This study represents the first comprehensive report of groundwater arsenic contamination status in the Kolkata Municipal Corporation (KMC). During the past 23 years, 4210 groundwater samples were analysed from all 141 wards in the KMC: 14.2% and 5.2% samples had arsenic >10 μg/l and >50 μg/l, respectively, representing 77 and 37 wards. The study shows that the number of arsenic contaminated samples (and wards) in the southern part of the KMC exceeds that of other parts of the city. The daily intake of arsenic from drinking water was estimated as 0.95 μg per kg bw and the cancer risk was estimated as 1425/106. Analyses of biological samples (hair, nail and urine) showed elevated concentrations of arsenic indicating the presence of subclinical arsenic poisoning, predicting an enhanced lifetime cancer risk for the population in southern part of the KMC. In the KMC, groundwater is not a sustainable source of freshwater due to arsenic, high iron, hardness and total dissolved solids. Its continued use is impelled by the lack of an adequate infrastructure to treat and supply surface water and in some wards the unaccounted for water (UFW) is even >45% incurred during distribution. The rare imposition of a water tax makes the water supply systems unsustainable and fosters indifference to water conservation. To mitigate the arsenic problem, continuous groundwater monitoring for pollutants, a treated surface water supply with strict policy implications, rainwater harvesting in the urban areas and introduction of water taxes seem to be long-term visible solutions.

During a 28-year field survey in India (1988–2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

During our last 27 years of field survey in India, we have studied the magnitude of groundwater arsenic and fluoride contamination and its resulting health effects from numerous states. India is the worst groundwater fluoride and arsenic affected country in the world. Fluoride results the most prevalent groundwater related diseases in India. Out of a total 29 states in India, groundwater of 20 states is fluoride affected. Total population of fluoride endemic 201 districts of India is 411 million (40% of Indian population) and more than 66 million people are estimated to be suffering from fluorosis including 6 million children below 14 years of age. Fluoride may cause a crippling disease. In 6 states of the Ganga-Brahmaputra Plain (GB-Plain), 70.4 million people are potentially at risk from groundwater arsenic toxicity. Three additional states in the non GB-Plain are mildly arsenic affected. For arsenic with substantial cumulative exposure can aggravate the risk of cancers along with various other diseases. Clinical effects of fluoride includes abnormal tooth enamel in children; adults had joint pain and deformity of the limbs, spine etc. The affected population chronically exposed to arsenic and fluoride from groundwater is in danger and there is no available medicine for those suffering from the toxicity. Arsenic and fluoride safe water and nutritious food are suggested to prevent further aggravation of toxicity. The World Health Organization (WHO) points out that social problems arising from arsenic and fluoride toxicity eventually create pressure on the economy of the affected areas. In arsenic and fluoride affected areas in India, crisis is not always having too little safe water to satisfy our need, it is the crisis of managing the water.

Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005-2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been made beyond what is in the officially prescribed compendia (which are included) and recent reviews are available. (C) 2014 Elsevier B.V. All rights reserved.

•Arsenic contamination of groundwater in all 17 blocks of Nadia, India.•People exposed to contaminated water, may suffer from skin lesions and cancer.•Arsenic and iron in groundwater with depths, arsenic in biologic samples.•Dermal and neurologic effects of arsenic, arsenical toxicity in children.•Results are compared with two highly affected districts of West Bengal.

Background: Fallopian tubes are common surgical specimen in the pathology laboratory; still there is a lack of data to describe the frequency of various histological fi ndings. The aim and objectives of this study was to describe the various histopathological fi ndings of fallopian tubes. Materials and Methods: Two thousand fi ve hundred and seventy fi ve cases where fallopian tubes were removed either separately or along with other female genital tract organs were studied retrospectively and their histopathological fi ndings documented. Results: Ectopic pregnancy comprised maximum number of cases closely followed by salpingitis. Primary neoplastic lesions were rare as compared to secondary malignancies. Serial sections of fallopian tube and sections from representative areas are essential for a pathologist so that the diagnosis of these pathological entities is not missed. Conclusion: Though the fallopian tubes remain unremarkable in majority of the surgical pathological specimens, it must be subjected for histopathological examination to demonstrate the pathological lesions. Journal of Pathology of Nepal (2013) Vol. 3, No.1, Issue 5, 356-360 DOI: http://dx.doi.org/10.3126/jpn.v3i5.7858

The study investigated the extent of soil arsenic (As) contamination in agricultural plots in Bengal Delta through contaminated groundwater irrigation. Edaphic levels of As and oxidizable organic carbon (OOC) were tested along a depth gradient (0 to 160 ft) in agricultural plots.

The authors’ survey of the Ganga–Meghna–Brahmaputra (GMB) plain (area 569,749 km2; population >500 million) over the past 20 years and analysis of more than 220,000 hand tube-well water samples revealed groundwater arsenic contamination in the floodplains of the Ganga–Brahmaputra river (Uttar Pradesh, Bihar, Jharkhand, West Bengal, and Assam) in India and the Padma–Meghna–Brahmaputra river in Bangladesh. On average, 50 % of the water samples contain arsenic above the World Health Organization guideline value of 10 μg/L in India and Bangladesh. More than 100 million people in the GMB plain are potentially at risk. The authors’ medical team screened around 155,000 people from the affected villages and registered 16,000 patients with different types of arsenical skin lesions. Arsenic neuropathy and adverse pregnancy outcomes have been recorded. Infants and children drinking arsenic-contaminated water are believed to be at high risk. About 45,000 biological samples analyzed from arsenic-affected villages of the GMB plain revealed an elevated level of arsenic present in patients as well as non-patients, indicating that many are sub-clinically affected. In West Bengal and Bangladesh, there are huge surface water in rivers, wetlands, and flooded river basins. In the arsenic-affected GMB plain, the crisis is not over water scarcity but about managing the available water resources.

The transmembrane protein α-hemolysin pore has been used to develop ultrasensitive biosensors, study biomolecular folding and unfolding, investigate covalent and noncovalent bonding interactions, and probe enzyme kinetics. Here, we report that, by addition of ionic liquid tetrakis(hydroxymethyl)phosphonium chloride solution to the α-hemolysin pore, the α-hemolysin channel can be controlled open or closed by adjusting the pH of the solution. This approach can be employed to develop a novel molecular switch to regulate molecular transport and should find potential applications as a "smart" drug delivery method.

The electrochemical reduction of inorganic As on a graphite cathode depends on the current density. We observed that while only inorganic As(III) is reduced to AsH3 at low current densities, at high current densities both forms of inorganic As are reduced. We describe a unique electrochemical reactor in which the cylindrical anode compartment is isolated from the outer concentric cathode compartment by a Nafion tube in which a hole is deliberately made and the entire anode compartment is inside the cylindrical cavity of a small volume (∼115 μL) cathode chamber. The evolved arsine is then quantitated by gas-phase chemiluminescence (GPCL) reaction with ozone; the latter is generated from oxygen formed during electrolysis. For the dimensions used, inorganic As(III) can be selectively determined at a current of 0.1 A while total inorganic As (both As(III) and As(V)) respond equally at an applied electrolysis current at 0.85 A, without any sample treatment. For a 1-mL sample, the system provides a limit of detection (LOD, S/N = 3) of 0.09 μg/L for total As (i = 0.85 A) and an LOD of 0.76 μg/L for As(III) (i = 0.10 A); As(V) is obtained by difference. Comparison of ICP-MS results for total As in groundwater samples that span a large range of concentration and total inorganic As determined by the present method showed a high correlation (r2 = 0.9975) and a near unity slope. The basic electrochemical arsine generation technique and current-differentiated oxidation state speciation should be applicable as the front end to many other arsenic measurements techniques, including atomic spectrometry.

We describe matrix-isolated, reaction chemistry based measurement of arsenic in water down to submicrograms per liter levels in a system that requires only air, water, electricity, and dilute sulfuric acid, the bulk of the latter being recycled. Gas phase chemiluminescence (GPCL) measurement of arsenic is made in an automated batch system with arsenic in situ electroreduced to arsine that is reacted with ozone to emit light. The ozone is generated from oxygen that is simultaneously anodically produced. Of 22 different electrode materials studied, graphite was chosen as the cathode. As(V) is reduced much less efficiently to AsH(3) than As(III). Prereducing all As to As(III) is difficult in the field and tedious. Oxidizing all As to As(V) is simple (e.g., with NaOCl) but greatly reduces subsequent conversion to AsH(3) and hence sensitivity. The rate of the AsH(3)-O(3) GPCL reaction and hence signal intensity increases with [O(3)]. Using oxygen to feed the ozonizer produces higher [O(3)] and substantial signal enhancement. This makes it practical to measure all arsenic as As(V). The system exhibits an LOD (S/N = 3) for total arsenic as As(V) of 0.36 microg/L (5 mL sample). Comparison of total As results in native and spiked water samples with those from inductively coupled plasma mass spectrometry (ICPMS) and other techniques show high correlation (r(2) = 0.9999) and near unity slopes.

INTRODUCTION:The people in Berhait block, Sahibganj district, Jharkhand state, India, have been exposed chronically to fluoridecontaminated 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.

An automated hydride generation (AHG) interface to inductive coupled plasma mass spectroscopy (ICPMS) was developed for measuring arsenic in environmental samples. This technique provides statistically indistinguishable response slopes (within about 3%) for hydride generation-ICPMS (HG-ICPMS) analysis of all major As species, inorganic As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and inorganic As(V); this has not previously been achieved. Previously, sample pretreatment to convert all forms of As into As(V) has been a prerequisite for measuring total arsenic in complex matrices. Under our operating conditions, arsenobetaine (AsB), until now regarded to be inert, also generates a hydride (albeit the response is only approximately 7% of others). The limit of detection (LOD) based on three times the standard deviation of the blank with this technique for AsB, DMA, As(III), MMA, and As(V) is 90, 66, 63, 63, and 63 pg As, respectively. This AHG-ICPMS technique was compared with a flow injection-UV photolysis-HG-ICPMS (FI-UV-ICPMS) and liquid chromatography-UV-HG-ICPMS analysis of arsenic content in National Institute of Standards & Technology (NIST) standard rice flour (standard reference material: SRM 1568a) and rice samples collected from West Bengal, India. Both oxidative acid digestion and methanol:water (1:1) extraction were used. The analytical results for total As in the SRM 1568a digest were 99.2 +/- 0.6 and 100.2 +/- 0.8% of the certified value (290 +/- 3 microg As/kg) by the AHG-ICPMS and the FI-UV-HG-ICPMS techniques, respectively. For rice extracts and the digests, the two techniques provided results that were correlated with linear r2 values of 0.9988 and 0.9987 with intercepts statistically indistinguishable from zero. Chromatographic analysis indicated that As in these rice samples were 75-90% inorganic.

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.

An inexpensive sensitive gas-phase chemiluminescence (GPCL) based analyzer for arsenic is described; this device utilizes manual fluid dispensing operations to reduce size, weight and cost. The analyzer in its present form has a limit of detection (LOD, S/N = 3) of 1.0 microg/L total inorganic As (peak heightbased, 3 mL sample). The system was used to measure low level arsenic in tap water samples from Texas and New Mexico and compared with results obtained by inductively coupled plasma-mass spectrometry (ICP-MS) as well as those from an automated GPCL analyzer. Good correlations were observed. Higher levels of As (50-500 microg/L, As(III), As(V) and mixtures thereof) were spiked into local tap water; the recoveries ranged from 95 +/- 2% to 101 +/- 1%. A single instrument weighs less than 3 kg, consumes <25 W in power, can be incorporated in a briefcase and constructed for <$US $1000. It is easily usable in the field.

A gas phase chemiluminescence (GPCL)-based method for trace measurement of arsenic has been recently described for the measurement of arsenic in water. The principle is based on the reduction of inorganic As to AsH3 at a controlled pH (the choice of pH governs whether only As(III) or all inorganic As is converted) and the reaction of AsH3 with O3 to produce chemiluminescence (Idowu et al., Anal. Chem. 78 (2006) 7088–7097). The same general principle has also been used in postcolumn reaction detection of As, where As species are separated chromatographically, then converted into inorganic As by passing through a UV photochemical reactor followed by AsH3 generation and CL reaction with ozone (Idowu and Dasgupta, Anal. Chem. 79 (2007) 9197–9204). In the present paper we describe the measurement of As in different soil and dust samples by serial extraction with water, citric acid, sulfuric acid and nitric acid. We also compare parallel measurements for total As by induction coupled plasma mass spectrometry (ICP–MS). As(V) was the only species found in our samples. Because of chloride interference of isobaric ArCl+ ICP–MS analyses could only be carried out by standard addition; these results were highly correlated with direct GPCL and LC–GPCL results (r2 = 0.9935 and 1.0000, respectively). The limit of detection (LOD) in the extracts was 0.36 μg/L by direct GPCL compared to 0.1 μg/L by ICP–MS. In sulfuric acid-based extracts, the LC–GPCL method provided LODs inferior to those previously observed for water-based standards and were 2.6, 1.3, 6.7, and 6.4 μg/L for As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA), respectively.

In the present study, pressurised liquid extraction and ultrasound probe sonication, for the latter in combination with a mixed enzymatic treatment in case of rice and straw samples, were applied as sample preparation prior to arsenic speciation analysis by high pressure liquid chromatography coupled to inductively coupled plasma mass spectrometric detection (HPLC-ICP-MS). A significant number of samples as different as rice, straw, soil, nail and hair, all coming from the heavily arsenic-contaminated Middle and Lower Ganga plain area, could be investigated with validated methods, supported by high speed extraction methods. For rice and paddy samples, inorganic arsenic counted up to 70-98% of the total arsenic content, being the major species As (III). The levels of arsenic obtained from straw and soil samples are significantly higher than the background levels, being the major species As (V), thus increasing human exposure to arsenic via the soil-plant-animal-human pathway. Concentrations found in hair and nails were significantly higher than their background levels: 39- and 20-fold for hair and nails, respectively. These samples contained mainly inorganic arsenic in its tri- and pentavalent forms. Results indicate that, under the local frame conditions, arsenic mainly enters into the food chain via its more problematic inorganic forms. Arsenic speciation analysis proves to be a powerful tool for a complete analytical assessment in epidemiological studies covering the endemic areas.