A University College London scientist is accusing researchers at the British

Geological Survey (BGS) of "withholding vital figures" on arsenic poisoning

of groundwater in Bangladesh. John McArthur claims that comprehensive water

quality data collected by BGS two years ago will help determine where "safer

wells can be dug in the absence of practical chemical treatments for the

poisoned wells". BGS has refused to make all the data available until later

this year "because in some cases" they "were not sure of it, and in other

cases it was not important". BGS also "wanted to have the first chance to

look at [their] data properly" themselves.

Contact: Dr John M. McArthur, mailto:j.mcarthur@ucl.ac.uk,

http://www.ucl.ac.uk/geolsci/people/mcarthur/homejmca.htm ; Dr David G.

Kinniburgh, BGS, mailto:d.kinniburgh@bgs.ac.uk,

http://www.bgs.ac.uk/arsenic/home.html

(New Scientist, 12 February 2000.

http://www.newscientist.com/news/news.jsp?id=ns222529)

Source: SOURCE-WEEKLY

An article that has an Eh/pH diagram for As(V)/As(III) that interfaces with iron system has been published in this issue. The reference is: Roussel, C., H. Bril and A Fernandez. 2000. Arsenic speciation: Involvement in evaluation of environmental impact caused by mine wastes. J. Environ. Qual. 29: 182-188.

.The study supports the concept that As, when released from As bearing sulfides by oxidation of the sulfide -- and presumably As too to As(III), would be mobile, but that it would be immobilized as it is oxidized to As(V) and becomes arsenate and then tied up with iron "oxides" -- they seem to have found poorly crystalline lepidocrocite.

ACCESS TO SAFE DRINKING WATER DECLINES BY 17 PERCENT.

UNICEF’s Chief of Water and Environmental Sanitation, Mr. Colin Davis, said at a briefing that, Bangladesh has so far sunk about 5 million tubewells so as to provide safe drinking water to 97% of the population. After the detection of arsenic contamination of ground water, access has dropped to 80%. Mr. Davis said the Department of Public Health Engineering has, with UNICEF support, tested 51,000 tubewells since 1996. High levels of arsenic was found in 29 percent of the tubewells tested. According to a UNICEF study, access to safe drinking water in Bangladesh has declined by 17% in the last three years due to arsenic contamination.

UNICEF PLEDGES FUNDS TO COMBAT ARSENIC POISONING

According to UNICEF, 59 out of 64 districts in the country are affected, exposing a staggering 75 - 80 million people to risk from arsenic-poisoning. The DPHE and UNICEF conducted a survey of nearly 400 thanas, in a little over half of which no arsenic was detected. About one in every five tubewells were said to be affected, which has also led to a fierce controversy. There are 4.5 million tubewells in the country, only a quarter built by the government, and it will be plainly difficult to survey all of them, which means that it is not clear how many are contaminated. While shallow tubewells are thought to be more susceptible, some of those which have been sunk deeper do also contain arsenic, like the case cited of ten deep tubewells near Calcutta.

UNICEF has however, assured Bangladesh of its increased financial support to help fight arsenic contamination which has affected nearly 50% of the population. UNICEF Executive Director Carol Bellamy made the pledge while on a three-day visit to Bangladesh in response to appeals made by Prime Minister Sheikh Hasina and Family Welfare Minister Salahuddin Yusuf. Yusuf told Carol Bellamy that 5,000 cases of arsenic poisoning have been reported. Some 80 million of the country's more than 120 million people face the risk of poisoning from ground water.

However it would not be safe to assume that any region is safe without solid evidence.. There are also other parameters to be considered for which there is no available data such as for selenium. Has there been any tests made for viruses in water supplies (in both surface or groundwater)? Quite simply all sources of water should be tested for arsenic for although tests done so far on surface water have not indicated the presence of arsenic -- this should not be taken for granted.

In Jhenaidah arsenic in the groundwater has now crossed the permissible level of 0.05 mg/litre in 159 tubewells. According to the Department of Public Health Engineering, there are in total, 51, 733 tubewells in the district out of which 802 were tested. The water in 159 of the tubewells tested have been found dangerous for human consumption. The following table shows the thana-wise break up of arsenic-contamination.

N.B. Kaliganj, Shailakupa and Harinakunda are the most affected areas.

Comilla

There are a total of 41,943 tubewells in 12 thanas of this district. The Public Health Department conducted survey on 3026 tubewells and found that 2391 tubewells were contaminated by arsenic. All thanas, with the exception of Sadar, Chawddagram, Burichong and Brahmanpara were affected by arsenic-contamination.

Around 1000 people are suffering from arsenic-related diseases. The following table shows the thana-wise break up of arsenic-contamination.

Manikganj

In Manikganj, few people are aware of this silent killer. There are in total around 70,000 tubewells out of which 5,713 tubewells have been tested. Arsenic has been found in 2,014 of the tubewells tested. 12 lac people are consuming this water and are estimated to be at risk.

Narayanganj

In Narayanganj district, three thanas are severely affected with arsenic-contamination. These thanas are Sonargoan, Bandar, Arihajar. Ten thousand people are estimated to be at risk from arsenic-related diseases.

Harvard University

Environmental Sciences and Engineering

The Harvard project is composed of several parts.

1. Examining role of nutrition in arsenic poisoning

2. International database for dissemination of information

3. Geochemistry, Hydrology, Geology, etc. and

4. Water resources management in Bangladesh with a focus on the health risk.

Dr. Richard Wilson of the Harvard University USA is head of the Arsenic Project and Ms. Tania Hakim, a Bangladeshi, who began the project a few years ago is project coordinator.

A team is now visiting Bangladesh to determine for themselves the extent and intensity of arsenic-contamination.

The project team hopes to help by undertaking a careful study of the problem and its remediation. A vital issue is whether or not an appreciable amount of arsenic enters through the food chain.

Most of the water from tubewells are used for agriculture and irrigation. If the arsenic ion the tubewell water does not affect the crops grown on the soil these wells will not need do not have to be tested or changed. This will make the whole remediation problem easier. Therefore it is important to examine crop uptake.

Dr. Winston Yu and Dr. Charlie Harvey are currently writing a paper on the health effects we are likely to see in Bangladesh due to this disaster....

A member of the team says: "Part of the research is to figure out what arsenic concentration levels might look like over time. If a well is clean now, if it will be contaminated, and if so - when? The shallow wells are clean most likely due to fluctuations in the water table. That some deep tube wells are contaminated is an interesting finding."

1) The processes used in arsenic affected area of Chile and Taiwan in removing arsenic from drinking water at full-scale treatment plant (for high-level arsenic removal) is coagulation. Addition of iron or aluminium coagulants to water facilitates the conversion of soluble arsenic species into insoluble reaction products, which are formed through adsorption mechanisms onto coagulated floc. Because good floc formation followed by filtration is crucial to arsenic removal, a high turbidity effluent indicates poor floc formation and is likely to reduce the efficiency of arsenic removal.

2) The University of Connecticut (patent pending) has claimed a novel and cost effective Arsenic Remediation Technology (AsRT) for the immobilization of inorganic arsenic such as arsenate and arsenite. The technology uses iron filings (zero valent iron) and sand to reduce inorganic arsenic species to iron co-precipitates, mixed precipitates, and in conjunction with sulfates to arsenopyrites.

3) In Hungary, the arsenic contamination from groundwater sources (artesian wells) caused serious problem (400000 people are at risk) and ways in removing arsenic have been investigated for about a decade now. A promising, inexpensive solution to the problem was adopted. The arsenic concentration of even high organic matter containing artesian waters can readily be reduced to under the 0.05 mg/l limit, by using the Mg (OH)2 method either on large-scale or in households. The procedure is simple (only needs adding of MgO or MgCl2 and NaOH) efficient and safe.

An Arsenic Treatment plant has been set up on an experimental basis in the district of Meherpur with the financial and technical assistance from the Netherlands. The plant can purify 65,000 gallons of water per hour. The cost of the plant is 3 crore Taka. The plant is expected to fill the demand for pure water for approximately 50,000 people. The overhead tank has a capacity of 1 lac (100,000) gallons.

An arsenic sludge treatment plant has also been included in the project on the bank of the River Bhairab. After purifying the water, the arsenic sludge passes via a pipeline and accumulates in the sludge treatment plant. The sludge is precipitated with iron under the graveyard. According to the authorities, this procedure will not have any harmful impact on the environment.

Scientists from the School of Environmental Studies went to six arsenic affected districts during 1993-1995 to see how the technique works in field. We installed the filtering system in the homes of six families in each of the six affected districts (North 24-Parganas, South 24-Parganas, Nadia, Bardhaman, Murshidabad and Malda) with an elevated level of arsenic in their hand-tubewells.

After being satisfied with the results of the field trial we sent the system to various National recognised scientific institutes for its evaluation. The agencies evaluated our system were

National

1. Industrial Toxicological Research Center, Lucknow (Report Annexure 1)

2. National Test House, Calcutta (Report Annexure 2)

3. National Environmental Engineering Research Institute, Nagpur (Report Annexure 3)

4. Gaighata Science Organization, North 24-Parganas, WB (Report Annexure 4)

Two-organization (1) Asia Arsenic Network Japan (AAN-Japan) and (2) Asia Arsenic Network, Thailand Bureau studied our system themselves in field where we installed our system in W. Bengal. AAN-Japan also wrote to Chief Engineer, PHED, West Bengal about suitability of our system Being satisfied with our arsenic removal system AAN-Japan purchased 300 units from CSIR-New Delhi and installed in Bangladesh . Dr. Chakraborti went to Bangladesh to install the filtering units.

World Health Organization after purchasing 50 filtering system from CSIR, further ordered 500 filtering system for Bangladesh.

Evaluation Report of West Bengal Government (PHED, West Bengal)

Public Health Engineering Department (PHED) after discussing with CSIR representative and SOES decided to test 300 filtering units in arsenic affected villages of W. Bengal. During 29th December 1995 PHED, West Bengal ordered for purchase of 3000 Filter-Tablet system from CSIR through School of Environmental Studies, Jadavpur University for evaluation. We have not yet received any detailed study report from PHED, West Bengal.

This is an ongoing project by CSIR. The major role of analysis (100%) is through NEERI-Nagpur and partly by PHED (10%) and SOES (10%). Although SOES financed for 10% analysis but SOES from its own fund is doing 100% analysis. National Physical Laboratory (NPL), CSIR, New Delhi through CSIR will process and evaluate results.

From our field report we can comment now that Field Trial through actual users is the sure test of a technology. We learnt more about the draw back of our system, what villagers need through interactions with villagers. Laboratory result, field trial result through our experts may show 100% efficiency but users may use it in a different way so that the system may not be as efficient as it should be. For success of the technology we need to make people more aware and educate the user before, during and after installation of the system.

A few examples how villagers used our filter -tablet system will explain why

In earthen pot/ plastic jar one user fitted the filter to the out side of the pot with up side down. One user added 5 tablets for 20 liter of water to get better quality of water. When we asked why did he do this! He replied if one tablet would made good water five tablets will make better water.

In our laboratory experiment we found tablets are effective up to 15 months (as we kept in dark). The villagers keep the box of tablet near the oven or outside where sun rays enter, thus power of oxidation of tablet is partially lost and arsenic removal efficiency will decrease.

Our report with full comments will be available after May 2000.

ISSER-USA wants to evaluate our system for their use in Bangladesh.

A meeting was held in the DPHE conference room on March 8, 2000. Organised by the LCG sub-group on water supply and sanitation of World Bank its objective was to define the proposal formulated by the working group under the Arsenic Mitigation Programme.

The members of the working group include Mr. Ainun Nishat; Mr. Tanvir Ahsan; Mr. Shafiul A. Ahmed; Mr. Peter Wurzel; Mr. Philippe Barragne; Ms. Sharmeen Murshid; Ms. Elizabeth Jones and Mr. Han Heijnen.

.

According to the Government of Bangladesh, 60% of the patients suffering from arsenocosis are male. Of these most (55% of the total) are in the age group 16- 40 years. 14.5 % of all identified patients are under 15 years.

Dr. Iftekhar Hussain told delegates at a seminar organised by NIPSOM in Barisal District that soon 1 in 5 persons who have been affected by arsenic will likely to be attacked with cancer.

The tender called by Bangladesh Arsenic Water Mitigation Project (funded by WORLD BANK) calls for a qualitative test capable of detecting 10 ppb level As in Water using only Analytical grade chemicals. Analytical grade chemicals as per the following manufacturers...

E.Merck

BDH

GFS

Fluka

...... all contain around 500 ppb of Arsenic. The SUPRA PURE grade of E.Merck lists As at 5 ppb max. on the container. For achieving a 10 ppb detection limit through solution route the recommended acid should be a minimum of the SUPRA PURE GRADE or similar grade from other manufacturers.

Also the water to be used for the preparation of the reagents etc. should have 18.2 MWð resistivity. Analysis of arsenic in water samples at levels as low as 10 ppb via arsine generation calls for quality inputs.

The Zn reduction method or the Borohydride reduction method requires Arsenic free Potassium Iodide, Hcl as well as Zinc or Borohydride. When it is required to determine As at 10 ppb level, all the inputs put together should not contribute Arsenic to the level of the sample. It is then that a signal of twice the standard deviation of the blank can be accepted as the minimum detectable quantity.

Experts say it is not possible to obtain the the detection limit of 10 ppb with the listed specifications for the reagents & therefore the specifications cited in the tender are inadequate.

As it is not possible to discriminate visually the colour changes that result as a consequence of the concentration changes in the range of 10 to 50 ppb. the choice of strip test for qualitative determination of Arsenic in the range of 10 to 100 ppb is not the right choice. (Unless of course the purest forms of Zn, SnCl4, HCl etc. are employed.

The recent outbreak of arsenic in groundwater of Bangladesh has prompted the widespread use of arsenic field kits. The kit involves the generation of arsine (AsH3) from inorganic arsenic species by reduction with Zn and HCl. The arsine then reacts with a test strip containing HgBr2 to produce a colour that is compared with a colour scale for quantitation. It is known that arsine gas is one of the most toxic substances known to man. The objective

of this work is to measure the concentration of ambient arsine produced during the test and suggest a safe handling procedure. The analytical method is based on integrated AsH3 measurement by a single-point arsine monitor. The method can be used to measure 4-50 ppb arsenic in water with 10% in precision and accuracy. Experiments show that a typical test kit produces arsine with a 90% efficiency. The concentration of arsine produced even at low level can be more than 9 times above the 50 ppbv threshold limiting value (TLV). Actual kit experiments show that 50% of the arsine escapes the reaction cell during the test. We estimate that the maximum arsine concentration in the immediate vicinity of the kit can be more than 35 times TLV of arsine from a single experiment with 100 ppb total arsenic in solution. Particularly, field workers performing a large number of tests in highly affected

areas are exposed to a much higher level of arsine. We suggest that the tests should be performed in well-ventilated places and that the worker should be provided with a gas mask to minimise arsine inhalation.

The Merck field kit (Arsenic Quant Test Strips, Alfa-Aesar, USA) for semiquantitative determination of arsenic ions was used to generate arsine under normal laboratory conditions. The reagents provided with the field kit, Zn dust and 32% HCl, were used throughout the experiment. Ambient AsH3 gas concentration was measured by a commercial single-point arsine monitor (SPM, Hydride Chemcassette Detection System by Zellweger Analytics, Inc., Lincolnshire, IL). The instrument works by measuring the change in colour of a proprietary reagent (silver nitrate as the main component) on a paper tape by reflectance photometry. As an ambient arsine monitor, the instrument pumps in air through an inlet at 350 mL/min. The monitor has two alarm levels at 25 and 0 ppbv. Although the alarms can be disabled, we decided to leave them on in order to simulate a toxic hazardous

condition.

The arsenic calamity of Bangladesh presents a challenge n field analytical methodology for rapid and accurate measurement of inorganic arsenic in drinking water. The kit is not only inadequate to screen water samples containing less than 100 ppb of arsenic, it also produces toxic arsine gas that may be a health hazard. We believe the kit experiment

should be performed either under a working fume hood or in the open field with good airflow. The latter may cause unacceptable results as discussed earlier. Particularly, workers performing a large number of tests in highly affected areas should be provided with a gas mask to minimise arsine inhalation.

Recommendations when using Merck Kits are as follows:

1) If the range of arsenic in the water is more than 100 ppb, the tubewell should be marked red.

2) If the result is 100 ppb, it should be retested in a laboratory with instruments that can detect arsenic below 100 ppb.

3) Any organisation involved in water supply should take approval from the Government of Bangladesh and WHO regarding the bacterial test and recommended permissible level of arsenic in the water.

4) To test for arsenic in water, the following organisations have laboratory facilities.

DPHE (three laboratories)

BSIT

Dhaka Community Hospital has also set up a testing laboratory with the help of Dr. Dipankar Chakraborty of SOES, Javadpur, Calcutta.

According to a research study, urine may provide a guideline to ascertain whether a person is still consuming arsenic-contaminated water or not.

The research aimed at identifying the bio-chemical markers of arsenicism, a state of chronic arsenic contamination, to aid in diagnosis, treatment and prognosis. the research was carried out at the Biochemistry Department of Bangabandhu Sheikh Mujib Medical University.

The Head of the Department, Prof. Mohammad Suhrab Ali, now a member of Public Service Commission, and his associates carried out the 10-month-long study from July 1998 to April 1999.

A modified replica of earlier studies, it was undertaken to compare and contrast three different bio-markers - hair, nail and urine - of arsenicism from drinking water.

Blood arsenic is not considered to be a good indicator because it is passed through the blood stream within hours of absorption.

In an unexposed person, arsenic concentration in urine ranges from 0.01-0.05 milligram/litre. In hair usually below one mg/kg and in blood 0.0015-0.0025 mg/litre.

In the study, samples were collected from Hatkapa, Moghbazar, Millkanda, Charalal of Sonargaon, Narayanganj, Nababganj of Rajshahi and Daudkandi of Comilla which were already declared as arsenic-contaminated areas.

A total of 30 subjects were included in the study. They were categorised into two groups - Withdrawal group (Group-I): Subjects who had arranged more or less safe drinking water and Exposed group (group-II): Subjects who were consuming more or less arsenic-contaminated water.

Some 13 subjects were in group 1 and 17 in group 2. Among the 30 subjects, 9 were female within the age limit of 18 to 70 years. The mean age was 31.8 years.

From each subject single void urine; about 50 milligram (mg) hair; and about 100 mg nail samples were collected for analysis.

Mean arsenic content of nail was 4.94 mg/kg in the withdrawal group and 7.85 mg/kg in the exposed group. The mean arsenic content of hair was 2.29 mg/kg in the withdrawal group and 3.73 mg/kg in the exposed group.

Urine samples in the withdrawal group were negative for arsenic in 8 subjects and positive for 5. In the exposed group urine samples were negative for arsenic in three subjects and positive in 14 subjects.

Urine samples positive for arsenic were significantly higher in the exposed group.

The researchers said their findings indicated that hair or nail sample cannot tell whether a person is still consuming arsenic-contaminated water or not but urine samples can. They have also found a strong correlation between arsenic in hair and arsenic in nails, indicating that nail samples may provide a suitable alternative to hair in diagnosing chronic

arsenicosis.

Prof. Suhrab and his associates found that when all the subjects in the study were considered as a single group, the mean arsenic content in nail samples was 6.47 mg/kg which was greater than that of the hair samples which was 3.15 mg/kg.

The difference was statistically significant and indicated that nail samples may be more reliable in the diagnosis of chronic arsenicosis. (UNB)

The concentration on " chemical treatment at household level" as a solution for arsenic in the groundwater has resulted in an increase in the use of aluminium sulphate. Yet this could be a cause of aluminium poisoning. As, according to the experts, a person who already has arsenic related diseases will have a greater manifestation of arsenic poisoning, this should be of concern.

In other words if treatment to remove arsenic from the water is done at home, the risk of aluminium intoxication is vastly increased as the floc ( aluminium hydroxide) that separates out when the sulphate is mixed with water is amphoteric- i.e., it dissolves in both alkaline and acidic solutions. When aluminium sulphate mixes with water it release both aluminium hydroxide solid AND sulphuric acid. If too much aluminium sulphate is added, the acidity, due to the sulphuric acid, becomes so high that the hydroxide re dissolves. This gives a clear and apparently pure looking solution which people think is safe to drink.

Since so many people are already vulnerable to arsenic poisoning as well as iodine deficiency, it is totally unacceptable to discount exposure to a known neurotoxin-and one with such devastating results - on people already under severe environmental challenge. Exposure to environmental aluminium is one of the great disasters of our time and one which will eventually become much more widely accepted as the evidence continues to accumulate. And since lemons are used so extensively in Bangladesh in cooking, you get primary attack on the aluminium pots by the acidity of the lemon, then the formation of an aluminium citric acid chelate, These chelates are one of the most dangerous routes of infiltration into the body for aluminium , and wherever special circumstances, such as this arise, it is highly dangerous to use aluminium for cooking utensils. (Doug Cross-Environment Consultant).

A recent study by Koji Arizono and other researchers at the Prefectural University of Kumamoto and the University of Nagasaki, Japan shows that bisphenol-A (BPA) in plastic tableware and other utensils leached into hot liquid. Worn or scratched products leached even greater amounts of the chemical. Low doses of bisphenol-A(BPA) have been found to cause reproductive malformations in male rat off-spring, including deformed genitals and enlarged prostates. With new research indicating that plastic feeding bottles and utensils in common use could have serious consequences for human life, this is of concern as plastic buckets are in use in the treatment of arsenic contaminated water. BPA leaches out of plastic even at temperatures as low as 60 degrees Celsius therefore the use of plastic buckets for treating arsenic-contaminated groundwater could therefore be dangerous without the addition of aluminum sulphate to the water.

Source : Local newspapers & the InterNet.

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