Ganga-Meghna Brahmaputra || West Bengal || Bangladesh || Middle Ganga Plain, Bihar || Uttarpradesh
Jharkhand || North-East Hilly States || Rajnandgaon, Chattisgarh || Behala, Kolkata, WB || As toxicity- Homeopathic Treatment
Effectiveness & Reliability - As Field Testing Kits || Utility Of Treatment Plant
Causes, Effects & Remedies - Groundwater As Calamity || References

Arsenic Poisoning in Bihar : Environmental Health

Background

ABSTRACT

The pandemic of arsenic poisoning due to contaminated groundwater in West Bengal, India and all of Bangladesh has been thought limited to the Ganges Delta (the Lower Ganga Plain) despite early survey reports of arsenic contamination in groundwater in the Union Territory of Chandigarh and its surroundings in the northwestern Upper Ganga Plain and recent findings in the Terai area of Nepal. Anecdotal reports of arsenical skin lesions in villagers led us to evaluate arsenic exposure and sequelae in the Semria Ojha Patti village in the Middle Ganga Plain, Bihar, where tube wells replaced dug wells about 20 years ago. Analyses of the arsenic content of 206 tube wells (95% of the total) showed 56.8% to exceed arsenic concentrations of 50 µg/L with 19.9% >300 µg/L, the concentration predicting overt arsenical skin lesions. On medical examination of a self-selected sample of 550 (390 adults; 160 children), 13% of the adults and 6.3% of the children had typical skin lesions, an unusually high involvement for children, except in extreme exposures combined with malnutrition. The urine, hair, and nail concentrations of arsenic correlated significantly (r=0.72–0.77) with drinking water arsenic concentrations up to 1654 µg/L. On neurological examination, arsenic-typical neuropathy was diagnosed in 63% of the adults, a prevalence previously seen only in severe, subacute exposures. We also observed an apparent increase in fetal loss and premature delivery in the women with the highest drinking water arsenic. The possibility of contaminated groundwater at other sites in the Middle and Upper Ganga plain merits investigation.

INTRODUCTION

Groundwater arsenic contamination in Lower Ganga Plain of West Bengal, India was first identified (Saha 1983) in July 1983. Garai et al. (1984) reported 16 patients in 3 families from one village of 24 Parganas district. Saha (1984) further reported 127 patients with arsenical skin lesions from 25 families of 5 villages in 3 districts. Over the last 15 years, as of July 2002, we have analyzed >125,000 water samples, >30,000 urine/hair/nail/skin scale samples, screened ~100,000 people in West Bengal for arsenical skin lesions and have registered 8500 people with arsenical skin lesions from 255 affected villages out of 306 screened. We have identified tube wells with arsenic concentrations >50 µg/L in over 3000 villages. Our overall study indicates that more than 6 million people from 9 affected districts (population ~50 million) of 18 total districts (total population ~80 million) are drinking water containing =50 µg/L arsenic and >300,000 people may have visible arsenical skin lesions (Chakraborti et al. 2002). The arsenic content of the biologic samples indicates that many more may be subclinically affected. In 1995, we identified 3 villages in 2 districts of the Padma–Meghna–Bramhaputra (PMB) delta of Bangladesh (Post Conference Report 1995), where groundwater contained =50 µg/L arsenic. The present situation is that in 2000 villages, in 50 of the total 64 districts of Bangladesh, groundwater contains arsenic >50 µg/L; and the British Geological Survey (BGS) estimates that more than 35 million people are drinking water containing arsenic =50 µg/L (BGS Technical Report 2001). In the combined areas of West Bengal and Bangladesh around 150 million people are at risk from groundwater arsenic contamination (Rahman et al. 2001). Despite years of research in West Bengal and Bangladesh, additional affected villages are identified by virtually every new survey. We feel our present research may be only the tip of the iceberg representing the full extent of arsenic contamination.?Although West Bengal’s arsenic problem reached public concern almost 20 years ago, there are still few concrete plans, much less achievements, to solve the problem. Villagers are, usually, more severely affected than 20 years ago. Even now, many drinking arsenic contaminated water are not even aware of this fact and its consequences. The source of arsenic in deltaic plain of West Bengal is considered to be the arsenic rich sediments transported from the Chotonagpur Rajmahal Highlands (Acharya et al. 2000; Saha et al. 1997) and deposited in sluggish meander streams under reducing conditions. It has been reported by Acharya et al. (1999) that the groundwater of Uttar Pradesh and Bihar has low concentrations of iron (0 to 700 µg/L) and on this basis Archarya et al commented “the relatively low value of dissolved iron upstream of the Ganges delta indicates that the environment may not be sufficiently reducing to mobilize iron and arsenic”. No detailed groundwater analysis for arsenic is available for the Middle and Upper Ganga Plains. The Upper, Middle, and Lower Ganga Plains (Figure 1) are the most thickly populated areas of India. The fertile land and surplus in food production of the Gangetic Plain feeds India. The primary states of the Upper and Middle Ganga Plains are Uttar Pradesh (238,000 sq. km area; 166 million population) in the Upper Plain, and Bihar (94,163 sq. km area; 83 million population) in the Middle Ganga Plain and partly in the Upper. Our studies since 1988 have centered on the severe arsenic contamination of groundwater in the Lower Ganga Plain of West Bengal and Bangladesh. We recently found severe groundwater arsenic contamination in the Bhojpur district, Bihar, which is in the Middle Ganga Plain. In 1976 there was a preliminary report of groundwater arsenic contamination from the Union Territory of Chandigarh and its surroundings (Datta 1976a, 1976b) in the northwestern Upper Ganga Plain. A recent report (Tandukar et al. 2001) shows groundwater in the Lower Plain area (Terai) of Nepal to be arsenic contaminated. The data from the Terai area together with our findings in the Bhojpur district of Bihar, about 200 km?south of Nepal, support further investigation of groundwater arsenic in the Middle and Upper Ganga Plains. Our available information has excluded the possibility of an anthropogenic
source of groundwater arsenic in the area of Bhojpur, the subject of this report. The present communication describes the groundwater arsenic contamination and an initial evaluation of the prevalence of arsenic toxicity in Semria Ojha Patti village in the Middle Ganga Plain of Bihar. The arsenical dermatosis, arsenical neuropathy, and arsenic toxicity among children are quite similar to that observed in West Bengal and Bangladesh (Biswas et al. 1998; Chowdhury et al. 1999, 2000a, 2000b; Mandal et al. 1996; Rahman et al. 2001; Roy Chowdhury et al. 1997). Our preliminary observations of an unusual reproductive toxicity indicate a particularly severe exposure.

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