Kshitish Chandra Saha

Arsenic calamity in the Indian subcontinent What lessons have been learned

Groundwater arsenic (As) contamination in West Bengal (WB, India) was first reported in December 1983, when 63 people from three villages of two districts were identified by health officials as suffering from As toxicity. As of October 2001, the authors from the School of Environmental Studies (SOES) have analyzed >105 000 water samples, >25 000 urine/hair/nail/skin-scale samples, screened approximately 86 000 people in WB. The results show that more than 6 million people in 2700 villages from nine affected districts (total population approximately 42 million) of 18 total districts are drinking water containing >/=50 mug l(-1) As and >300 000 people may have visible arsenical skin lesions. The As content of the physiological samples indicates that many more may be sub-clinically affected. Children in As-affected villages may be in special danger. In 1995, we had found three villages in two districts of Bangladesh where groundwater contained >/=50 mug l(-1) As. The present situation is that in 2000 villages in 50 out of total 64 districts of Bangladesh, groundwater contains As above 50 mug l(-1) and more than 25 million people are drinking water above >/=50 mug l(-1) As. After years of research in WB and Bangladesh, additional affected villages are being identified on virtually every new survey. The present research may still reflect only the tip of iceberg in identifying the extent of As contamination. Although the WB As problem became public almost 20 years ago, there are still few concrete plans, much less achievements, to solve the problem. Villagers are probably in worse condition than 20 years ago. Even now, many who are drinking As-contaminated water are not even aware of that fact and its consequences. 20 years ago when the WB government was first informed, it was a casual matter, without the realization of the magnitude this problem was to assume. At least up to 1994, one committee after another was formed but no solution was forthcoming. None of the expert reports has suggested solutions that involve awareness campaigns, education of the villagers and participation of the people. Initially, international aid agencies working in the subcontinent simply did not consider that As could be present in groundwater. Even now, while As in drinking water is being highlighted, there have been almost no studies on how additional As is introduced through the food chain, as large amounts of As are present in the agricultural irrigation water. Past mistakes, notably the ceaseless exploitation of groundwater for irrigation, continue unabated today; at this time, more groundwater is being withdrawn than ever before. No efforts have been made to adopt effective watershed management to harness the extensive surface water and rainwater resources of this region. Proper watershed management and participation by villagers are needed for the proper utilization of water resources and to combat the As calamity. As in groundwater may just be natures initial warning about more dangerous toxins yet to come. What lessons have we really learned?

Chronic Arsenic Toxicity in Bangladesh and West Bengal, India—A Review and Commentary

Fifty districts of Bangladesh and 9 districts in West Bengal, India have arsenic levels in groundwater above the World Health Organizations maximum permissible limit of 50 μg/L. The area and population of 50 districts of Bangladesh and 9 districts in West Bengal are 118,849 km2 and 104.9 million and 38,865 km2 and 42.7 million, respectively. Our current data show arsenic levels above 50 μg/L in 2000 villages, 178 police stations of 50 affected districts in Bangladesh and 2600 villages, 74 police stations/blocks of 9 affected districts in West Bengal. We have so far analyzed 34,000 and 101,934 hand tube-well water samples from Bangladesh and West Bengal respectively by FI-HG-AAS of which 56% and 52%, respectively, contained arsenic above 10 μg/L and 37% and 25% arsenic above 50 μg/L. In our preliminary study 18,000 persons in Bangladesh and 86,000 persons in West Bengal were clinically examined in arsenic-affected districts. Of them, 3695 (20.6% including 6.11% children) in Bangladesh and 8500 (9.8% including 1.7% children) in West Bengal had arsenical dermatological features. Symptoms of chronic arsenic toxicity developed insidiously after 6 months to 2 years or more of exposure. The time of onset depends on the concentration of arsenic in the drinking water, volume of intake, and the health and nutritional status of individuals. Major dermatological signs are diffuse or spotted melanosis, leucomelanosis, and keratosis. Chronic arsenicosis is a multisystem disorder. Apart from generalized weakness, appetite and weight loss, and anemia, our patients had symptoms relating to involvement of the lungs, gastrointestinal system, liver, spleen, genitourinary system, hemopoietic system, eyes, nervous system, and cardiovascular system. We found evidence of arsenic neuropathy in 37.3% (154 of 413 cases) in one group and 86.8% (33 of 38 cases) in another. Most of these cases had mild and predominantly sensory neuropathy. Central nervous system involvement was evident with and without neuropathy. Electrodiagnostic studies proved helpful for the diagnosis of neurological involvement. Advanced neglected cases with many years of exposure presented with cancer of skin and of the lung, liver, kidney, and bladder. The diagnosis of subclinical arsenicosis was made in 83%, 93%, and 95% of hair, nail and urine samples, respectively, in Bangladesh; and 57%, 83%, and 89% of hair, nail, and urine samples, respectively in West Bengal. Approximately 90% of children below 11 years of age living in the affected areas show hair and nail arsenic above the normal level. Children appear to have a higher body burden than adults despite fewer dermatological manifestations. Limited trials of 4 arsenic chelators in the treatment of chronic arsenic toxicity in West Bengal over the last 2 decades do not provide any clinical, biochemical, or histopathological benefit except for the accompanying preliminary report of clinical benefit with dimercaptopropanesulfonate therapy. Extensive efforts are needed in both countries to combat the arsenic crisis including control of tube-wells, watershed management with effective use of the prodigious supplies of surface water, traditional water management, public awareness programs, and education concerning the apparent benefits of optimal nutrition.

Impact of safe water for drinking and cooking on five arsenic-affected families for 2 years in West Bengal, India

The groundwater in seven districts of West Bengal, India, covering an area of 37,000 km2 with a population of 34 million, has been contaminated with arsenic. In 830 villages/wards more than 1.5 million people, out of the total population, drink the arsenic-contaminated water. Safe water from a source having < 0.002 mg 1(-1) arsenic has been supplied for 2 years to five affected families comprising 17 members (eight of them with arsenical skin-lesions) of different age groups for impact assessment study in terms of loss of arsenic through urine, hair and nail. The study indicates random observable fluctuations of arsenic concentration in urine among members on different scheduled sampling days with a declining trend, particularly during the first 6 months. Furthermore, the investigation showed that despite having safe water for drinking and cooking, the study group could not avoid an intake of arsenic, time and again, through edible herbs grown in contaminated water, food materials contaminated through washing, and the occasional drinking of contaminated water. After minimizing the level of contamination, a noteworthy declining trend after 8 months was observed in urine, hair and nails in all the cases, but not to that level observed in a normal population, due to prevailing elevated background level of arsenic in the area. The eight members, who had already developed skin lesions, are far from recovering completely, indicating a long-lasting damage. Statistical interpretation of the data are considered.

Neuropathy in Arsenic Toxicity from Groundwater Arsenic Contamination in West Bengal, India

Abstract Large number of people from 9 out of 18 districts of West Bengal, India are endemically exposed to arsenic contaminated groundwater due to drinking of tubewell water containing arsenic level above World Health Organizations maximum permissible limit of 50 µg/L. From our ongoing studies on neurological involvement in patients of arsenicosis from different districts of West Bengal, we report our findings in a total of 451 patients of three districts (Murshidabad, Nadia, and Burdwan), comprising 267 males and 184 females with age ranging from 11 to 79 years. They all had arsenical skin lesions, positive biomarkers and identified source of arsenic contaminated water drinking. Peripheral neuropathy was the predominant neurological complication in these patients affecting 154 (37.3%) of 413 patients of Group 1 and 33 (86.8%) of 38 patients of Group 2. Other possible causes and alternative explanations of neuropathy were excluded. The temporal profile in most of the cases (154 of Group 1) were of chronic affection while the 33 patients of Group 2 developed both neuropathy and dermopathy subacutely. Subacutely affected Group 2 patients had much higher incidence of neuropathy. Paresthesias and pains in the distal parts of extremities were much higher in incidence in Group 2 (73.7% and 23.7% respectively) than in Group 1 (18.4% and 11.1%). Distal limb weakness or atrophy was evident in 7.3% in Group 1 and 10.5% in Group 2. Overall, sensory features were more common than motor features in patients of neuropathy and sensory neuropathy was diagnosed in 30% and 76.3% and sensorimotor in 7.3% and 10.5% respectively in Group 1 and Group 2 subjects. Nerve conduction and electromyographic studies performed in 88 cases revealed dysfunction of sensory nerve in 45% and 27% and of motor nerve in 20% and 16.7% of patients with moderate degree and mild degree of clinical neuropathies respectively. Evoked potential studies performed in 20 patients were largely normal except for two instances each of abnormal visual evoked potential and brainstem auditory evoked potential findings. Prognosis was favorable in mild and early diagnosed cases of neuropathy whereas most of the other more severe and late diagnosed cases showed slow and partial recovery or even deterioration. Outcome in neuropathic patients of arsenicosis and long term toxic neurologic effects yet unexplored and unknown remain as matters of future concern requiring close monitoring.

Arsenic Groundwater Contamination and Sufferings of People in North 24-Parganas, One of the Nine Arsenic Affected Districts of West Bengal, India

Abstract To understand the magnitude of the arsenic calamity in West Bengal, a detailed study spanning 7 years was made in North 24-Parganas, one of the nine arsenic affected districts. Area and population of North 24-Parganas district are 4093.82 sq. km and 7.3 million, respectively. Fourty eight thousand and thirty water samples were analyzed from hand tubewells of North 24-Parganas in use for drinking, cooking and 29.2% of the tubewells were found to have arsenic above 50 µg/L, the maximum permissible limit of World Health Organization (WHO) and 52.8% have arsenic above 10 µg/L, WHO recommended value of arsenic in drinking water. Out of the 22 blocks of North 24-Parganas, in 20 blocks arsenic has been found above the maximum permissible limit and so far in 16 blocks people have been identified as suffering from arsenical skin lesions. From the generated data, it is estimated that about 2.0 million and 1.0 million people are drinking arsenic contaminated water above 10 µg/L and 50 µg/L level, respectively in North 24-Parganas alone. So far, in our preliminary study 33,000 people have been examined at random from arsenic affected villages in North 24-Parganas and 2274 people have been registered with arsenical skin lesions. Extrapolation of the available data indicates about 0.1 million people may be suffering from arsenical skin lesions from North 24-Parganas alone. A sum of 21,000 hair, nail, and urine samples analyses from arsenic affected villages show 56%, 80%, and 87% people have arsenic in biological specimen more than normal/toxic (hair) level, respectively. Thus, many may be subclinically affected. Due to use of arsenic contaminated groundwater for agricultural irrigation, rice and vegetable are getting arsenic contaminated. Hence there is an additional arsenic burden from food chain. People from arsenic affected villages are also suffering from arsenical neuropathy. A followup study indicates that many of the victims suffering from severe arsenical skin lesions for several years are now suffering from cancer or have already died of cancer.

Murshidabad—One of the Nine Groundwater Arsenic-Affected Districts of West Bengal, India. Part II: Dermatological, Neurological, and Obstetric Findings

Introduction. To understand the severity of related health effects of chronic arsenic exposure in West Bengal, a detailed 3-year study was carried out in Murshidabad, one of the nine arsenic-affected districts in West Bengal. Methods. We screened 25,274 people from 139 arsenic-affected villages in Murshidabad to identify patients suffering from chronic arsenic toxicity for evidence of multisystemic features and collected biological samples such as head hair, nail, and spot urine from the patients along with the tubewell water they were consuming. Results. Out of 25,274 people screened, 4813 (19%) were registered with arsenical skin lesions. A case series involving arsenical skin lesions resulting in cancer and gangrene were noted during this study. Representative histopathological pictures of skin biopsy of different types of lesions were also presented. Out of 2595 children we examined for arsenical skin lesions, 122 (4%) were registered with arsenical skin lesions, melanosis with or without keratosis. Different clinical and electrophysiological neurological features were noticed among the arsenic-affected villagers. Both the arsenic content in the drinking water and duration of exposure may be responsible in increasing the susceptibility of pregnant women to spontaneous abortions, stillbirths, preterm births, low birth weights, and neonatal deaths. Some additional multisystemic features such as weakness and lethargy, chronic respiratory problems, gastrointestinal symptoms, and anemia were also recorded in the affected population. Discussion. The findings from this survey on different health effects of arsenic exposure were compared to those from previous studies carried out on arsenic-affected populations in India and Bangladesh as well as other affected countries. Conclusion. Multisystemic disorders, including dermal effects, neurological complications, and adverse obstetric outcomes, were observed to be associated with chronic arsenic exposure in the study population in Murshidabad, West Bengal. The magnitude of severity was related to the concentration of arsenic in water as well as duration of the exposure.

Arsenic contamination of groundwater and its health impact on residents in a village in West Bengal, India

An in-depth study was carried out in Rajapur, an arsenic-affected village in West Bengal, India, to determine the degree of groundwater contamination with arsenic and the impact of this contamination on residents. The flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) method was used to measure arsenic concentrations in water and biological samples. Dermatologists recorded the dermatological features of arsenicosis. Out of a total of 336 hand-pumped tube-wells in Rajapur, 91% (307/336) contained arsenic at concentrations > 10 microg/l, and 63% (213/336) contained arsenic at > 50 microg/l. The type of arsenic in groundwater, the variation in concentrations of arsenic as the depth of tube-wells changed, and the iron concentration in the wells were also measured. Altogether 825 of 3500 residents were examined for skin lesions; of these, 149 had lesions caused by exposure to arsenic. Of the 420 biological samples collected and analysed, 92.6% (389) contained arsenic at concentrations that were above normal. Thus many villagers might be subclinically affected. Although five arsenic-filtering devices had been installed in Rajapur, it appears that villagers are still exposed to raised concentrations of arsenic in their drinking-water. Detailed village-level studies of arsenic-affected areas in West Bengal are required in order to understand the magnitude of contamination and its effects on people. Villagers are ill-informed about the dangers of drinking arsenic-contaminated water. The contamination could be brought under control by increasing community awareness of the dangers and implementing proper watershed management techniques that involve local people.

Diagnosis of Arsenicosis

Abstract Arsenicosis is chronic subclinical or clinical toxicity due to high level of arsenic in body. Diagnosis of arsenicosis was derived by chronological establishment of facts: (a) arsenic as the cause of malady, (b) drinking water (tubewell water) as the vehicle of arsenic, (c) soil as the source of arsenic, (d) mechanism of leaching of arsenic from soil, and (e) cause of prevalence in particular areas of the country. Arsenicosis has been classified by the author into 4 stages, 7 grades and 20 subgrades. Stage I is pre-clinical or grade O. While clinical features were not found at this stage, high level of arsenic metabolites was observed in urine. As disease progressed to stable phase of grade O, high level of arsenic was also found in nails, hair, and skin scales. Stage II or clinical stage is divided into 4 grades, (1) Melanosis, (2) Spotted keratosis in palms/soles, (3) Diffuse keratosis in palms/soles, and (4) Dorsal keratosis. Clinical complications are grouped in stage III and grade 5. Malignancy is considered in stage IV and grade 6. There is a concern of both underdiagnosis and overdiagnosis. Therefore, cases of arsenicosis should be cautiously evaluated. Melanosis was the earliest cutaneous sign of clinical arsenicosis. Mild cases of melanosis could only be revealed by a thorough comparison with normal palms. Similarly mild cases of keratosis might not be visible and could only be revealed by careful palpation of palms and soles. Combination of melanosis and keratosis in adults indicated clinical diagnosis of arsenical dermatosis (ASD) that should be confirmed by showing high arsenic concentration in body tissues e.g., nails, hair, skin scales. Isolated melanosis or keratosis in newborn or children below 2 years almost negated the diagnosis of arsenicosis. Genetic melanosis or keratosis is often present since birth. Isolated melanosis or keratosis in adults should be differentiated from non-arsenical dermatosis and proven by absence of high arsenic level in nails and hair. Non arsenical causes of diffuse melanosis, spotted melanosis or leucomelanosis and localized or generalized keratosis can be clinically differentiated from arsenicosis by absence of pigmentation and keratosis in palms/soles.

Arsenic in groundwater in six districts of West Bengal, India: the biggest arsenic calamity in the world: the status report up to August, 1995

In six districts of West Bengal: Malda, Murshidabad, Bardhaman, Nadia, 24-Parganas (North) and 24-Parganas (South), arsenic has been found in groundwater above the maximum permissible limit recommended by WHO. The current provisional arsenic level in drinking-water from WHO is 0.01 μl−1 (WHO, 1993). This water is used by villagers for drinking, cooking and other household purposes. Saha (Saha, 1984, 1985, 1995; Saha and Poddar, 1986) reported 1214 cases of chronic arsenical dermatosis from drinking arsenic contaminated tube-well water in 47 villages in these six districts. During January 1988-August 1995 a further survey was conducted by the School of Environmental Studies in these districts and the present estimation indicates that 44 blocks in these six districts are affected that includes 466 villages and many municipal areas. About 1.0 million people were drinking arsenic-contaminated water and about 200000 people have arsenical skin lesions. The total population and area of these six districts are 30 million and 34000 km2 respectively. Every month we are finding additional arsenic-affected villages. These 30 million people are at risk.

Murshidabad—One of the Nine Groundwater Arsenic-Affected Districts of West Bengal, India. Part I: Magnitude of Contamination and Population at Risk

Introduction. To understand the severity of the arsenic crisis in West Bengal, India, a detailed, 3-year study was undertaken in Murshidabad, one of the nine arsenic-affected districts in West Bengal. The district covers an area of 5324 km2 with a population of 5.3 million. Methods. Hand tubewell water samples and biologic samples were collected from Murshidabad and analyzed for arsenic by FI-HG-AAS method. Inter laboratory analysis and analyses of standards were undertaken for quality assurance. Results. During our survey we analyzed 29,612 hand tubewell water samples for arsenic from both contaminated and noncontaminated areas, and 26% of the tubewells were found to have arsenic above 50 µg/L while 53.8% had arsenic above 10 µg/L. Of the 26 blocks in Murshidabad, 24 were found to have arsenic above 50 µg/L. Based on our generated data we estimated that approximately 0.2 million hand tubewells are installed in all 26 blocks of Murshidabad and 1.8 million in nine arsenic-affected districts of West Bengal. It was estimated on the basis of our data that about 2.5 million and 1.2 million people were drinking arsenic-contaminated water with concentrations above 10 and 50 µg/L levels respectively in this district. The analysis of total 3800 biologic (nail, urine, and hair) samples from arsenic-affected villages revealed that 95% of the nail and 94% of the urine samples contained arsenic above the normal levels and 75% of the hair samples were found to have arsenic above the toxic level. Thus, many villagers in the affected areas of Murshidabad might be subclinically affected. Discussion and Conclusion. Comparing our extrapolated data with international dose response results, we estimated how many people may suffer from arsenical skin lesions and cancer. Finally, if the exposed population is provided safe water, better nutrition, and proper awareness about the arsenic problem, lives can be saved and countless suffering of the affected population can be avoided.