Archive for the 'Groundwater Pollution' Category

10
May
11

Arsenic in groundwater

By Prof D Chandrasekharam Closed
Categories: Groundwater Pollution

“ Beware of arsenic in drinking water” Bombay times, 8th May 2011 is nothing new. It seem that the editor has asked his juniors to fill this space ( other wise going empty!!) with some sensitizing news and the youngster unaware of the worldly problems, filled this void with this news. Arsenic contamination in groundwater in West Bengal and Bangladesh is a global calamity! Why USA and Bangladesh, there are half dozen top Institutes in India working on this problem and suggesting remedial measures. The reporter should have called some one with this knowledge and filled this void space with better and updated news instead of publishing stale news. Some recent updates are given below for those keen in getting knowledge beyond what is casually reported in the above news paper. Let us be concerned with the state within our own country first and what ever is applicable to West Bengal is true to Bangladesh as well,  since both regions have more or less similar geological formations and both the regions are drained by the rivers originating from the Himalayas.

 Both West Bengal and Bangladesh are affected by arsenic and for over couple of decades, people in WB and BD are drinking groundwater with high arsenic levels. The permissible limit of arsenic in drinking water is prescribed by the World Health Organization is 10 to 50 µg/L. 10 µg/L being the limit for developed countries while 50 µg/L is for the developing countries. Countries like India and China were following 50 µg/L limit but recently China has reduced the limit to 10 µg/L.   Let us not debate on why some of the countries are not following 10 µg/L limit now (it is a issue related to commercial vs political lobby)

 Arsenic is a killer element. Groundwater in West Bengal and Bangladesh is contaminated with arsenic and people are drinking arsenic contaminated water for the last several decades. Since it is tasteless, millions drink such water unknowingly and succumb to its poisonous effect. Nearly 40 % of 80 million people in West Bengal are suffering from arsenic related diseases like conjunctivitis, melanosis, hyperkeratosis, and hyper pigmentation. In certain areas gangrene in the limb, malignant neoplasm and even skin cancer have also been observed. Children are the worst affected. In West Bengal, Nadia, Hoogly, 24 Parganas (N & S), Murshidabad, Burdwan and Malda are the seven districts that are worst affected. The arsenic content in groundwater in West Bengal is ~ 3200 µg/L.  According to WHO this problem in West Bengal and Bangladesh is termed as global problem and several scientific bodies are seeking solution to this problem.  Wrst Bengal and Bangladesh has now become a field laboratory with several international organizations working on this problem. A few of the organizations include: Royal Institute of Technology – KTH, Stockholm Sweden, Government of the Netherlands, Commonwealth Science Council/ Science and Technology Division, University of  Karlsruhe, Germany, UNICEF, CARE, WHO, Dainichi Consultants Japan, London Arsenic Group, University of California, Berkeley, USGS, British Geological Survey and several institutes from India.

 During eighties, to prevent cholera and typhoid menace from surface water bodies that were extensively used by the population to meet their daily needs, UNICEF advocated using groundwater. Arsenic was not detected earlier but during the course of routine quality, check arsenic was detected at levels above permissible level for drinking water. But by then it was too late and several thousands of people of earlier generation were affected. Thus by accident high levels of arsenic was detected in groundwater. Now diseases related to arsenic fom groundwater are affecting third or fourth generation in West Bengal.

 When bore well culture was introduced in West Bengal, it became shot in hand for the farmers since bore-well irrigation started giving the farmers comfortable life and they were able to rise crops through-out the year. This feel-good factor encouraged extensive bore-well irrigation and the number of bore wells increased from about 20,000 in 1976 to 5,50,000 in 2001.  Since then this number started growing beyond expectation.  Thus bore-well irrigation practice made the rural population to exploit groundwaters without any control.  Arsenic that was found only in the groundwater earlier  has now entered the food chain.

 Thus from groundwater arsenic menace has entered the food chain through irrigation practice. A large number of bore wells operate continuously pumping groundwater from different depths to rice fields. The amount of water required is quite large since 90% of the land in West Bengal is under rice cultivation.  The arsenic content in the water pumped for irrigation is same as that mentioned above ( 3200 µg/L). A recent study conducted in parts of West Bengal has revealed that paddy crop has maximum concentration of arsenic scavenged from groundwater. The arsenic content in rice grain is 0.3 mg/L, in husk it is 1 mg/L and in the steam and leaves it is > than 2 mg/L. The root accumulate large amount of arsenic. In the present study it was found to be as high as 169 mg/L. Except roots, all parts of rice plant is eaten by humans and animals. Now we are in an arsenic web!! This problem is no longer confined to West Bengal and Bangladesh. Besides rice, the vegetable cultivated through irrigation also have high levels of arsenic.  Common leafy vegetable like Red Spinach, Amaranth, Chinese Spinach, Indian Spinach have arsenic content > 0.3 mg/L. 

 Thus while countering one disease ( cholera/typhoid) the then advisors gifted West Bengal and Bangladesh with a major and irreversible catastrophe. Perhaps the wisest thing that could have been done is to boil the surface water and drink to counter cholera and typhoid.  Because of bore-well irrigation the entire aquifer (s) are contaminated.

 Remedial measures that are suggested to the rural population by the multinationals are too expensive.

 Now arsenic is also found in amount larger than 50 µg/L in all the NE states of India ( Manipur, Assam, Tripura, Arunachal Pradesh, Meghalaya and Nagaland) and it also slowly surfacing in other parts of the country.  Arsenic contaminated groundwater is reported within the Godavari sub-basins bordering Chattisgarh.  Millions of population depend on groundwater in the rural areas. Both arsenic and fluoride has become a nightmare to rural population.

21
Aug
10

Groundwater, arsenic and irrigation

By Prof D Chandrasekharam Closed
Categories: Groundwater Pollution

Tube well irrigation in West Bengal and Bangladesh is very common. Nearly 9,00,000 tube wells n Bangladesh and 5,50,000 in West Bengal constantly pump groundwater to irrigate rice fields. The groundwater contains greater than 3.2 mg/L of arsenic. In Bangladesh nearly 2 million ha of land is irrigated using arsenic rich groundwater while a little less than 2 million ha land is under irrigation through arsenic contaminated groundwater in West Bengal. Estimates by FAO indicates that 1 million kg of arsenic is added to arable soil every year in these regions. From groundwater, arsenic now has entered the food chain and both As (III) and As (V) is found to enter the rice plant and other vegetable by different mechanism. Thus an arsenic – path – chain, from water to food through soil  has been established. A large number of scientific reports have documented these facts and a great debate is on at several international conferences on the fate of human race due to this menace. In fact more recent studies indicate that the entire Gangetic drainage basin is affected arsenic problem. What is not clear is  1) the fate of arsenic that enters the animals through fodder, 2) crop growth and yield, 3) mechanism of up-take of arsenic by plants 4) genetic effect on humans and animals. This opens up a chain of problems that need to be addressed by the future scientists. Now it is clear that this problems has to be tackled, not by a single group, but by a multi disciplinary group consists of geologists, biologists and  physicians.

 Mind set and will to change is what is needed to tackle this problem failing which generations may get affected in future……..read the article posted in Down to Earth in 2006!!

Arsenic 3 Nov 06_Down to Earth

14
Aug
10

Arsenic in groundwater is a global calamity!!

By Prof D Chandrasekharam Closed
Categories: Groundwater Pollution

Arsenic is a killer element. Groundwater in West Bengal and Bangladesh is contaminated with arsenic and people are  drinking arsenic contaminated water for the last several decades. Since it is tasteless, millions drink such water unknowingly and succumb to its poisonous effect. Nearly 40 % of 80 million people in West Bengal are suffering from arsenic related diseases. Children are the worst affected. The arsenic content in groundwater in West Bengal is ~ 3.2 mg/L while the limit is between 10 to 50 mgm/L. In fact several SE countries have this problem.  According to WHO this problem in West Bengal and Bangladesh is termed as global problem and several scientific bodies are seeking solution to this problem. Now from groundwater this menace has entered the food chain through irrigation practice. A large number of bore wells operate continuously pumping groundwater from different depths to rice fields. The amount of water required is quite large since 90% of the land in West Bengal is under rice cultivation.  The arsenic content in the water pumped for irrigation is same as that mentioned above. A recent study conducted in parts of West Bengal has revealed that paddy crop has maximum concentration of arsenic scavenged from groundwater. The arsenic content in rice grain is 0.3 mg/L, in husk it is 1 mg/L and in the steam and leaves it is > than 2 mg/L. The root accumulate large amount of arsenic. In the present study it was found to be as high as 169 mg/L. Except roots, all parts of rice plant is eaten by humans and animals. Now are in an arsenic web!! Now this problem is no longer confined to West Bengal and Bangladesh. Besides rice, the vegetable cultivated through irrigation also have high levels of arsenic.  Common leafy vegetable like Red Spinach, Amaranth, Chinese Spinach, Indian Spinach have arsenic content > 0.3 mg/L.  With the growing awareness on contaminated groundwater, arsenic contamination is slowly surfacing in other parts of the country.  Arsenic contaminated groundwater is reported within the Godavari sub-basins bordering Chattisgarh.  Millions of population depend on groundwater in the rural areas. Both arsenic and fluoride has become a nightmare to rural population.   

 

for more details go to the link

Food and Water Security

 

 

 

25
Jul
10

Arsenic in groundwater- West Bengal

By Prof D Chandrasekharam Closed
Categories: Groundwater Pollution

Arsenic in groundwater is becoming a difficult problem in many parts of the country. This problem is acute in West Bengal and is spreading to other parts of the country with awareness to quality of drinking water is growing.

Take the case of West Bengal. In 1959, minor-irrigation projects were started in the state in collaboration with the Exploratory Tube-well Organization of the Union government. As per the 2001 census, there are about 5, 50,000- tube wells in the state; 64 per cent of 54640 square kilometres of cultivable land in the state is under irrigation — by tube wells that tap groundwater. Irrigated farming has supported millions of people, but that has a horrible spin off: arsenic levels have risen in the shallow aquifers of West Bengal. But how did irrigation lead to such pollution? The water used for farming had high levels of arsenic and the arsenic accumulated in the roots of rice plants — its levels are reported to be as high as 169 parts per million. When these roots were ploughed back into the soil, during subsequent irrigation arsenic released from roots found their way to the shallow aquifers. The paddy stem, leaves, the grain and the husk have arsenic concentration far above the level prescribed by the World Health Organization. All these parts are consumed by man and animals!! Now even the kitchen vegetables also registered arsenic levels above the prescribed limit.  Now arsenic has entered the food chain in West Bengal. This development began a couple of decades ago and is continuing unabated. Groundwater irrigation was envisaged as a panacea for food shortage, it has polluted drinking water and killed many. The Water Investigation and Development Department, which oversees water quality has completely ignored the problem. And preliminary studies indicate that the rot is spreading to parts of Northeast India.

What can be done?

            There are several technologies to remove arsenic from drinking water  — some of these are reverse osmosis, precipitation and flocculation and solar oxidation. But these are costly and unfeasible to implement and practice by the rural population.

            Providing safe drinking water to rural communities is an integrated effort, which requires engaging skills of hydrologists, engineers, medical experts and non-governmental organisations. These specialists should be involved in identifying the areas affected by arsenic and in collecting data about the extent of the problem. Once this is done, the affected basins should be mapped and permanent observation basins identified. This will not only create a good data bank on individual basins but also trained personnel who can be consulted to oversee the problem in future.

            Tackling the arsenic problem also requires changing people’s mindsets. Since the chemical does not affect humans overnight, there is always a tendency to procrastinate on solutions. The state groundwater organisations and public health departments should take the help pf grassroots bodies in raising people’s awareness in the affected areas.   

Over the long-term

But these are all short-term solutions. There is no viable long-term panacea except harnessing surface water to mitigate both drinking water and arsenic problems. The large volumes of surface water that gets discharged into the seas every year can easily be used for these purposes. For example, the government of Meghalaya has created an excellent lake to store surface water; this reservoir supplies water to communities in Shillong. Facilities to create such water bodies exist in all the northeast states. Besides, the entire region has a good water drainage system; interlinking them scientifically could provide water for irrigation as well as for drinking.  The microbial problem associated with surface water sources can easily be tackled compared to removal of arsenic in groundwater. Of course, interlinking has political problems which can be solved. This is much easier than saving millions from arsenic related diseases. Making the project completely transparent would take care of the problem to a great extent: the data generated should be made available in the public domain. Academic institutions and the state public works departments should collaborate in the endeavour.