Bishwajit Nayak

Status of groundwater arsenic contamination in the state of West Bengal, India: a 20-year study report.

Since 1988 we have analyzed 140 150 water samples from tube wells in all 19 districts of West Bengal for arsenic; 48.1% had arsenic above 10 microg/L (WHO guideline value), 23.8% above 50 microg/L (Indian Standard) and 3.3% above 300 microg/L (concentration predicting overt arsenical skin lesions). Based on arsenic concentrations we have classified West Bengal into three zones: highly affected (9 districts mainly in eastern side of Bhagirathi River), mildly affected (5 districts in northern part) and unaffected (5 districts in western part). The estimated number of tube wells in 8 of the highly affected districts is 1.3 million, and estimated population drinking arsenic contaminated water above 10 and 50 microg/L were 9.5 and 4.2 million, respectively. In West Bengal alone, 26 million people are potentially at risk from drinking arsenic-contaminated water (above 10 microg/L). Studying information for water from different depths from 107 253 tube wells, we noted that arsenic concentration decreased with increasing depth. Measured arsenic concentration in two tube wells in Kolkata for 325 and 51 days during 2002-2005, showed 15% oscillatory movement without any long-term trend. Regional variability is dependent on sub-surface geology. In the arsenic-affected flood plain of the river Ganga, the crisis is not having too little water to satisfy our needs, it is the crisis of managing the water.

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.

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.

Health effects of groundwater fluoride contamination.

Introduction: The people in Berhait block, Sahibganj district, Jharkhand state, India, have been exposed chronically to fluoride-contaminated groundwater. Hereby, we report the clinical effects of chronic exposure to fluoride. Methods: The study population was a convenience sample of 342 adults and 258 children living in the affected area. All volunteers filled out questionnaires and were examined. Well water from the six affected villages and urine samples were analyzed for fluoride using an ion-sensitive electrode. Results: Twenty-nine percent of 89 well water samples had fluoride concentrations above the Indian permissible limit of fluoride in drinking water. Eighty-five children and 72 adults had clinical fluorosis. Urine fluoride concentrations in children were 0.758–2.88 mg/L whereas in adults they were 0.331–10.36 mg/L. Discussion: Clinical effects of fluoride included abnormal tooth enamel in children; adults had joint pain and deformity of the limbs and spine, along with ligamentous calcifications and exostosis formations in seven patients. Elevated urine fluoride concentrations supported the clinical diagnosis of fluorosis. Owing to insufficient fluoride-safe wells and lack of awareness of the danger of fluoride toxicity, villagers often drink fluoride-contaminated water. Conclusion: Villagers of Berhait block, including children, are at risk from chronic fluoride toxicity. To combat the situation, villagers need fluoride-safe water, education, and awareness of the danger about fluoride toxicity.

Arsenic exposure through groundwater to the rural and urban population in the Allahabad-Kanpur track in the upper Ganga plain

This preliminary study reports for the first time that part of the rural population in the Allahabad district and the urban population in the Suklaganj-Kanpur of Unnao district in the Allahabad-Kanpur track of the upper Ganga plain are drinking and using for agricultural irrigation arsenic contaminated water (maximum arsenic concentrations in drinking water and urine are 707 and 1744 microg L(-1) respectively) mostly from shallow hand tube-wells (depth 7.5-40 m) without knowing that these are arsenic contaminated.

Groundwater arsenic contamination in the Sahibganj district of Jharkhand state, India in the middle Ganga plain and adverse health effects

A detailed study in the Sahibganj district of Jharkhand state in the middle Ganga plain was carried out to determine the severity of groundwater arsenic contamination and related adverse health effects due to chronic arsenic exposure. Arsenic was analyzed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) in water and biological samples in both contaminated and noncontaminated areas. Health effects in three villages where tubewells (n = 178) were highly contaminated (91, 79.8, and 42% above 10, 50, and 300 µg L−1) were determined. Analyses of a total of 367 biological samples (nail, hair, and urine) from affected villages revealed that an average 88% of samples contained arsenic above normal level. Out of 522 people screened from these three villages, 71 were registered with arsenical skin lesions. A case involving arsenical skin lesions resulting in cancer was noted during the study. A representative histopathological picture of skin biopsy was presented. Out of 40 children examined, nine were registered with arsenical skin lesions. A child of 18 months drinking arsenic concentration water 1150 µg L−1 displayed arsenical skin lesions, indicating arsenical skin lesions may appear earlier if arsenic concentration is high in drinking water. Different clinical and electrophysiological neurological features and abnormal quantitative sensory perception thresholds were noted amongst patients. Provision of safe water, better nutrition, and proper awareness about the arsenic danger to exposed population may save lives and avoid sufferings.