis. It is not painful or ichy in the beginning, but in later stage, may start rotting and develop gangrenous ulcers. This is called pre-cancerous stage which may cause skin cancer, such as squamous cell carcinoma and basal cell carcinoma. The hardening of the palms and foot-soles is called diffuse Keratosis. Warlike seeds are seen growing on this keratosis of palms and soles. Such tumors may also occur otherwise, which is known as spotted kurtosis.

Due to arsenic toxicity, limbs may be affected by ulcer or gangrene, which in some cases have to be amputated.

Moreover, general weakness, burning sensation, hot feeling, chronic cough etc. May be evident in such patients.
 

Social problems associated with Arsenicosis

A number of social problems arise out of arsenic poisoning of human beings such as:

• Mistaking the skin disorder for leprosy or some other contagious disease and the resultant quarantining;

• The affected are refused water from the neighbors tube-wells;

• The affected are being avoided or discouraged to appear in the public;

• The affected children are being debarred from attending schools, the adults discouraged to attend offices, go shopping, visit medical professionals in the hospital etc.

• With advancement of the disease, patients are rendered incapable of laboring/selling labor and hence victimized by poverty;

• Affected young women being compelled to stay unmarried;

• Diseased married women being sent back to their parents with children;

• Affection of one in jeopardizing the lives of both members of a couple;

• Eligible persons are refused jobs when found to be suffering from arsenicosis etc.

How to Ascertain Arsenic Contamination in Humans

From the symptoms, if someone is suspected to have arsenicosis, then his source of drinking water must be found and water sample tested. If it is found to contain arsenic in greater than acceptable limit (the limit being 0.05mg/l), then drinking that (tube-well) water has to be stopped forthwith. Unfortunately, we don’t have facilities for testing such tonicities available to our people. The DCH has an arrangement of having suspected tube-well water samples tested for presence at the SOES  laboratory at Jadavpur West Bengal in India. This test is carried out at Jadavpur according to AAS method. Bangladesh Atomic Energy Commission and BCSIR laboratories also carry out water tests following AAS method. Anyone can contact either source or any of their associates or the local health dept officials at any place. People may also get in touch with the DPHE officials in this regard. At present the DPHE has facilities to carry out such tests in its Rajshahi, Comilla, Mymensingh and Khulna laboratories following ‘spectrophotometer’ method. NGO and other agencies have limited facilities for such tests in kit method. It should be kept in mind that the tube-well pumping water, which is considered safe, might not remain so if it is within the arsenic contamination zone. So, such tube-wells should be tested every six months or so such contamination.
 

Treatment for Arsenic Poisoning

At any early stage of apparent contamination through drinking water,

• Drinking water from contaminated source must be stopped forth-with and

• Taking nutritious, especially foods rich in Vitamin A, B, C and E will cure the apparent contamination

Advanced level of toxicity is difficult cure but medical consultations are a must in all cases.

It also needs to be remembered that arsenic toxicity is not contagious or hereditary manifestations. It is known to be caused by drinking arsenic contaminated water in our country and it can be rid of if we stop drinking such water. We should not avoid such patients and offer -all co-operation so that their rehabilitation becomes an easier (through time-consuming in many cases) process.
 

How to Combat Arsenic Contamination

Change of habits is the chief tool of combating arsenic toxicity. Only decades back, it was customary in our rural areas to collect drinking water in the afternoon, allow it to settle throughout the night and use it for drinking the next day. But due to the increase in the number of tube-wells and tube-well water being easily available round the clock to everyone, our people became gradually used to drinking tube-well water straight from the pump. Moreover, we like to pump out the water deposit in the tube first before drinking the fresh (!) water which is cooler in summer and less cool in winter. All these changed habits only compel us to drink water that is richer in arsenic and all other mineral contents.

Due to awareness of hygiene, our people got accustomed to drinking tube-well water, to avoid diarrhea disease mainly. But some tube-wells have fallen in the grip of arsenic toxicity lately and as a result, we are faced with a great threat to our public health to day.

Now is our time to get back to our old habit of drinking surface water first to ward off arsenic poisoning. Then we have to –

1.   Test all tube-wells for arsenic pollution and use only the arsenic free tube-well water for drinking and cooking

2.   Use dug-well or pond water, in case all tube-wells are found to be polluted;

3.   Use pond water after treating it, when there is no alternative;

4.   Use river water after treatment when none of the above is available;

5.   If arsenic poisoned water must be taken, then we t collect the water and allow it to deposit sediments before using it. This water has to contain iron in that case. After allowing the water-filled pitcher to settle for 12 to 24 hours, three-fourths of the water from the upper part of the pot has to be poured slowly into another clean container. This water had better be filtered with the help of a 4-5 layered clean gauzy material which should reduced its arsenic contents by at least 70%. The water then may be filtered further before drinking.

6.   Alum treatment: An alum nugget (not powdered) may be dipped for a second in the pitcher full of iron and arsenic polluted water to ease its arsenic deposition process. Later, this water has to be treated as per method mentioned in (5) before using.

Why treat water? It must be remembered that oxygen in atmosphere reduces the arsenic content in water. The sediment-rich water left must be poured carefully into a dung-heap to neutralize its arsenic toxicity.
 

It should be reiterated here that groundwater is being exploited recklessly in Bangladesh as it has been in the neighboring Indian state of West Bengal. In Bangladesh, large-scale irrigation started with deep tube-wells in the later part of the ‘60s. Although the country has huge wetlands, flooded in the river basins, ox-bow lakes and high rainfall, groundwater is consider the major source of water in many districts and its use is increasing every-day. To combat this situation, we need urgent watershed management and awareness campaigns at the grassroots level. Villagers must be made aware of the hazards of drinking arsenic – contaminated water and cooking with it and informed that the diseases are not contagious. Safe tube-wells must be marked properly and villagers urged to drink their water only. All such tube-well should be checked once every three months. Deep tube-wells are also to be checked at regular intervals. People should be encouraged to drink safe water and eat nutritious foods both toward off and get cured of sweet water are among the highest in the world. Moreover, annual rainfall is also more than 2000mm. The arsenic calamity of Bangladesh can be curbed if withdrawal of groundwater is restricted, surface water properly utilized and rainwater harvested. We need a suitable ‘watershed Management’ most urgently.

This page last update: May 15, 2003