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Due to special geological conditions, India's drinking water is often contaminated with arsenic, fluorides, and iron compounds that occur naturally in the soilStage Image

Due to special geological conditions, India's drinking water is often contaminated with arsenic, fluorides, and iron compounds that occur naturally in the soil

© Laif

Focus on arsenic poisoning

Water testing labs to prevent arsenic poisoning

2013/9/16

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Since the 1990s, people in the state of West Bengal in India have known how contaminated their groundwater is with toxic substances. In spite of this risk, millions of new wells have been dug since then. Information campaigns and water testing labs such as the ones that EMD Millipore has helped to set up to prevent arsenic poisoning are now helping to make life safer for the region’s inhabitants.

  • Michael Berg, an environmental geochemist at the water research institute Eawag
  • Michael Berg, an environmental geochemist at the water research institute Eawag
    © Eawag

    This death comes silently, invisibly, and slowly. It all began very promisingly decades ago, when international aid organizations became aware of the disastrous drinking water situation in India’s rural areas. Quick action was needed, because village ponds were used not only to obtain drinking water but also to water animals and serve as latrines.

    As a result, large-scale aid projects were launched to replace these ponds with wells that allowed the villagers to drink clean, germ-free groundwater instead of polluted, germ-infected surface water. However, there was a problem with the wells that was not discovered until decades later.

    The supposedly clean groundwater from the wells contained threats other than germs: arsenic, fluoride, and iron compounds. Arsenic, in particular, slowly poisons people over a period of years or even decades. Water testing systems from EMD Millipore are now helping to detect these toxic substances in drinking water. The company is working together with the government authorities of the state of West Bengal to set up water testing labs throughout the region.

    The partners aim to make the local people feel safe again — a feeling they have lost due to widespread cases of arsenic poisoning. After feeling great relief that the improved drinking water supply had caused infectious diseases to wane, people were shocked to realize that the water hadn’t become safer after all.

    “In the 1980s, a physician in West Bengal noticed that people were suffering from strange pigmentations and other skin diseases,” says Michael Berg, an environmental geochemist at the Eawag water research institute in Switzerland, who studies the contamination of drinking water with heavy metals worldwide. “The doctor thought that arsenic could be the cause. After extensive research, arsenic was found in large amounts in the drinking water.”
  • Testing for arsenic at a well in IndiaEnlarge
  • Testing for arsenic at a well in India
    © EMD Millipore

    Up to 100 times higher than the permissible limit


    Unlike diarrheal diseases, which quickly cause symptoms that allow the diseases to be traced to the drinking water, the continuous ingestion of toxic substances has less obvious effects. “It often takes ten to 15 years for arsenic poisoning to lead to obvious symptoms,” explains Berg.

    In its pure form, arsenic is a harmless element. However, its compounds with elements such as oxygen are highly toxic. A single dose of 1.5 milligrams per kilogram of body weight is fatal to human beings. Although people don’t have to be afraid of consuming such a large dose from the drinking water, steadily poisoning the body with smaller doses causes skin diseases and increases the risk of dying of cancer.

    That is why the World Health Organization (WHO) stipulates a limit of 10 micrograms of arsenic per liter of drinking water. “In West Bengal, the concentration is generally 10 to 20 times higher, and we have even had cases when it was up to 100 times higher,” explains Berg. The intensity of the illness and its symptoms increases with the dose and the length of time that the poison is consumed.
    EMD trains the teams at the water testing labs

    EMD trains the teams at the water testing labs

    © EMD Millipore

    Drinking water contaminated with arsenic is also a problem in China, Indonesia, Vietnam, and Cambodia. It can potentially arise in any region where sediments are released by the interplay between rivers and mountains and where the inhabitants get their drinking water from wells. “Arsenic can be found in the soil all over the world, including in Germany and Switzerland,” says Berg.  “The difference here is that we have alternative sources of drinking water.” The problem, he explains, is neither new nor man-made. “However, it didn’t become a problem until contaminated groundwater was extensively used for drinking purposes,” he adds.
  • Prantik Mukherjee from EMD Millipore Lab Essentials manages the project on behalf of EMD
  • Prantik Mukherjee from EMD Millipore Lab Essentials manages the project on behalf of EMD
    © EMD

    449 million people at risk


    The situation is especially critical for the people living in the Ganges Delta, one of the world’s largest sedimentary basins. The soil in the delta consists of layers of arsenic-bearing sediments that were carried by rivers from the Himalayas down to the Bay of Bengal. The pumping action of the wells releases the arsenic from the water-bearing sediments. The WHO estimates that this contamination poses a health risk to 449 million people.

    “We are proud to be able to do something for our country and our people.“

    Prantik Mukherjee
    EMD Millipore Lab Essentials

    The 100 water testing laboratories that EMD Millipore has helped set up in West Bengal to date are used to detect not only arsenic and fluoride but also other substances such as nitrates from over-fertilized soils. Once the problem has been recognized, the toxic substances can be filtered out of the water relatively easily. One of the ways to remove arsenic is to use a clay or plastic container filled with a mixture of sand, coal, and iron filings.  

    The arsenic ions adhere to the iron filings so that the water that flows out at the bottom is largely free of arsenic. According to researchers, it is crucial that the local people be sensitized to the issue and made aware of the dangers of chronic arsenic poisoning. As a result, EMD also supports the Indian government’s efforts to provide information and teach people about water quality.

    “This project gave us the opportunity to combine business activities with social commitment. We’re proud to do something for our country and our fellow citizens,” says Prantik Mukherjee from EMD Millipore Lab Essentials, who manages the project on behalf of EMD Millipore. For its dedication, the project team received the 2012 EMD Award in the Customer Orientation category.

    2013/9/16

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    About arsenic
    Arsenic poisoning can be either acute or chronic. Depending on a person’s weight, 60 to 170 milligrams of arsenic trioxide (an arsenic-oxygen compound) is enough to kill a human being. Because acute arsenic poisoning used to be undetectable, the substance was a popular means of committing murder.

    The poison interferes with the body’s DNA repair and cellular metabolism, and this interference can cause cramps, nausea, internal bleeding, and diarrhea. It can ultimately lead to kidney failure, cardiac arrest, coma, and death.

    Chronic arsenic poisoning through anionic arsenic (arsenic dissolved in groundwater) can lead to skin diseases and damaged blood vessels. Because the poison also deactivates tumor-suppressing proteins, it can cause malignant tumors in the skin, lungs, liver, and bladder.



     
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