Water Health Educator
Water in Bangladesh:
The Impact of Arsenic
Bangladesh is one of the poorest and densest countries in the world. Approximately the equivalent of half the population of the United States lives in an area the size of the state of Iowa. Similar to other developing countries, more and more people are moving from rural to urban areas to try to make more money. In Bangladesh’s capital city, Dhaka, many of these migrants end up in slum communities which are the most densely settled areas in the country. Dhaka has a population of about 160 million- of these people 32 million do not have access to clean water, 75 million do not have access to sanitation services, the infant mortality is 6 percent and 45 percent live in poverty. Many live on less than $1 a day. Water and sanitation problems arise from poverty, overcrowding, poor housing and inadequate waste disposal. Like urban areas, rural communities are also affected by poor water quality and scarcity. About 90 percent of the population uses groundwater as their primary fresh water source. Sanitary groundwater is becoming harder and harder to find for multiple reasons. In coastal areas, groundwater is salty due to soil desiccation and tidal flooding. Shrimp cultivation is commonly done in large bodies of fresh water which leads to contamination. In addition, climate change and the increase in natural disasters that accompany it can cause damage to water and sanitation infrastructure and threaten the supply of natural resources. A rise in sea level can also cause more communities further inland to be affected by the salinization of groundwater. Even when considering the above mentioned water quality and supply problems, Bangladesh is most severely impacted by the presence of arsenic in groundwater wells. Until the early 1970’s, most people got their drinking water from shallow, hand dug wells, rivers and ponds. Diarrheal diseases and cholera were a problem due to drinking contaminated water. In the late 1970’s, international donors spent millions of dollars digging wells in Bangladesh. The wells had steel pipes with hand pumps that tapped into groundwater in the Ganges floodplain. After the installation of the wells, water related disease mortality did decrease however in the 1990’s many of the wells were found to be contaminated with arsenic. The World Health Organization (WHO) has called the exposure to be “the largest mass poisoning of a population in history.” One article estimates that more than 40 million people have been exposed to arsenic levels up to 1200 parts per billion (ppb), which is 240 times what is considered acceptable by the Bangladeshi government. Bangladeshi government scientists estimated in the late 1990’s that more than 20 percent of the drinking water was contaminated with more than 50 ppb’s of arsenic. problems. Long term intake of arsenic can lead to bladder, kidney, lung or skin cancers, skin disorders, disfigurement, gangrene and heart disease. There are currently no effective treatments for arsenic poisoning however taking certain vitamins can relieve some of the symptoms. A Lancet study followed about 12,000 people residing in Dhaka for ten years and found more than 20 percent of the deaths in this population to be caused by arsenic. The authors explained that even exposure to low doses of arsenic could increase the chance of early death and that damage from the arsenic is most likely permanent. They found that more than 75 percent of the sample drank water contaminated with arsenic above World Health Organization standards.When a well is determined to be contaminated with arsenic concentrations over the national standard, it is painted red which means the community should no longer be using it as a water source. In some cases, all of the wells in a community have been deemed unusable which forces the people to find alternative water sources. Many times the only alternatives are the unprotected water sources used before the wells were installed including ponds or ditches. As a result of this, there has been an increase in diarrheal illness which has especially affected children and led to an increase in child mortality. People will often still use the contaminated wells since their only other alternatives are to use bacteria contaminated sources or to walk long distances to other wells.A 2002 study published in the journal Nature Geoscience focused on research done by MIT scientists who were attempting to determine how the arsenic is getting into the water supply. Using a six square mile test site, they found that organic carbon from shallow ponds dug to provide soil for flood protection sinks in the water, seeps underground and bacteria then digest them, freeing arsenic that was trapped in the sediment. The groundwater then carries arsenic into the wells. Based on their research, they recommended digging deeper wells where there is less arsenic present. Also, they mentioned that rice fields help to filter arsenic from water so building wells under these fields could be another possible solution. Unfortunately, not many can afford to dig wells at the depth recommended. Researchers at Berkeley have also been working on finding effective ways to remove arsenic from the water in Bangladesh and have recently filed two patents. The first involves adding coal ash that has been coated with ferric hydroxide to water. The arsenic will bind to the ash which allows it to be easily filtered out. This would only cost around $2 per person per year. The second solution was developed in 2005 and is based on electrochemistry. The device removes arsenic from the drinking water and besides purchasing the device the only thing required is one D cell battery per person per year. Another option some communities are using is harvesting rainwater in tanks. The limitations to this method are that in the dry season there is inadequate supply and the tanks only hold a limited amount. They are, however, easy to maintain and use. When the tanks are empty, many communities use a traditional way of filtering water, through multiple layers of cotton fabric. In 2010, the United Nations (UN) and the government of Bangladesh announced their goal to provide safe drinking water to all by 2011. Although it was a commendable goal, they far underestimated the extent of those who are impacted by arsenic contamination. The UN, WHO and international donors will be key to determining a solution for the arsenic contamination of water in Bangladesh and action must be taken to not only prevent it from continuing to get in the water supply but also to address the health complications it has caused.
Early symptoms of arsenic poisoning include melanomas on the chest and hands, white skin blotches known as leukomelanosis, keratosis, warts that begin on the palms and soles of the feet and eventually cover the body, acute conjunctivitis and respiratory
Water Innovator: Dr. Abul Hussam
By Saima Hedrick
Natural arsenic contamination of groundwater used as source of drinking water is a major problem in Bangladesh, India, Mongolia, China and many other countries.
Arsenic, even at low level (10 micrograms per liter of water), can cause diabetes , nervous system damage, a weakened immune system, and various forms of cancer. I had the opportunity to speak with a distinguished researcher, Professor Abul Hussam, from George Mason University’s (GMU) Department of Chemistry and Biochemistry. Dr. Hussam is an analytical and environmental chemist who has developed the SONO filter which can remove arsenic from water.
Saima: What gave you the idea to develop an arsenic filter?
Dr. Hussam: Well, that is a long story. The arsenic problem was discovered first in West Bengal, India and then in Bangladesh in 1997. In 1998 reports began to show up in international media confirming that Bangladesh had a huge arsenic problem. At the time, I was working on various trace analyses and knew a little bit about how to measure arsenic. That’s how it all started. There was a West Bengal group that was measuring arsenic levels in my hometown, Kushtia, Bangladesh.
My brother and my relatives were still living there and they asked me to develop a way to measure the arsenic concentration in the tube wells. So my brother and I began measuring and found that 60-70% of the wells in the town were contaminated. I measured the first few samples from the 3 tube wells at my home and found that all of them were contaminated. Then we started to think about a solution since there was no access to potable water except the tube-wells. That is when we began working on a filtration system that could be produced locally, in large quantities, and easily maintained.
Identification of the exact sorbent compound and the testing of the removal methods were done at my lab at George Mason. Once we confirmed that the removal process was effective, we developed the filter and tested it in my hometown Kushtia. We then disseminated the filter to relatives and other people and published the results in an international peer review journals. After that we improved the technology to make it more efficient, known as the SONO filter.
Saima: How costly is the production of one unit?
Dr. Hussam: We knew we had to use available resources in Bangladesh. We found that iron turnings were readily available and we could process them to make them more stable and use them in the filter without significant cost. We purchase the iron turnings by the ton and labor is relatively inexpensive. For each filter you need two large plastic buckets, which are the most expensive item in Bangladesh. Overall, each filter costs approximately 25 dollars to manufacture.
Saima: Did you have funding to manufacture and disseminate the filters?
Dr. Hussam: In Bangladesh, the work was funded by my family. My father and my brother are both physicians and have their own clinical laboratories in which the experiments could be done. We used our own finances to do the initial experimentation. The filters are now manufactured by an NGO named Manob Sakti Unnayan Kendro (MSUK).
To date, they have manufactured 250,000 filters. The material that is used within the filter, the composite iron matrix (CIM), is under patent owned by GMU. GMU gave MSUK exclusive rights to manufacture and market the CIM for the filter in Bangladesh.
Saima: Do you know people who have arsenicosis (arsenic poisoning)?
Dr. Hussam: There are hundreds of people in Kushtia alone with arsenicosis. I have seen many of them at the clinical lab in Kushtia. We may have drank the arsenic contaminated water for 15-20 years but do not have any visible manifestations of arsenicosis. However, we believe that many of our relatives died from cancer after ingestion of the arsenic contaminated water. The types of cancer that they died of were unusual for that population.
Saima: What happens when the filters are spent?
Dr. Hussam: The material in the filter is guaranteed to work for 5 years and expected to work for 11 years. A very large number of the filters have been working since they were placed, which is 8 years now. The material will not be used up in less than 5 years. We have a process of buying the filter back and the consumer needs to pay a little more to get a new filter. We can recycle the iron or sell it to the metal industry.
Even if the consumer threw the filter out in the open, it will not contaminate the ground because the mechanism in the CIM mimics the natural arsenic trapping process in the soil. Most of our filters are still working so we have not had to recycle the filters in large quantities yet.
Saima: What do you hope to do with this project in the future?
Dr. Hussam: Our filter is the only arsenic removal filter made in Bangladesh. There are a few others made in Japan, Germany, and Canada but they are very expensive. We are the only producers of these economical filters in West Bengal, Nepal, and Bangladesh. We have sent some filters to Egypt to filter Nile water because this filter removes more than just arsenic. We have sent some more filters to the Marine Science Institute in North Caroline to study how effective it is with bacteria removal. This filter will remove some contaminants in river water, lake water and groundwater.
Several researchers around the world have requested materials from us to do testing. A group from Cameroon and another from Argentina have requested the technology from GMU to test it there. The filter is one of the best for the price. We have plans to develop a filter for household use that can be attached to a pipe. For the US, we would like to develop this filter to remove a maximum of 300 parts per billion (ppb). In Bangladesh, however, the filter has to remove 2,000 - 3,000 ppb.
Saima: Do you think that this filter could be used for hexavalent chromium removal as well?
Dr. Hussam: That is a good question. It has not yet been tested. However, the basic science research was done in the 1970s. At that time, zero-valent iron was used to remove chlorinated hydrocarbons, toxic organic compounds, and chromium. So there is evidence that it may be possible. We know that the filter can remove lead, cadmium, copper, and manganese. Nepal groundwater has a lot of lead that can be removed using this filter.
Saima: Do you think that your filter can fix Bangladesh’s arsenic problem?
Dr. Hussam: We are trying to develop more commercial filters to propagate the technology. Even 250,000 filters only cover 1% of the total need. We do not think we can meet the entire need unless we have a filter that is even more efficient than the current one. We are currently working on other methods and products so we hope to find a solution.
Dr. Hussam has a few pending patents and more on the way. In addition to his 2007 Grainger Challenge Award from the National Academy of Engineering, he has been called a “hero of the environment” by Time magazine, and was awarded the “Outstanding American by Choice” certificate by the U.S. Citizenship and Immigration Services (USCIS) for his contribution to solve the arsenic crisis.
by Saima Hedrick
Arsenic is naturally occurring element that is found in the Earth’s crust. It has metallic properties and is not soluble in water by itself. However, in combination with other elements it can become soluble in water. In the environment, trace amounts can be found in most bodies of water, but levels are highest in areas near volcanic rock and arsenic deposits. Man-made arsenic contamination can increase the levels of arsenic in the water and air.
Bodies of water that are naturally contaminated with arsenic pose the largest threat as this means that nearby populations will consume it regularly, over a long period of time. Current water treatment technologies are not capable of removing the arsenic from drinking water. Food is the next largest source of arsenic exposure. Arsenic bioaccumulates in the tissue of many organisms, which are then consumed by the local population. Cigarette smoke also contains trace amounts of arsenic and can significantly increase the risks of lung cancer when used with other forms of arsenic.
The actual level of exposure depends on the size and solubility of the particles. Highly soluble particles can more easily enter the lining of the lungs and the gut, and then be transferred into the blood. When consumed in contaminated water, arsenic enters the body through the intestinal tract and can be eliminated in small enough amounts. Otherwise, it is transported throughout the body and is stored in many locations including internal organs as well as skin, nails and hair. Long-term consumption of low amounts of arsenic causes arsenic poisoning, also known as arsenicosis, which has many deleterious health effects. Arsenic disrupts adenosine triphosphate (ATP), which is the major energy compound in the human body essential for normal body function. It can contribute to a weakened immune system, and cause diabetes and nervous system damage. Exposure can also cause various forms of cancer, and therefore arsenic and arsenic compounds are classified as Group 1 carcinogens.
The extent of arsenic exposure in the human body can be measured in the blood, hair, nails and urine. If recent, exposure can be measured in the urine since the body can filter out small amounts of arsenic naturally. If urine levels indicate an unusually high amount, the blood can be tested to determine how severe the poisoning is. Testing of hair and nail samples is conducted to determine how long ago the individual was exposed since the arsenic persists in these tissues.
To minimize exposure, people need to be aware of the levels of arsenic in their drinking water and limit their consumption of foods that may be contaminated. For information about your drinking water, visit the EPA Local Drinking Water Information page, or Private Wells page. For information on food recalls for contamination, visit the FDA Safety Recalls page.