The Subcontinent in the Grip of Arsenic/Eng
The Subcontinent in the Grip of Arsenic
In the twenty-first century, arsenic pollution has emerged as a deadly silent curse facing the environment and human civilization. This tasteless and odorless metalloid (atomic number 33) has created a terrible crisis known as “The Subcontinent is in the Grip of Arsenic” in the lives of millions of people in the Ganga-Brahmaputra and Padma-Meghna basins. Arising from the unplanned extraction of groundwater and the unchecked use of chemicals, this toxic hazard has today taken an epidemic form across the entire region, including India and Bangladesh. Exceeding the limits set by WHO, this ‘fatal trap’ is silently engulfing almost every organ of the human body. To break free from this situation, what is needed today is deep awareness at all levels, groundwater conservation, and effective scientific measures.
The Subcontinent is in the Grip of Arsenic
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Arsenic (As; 3d¹⁰4s²4p³), a tasteless and odourless metalloid, is one of the greatest horrors of the present century. It can be called a most secret deadly trap of human civilization. In the Periodic Table, it coexists in Group VA with deadly substances like nitrogen, phosphorus, antimony, bismuth, etc. Its atomic number is 33 and atomic mass is 74.9. Its melting point is 1090K or 817° Centigrade and boiling point is 887K or 614° Centigrade. Arsenic is mainly found in three allotropes. Common arsenic is mainly grey in colour, its density is 5.37 gm/cubic cm. The most alkaline allotrope of arsenic is yellow in colour, it is unstable and rare. Its density is 1.97 gm/cubic cm. The third allotrope of arsenic is black in colour. German alchemist Albertus Magnus identified arsenic in 1250. According to the WHO, the Maximum Contaminant Level of arsenic in drinking water is 10 ppb, although in two countries of the subcontinent, India and Bangladesh, this level is present up to 50 ppb.[Ar]
The Subcontinent in the Grip of Arsenic
The effect of arsenic pollution in the subcontinent first came to public notice in 1982 in some districts of West Bengal, and it was recognised in 1983. And thereafter, the presence of arsenic was discovered in 6 districts on the eastern border of West Bengal adjoining Bangladesh. These districts are Malda, Murshidabad, Nadia, North 24 Parganas, South 24 Parganas and Bardhaman. According to the Institute of Public Health Engineering, the drinking water of 104 blocks in 11 districts of West Bengal is dangerously contaminated with arsenic, the rate being 0.1 mg per litre of drinking water. Whereas according to WHO, the maximum permissible limit of arsenic in drinking water is 0.05 mg per litre or 50 ppm. According to the Institute of Public Health Engineering, among the said 11 districts, the condition of 5 districts is alarming. Among them, 5,70,500 people in 6 blocks of Purba Bardhaman; 20,15,663 people in 8 blocks of Malda district; 23,87,365 people (90%) in Murshidabad; and about 83% of people in 10 blocks of Uttar Dinajpur are in the grip of arsenic. The School of Environmental Studies (SOES), Jadavpur University, in 2001 collected and tested 105,000 drinking water samples and 25,000 biological samples from 9 of the 18 districts of West Bengal and found that out of a total population of 42 million in 2,700 villages of these 9 districts, 6 million population use drinking water with arsenic amount ≥50 μg l⁻¹ and the effect of arsenic is evident in the bodies of about three lakh population. In 2008, the presence of arsenic was detected in Rajnandgaon village of Chhattisgarh. On the other hand, the picture of neighbouring Bangladesh is also terrible. The Department of Public Health Engineering of Bangladesh discovered the presence of arsenic for the first time in 1993 at Borgharia mouza, which came to public notice in February 1995 at a seminar organised by the School of Environmental Studies, Jadavpur University, West Bengal. According to a WHO report, 41 out of 64 districts of Bangladesh are more or less in the grip of arsenic. Under the BAMWSP project, 27% of 50 lakh tube wells in 270 upazilas of Bangladesh have arsenic above the tolerance limit, among them Chandpur (90%), Munshiganj (83%), Gopalganj (79%), Madaripur (69%), Noakhali (69%) are more arsenic-prone. According to UNICEF (2008), 20% of deaths in Bangladesh occur due to the effect of arsenic. According to the British Geological Survey (1998), from an observation in Bangladesh in 2000, it was known that in 50 of the 64 districts of Bangladesh, the amount of arsenic in groundwater is more than 50 μg l⁻¹ and more than 25 million population use water with arsenic ≥50 μg l⁻¹ as drinking water. The Terai region of neighbouring Nepal is highly arsenic-prone. Here, in Newalparasi district, arsenic was found in more than 10 ppb in 26% of shallow tube wells. The Japan International Cooperation Agency and the Environment found evidence of arsenic in more than the ‘WHO’ permitted level in 72% of deep wells in the Kathmandu Valley of Nepal and measured this level as 50 ppb in 12% of wells. On the other hand, after testing 1200 drinking water samples of Pakistan, it was found that 50-60 million population here use water with 50 mg/L arsenic as drinking water.
The Subcontinent in the Grip of Arsenic
In the riverine subcontinent, just as the river is one of the main natural blessings for sustaining life, the subcontinental population is not free from its curse either. The Ganga-Brahmaputra (WB) and Padma-Meghna (BD) valley regions of South Asia, i.e. the subcontinent, are one of the main fields of arsenic. In a recent survey, it was found that about 50 crore population of about 51 lakh sq. km area comprising Bangladesh; West Bengal, Bihar, Jharkhand, Uttar Pradesh under the Ganga-Meghna-Brahmaputra river basin are in the grip of arsenic. The amount of arsenic present in the groundwater of 13 districts adjoining the Ganga and Gandak in Bihar is 0.05 mg/L. In this field of South Asia, weathered rock debris originating from the Himalayas is transported by rivers and deposited in the lower basin region. As this water flow continues for a long time, the accumulation of arsenic in the lowland region also continues. Since this lowland region is formed of sedimentary rocks, when arsenic reaches there along with other minerals, due to the low amount of iron oxide and aluminium, this arsenic, unable to accumulate on the surface of the soil, gradually descends downwards with the downward water. Again, due to the presence of a large amount of arsenic in underground rocks like Nickolite, Scorodite, Arsenopyrite etc., when water crosses this rock layer, it carries the arsenic particles and deposits them underground. In the Gangetic delta region, the effect of arsenic is greater at a depth of more than 20 metres and less than 100 metres. But due to excessive extraction of groundwater in this part, arsenic is also entering the lower or deeper level along with the water table. As a result, the deeper part is also not free from arsenic pollution. Again, as the river basins are highly agricultural, arsenic emitted from pesticides, chemical fertilisers used in agricultural land and arsenic-containing water discharged from various industries mix with soil water and have built up this large reservoir of arsenic. In the subcontinent, mainly two types of arsenic are noticeable, namely – Holocene age deposited Grey Micaceous sand which is available in sufficient quantity in the shallow part and Pleistocene age deposited Brown Sand which is available in the deep part.
The Subcontinent in the Grip of Arsenic
The effect of arsenic on public life is terrible. In ancient times, news of the killing of many secret kings with arsenic is known. From the seventeenth to the twentieth century, arsenic was again used in curing diseases. If 120 to 180 grams of arsenic enters the body, death is inevitable within 24 hours. This amount of arsenic is called Acute Toxicity. A slightly less amount than this amount is known as Chronic Toxicity. Due to its effect, along with abnormal changes in various organs of the body, black spots appear. According to the Lemont Study, in South-East Asia, one in every 18 adults dies due to the effect of arsenic. According to the 2014 Mailman Study, 1 in every 5 people dies due to the effect of arsenic. Due to such deadly power of arsenic, arsenic is called the ‘Poison of Kings’. In acute poisoning of arsenic, external symptoms start to appear within 30 minutes. And in chronic poisoning (such poisoning occurs due to drinking arsenic-contaminated water for a long time) structural and functional abnormal changes occur in the human body. Due to its effect, the gastro-intestinal system is affected and as symptoms, inflammation in the stomach, pain in the lower abdomen is felt. Besides, the oral cavity dries up and vomiting occurs, the incidence of diarrhoea increases and garlic odour is found in the stool. Due to the effect of arsenic, respiration and lungs are also damaged. The wall of the pulmonary blood network decays and breathing is hampered. Due to the effect of arsine gas, oxygen supply in the blood decreases, the voice breaks and lung inflammation and asthma appear. Due to the effect of arsenic, itching on the skin, black spots on the skin of hands and feet are observed. Hair falls out, kidneys are damaged and blood cells and protein are excreted with urine. The prevalence of cancer increases. In the words of one of the foremost arsenic experts, Professor pharmacologist Joseph Graziano of Mailman and Earth Institute, “No organ system goes untouched,” from this the horror of arsenic can be very easily understood.
The Subcontinent in the Grip of Arsenic
After the presence of arsenic in West Bengal in the subcontinent first came to public notice, the School of Environmental Studies under the supervision of Jadavpur University called for a Vigorous Research and in 1995 the first international seminar was held. Thereafter, in February 1998, at Dhaka Community Hospital, a seminar titled “Arsenic of Ground Water in Bangladesh: Cause Effect and Remedies” and on 12 April 1999, a seminar titled “Aquifer Pollution by Arsenic in Bangladesh and West Bengal” were organised consecutively. In the same year, in June, at Rajshahi University, under the supervision of life and earth scientists, in a programme called “National Workshop on Arsenic Pollution in Bangladesh: Its Cause, Effects and Mitigation”, the effect of arsenic pollution and the technological ways to remove it were discussed in the light of various research papers. In 2003, 2-3 March (Calcutta) & 5-6 March (Dhaka) The Fifth International India Bangladesh Symposia was held. On 16 March 2003, in Kyoto city of Japan, a conference called “The Third World Water Forum: Technological and Policy Dimensions of Arsenic Contamination in the Asian Region – Water Supply, Sanitation, Hygiene, and Water Pollution Session” was held. UNICEF and World Bank advised digging deep wells to mitigate the effect of arsenic in the subcontinent. Several methods are in use for removing arsenic from water, namely: Iron Exchange, Reverse Osmosis Ceramic Filter, Adsorption on different materials during Filtration, etc. Among them, the first three are expensive. The filter invented by following the fourth method is now available in the market. Besides, to reduce the level of arsenic in drinking water, 0.1 gram of alum (Commercial Alum) per litre of water can be used. Again, to reduce the tendency of arsenic in the groundwater level, three methods are in use in the subcontinent, namely: Physical or Chemical Remediation, Biological Remediation, and Macrobiological Bioremediation, etc. Among these, in the first method, the level of arsenic can be reduced through Oxidation, Precipitation and Adsorption and Ion Exchange. In the second method, arsenic is diluted by planting certain plants through a few specific methods, this is a slow method; the methods are Phyto-extraction, Phyto-stabilization, Rhizo-filtration, Phyto-volatilization, etc. The third method is considered cheap and environment-friendly. It is completed through two processes, namely – Bio-stimulation Process and Bio-augmentation. Besides, in India, the Public Health Engineering Department of the State is working to spread awareness about arsenic through various local clubs and NGOs.
The Subcontinent in the Grip of Arsenic
Arsenic is a daunting terror of the present century. This terror is mixed with water, a most essential element for sustaining life in the living world. Some amount of arsenic is naturally present in every living body, after this, if the supply of this poison from outside continues, it need not be said that the population of the subcontinent will face dire danger in the near future. Therefore, to establish an arsenic-free environment, we have to be vigilant at every moment. Public awareness has to be built up. The light of awareness has to be spread in every district, block and even in the neighbourhood of every village affected by arsenic. If the presence of arsenic in drinking water of any place is detected, it should be informed to the local health officer. When digging a new well/tube well, it is desirable to test the level of arsenic in the water and only then drink it. Where one’s own little awareness is capable of giving oneself and others a healthy life, there should be no miserliness in acquiring awareness. Finally, it must be said that in facing all the environmental problems of the 21st century, the only and infallible step is ‘tree planting’, in this case too it is no exception. Along with following ‘One Child, One Tree’, we have to build up forest cover around us unitedly. The government has to continue the uninterrupted supply of drinking water in arsenic-affected areas. In each block, soil should be tested continuously to determine the amount of arsenic present in it, if possible, the arsenic map of that area should be hung in every local panchayat and primary health centre so that people can be informed about the arsenic level in the drinking water of their area. It must be remembered that today’s work is the basis of tomorrow’s fruit, therefore, if we can increase the groundwater level by preventing wastage of water and implementing the ‘Jal Dharo Jal Bharo’ project for healthy life and future generations, it is hoped that the effect of arsenic will also reduce to some extent.
Sources: Arsenic Wikipedia Arsenic Vikaspedia Arsenic Banglapedia Environmental Science and Bio-Geography :- Professor Shamsur Rahman Arsenic Contamination in Soil and Sediment in India: Sources, Effects, and Remediation : Anamika Shrivastava & Devanita Ghosh & Ayusman Dash & Suatapa Bose Various articles on Arsenic
© Gopal Mondal
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