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Report. Arsenic contamination in groundwater in six districts of West Bengal, India: the biggest arsenic calamity in the world
... 5 Arsenic in its inorganic form is poisonous and its toxicological effects environmentally have led to serious public health issues in several parts of the world, including various parts of West Bengal, Bihar, Jharkhand and Uttar Pradesh in India. 6 Interestingly, a study conducted in Chile to assess the proportion of deaths due to cancers during high exposure to inorganic arsenic in city water found that there was reduced mortality in breast cancer patients during the same period. Smith et al thus concluded in their study that the major reduction in breast Keywords ► breast cancer ► homeopathy ► arsenic trioxide ► Arsenicum album ► apoptosis ► cell cycle ► migration ► ROS generation ► hallmarks of cancer Abstract Background Arsenic trioxide (As 2 O 3 ) has been in therapeutic use since the 18th century for various types of cancers including skin and breast; however, it gained popularity following FDA approval for its use against acute promyelocytic leukemia. ...
Background: Arsenic trioxide (As2O3) has been in therapeutic use since the 18th
century for various types of cancers including skin and breast; however, it gained
popularity following FDA approval for its use against acute promyelocytic leukemia.
This present work was designed to evaluate the anti-cancer potential of a homeopathic potency of arsenic trioxide (Arsenicum album 6C) in hormone dependent breast cancer.
Methods: Breast cancer cells (MCF7) were treated with Arsenicum album (Ars 6C) to evaluate its anti-proliferative and apoptotic potential. We examined the effect of Ars 6C on the cell cycle, wound healing, reactive oxygen species (ROS) generation, and modulation of expression of key genes which are aberrant in cancer.
Results: Treating breast cancer cells with Ars 6C halted the cell cycle at the sub-G0 and G2/M phases, which could be attributed to DNA damage induced by the generation of ROS. Apoptotic induction was associated with upregulation of Bax expression, with concurrent downregulation of the Bcl-2 gene. Ars 6C was also seen to reverse epithelial to mesenchymal transition and reduce the migration of breast cancer cells.
Conclusion The findings suggest that Ars has significant anti-proliferative and apoptotic potential against breast cancer cells. Further studies are required to elucidate the mechanism by which Ars exerts its effect in the in vivo setting.
... Different countries, including India, China [5], Vietnam, Taiwan, United States, Chile [6,7], Argentina, Mexico [8], Bangladesh [9], Poland, New Zealand, Japan, Canada and Hungary [10] are badly affected by arsenic-contaminated water. West Bengal (India) and Bangladesh are two of the most arsenic-polluted countries in the world, with arsenic levels in drinking water well above the WHO standard of 10 µg L −1 [11]. ...
(1) Background: In this investigation, a composite of MgO nanoparticles with Itsit biochar (MgO-IBC) has been used to remove arsenate from contaminated water. The reduced adsorption capacity of biochar (IBC), due to loss of functionalities under pyrolysis, is compensated for with the composite MgO-IBC. (2) Methods: Batch scale adsorption experiments were conducted by using MgO-IBC as an adsorbent for the decontamination of arsenate from water. Functional groups, elemental composition, surface morphology, and crystallinity of the adsorbent were investigated by using FTIR, EDX, SEM and XRD techniques. The effect of pH on arsenate adsorption by MgO-IBC was evaluated in the pH range of 2 to 8, whereas the temperature effect was investigated in the range of 303 K to 323 K. (3) Results: Both pH and temperature were found to significantly influence the overall adsorption efficiency of MgO-IBC for arsenate adsorption with lower pH and higher temperature being suitable for higher arsenate adsorption. A kinetics study of arsenate adsorption confirmed an equilibrium time of 240 min and a pseudo-second-order model well-explained the kinetic adsorption data, whereas the Langmuir model best fitted with the equilibrium arsenate adsorption data. The spontaneity and the chemisorptive nature of arsenate adsorption was confirmed by enthalpy, entropy, and activation energy. Comparison of adsorbents in the literature with the current study indicates that MgO-IBC composite has better adsorption capacity for arsenate adsorption than several previously explored adsorbents. (4) Conclusions: The higher adsorption capacity of MgO-IBC confirms its suitability and efficient utilization for the removal of arsenate from water.
... [2][3][4][5][6][7][8][9][10] Limited information are available regarding the disease burden due to arsenicosis in West Bengal, India. All figures quoted in various publications in regard to disease burden [11][12][13][14] are based on cases identified by scattered case detection program in the arsenic affected areas of different districts of the state. In an epidemiological survey carried out in one of the affected districts of West Bengal (South 24 Parganas), where 7683 people were examined in 57 arsenic affected villages, the prevalence of arsenical skin lesion was found to be 4.6%. ...
Background: Various clinical features are reported in arsenicosis cases in different case and cross sectional studies. The current study examines the specificity of these features in arsenicosis cases compared to arsenic exposed and unexposed controls. Methods: A stratified multi-stage design was adopted for selection of participants in two districts of West Bengal. The three cohorts consisted of 108 arsenicosis cases and 100 each of arsenic exposed and unexposed controls. Socio demographic characteristics and clinical features were recorded in field study. Water samples taken by the participants and their urine and hair samples were estimated for arsenic. Results: Mean peak arsenic level in drinking water was 259.53 ± 161.49 μg/L and 259.53 ± 161.49 μg/L (p>0.05) among arsenicosis cases and arsenic exposed controls respectively while it was below detection limit in unexposed controls. There was no difference in arsenic level in urine and hair among the former group. Significantly higher number of arsenicosis cases was found among poor farmers and agricultural laborers. There was no difference in BMI and smoking habit among the three cohorts. Chronic lung Disease was present in 40.74% of arsenicosis cases compared to 8% exposed (p0.001) and 5% unexposed (p<0.001) controls. Peripheral neuritis was observed only in two arsenicosis cases. Further, significant number of these cases had weakness and hypertension compared to controls. Conclusion: Poor people are predominantly affected due to arsenicosis in West Bengal. Skin lesions and chronic lung disease are the major causes of morbidity in these people.
... A few studies have indicated that groundwater arsenic contamination is typically confined to the Ganges delta alluvial springs, including sediments transported from Bihar's sulfide-rich mineralized regions. Research has shown that the vast portion of Indo-Gangetic alluvium extending further west and Brahmaputra alluvium has increased arsenic groups in wells placed in the late Quaternary and Holocene springs (Bhattacharya et al. 1997;Chatterjee et al. 1995). Major supply of arsenic in groundwater is of geogenic origin and is elaborately connected to the geological formation system and groundwater flow regime. ...
Groundwater pollution of arsenic and fluoride is a serious issue; it has gained a serious amount of consideration in the previous few years and the researchers are working towards various ways to control the pollution. They have got such great attention because of their ability, aggregation in the human body and toxicity. Fluoride and arsenic enter the drinking water resources through different sources. These contaminants also have an ill effect on the agriculture sector of the country as they pollute the soil and the crops. Human body is sensitive to arsenic. Arsenic gets into the body through arsenic-contaminated . As per BIS Standards the acceptable limit of Arsenic is 0.01 mg/l (ppm) or 10 µg/L (ppb) for water. In crops of wheat and paddy root, stem, leaf and grain contamination of arsenic was present. In some crops like wheat and paddy their roots have the highest arsenic concentration of 4.82 mg/kg and 40.3 mg/kg, respectively. WHO allowable limit is 1.0 mg/kg. The allowable limit of arsenic in water used for agricultural purposes is 0.10 mg/l as given by FAO (Food and Agriculture Organization). Many technologies based on adsorption, membrane process, oxidation, ion exchange and co precipitation are developed and used for the expulsion of arsenic from polluted water; creative innovations for the expulsion of arsenic from groundwater like phytoremediation, biological treatment, permeable reactive barriers and electro kinetic treatment are likewise being utilized to treat arsenic-contaminated water. These advances might be applied at full scale to treat arsenic-defiled springs. For the case of Fluoride it was observed that the majority of the states in India have crossed the permissible limitExcess fluoride in the drinking resources leads to fluorosis which does not have a cure.
... Most of the tube well water was found to contain equal amounts of both trivalent arsenite (H 2 AsO 3 ) and pentavalent arsenate (H 2 AsO 4 ). Neither MMAA (monomethyl arsonic acid) nor DMAA (dimethyl arsinic acid) could be detected (Das et al. 1994b). ...
Arsenic Contamination in Bangladesh Groundwater: A Great Environmental and Social Disaster. , 12(3): 235-253.
... At present serious arsenic contamination of drinking water has been reported from various countries of the world, including Bangladesh, (1) th" West Bengal region of India, (2,3) South-Western Taiwan,(4,s) Inner Mongolia, China,(5-?) urrd Vietnam. ...
Adsorption of arsenic by three soils and their clay fractions were studied separately in order to evaluate their potential in reducing arsenic mobility and bioavailability, and the possible application of this' technique for the remediation of soils contaminated with arsenic. The soil series selected were Ghior (high clay content), Ghatail (medium clay content) and Rajoir (organic soil). The maximum amount of arsenic was adsorbed by Ghior soil, followed by the Ghatail soil while the minimum was adsorhed by the organic soil, the Rajoir soil. Variations in adsorption of As among soils were attributed to the content and nature of the clay fractions, presence of organic matter, iron content and magnitude of CEC. A positive relationship (r = 0.9079) was noticed between the adsorption of arsenic and clay content of the soils. A fairly noticeable inverse relationship was observed between the adsorption of arsenic and organic matter (r =-0.9577), Fe content (r =-0.8584) and cation exchange capacity (r =-0.9316) of the soils. Adsorption of arsenic by clay fractions of the corresponding soils showed somewhat similar trend to that of the adsorption of arsenic by soils. The extent of adsorption appeared to have varied with the variation of mineral types in the clay fractions of the soils. The illitic minerals present in the clay fractions were probably mainly responsible for the adsorption of arsenic.
... This may be due to the short duration of exposure and the fact that cancer is usually attributed to long-term chronic exposure. Earlier studies have shown a positive correlation between iAs concentration in the water and its concentration in the body tissues and fluids of exposed populations (Aposhian et al. 2000;Chen et al. 2013;Das et al. 1994Das et al. , 1995. Hence, dose-response relationships between iAs exposure and undesirable health effects were assessed. ...
Island populations are rarely studied for risk of arsenic (As) poisoning. As poisoning, multimetal contamination and people’s perceptions of health risks were assessed on India’s Majuli Island, the largest inhabited river island in the world. This holistic approach illustrated the association of groundwater contamination status with consequent health risk by measuring levels of inorganic arsenic (iAs) in groundwater, borehole sediment and biological samples (hair, nails and urine). Piper and Gibbs’s plots discerned the underlying hydrogeochemical processes in the aquifer. Demographic data and qualitative factors were evaluated to assess the risks and uncertainties of exposure. The results exhibited significant enrichment of groundwater with As, Mn and Fe along with significant body burden. Maximum Hazard Index values indicated severe non-carcinogenic health impacts as well as a significantly elevated risk of cancer for both adults and children. Most (99%) of the locally affected population did not know about the adverse health impacts of metal contamination, and only 15% understood bodily ailments and health issues. Various aspects of the island environment were used to elucidate the status of contamination and future risk of disease. A projection showed adverse health outcomes rising significantly, especially among the young population of Majuli, due to overexposure to not only As but also Ba, Mn and Fe.
... Arsenic contamination of the groundwater has been reported in many countries in different parts of the world. For example, high concentration of As in the groundwater of many countries like India (Das et al, 1994;Chattarjee and Mandal, 1995), Bangladesh (Karim, 2000;Smedley and Kinniburgh, 2002), Taiwan (Chen et al, 1994;Hricko, 1994), Mongolia (Fujinoa et al, 2004), and China (Hricko, 1994;Niu et al, 1995) used for drinking and cooking has caused symptoms of chronic As poisoning like arsenicosis and keratosis to the local hu-man population. Recent advances in the analysis of As as well as more detailed studies of its human health effects show that As is carcinogenic even at minute concentrations; so that the World Health Organization (WHO) lowered the provisional guideline for As concentration in drinking water from 50 to 10 µg/L that was immediately adopted by developed countries like Japan and USA (WHO, 1993;USEPA, 2002). ...
Arsenic (As) is a toxic element found in both natural and anthropogenic sources. High concentration of this element was recently uncovered in the groundwater of Sumbawa Island, Indonesia. To mitigate this problem, As adsorption potential of natural geological materials like lignite, bentonite, shale, and iron sand obtained in Indonesia were evaluated by batch experiments. Arsenic adsorption onto these materials was investigated as a function of solution pH, particle sizes of adsorbents and coexisting sulfate concentration. In addition, batch leaching experiments were performed to elucidate the stability of geogenic As present in all adsorbents at different pHs. The results showed that among these natural materials tested, lignite was the most effective adsorbent of As(V) followed by bentonite, shale and then iron sand, and that the amounts of As(III) adsorbed onto all adsorbents were lower than those of As(V).This indicates that As(III) is more mobile in comparison to As(V). The adsorption isotherms of As(III) and As(V) conformed to non-linear types, either Langmuir or Freundlich. It was found that adsorption of As onto these natural adsor-bents was pH-dependent. This could be attributed to the changes in the surface charges of the adsorbents with pH. With respect to the adsorbent particle size, the amount adsorbed somewhat increased with decreasing particle size, which could be explained by the larger surface area of the smaller particles. Acidic (pH < 6) and alkaline (pH >10) conditions destabilized the geogenic As content of the adsorbents, indicating that the effectiveness of these natural materials as adsorbents is greatly limited by the pH of the contaminated system.
... Arsenic (As), which is toxic to most living organisms, causes potentially serious environmental problems throughout the world because of the contamination of soils and groundwater. The use of As contaminated groundwater for drinking and cooking in many parts of the world, including Bangladesh [1] [2], Taiwan [3] [4], China [4] [5], Mexico [6], Argentina [7], Chile [8], India [9][10] [11] and Mongolia [12] has been linked to increase the incidence of keratosis, cardiovascular illnesses and certain types of cancers. Numerous technologies and processes are now available for the removal of liquid-phase As like chemical precipitation, ion exchange, adsorption onto activated alumina and Fe-(oxy)hydroxides, reverse osmosis, modified coagulation/filtration, modified lime softening, electro deposition and oxidation/filtration [13]. ...
This paper presents the adsorption behavior of arsenic (As) onto lignite in saturated column experiments under various flow rates and adsorbent thicknesses. The lignite sample originated from Indonesia is predominantly composed of organic matter with minor amounts of pyrite (FeS 2). Arsenic content of lignite is 1.8 mg/kg with high sulfur content of 10.8 wt. %. The experiments were performed at room temperature using a glass column with an inner diameter of 2.4 cm and total length of 30 cm. Different lignite bed thicknesses (6 and 12 cm) at a constant flow rate of 0.85 cm 3 /min and a fixed lignite bed thickness of 12 cm with different flow rates (0.85 and 0.22 cm 3 /min) were conducted. All effluents had acidic pH (1.04 to 3.36) and were under oxidizing conditions (Eh: +554-+629 mV) regardless of the flow rate and lignite bed thickness. The breakthrough of As indicated both leaching and adsorption regions. The leaching of As could be attributed to very high concentration of dissolved organic carbon (DOC) that competes with As for Adsorption sites. Leaching region occurs until ca. 69 mL (ca. 1.35 h) at a thinner lignite bed. After this, the concentration of As in the effluent slowly increased and then reached the influent As concentration. In contract, the retardation of As observed until ca. 159 mg/L (ca. 3.15 h) at a thicker lignite bed, indicating that the As adsorption increased substantially at thicker lignite bed. Decreasing the flow rate (0.22 cm 3 /min) had a similar effect with case 2, that is, the As adsorption increased substantially. Based on these results, As removal efficiency under flow-through conditions is strongly influenced by thickness of adsorbent but not the flow rate.
... Arsenic (As), which is toxic to most living organisms, causes potentially serious environmental problems throughout the world because of the contamination of soils and groundwater. The use of As contaminated groundwater for drinking and cooking in many parts of the world, including Bangladesh [1] [2], Taiwan [3] [4], China [4] [5], Mexico [6], Argentina [7], Chile [8], India [9][10] [11] and Mongolia [12] has been linked to increase the incidence of keratosis, cardiovascular illnesses and certain types of cancers. Numerous technologies and processes are now available for the removal of liquid-phase As like chemical precipitation, ion exchange, adsorption onto activated alumina and Fe-(oxy)hydroxides, reverse osmosis, modified coagulation/filtration, modified lime softening, electro deposition and oxidation/filtration [13]. ...
This paper presents the adsorption behavior of arsenic (As) onto lignite in saturated column experiments under various flow rates and adsorbent thicknesses. The lignite sample originated from Indonesia is predominantly composed of organic matter with minor amounts of pyrite (FeS 2). Arsenic content of lignite is 1.8 mg/kg with high sulfur content of 10.8 wt. %. The experiments were performed at room temperature using a glass column with an inner diameter of 2.4 cm and total length of 30 cm. Different lignite bed thicknesses (6 and 12 cm) at a constant flow rate of 0.85 cm 3 /min and a fixed lignite bed thickness of 12 cm with different flow rates (0.85 and 0.22 cm 3 /min) were conducted. All effluents had acidic pH (1.04 to 3.36) and were under oxidizing conditions (Eh: +554-+629 mV) regardless of the flow rate and lignite bed thickness. The breakthrough of As indicated both leaching and adsorption regions. The leaching of As could be attributed to very high concentration of dissolved organic carbon (DOC) that competes with As for Adsorption sites. Leaching region occurs until ca. 69 mL (ca. 1.35 h) at a thinner lignite bed. After this, the concentration of As in the effluent slowly increased and then reached the influent As concentration. In contract, the retardation of As observed until ca. 159 mg/L (ca. 3.15 h) at a thicker lignite bed, indicating that the As adsorption increased substantially at thicker lignite bed. Decreasing the flow rate (0.22 cm 3 /min) had a similar effect with case 2, that is, the As adsorption increased substantially. Based on these results, As removal efficiency under flow-through conditions is strongly influenced by thickness of adsorbent but not the flow rate.
... Ironically, while As contamination in drinking water has attracted much attention, arsenic contamination in food and water has become a menace. Related health hazards for millions and deaths have been reported by many researchers (Das et al. 1995;Mitra et al. 2002;Sanyal and Dhillon 2005). Arsenic uptake by crop plants grown in contaminated soils having the high concentration of arsenic has also been observed by Ghosh et al. (2004), ICAR (2005) and Jones (2007). ...
A field experiment was conducted in an arsenic endemic area of West Bengal, India (22°57ʹN, 89°33ʹE) in 2010-2012 to understand different prevalent cropping systems of the area as to nature of arsenic uptake by the crops and influence of different sources of irrigation water. The experiment was laid out in split plot design consisting two irrigation managements [I1: irrigation with shallow tube well (STW) and I2: irrigation from harvested pond water (PW)] in main plot and four cropping systems in sub plot were C1: pea- summer rice- cowpea, C2: potato- green gram- elephant foot yam (EFY), C3: wheat- jute- winter rice and C4: French bean- sesame- winter rice. Irrigation from PW recorded less arsenic uptake compared to STW. Arsenic uptake was minimum with French bean- sesame- winter rice (C4), followed by potato - green gram - EFY (C2). System equivalent yield was the highest with C2. The highest return was recorded with C2 and the return per dollar (USD) investment was the maximum with C1, followed by C2. Potato- green gram- EFY (C2) proved to be the better option for the farmers in arsenic contaminated area with greater yield potential, highest return per dollar investment and less arsenic uptake.
... Groundwater of Wes Bengal basin in India is one of the most affected provinces of geogenic arsenic contamination [6]. The oxidation of sulphide minerals considered as one of the most natural processes which caused groundwater arsenic contamination in this area [45]. In this case, oxidative weathering and dissolution of arsenic containing minerals viz. ...
High arsenic (As) fluoride (F-) nitrate (NO 3-) and salinity concentrations in groundwater are widespread problems in different part of Indian states. The various types of geological settings, hydro-chemical and diversified litho-logical characteristics as well as climatic condition are major responsible factors for enrichment of these contaminants in aquifer system. However, groundwater of Ganga–Meghna-Brahmaputra basin is in more vulnerable condition due to geogenic contamination. Furthermore, alluvial aquifers viz. Holocene alluvial and deltaic sediments are more contaminated due to the high concentration of arsenic, fluoride and nitrate. The mechanism of release of these contaminants in groundwater have been identified where numerous bio-geo-chemical process especially oxidation of sulphide mineralsis responsible for releasing of arsenic, weathering of granitic complex rocks are responsible for fluoride and leaching of agricultural waste is responsible for nitrate concentration in groundwater. In addition, evaporation, dissolution, precipitation, adsorption, co-precipitation, ion-exchange, oxidation-reduction and nature of aquifer have been identified as responsible factors for availability of these contaminants in the groundwater. Similarly, groundwater salinity problem has been detected in arid and semi arid as well as coastal region of India which is mainly due to over exploitation of groundwater. In this study, we have broadly discussed about the mechanism of release of these contaminants and their responsible factors with the help of different published research papers.
... Arsenicosis patients are often identified as lepers, and are ostracised (Das et al. 1994; Das 1995; DCHT 1998). Children of arsenicosis patients are not allowed to attend social and religious functions. ...
... Historically, several regions have been affected by contamination from geologic sources, like Taiwan (Williams, 1997), Córdova, Argentina (Thor nton et to the, 1997), Mexico (Cebrian et al., 1983) as well as west Bengal, India. This has been considered a case of world calamity due to aquifer contamination by arsenic (As) (Badal et al., 1996). In these cases the contamination is associated to the pyrite oxidation. ...
This paper describes the results of a geomathematical analysis of natural and artificially
induced arsenic sources in groundwater in a hard rock aquifer. Data on chemical composition,
ground water levels, and other physical variables were collected systematically but discontinuously
between 1974 and 2001. A special survey was carried out in 2002 to clarify
several geologic settings. Geomathematical tools involved factor and cluster analysis, kriging
mapping techniques and information theory resources. Results allowed to assess the actual informativity
of the monitoring network and optimise its spatial distribution, operation frequency
and data collection structure, the improvement of the transit time of arsenic in groundwater, and
to separate artificial sources from natural sources of arsenic occurrence. Surface waters appears
to be contaminated by arsenic coming from lateral flow migration and leaching of concentrates
in zones close to the surface water divides.
... Organic forms of As may also be present in surface waters, but usually occur in smaller quantities than inorganic species. The long-term intake of small doses of inorganic As has been linked to several diseases in humans including liver, bladder, kidney and skin cancers (Chatterjee et al., 1995). As a result, Health Canada adopted the World Health Organization recommendation of 10 µg/L as the maximum allowable concentration of total As for potable water in the Canadian Drinking Water Guideline (Health Canada, 2014). ...
Ninety-eight lakes were sampled within a 30 km radius of the City of Yellowknife to document elemental concentrations in surface waters in an area exposed to 50 years of emissions from gold ore processing. Concentrations of As, Sb, and SO4 are elevated in lakes within 17.5 km of Giant Mine relative to lakes beyond this distance. Arsenic concentrations were highest in small lakes (< 100 ha) that were downwind and proximal to the historic stacks, suggesting a gradient in impact from historic roaster operations at Giant Mine consistent with the predominant wind direction in the region. Concentrations of As exceeded the federal drinking water guideline of 10 µg/L for many of the lakes sampled within 12 km of the roaster stacks, and in some lakes were more than 60 times this limit. This study provides an extensive survey of elemental concentrations in regional lakes surrounding the City of Yellowknife and should be supported by future work to investigate drivers of variation in As concentration in surface waters, interannual variability in water chemistry, and the long-term fate of As and other elements of potential concern in these lakes.
... Geogenic sources of As in water can occur in aquifers under reducing conditions as evidenced by groundwater in the West Bengal/Bangladesh delta region (Das et al., 1995;Kinniburgh and Smedley, 2001;Chakraborti et al., 2010;Chatterjee et al., 2010). This was brought to light following an extensive borehole drilling programme started in the 1970s by UNICEF in order to protect the local population from having to use bacterially contaminated surface waters. ...
Solar oxidation to remove arsenic from water has previously been investigated as a batch process. This research has investigated the kinetic parameters for the design of a continuous flow solar reactor to remove arsenic from contaminated groundwater supplies. Continuous flow recirculated batch experiments were carried out under artificial UV light to investigate the effect of different parameters on arsenic removal efficiency. Inlet water arsenic concentrations of up to 1000 μg/L were reduced to below 10 μg/L requiring 12 mg/L iron after receiving 12 kJUV/L radiation. Citrate however was somewhat surprisingly found to promote a detrimental effect on the removal process in the continuous flow reactor studies which is contrary to results found in batch scale tests. The impact of other typical water groundwater quality parameters (phosphate and silica) on the process due to their competition with arsenic for photooxidation products revealed a much higher sensitivity to phosphate ions compared to silicate. Other results showed no benefit from the addition of TiO2 photocatalyst but enhanced arsenic removal at higher temperatures up to 40 °C. Overall, these results have indicated the kinetic envelope from which a continuous flow SORAS single pass system could be more confidently designed for a full-scale community groundwater application at a village level.
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... Groundwater contaminations with arsenic are also serious problems in Bangladesh. Oxidation of pyrite and arsenopyrite add As in the Bengal Delta Sediments due to excessive withdrawal and lowering of groundwater (Das et al. 1995; Chowdhury et al. 1999). These contaminated groundwater is used for irrigation as well as for drinking purpose in Bangladesh. ...
Effects of arsenic (As) on seed germination, root and shoot length and biomass of rice varieties were investigated to elucidate the toxicity of As. Nine rice varieties viz. BR 11, BR 22, BRRI dhan29, BRRI dhan33, BRRI dhan39, BRRI dhan40, BRRI dhan47, BRRI dhan49 and BRRI dhan53 were grown with different levels of As (0, 15, 40, 70, 100 and 150 ppm). The experiment was laid out in a complete block design with three replications. Results showed that the germination percentage, root and shoot length and biomass of all rice varieties were gradually decreased with the increasing concentration of As solution. Among the rice varieties, BR 11, BR 22 and BRRI dhan49 showed highest degree of tolerance while BRRI dhan29 was the most susceptible to As toxicity.
Geogenic groundwater contaminants (GGCs) affect drinking-water availability and safety, with up to 60% of groundwater sources in some regions contaminated by more than recommended concentrations. As a result, an estimated 300-500 million people are at risk of severe health impacts and premature mortality. In this Review, we discuss the sources, occurrences and cycling of arsenic, fluoride, selenium and uranium, which are GGCs with widespread distribution and/or high toxicity. The global distribution of GGCs is controlled by basin geology and tectonics, with GGC enrichment in both orogenic systems and cratonic basement rocks. This regional distribution is broadly influenced by climate, geomorphology and hydrogeochemical evolution along groundwater flow paths. GGC distribution is locally heterogeneous and affected by in situ lithology, groundwater flow and water-rock interactions. Local biogeochemical cycling also determines GGC concentrations, as arsenic, selenium and uranium mobilizations are strongly redox-dependent. Increasing groundwater extraction and land-use changes are likely to modify GGC distribution and extent, potentially exacerbating human exposure to GGCs, but the net impact of these activities is unknown. Integration of science, policy, community involvement programmes and technological interventions is needed to manage GGC-enriched groundwater and ensure equitable access to clean water. Sections
Water resources of Pakistan are seriously depleting due to mismanagement. One of the major issues in the depletion of water resources in Pakistan which makes water not assessable to use is its contamination. The issue of arsenic contamination has emerged as a serious health concern in Pakistan. Pakistani population is exposed not only to toxic but poisonous levels of arsenic contamination. Only in Punjab province more than 20% population is exposed to arsenic levels of more than 10 ppb out of which 3% are exposed to more than 50 ppb levels of arsenic contamination. Various studies have shown the arsenic contamination in both shallow and deep aquifers. This chapter will give a comprehensive overview of arsenic contamination in water resources of Pakistan, their associated health risks, and possible remediation strategies to reduce exposure of arsenic contamination in Pakistani population.KeywordsContaminationArsenicWater resourcesHealthDiseases
Groundwater is a vital resource that accounts for around 30% of the world’s freshwater resources. In arid and semi-arid zones,
the human dependency on groundwater is comparatively very high, and its quality signifcantly impacts human health. Both
anthropogenic and natural factors have led to changes in hydrodynamics of groundwater resources and water security issues in
various regions of the globe. Thus, the bibliometric search methods were conducted to assess the dynamics of “Groundwater
Research” in India based on scientifc literature published from 1989 to 2020. In this regard, the Web of Science Core Collection
database has been used to extract the literature amounting to 3848 document types. Analysis and mapping of the searched data
have been compiled using Microsoft Excel, bibliometrix R-Package Biblioshiny, BibExcel, HistCite and VOSviewer tools,
which enabled to assess of the development of the literature, identifcation of documents types, most prolifc authors, countries,
institutions, highly cited articles, productive journals, bibliographic coupling, keywords and hotspot topics. The signifcant
fndings highlight that the number of research publications has increased signifcantly over the last few decades in India to
promote groundwater scientifc study and research. The study highlight that the research articles are the most preferred document
type, and India’s collaboration in groundwater research is highest with the USA. The Journal of the Geological Society of India
is the most preferred journal for research publication and the highest count of publication contributions from the Indian Institutes
of Technologies. The present review study will assist institutions in providing the current “Groundwater Research” gap in the
country and will facilitate the future productive research output in groundwater research.
In this growing age of population,agriculture plays a significant role by providing food and employment to millions of people. But to meet the growing need of food day by day the demand of fast and quality plant production becomes a must. Fertilization is one of such activities which are people accustomed to do for this purpose from a very long time. But the excessive uses of chemical fertilizers are showing negative influence on the environmental and public health. The paper mainly focuses on how the excessive use of chemical fertilizers are affecting the soil health as well as the water bodies by accumulating heavy metals (HMs) and other chemical elements present in them and the possible remediation measures.In adequate levels, all heavy metals are hazardous. However, some of them e.g., arsenic (As), lead (Pb) and Cadmium (Cd) are of particular relevance due to their environmental concentrations. The paper also provides a comprehensive discussion of the sources, uses, toxicity, and remediation of these particular HMs.
Geo-environmental studies were initiated in R opar and Ludhiana districts, covering an area
of 5942 sq. km on 1:1,25,000. The work included invent ory, collection and synthesis of data from
unpublished reports and maps, collection of str eam sediment I soil and water samples and
preparation of various thematic maps based on Land sat Imageries with limited field checks.
The area covered forms a part of the Indo-Ga ngetic Plain and comprises the Siwaliks and
Quaternary deposits. The Quaternary sediments are of both fluvial as well as Aeolian origin. Four
phases of alluvial (Piedmont deposits, Older Alluvium, Newer Alluvium and Recent Alluvium) and
two phases of Aeolian deposition (semi-consolidated dunes and sand sheet) have been recognized
in the area. The fluvial and Aeolian agencies have played an active role in sculpturing the present
landscape. The main erosional feature carved out by fluvial action is the 1-6m high bluff. The
Siwalik Upland, Piedmont Surface, Older Alluvial Surface, Newer Alluvial Surface and Aeolian
Surface are the five major geomorphic surfaces. Minor terraces, ox-bow lakes, abandoned channels,
point bars and channel bars are the other geomorphological features noticed in the area.
In Ropar district, ground water potential is quite good except in a narrow belt along the
Siwaliks known as Kandi area. The ground water o ccurs under unconfined condition at a depth of
40m bgl. The water bearing sediments comprise sa nds of various fractions. It is fresh throughout
Ropar district and suitable for irrigation. Ther e is extensive withdrawal of ground water for
agricultural, industrial and domestic purposes as compared to the recharge. The ground water is
alkaline with little or no carbonates and generally hard in Ludhiana district. The average annual
ground water recharge in Ropar district was es timated to be 53,363 ha. M. on the basis of 1977-79
data. The discharge of ground water exceeds th e recharge by about 247.45 million cubic meters
annually. This has resulted in general decline of water table, but for along the canal courses where
there is rise in water table due to seepage. This imbalance, in recharge and discharge relationship is
the result of damming of River Sat 1uj at Bhakra and indiscriminate installation of shallow tube
wells.
ii
Ropar district has considerable hydroelectri c and irrigational potential. Bhakra Dam is
located across River Satluj, about 14 km upstream of Nangal. The total installed power generation
capacity of this project is 2050 MW. A well-knit network of canals for irrigation purpose has been
laid out by putting up barrages at Nangal and Ropa r. Besides, three minor flood moderation-cum-
irrigation earthen dams are under construc tion viz. 23m high and 325m long over Budki nadi near
Mirzapur village, 22.8m high and 417m long over Siswan nadi about 19 km NW of Chandigarh;
and 18m high and 210m long across Jainti Devi nadi, all in Ropar district.
The Ropar and Ludhiana districts lie in an area where earthquakes of slight to moderate
intensity are occasionally experienced. It is becau se of its tectonic setting with great Himalayan
Boundary Fault toward North, Chamba tear in the Ravi River and Ropar tear in the Satluj River.
Mention may be made of Nahan and Krol thru sts, Satlitta thrust, Hoshiarpur and Jawalamukhi
thrusts which also cause earthquakes of slight to moderate intensity in that region. Ropar finds its
place in zone IV in ISI Seismic Zoning map, where earthquake of intensity VIII are experienced on
MM scale.
Mineral resources of the area are calc-tufa, clays, River sand and brick clay. The calcareous
tufa deposits occur mainly around Khera Kalmot and Mehindpur of Anandpur sahib tehsil of Ropar
district. The total reserves of calc-tufa have been estimated to be 7,000 tonnes with average
composition of 40.36% CaO, 0.55% MgO and 20.07% acid insolubles. Good quality clays of
pozzolanic properties, for use in pottery, are found in the Siwaliks. Medium to coarse-grained sand
occurring in the flood plains of the Satluj and other streams finds use in making mortar with cement
for construction. The top brown, silty, loamy clay sequence of Older Alluvium, up to a depth of two
metres is extensively used for making bricks.
Land is mostly shared by activities like agricu lture, water resources, forests and habitation.
About 84% of the area is under cultiv ation, out of which some part has been utilised in developing
canals and drainage irrigation system. About 5.7% of the area is under forests, which is far less than
the minimum limit of forest area for the State. These two districts have 18 urban settlements and
1872 villages.
The Satluj River traverses through the central portion of Ropar district from Nangal to
Ropar, and thereafter flows along the northern margin of Ludhiana district. It maintains the quality
of water well within permissible limits, through its self-rejuvenation power, till the Budha Nala, a
natural drain passing through Ludhiana city discharges its untreated load into it. The toxic discharge
of the Budha Nala comes mainly from acrylic and wool dyeing, electroplating, heat treatment and
metal finishing units. Ludhiana city has got dubious distinction of being the most polluted city of
Punjab. Ludhiana district is also on record for giving the highest per hectare yield of wheat. In the
iii
wake of this green revolution, it is also leading in consumption of fertilizers, insecticides and
weedicides. Systematic sampling of soil/stream sediments and water on grid pattern has been
carried out and 196 samples collected for the assessment of non-point pollution due to these
chemicals, coupled with other factors such as transportation industry and brick burning. Geo-
environmental hazards of the area are wate r pollution, soil pollution, flooding of younger terrace
along River Satluj and disposal of fly ash of GGS Thermal Plant Ropar over huge areas thereby
rendering the land unsuitable for any other activity a nd other hazards associated with fly ash. Based
on the results of soil/stream sediment and water sa mples, various pockets affected by pollution and
deserving immediate attention have been demarcated
Health exposure and perception of risk assessment have been evaluated on the populations exposed to different arsenic levels in drinking water (615, 301, 48, 20 µg/l), rice grain (792, 487, 588, 569 µg/kg) and vegetables (283, 187, 238, 300 µg/kg) from four villages in arsenic endemic Gaighata block, West Bengal. Dietary arsenic intake rates for the studied populations from extremely highly, highly, moderately, and mild arsenic-exposed areas were 56.03, 28.73, 11.30, and 9.13 μg/kg bw/day, respectively. Acute and chronic effects of arsenic toxicity were observed in ascending order from mild to extremely highly exposed populations. Statistical interpretation using ‘ANOVA’ proves a significant relationship between drinking water and biomarkers, whereas “two-tailed paired t test” justifies that the consumption of arsenic-contaminated dietary intakes is the considerable pathway of health risk exposure. According to the risk thermometer (SAMOE), drinking water belongs to risk class 5 (extremely highly and highly exposed area) and 4 (moderately and mild exposed area) category, whereas rice grain and vegetables belong to risk class 5 and 4, respectively, for all the differently exposed populations. The carcinogenic (ILCR) and non-carcinogenic risks (HQ) through dietary intakes for adults were much higher than the recommended threshold level, compared to the children. Supplementation of arsenic-safe drinking water and nutritional food is strictly recommended to overcome the severe arsenic crisis.
Graphic abstract
Arsenic (As) toxicity is a global phenomenon, and it is continuously threatening human life. Arsenic remains in the Earth’s crust in the forms of rocks and minerals, which can be released into water. In addition, anthropogenic activity also contributes to increase of As concentration in water. Arsenic-contaminated water is used as a raw water for drinking water treatment plants in many parts of the world especially Bangladesh and India. Based on extensive literature study, adsorption is the superior method of arsenic removal from water and Fe is the most researched periodic element in different adsorbent. Oxides and hydroxides of Fe-based adsorbents have been reported to have excellent adsorptive capacity to reduce As concentration to below recommended level. In addition, Fe-based adsorbents were found less expensive and not to have any toxicity after treatment. Most of the available commercial adsorbents were also found to be Fe based. Nanoparticles of Fe-, Ti-, Cu-, and Zr-based adsorbents have been found superior As removal capacity. Mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.) removed As efficiently from water. Oxidation of AsO33− to AsO43−and adsorption of oxidized As on the mixed element-based adsorbent occurred by different adsorbents. Metal organic frameworks have also been confirmed as good performance adsorbents for As but had a limited application due to nano-crystallinity. However, using porous materials having extended surface area as carrier for nano-sized adsorbents could alleviate the separation problem of the used adsorbent after treatment and displayed outstanding removal performances.
Recent testing has shown that shallow aquifers of the Ravi River floodplain are more frequently affected by groundwater arsenic (As) contamination than other floodplains of the upper Indus River basin. In this study, we explore the geochemical origin of this contrast by comparing groundwater and aquifer sand composition in the 10-30 m depth range in 11 villages along the Ravi and adjacent Beas and Sutlej rivers. The drilling was preceded by testing wells in the same villages with field kits not only for As but also for nitrate (NO3⁻), iron (Fe), and sulfate (SO4²⁻). Concentrations of NO3⁻ were ≥20 mg/L in a third of the wells throughout the study area, although conditions were also sufficiently reducing to maintain >1 mg/L dissolved Fe in half of all the wells. The grey to grey-brown color of sand cuttings quantified with reflectance measurements confirms extensive reduction of Fe oxides in aquifers of the affected villages. Remarkably high levels of leachable As in the sand cuttings determined with the field kit and As concentration up to 40 mg/kg measured by X-ray fluorescence correspond to depth intervals of high As in groundwater. Anion-exchange separation in the field and synchrotron-based X-ray spectroscopy of sand cuttings preserved in glycerol indicate speciation in both groundwater and aquifer sands that is dominated by As(V) in the most enriched depth intervals. These findings and SO4²⁻ concentrations ≥20 mg/L in three-quarters of the sampled wells suggest that high levels of NO3⁻, presumably from extensive fertilizer application, may have triggered the release of As by oxidizing sulfide-bound As supplied by erosion of black shale and slate in the Himalayas. Radiocarbon dating of sub-surface clay cuttings indicates that multiple episodes of inferred As-sulfide input reached the Ravi floodplain over the past 30 kyr. Why the other river basins apparently did not receive similar inputs of As-sulfide remains unclear. High NO3⁻ in groundwater may at the same time limit concentrations of As in groundwater to levels lower than they could have been by oxidizing both Fe(II) and As(III). In this particular setting, a kit can be used to analyze sand cuttings for As while drilling in order to target As-safe depths for installing domestic wells by avoiding intervals with high concentrations of As in aquifer sands with the well screen.
This study presents a review conducted to critically evaluate the microbial fabrication and its subsequent effect on arsenic contamination in soil. Taking into consideration the global situation, the sources of arsenic, the microbial arsenic pathways and the impact of arsenic contamination on soil have been defined. Different published studies highlighted the biochemical and physiological molecular aspects of arsenic and evaluated their impacts on soil; in the current paper, the sources and extent of arsenic contamination and the translocation and speciation from microbes to soil are illustrated. This study also discusses the forms of water-soluble arsenic and whether these are more toxic than insoluble forms, as previously reported. In addition, this paper briefly illustrates the sources and coverage of arsenic contamination and arsenic speciation in contaminated soil globally. Some vital research findings are also discussed which relate to the scientific exploration of microbial arsenic systems in contaminated soil.
The groundwater has emerged as major reliable source for agriculture as more than 60% of irrigated agriculture and 85% of drinking water supplies are dependent on groundwater. Round-the-clock water availability at the point of use, less conveyance losses, judicious water use and less cost of pumping are the major reasons behind the increased pumping of groundwater irrigation, but declining quality of groundwater has been becoming an issue of a concern, and it can be attributed to water contamination and/or over-exploitation. The contamination is taking place through various sources and pathways like anthropogenic (agricultural, industrial and domestic) and natural (geogenic/pedogenic origin) reasons. The basic cause behind drastic decline in groundwater quality is lack of appropriate rules and regulations, but off late to protect groundwater and take safeguards against over-exploitation, Government of India, in 1970, framed a Model Groundwater (Control and Regulation) Bill for adoption by the states and later on in the year 2013 started Atal Bhujal Yojana (ABHY) which focuses on interventions to improve groundwater quality. The main parameters that are considered to assess the contamination of groundwater by CGWB are salinity level; concentrations of fluoride, nitrate, arsenic and iron; and concentration of heavy metals like lead, chromium and cadmium, and the groundwater of most of the states of India like Punjab, Haryana, Uttar Pradesh, West Bengal, Tamil Nadu and Telangana was found to be contaminated by all these elements. Iron was found to be major contaminant in most of the states followed by fluoride, nitrate, arsenic, salinity and lead contamination. The indicators like pH, TDS, BOD and COD and metals like Cr, Cd, Ni, Zn, Cu, Pb, etc. are measured to know the extent of contamination. Sizable area in the vicinity of industrial sites is found contaminated by different kinds of contaminants that are elaborated in the text with level of concentration occurring in soil, plant as well as groundwater. The heavy metal pollution index was calculated to measure the overall quality of groundwater in the Ankleshwar Industrial Estate of Gujarat in India. Various techniques for remediating the contaminated groundwater are also discussed.
This chapter provides the scientific backdrop to the interpretation and understanding of many diseases of the nails and their management. Embryogenesis represents the original growth of the nail, which is continued throughout life and reiterated when there is nail loss or recovery from surgery. An understanding of the regional anatomy and the physiology of the components enables analysis of clinical signs according to their biological origins. Addressing a presenting problem from first principles based upon the science of the nail unit will help clinicians to make a precise and accurate diagnosis. Scientists designing medication and physical mechanisms of engaging or interpreting nail disease will require the story of nail biology to be laid out for them in the language of anatomy and science. They will in turn be able to add to this story as much of the literature in nail biology comes from scientists addressing fundamental problems, using techniques found in other areas of medicine.
Water contamination by arsenic and health issues associated with the contaminated water are worldwide problems. Arsenic contamination in drinking water is causing severe health effects leading to death. The removal of arsenic (As) can be achieved by different methods, and it depends upon the composition of contaminated water. Treatment methods either transfer the pollutants from one phase to another or chemically oxidize to less toxic form. Separation and degradation methods include adsorption, chemical coagulation, membrane processes, electrocoagulation, chemical oxidation, and advanced oxidation processes; and biological methods including biological oxidation, phytoremediation, etc. are found to be efficient for the removal of As from water medium. There are several factors which have influence on each process; the removal efficiency depends upon the optimized conditions. This chapter provides a detailed review on the existing efforts for the As removal from aqueous medium, their advantages and limitations, etc.
Arsenic (As) is a toxic metalloid having a natural origin in the earth’s crust. Among the several sources of As pollution, geogenic As pollution through contamination of the groundwater in the deltaic basin of Bengal (region of Ganga and Padma river) covering India and Bangladesh is of great concern to the world as it paved its way for As to adversely affect the soil-plant-animal continuum. Arsenic in soil and water is transformed chemically and biochemically through different processes, namely, oxidation, reduction, methylation, and demethylation. Regarding the fate, As mobility depends upon the clay percent and mineralogical makeup of the soil, whereas As retention is facilitated by different soil physicochemical properties, adsorption and ion exchange process, organic fraction-As complexation equilibria, surface charge characteristics, and other nutrient element interactions in soils. Precipitation-coprecipitation and microbial transformation also govern the fate of As in soil and water. After interaction with soil and water, As is further translocated or metabolized to plant body in several inorganic and organic forms. In plant body, As accumulation pattern, in general, was observed to follow the order root > stem >leaf > economic produce. Several workers attempted to derive the toxicity symptoms and values in the plant as well as man’s edibility. Finally, speciation of total loading of As for the affected soils and the crops into arsenite and arsenate oxyanion species is important for characterizing the net toxicity of As in the given soil-crop systems.
Arsenic(As)-mediated contamination of groundwater resources in different parts of the world is a consequence of natural or anthropogenic sources, leading to adverse effects on the environment and human health. Millions of people from different countries are unfortunately consuming groundwater contaminated with alarming levels of As. Exposure to the high concentration of As for an extended period of time can cause devastating effects on human health such as skin lesions, cardiac disorders, discolouration and cancer. Until 2018, about 11 districts of Sindh and Punjab provinces in Pakistan had been found with As contamination in groundwater beyond the national defined permissible level, i.e. 50 µg/L. Tharparkar and Hyderabad (in Sindh province) along Indus river and Lahore and Kasur (in Punjab province) are well-known hotspots sites of natural geogenic As contamination in groundwater. Higher levels of Sulfates (SO4²⁻), Chloride (Cl⁻) and Carbonate (CO3²⁻) along with the elevated values of electrical conductivity and basic pH, as well as augmented presence of “As V” species, were all an indication of oxidizing condition in groundwater, and these oxidizing conditions are identified as the primary mechanism of As contamination into aquifers of Pakistan via oxidative dissolution. The main aim of this review is to summarize and discuss the current contamination status of As in groundwater water globally with a special focus on Pakistan scenario, isotopic evidence to track sources of groundwater recharge and its effects on As contamination in groundwater with various redox conditions prevailing in Pakistan. In addition, public health consequences of As contamination and mitigation strategies for As removal from water resources have been also highlighted. In this review, the data were extracted from various cutting edge studies published in national and international journals.
Skin lesion is one of the important health hazards caused by high intake of arsenic through drinking water and diet, and the other hazards include several types of cancers (viz. skin, lung and urinary bladder), ischemic heart disease, hypertension, etc. Two most important biomarkers to measure arsenic intake in a human body are arsenic concentration in urine and hair. The primary interest of this paper is the association between skin lesion and arsenic concentration in hair for participants with chronic arsenic exposure from West Bengal, India, using bivariate regression model based on copula function. The result showed participants with high arsenic concentration in hair had higher incidence of developing skin lesion. Arsenic concentration in hair was significantly higher for the participants with an arsenic concentration in water > 10 mg/L.
Arsenic poisoning from contaminated drinking water has evolved as one of the major health hazards in recent times. High concentrations of arsenic in water and soil have been found in many parts of the world. Developing countries like Taiwan, Chile, Argentina, Bangladesh, Nepal and Vietnam are most affected by the contamination of groundwater with arsenic. These countries also cannot afford expensive and large-scale treatments to remove arsenic from drinking waters to acceptable limits (10 ppb, as recommended by WHO and US EPA). The aim of this review is to summarize low-cost, effective conventional technologies currently described in the literature for arsenic removal that can be used in the third world and developing countries, compare them with the emerging technologies and discuss their advantages and disadvantages along with a brief analysis of arsenic chemistry.
Water is an inalienable resource for all kinds of life on Earth. Fast-developing urban population and ever-increasing industrial activities added with negative effects of climate change have made availability of adequate and suitable quantity of water a subject of intranational and international strife in many parts of the world, solution of which, at times, appear elusive. The oceans contain 96.5% of the water in the hydrosphere in the saline state. Only 2.4% is fresh water, but 87% of it resides in ice caps and glaciers. This means much less than 1% is available for the biosphere. Availability of this water is highly variable in space and time. Penetration of ground water
and accumulation of surface water in drainage basins and wetting of the land are effects of a complicated hydrologic cycle. It is notable that 95% of the liquid fresh water available is ground water in reality. Natural and anthropogenic pollution of ground water (and locally surface water also) is a menace in different parts of the world. Saving water resource is a loud cry today. Best way of doing it is by minimizing domestic and industrial consumption, recycling used water after proper treatment, making direct use of rain water, going for more scientific irrigation and reducing loss during transport through pipes. Desalination
of sea water is a far cry for general use at the moment. Water crisis is an acute problem in India. We should resort to as many of the above means as possible to restrain it before long. The usefulness of the river-linking proposal in India is still considered dubious.
Arsenic is a widespread metalloid in environment, whose exposure has been associated with a broad spectrum of toxic effects. However, a global view of arsenic-induced male reproductive toxicity is still lack, and the underlying mechanisms remain largely unclear. Our results revealed that arsenic exposure decreased testosterone level and reduced sperm quality in rats. By conducting an integrated proteomics and metabolomics analysis, the present study aims to investigate the global influence of arsenic exposure on the proteome and metabolome in rat testis. The abundance of 70 proteins (36 up-regulated and 34 down-regulated) and 13 metabolites (8 increased and 5 decreased) were found to be significantly altered by arsenic treatment. Among these, 19 proteins and 2 metabolites were specifically related to male reproductive system development and function, including spermatogenesis, sperm function and fertilization, fertility, internal genitalia development, and mating behavior. It is further proposed that arsenic mainly impaired spermatogenesis and fertilization via aberrant modulation of these male reproduction-related proteins and metabolites, which may be mediated by the ERK/AKT/NF-κB-dependent signaling pathway. Overall, these findings will aid our understanding of the mechanisms responsible for arsenic-induced male reproductive toxicity, and from such studies useful biomarkers indicative of arsenic exposure could be discovered.
In many areas of the world, notably the West Bengal region of India (Das et al., 1994; Chatterjee et al., 1995), south-western Taiwan (Shen, 1973; Hricko, 1994), and Inner Mongolia, China (Hricko, 1994; Niu et al., 1995; Luo et al., 1995), elevated concentrations of arsenic in drinking-water have resulted in symptoms of chronic arsenic poisoning in local populations. These elevated arsenic concentrations are usually of natural origin. In areas with current or historical mining activities, however, arsenic contamination of natural waters may be associated with leaching of mine tailings or deposition of arsenic released to the atmosphere during smelting processes as has occurred in southern Thailand (Choprapawon, 1995), Ghana (Bowell et al., 1994) and the western United States (Benner et al., 1995). Mitigation of arsenic exposure in such areas primarily involves substitution of drinking-water from alternate (uncontaminated) sources, or treatment of source waters that contain arsenic well in excess of the current standards. The current standard or maximum contaminant level (MCL) in the United States is 50μg/L (50ppb); the provisional guideline value recommended by the World Health Organization is 10μg/L (WHO, 1993; Pontius, 1994).
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.
The groundwater of the Bengal basin, in Bangladesh and West Bengal state of India, is found to be severely polluted by non-point sourced, geogenic arsenic (As), which has been regarded as the largest public health concern in the human history. The geomorphology and geology of the aquifers play very important role in the three dimensional existence of the As in the groundwater. The provenance of the groundwater As of Bengal basin may be hypothesized to be sourced to the Himalayan orogenic belt, where the contaminant might have originated by deep-seated tectono-magmatism and subsequently introduced to the surficial system by exhumation. Later, sedimentary processes transported the As-laden sediments from the orogenic belt to the peripheral foreland basin of Bengal where, under conducive biogeochemical environment, the As is released from the solid-phase to the circulating groundwater. Ferric hydroxides and pyrite are considered to be the two most important host minerals for As, although clay minerals may also act as important substrates for the sorbed As. The mobilized As then exists in the groundwater until a suitable geochemical sink is available. The mobilization process may be related to reductive-dissolution of metal oxides and hydroxides that exist in the unconsolidated sediments of the Bengal basin. Other mechanisms like pyrite oxidation, redox cycling in surficial soils, and competitive ion exchange are also accepted as potential mechanisms for arsenic mobilization, and multiple processes may simultaneously contribute to the mobilization of As. The processes are significantly complicated by redox disequilibria in the Bengal basin aquifers. These inorganic processes may have been significantly catalyzed and accentuated by microbially mediated activities. The tertiary source of groundwater As is the irrigation return flow from the agricultural fields.
Arsenic in groundwater and its accumulation in plants and animals have assumed a menacing proportion in a large part of West Bengal, India and adjoining areas of Bangladesh. Because of the tremendous magnitude of the problem, there seems to be no way to tackle the problem overnight. Efforts to provide arsenic free water to the millions of people living in these dreaded zones are being made, but are awfully inadequate. In our quest for finding out an easy, safe and affordable means to combat this problem, a homeopathic drug, Arsenicum Album-30, appears to yield promising results in mice. The relative efficacies of two micro doses of this drug, namely, Arsenicum Album-30 and Arsenicum Album-200, in combating arsenic toxicity have been determined in the present study on the basis of some accepted biochemical protocols.
Mice were divided into different sets of control (both positive and negative) and treated series (As-intoxicated, As-intoxicated plus drug-fed). Alanine amino transferase (ALT) and aspartate amino transferase (AST) activities and reduced glutathione (GSH) level in liver and blood were analyzed in the different series of mice at six different fixation intervals.
Both Arsenicum Album-30 and Arsenicum Album-200 ameliorated arsenic-induced toxicity to a considerable extent as compared to various controls.
The results lend further support to our earlier views that microdoses of potentized Arsenicum Album are capable of combating arsenic intoxication in mice, and thus are strong candidates for possible use in human subjects in arsenic contaminated areas under medical supervision.
This paper provides insight into the quality of groundwater used for public water supply on the territory of Temerin municipality (Vojvodina, Serbia). The following parameters were measured: color, turbidity, pH, KMnO4 consumption, total dissolved solids (TDS), EC, NH4+, Cl−, NO2−, NO3−, Fe, Mn, As, Ca2+, Mg2+, SO42−, HCO3−, K+, and Na+. The correlations and ratios among parameters that define the chemical composition were determined aiming to identify main processes that control the formation of the chemical composition of the analyzed waters. Groundwater from three analyzed sources is Na–HCO3 type. Elevated organic matter content, ammonium ion content, and arsene content are characteristic for these waters. The importance of organic matter decay is assumed by positive correlation between organic matter content and TDS, and HCO3− content. There is no evidence that groundwater chemistry is determined by the depth of captured aquifer interval. The main natural processes that control the chemistry of all analyzed water are cation exchange and feldspar weathering. The dominant cause of As concentration in groundwater is the use of mineral fertilizers and of KMnO4 in urban area. The concentration of As and KMnO4 in the observed sources is inversely proportional to the distance from agricultural land and urban area. 2D model of distribution of As and KMnO4 is done, and it is applicable in detecting sources of pollution. By using this model, we can quantify the impact of certain pollutants on unfavorable content of some parameters in groundwater.
The present study discusses elevated groundwater arsenic (As) and fluoride (F(-)) concentrations in Mailsi, Punjab, Pakistan, and links these elevated concentrations to health risks for the local residents. The results indicate that groundwater samples of two areas of Mailsi, Punjab were severely contaminated with As (5.9-507 ppb) and F(-) (5.5-29.6 ppm), as these values exceeded the permissible limits of World Health Organization (10 ppb for As and 1.5 ppm for F(-)). The groundwater samples were categorized by redox state. The major process controlling the As levels in groundwater was the adsorption of As onto PO4 (3-) at high pH. High alkalinity and low Ca(2+) and Mg(2+) concentrations promoted the higher F(-) and As concentrations in the groundwater. A positive correlation was observed between F(-) and As concentrations (r = 0.37; n = 52) and other major ions found in the groundwater of the studied area. The mineral saturation indices calculated by PHREEQC 2.1 suggested that a majority of samples were oversaturated with calcite and fluorite, leading to the dissolution of fluoride minerals at alkaline pH. Local inhabitants exhibited arsenicosis and fluorosis after exposure to environmental concentration doses of As and F(-). Estimated daily intake (EDI) and target hazard quotient (THQ) highlighted the risk factors borne by local residents. Multivariate statistical analysis further revealed that both geologic origins and anthropogenic activities contributed to As and F(-) contamination in the groundwater. We propose that pollutants originate, in part, from coal combusted at brick factories, and agricultural activities. Once generated, these pollutants were mobilized by the alkaline nature of the groundwater.
Arsenic is present in water, soil, and air in organic as well as in inorganic forms. However, inorganic arsenic is more toxic than organic and can cause many diseases including cancers in humans. Its genotoxic effect is considered as one of its carcinogenic actions. Arsenic can cause DNA strand breaks, deletion mutations, micronuclei formation, DNA-protein cross-linking, sister chromatid exchange, and DNA repair inhibition. Evidences indicate that arsenic causes DNA damage by generation of reactive free radicals. Nutritional supplementation of antioxidants has been proven highly beneficial against arsenic genotoxicity in experimental animals. Recent studies suggest that antioxidants protect mainly by reducing excess free radicals via restoring the activities of cellular enzymatic as well as non-enzymatic antioxidants and decreasing the oxidation processes such as lipid peroxidation and protein oxidation. The purpose of this review is to summarize the recent literature on arsenic-induced genotoxicity and its mitigation by naturally derived antioxidants in various biological systems.
In southern Punjab, arsenic (As) contents in groundwater is one of the major problems. A preliminary study was conducted to evaluate the extent of As concentration along with pH, electrical conductivity (EC), total dissolved salts (TDS), and heavy metals Cu, Ni, Cd, Fe, and Mn in 121 groundwater samples of the study area. The range values of As were below detection limit (BDL) to 100 ppb, pH (6.4–7.9), EC (0.503–40.8 mS/cm), Cu (BDL—1142 μg/L), Ni (BDL—179.2 μg/L), Fe (1.1–995.4 μg/L), and Mn (0.2–499.2 μg/L) in groundwater. The As concentration in 33.9 % samples was higher than prescribed limit (10 ppb) of WHO for drinking water while TDS in 70.3 %, Cu in 14 %, Ni in 5.7 %, Fe of 15.7 %, and Mn in 28.92 % were observed higher than their respective permissible limits. The correlation coefficient (r) was carried out for seven parameters, indicating positive correlation of As with Fe (0.27). Contamination index (C
d) of 44.9 % ground water was observed >3 indicating the extent of contamination. The present study indicated the water samples collected from riverine area had higher concentration of As than the samples from canal irrigated or in vicinity of the desert area.
En el Ecuador la ocurrencia de arsénico de origen natural ha sido recientemente encontrada en aguas geotermales, aguas subterráneas y superficiales y sedimentos. Un equipo de investigación de la ESPE determinó en el 2006, contenidos de arsénico en fuentes de agua geotermal, en aguas de los ríos o quebradas que reciben los residuales termales y en los sedimentos de esas microcuencas. En este estudio se monitorearon más de 20 fuentes de agua geotermal en las provincias de El Carchi, Imbabura, Pichincha, Cotopaxi y Tungurahua [38]. Las concentraciones de arsénico total presentes en las fuentes de agua termal de la provincia del Carchi oscilan entre 2 y 684 g/L. En la provincia de Imbabura la fluctuación es mucho mayor y varía de 4 a 969 g/L. En cambio, los contenidos de arsénico en las fuentes de la provincia de Pichincha fluctúan entre 11 y 405 g/L y en la provincia de Cotopaxi se tienen la menores concentraciones que van desde 4 a 45 g/L. En la provincia de Tungurahua en cambio el arsénico presente en las aguas termales es de 6 a 114 g/L [38].
En la remediación ambiental de la laguna de Papallacta por el derrame de crudo ocurrido en marzo del 2003, se encontraron a más hidrocarburos de petróleo totales, niveles de arsénico que oscilaban entre 390 y 670 g/L [40]. Posteriormente en otros análisis de arsénico practicados en muestras de agua de la laguna revelan concentraciones de arsénico que varían entre 330 y 600 μg/L. Además, en la caracterización realizada por De la Torre et al. en el 2003, encontraron también altas concentraciones de vanadio y níquel en el crudo de referencia y que pudo ocasionar elevados niveles de esos elementos en el agua de la laguna de Papallacta.
Ensayos de sorción prueban que las esferas de quitosano impregnadas con óxidos de Fe(III) y los gránulos de hidrotalcita recubiertos con óxidos de Fe(III) son selectivos para remover arsénico inorgánico total comparado con sulfatos (SO42-), cloruros (Cl-) y bicarbonatos (HCO3-). La preferencia del arsénico sobre el sulfato, cloruro o bicarbonato es debido a la formación de complejos estables de esfera interna entre el arsénico y las superficies de los OFH. Las esferas y gránulos son también factibles de una eficiente regeneración. Menos de 20 volúmenes de regenerante consistente de 3% de NaOH o 2%NaOH + 3%NaCl, son suficientes para recuperar más del 90% de los compuestos adsorbidos.
La concentración de arsénico en una columna empacada con quitosano modificado alcanza el nivel máximo de concentración permisible (10 g/L) luego de tratar aproximadamente 1500 volúmenes de lecho de agua de la laguna de Papallacta mientras que los sulfatos, cloruros y bicarbonatos irrumpen tempranamente en el ensayo y no muestran ninguna afinidad por los sitios reactivos del sorbente. Aunque fosfatos estuvieron disueltos en el agua de la laguna, el quitosano impregnado con OFH muestra una mayor capacidad de remoción de As; un factor de separación As/P igual a 2.7 confirma que el As(V) es más selectivo comparado con el fosfato. Sin embargo, la presencia del fosfato en el agua de la laguna reduce los sitios de sorción para remover el As(V) en las partículas de OFH. Además, se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos As-materia orgánica. Estos complejos son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
En un ensayo de lecho-fijo se observó que AsT alcanza 10 g/L luego de tratar aproximadamente 2500 volúmenes de lecho y 50 g/L después de hacer pasar 15000 volúmenes de lecho de agua contaminada con As proveniente del embalse de la EMAAP-Q. El quitosano impregnado con OFH muestra una capacidad de remoción significativa por el As y los aniones competidores no influencian en su sorción. Igualmente se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos, los que son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
La regeneración del Q-OFH es buena y se requieren únicamente 15 volúmenes de lecho para recuperar más del 75 % de arsénico retenido en el sorbente. Del balance de masa se calcula que la recuperación del AsT desde el sorbente es alrededor de 179.7µgAsT/g quitosano modificado. Igual que en la regeneración de columnas de lecho-fijo usando agua sintética, la red de poros es accesible al regenerante, produce un incremento de pH en la fase sólida y líquida y promueve la formación de los oxianiones de As y la desprotonización de la superficie de los óxidos de Fe(III), facilitando de esta manera la desorción de los compuestos arsenicales.
En el Ecuador la ocurrencia de arsénico de origen natural ha sido recientemente encontrada en aguas geotermales, aguas subterráneas y superficiales y sedimentos. Un equipo de investigación de la ESPE determinó en el 2006, contenidos de arsénico en fuentes de agua geotermal, en aguas de los ríos o quebradas que reciben los residuales termales y en los sedimentos de esas microcuencas. En este estudio se monitorearon más de 20 fuentes de agua geotermal en las provincias de El Carchi, Imbabura, Pichincha, Cotopaxi y Tungurahua [38]. Las concentraciones de arsénico total presentes en las fuentes de agua termal de la provincia del Carchi oscilan entre 2 y 684 g/L. En la provincia de Imbabura la fluctuación es mucho mayor y varía de 4 a 969 g/L. En cambio, los contenidos de arsénico en las fuentes de la provincia de Pichincha fluctúan entre 11 y 405 g/L y en la provincia de Cotopaxi se tienen la menores concentraciones que van desde 4 a 45 g/L. En la provincia de Tungurahua en cambio el arsénico presente en las aguas termales es de 6 a 114 g/L [38].
En la remediación ambiental de la laguna de Papallacta por el derrame de crudo ocurrido en marzo del 2003, se encontraron a más hidrocarburos de petróleo totales, niveles de arsénico que oscilaban entre 390 y 670 g/L [40]. Posteriormente en otros análisis de arsénico practicados en muestras de agua de la laguna revelan concentraciones de arsénico que varían entre 330 y 600 μg/L. Además, en la caracterización realizada por De la Torre et al. en el 2003, encontraron también altas concentraciones de vanadio y níquel en el crudo de referencia y que pudo ocasionar elevados niveles de esos elementos en el agua de la laguna de Papallacta.
Ensayos de sorción prueban que las esferas de quitosano impregnadas con óxidos de Fe(III) y los gránulos de hidrotalcita recubiertos con óxidos de Fe(III) son selectivos para remover arsénico inorgánico total comparado con sulfatos (SO42-), cloruros (Cl-) y bicarbonatos (HCO3-). La preferencia del arsénico sobre el sulfato, cloruro o bicarbonato es debido a la formación de complejos estables de esfera interna entre el arsénico y las superficies de los OFH. Las esferas y gránulos son también factibles de una eficiente regeneración. Menos de 20 volúmenes de regenerante consistente de 3% de NaOH o 2%NaOH + 3%NaCl, son suficientes para recuperar más del 90% de los compuestos adsorbidos.
La concentración de arsénico en una columna empacada con quitosano modificado alcanza el nivel máximo de concentración permisible (10 g/L) luego de tratar aproximadamente 1500 volúmenes de lecho de agua de la laguna de Papallacta mientras que los sulfatos, cloruros y bicarbonatos irrumpen tempranamente en el ensayo y no muestran ninguna afinidad por los sitios reactivos del sorbente. Aunque fosfatos estuvieron disueltos en el agua de la laguna, el quitosano impregnado con OFH muestra una mayor capacidad de remoción de As; un factor de separación As/P igual a 2.7 confirma que el As(V) es más selectivo comparado con el fosfato. Sin embargo, la presencia del fosfato en el agua de la laguna reduce los sitios de sorción para remover el As(V) en las partículas de OFH. Además, se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos As-materia orgánica. Estos complejos son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
En un ensayo de lecho-fijo se observó que AsT alcanza 10 g/L luego de tratar aproximadamente 2500 volúmenes de lecho y 50 g/L después de hacer pasar 15000 volúmenes de lecho de agua contaminada con As proveniente del embalse de la EMAAP-Q. El quitosano impregnado con OFH muestra una capacidad de remoción significativa por el As y los aniones competidores no influencian en su sorción. Igualmente se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos, los que son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
La regeneración del Q-OFH es buena y se requieren únicamente 15 volúmenes de lecho para recuperar más del 75 % de arsénico retenido en el sorbente. Del balance de masa se calcula que la recuperación del AsT desde el sorbente es alrededor de 179.7µgAsT/g quitosano modificado. Igual que en la regeneración de columnas de lecho-fijo usando agua sintética, la red de poros es accesible al regenerante, produce un incremento de pH en la fase sólida y líquida y promueve la formación de los oxianiones de As y la desprotonización de la superficie de los óxidos de Fe(III), facilitando de esta manera la desorción de los compuestos arsenicales.
En el Ecuador la ocurrencia de arsénico de origen natural ha sido recientemente encontrada en aguas geotermales, aguas subterráneas y superficiales y sedimentos. Un equipo de investigación de la ESPE determinó en el 2006, contenidos de arsénico en fuentes de agua geotermal, en aguas de los ríos o quebradas que reciben los residuales termales y en los sedimentos de esas microcuencas. En este estudio se monitorearon más de 20 fuentes de agua geotermal en las provincias de El Carchi, Imbabura, Pichincha, Cotopaxi y Tungurahua [38]. Las concentraciones de arsénico total presentes en las fuentes de agua termal de la provincia del Carchi oscilan entre 2 y 684 g/L. En la provincia de Imbabura la fluctuación es mucho mayor y varía de 4 a 969 g/L. En cambio, los contenidos de arsénico en las fuentes de la provincia de Pichincha fluctúan entre 11 y 405 g/L y en la provincia de Cotopaxi se tienen la menores concentraciones que van desde 4 a 45 g/L. En la provincia de Tungurahua en cambio el arsénico presente en las aguas termales es de 6 a 114 g/L [38].
En la remediación ambiental de la laguna de Papallacta por el derrame de crudo ocurrido en marzo del 2003, se encontraron a más hidrocarburos de petróleo totales, niveles de arsénico que oscilaban entre 390 y 670 g/L [40]. Posteriormente en otros análisis de arsénico practicados en muestras de agua de la laguna revelan concentraciones de arsénico que varían entre 330 y 600 μg/L. Además, en la caracterización realizada por De la Torre et al. en el 2003, encontraron también altas concentraciones de vanadio y níquel en el crudo de referencia y que pudo ocasionar elevados niveles de esos elementos en el agua de la laguna de Papallacta.
Ensayos de sorción prueban que las esferas de quitosano impregnadas con óxidos de Fe(III) y los gránulos de hidrotalcita recubiertos con óxidos de Fe(III) son selectivos para remover arsénico inorgánico total comparado con sulfatos (SO42-), cloruros (Cl-) y bicarbonatos (HCO3-). La preferencia del arsénico sobre el sulfato, cloruro o bicarbonato es debido a la formación de complejos estables de esfera interna entre el arsénico y las superficies de los OFH. Las esferas y gránulos son también factibles de una eficiente regeneración. Menos de 20 volúmenes de regenerante consistente de 3% de NaOH o 2%NaOH + 3%NaCl, son suficientes para recuperar más del 90% de los compuestos adsorbidos.
La concentración de arsénico en una columna empacada con quitosano modificado alcanza el nivel máximo de concentración permisible (10 g/L) luego de tratar aproximadamente 1500 volúmenes de lecho de agua de la laguna de Papallacta mientras que los sulfatos, cloruros y bicarbonatos irrumpen tempranamente en el ensayo y no muestran ninguna afinidad por los sitios reactivos del sorbente. Aunque fosfatos estuvieron disueltos en el agua de la laguna, el quitosano impregnado con OFH muestra una mayor capacidad de remoción de As; un factor de separación As/P igual a 2.7 confirma que el As(V) es más selectivo comparado con el fosfato. Sin embargo, la presencia del fosfato en el agua de la laguna reduce los sitios de sorción para remover el As(V) en las partículas de OFH. Además, se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos As-materia orgánica. Estos complejos son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
En un ensayo de lecho-fijo se observó que AsT alcanza 10 g/L luego de tratar aproximadamente 2500 volúmenes de lecho y 50 g/L después de hacer pasar 15000 volúmenes de lecho de agua contaminada con As proveniente del embalse de la EMAAP-Q. El quitosano impregnado con OFH muestra una capacidad de remoción significativa por el As y los aniones competidores no influencian en su sorción. Igualmente se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos, los que son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
La regeneración del Q-OFH es buena y se requieren únicamente 15 volúmenes de lecho para recuperar más del 75 % de arsénico retenido en el sorbente. Del balance de masa se calcula que la recuperación del AsT desde el sorbente es alrededor de 179.7µgAsT/g quitosano modificado. Igual que en la regeneración de columnas de lecho-fijo usando agua sintética, la red de poros es accesible al regenerante, produce un incremento de pH en la fase sólida y líquida y promueve la formación de los oxianiones de As y la desprotonización de la superficie de los óxidos de Fe(III), facilitando de esta manera la desorción de los compuestos arsenicales.
En el Ecuador la ocurrencia de arsénico de origen natural ha sido recientemente encontrada en aguas geotermales, aguas subterráneas y superficiales y sedimentos. Un equipo de investigación de la ESPE determinó en el 2006, contenidos de arsénico en fuentes de agua geotermal, en aguas de los ríos o quebradas que reciben los residuales termales y en los sedimentos de esas microcuencas. En este estudio se monitorearon más de 20 fuentes de agua geotermal en las provincias de El Carchi, Imbabura, Pichincha, Cotopaxi y Tungurahua [38]. Las concentraciones de arsénico total presentes en las fuentes de agua termal de la provincia del Carchi oscilan entre 2 y 684 g/L. En la provincia de Imbabura la fluctuación es mucho mayor y varía de 4 a 969 g/L. En cambio, los contenidos de arsénico en las fuentes de la provincia de Pichincha fluctúan entre 11 y 405 g/L y en la provincia de Cotopaxi se tienen la menores concentraciones que van desde 4 a 45 g/L. En la provincia de Tungurahua en cambio el arsénico presente en las aguas termales es de 6 a 114 g/L [38].
En la remediación ambiental de la laguna de Papallacta por el derrame de crudo ocurrido en marzo del 2003, se encontraron a más hidrocarburos de petróleo totales, niveles de arsénico que oscilaban entre 390 y 670 g/L [40]. Posteriormente en otros análisis de arsénico practicados en muestras de agua de la laguna revelan concentraciones de arsénico que varían entre 330 y 600 μg/L. Además, en la caracterización realizada por De la Torre et al. en el 2003, encontraron también altas concentraciones de vanadio y níquel en el crudo de referencia y que pudo ocasionar elevados niveles de esos elementos en el agua de la laguna de Papallacta.
Ensayos de sorción prueban que las esferas de quitosano impregnadas con óxidos de Fe(III) y los gránulos de hidrotalcita recubiertos con óxidos de Fe(III) son selectivos para remover arsénico inorgánico total comparado con sulfatos (SO42-), cloruros (Cl-) y bicarbonatos (HCO3-). La preferencia del arsénico sobre el sulfato, cloruro o bicarbonato es debido a la formación de complejos estables de esfera interna entre el arsénico y las superficies de los OFH. Las esferas y gránulos son también factibles de una eficiente regeneración. Menos de 20 volúmenes de regenerante consistente de 3% de NaOH o 2%NaOH + 3%NaCl, son suficientes para recuperar más del 90% de los compuestos adsorbidos.
La concentración de arsénico en una columna empacada con quitosano modificado alcanza el nivel máximo de concentración permisible (10 g/L) luego de tratar aproximadamente 1500 volúmenes de lecho de agua de la laguna de Papallacta mientras que los sulfatos, cloruros y bicarbonatos irrumpen tempranamente en el ensayo y no muestran ninguna afinidad por los sitios reactivos del sorbente. Aunque fosfatos estuvieron disueltos en el agua de la laguna, el quitosano impregnado con OFH muestra una mayor capacidad de remoción de As; un factor de separación As/P igual a 2.7 confirma que el As(V) es más selectivo comparado con el fosfato. Sin embargo, la presencia del fosfato en el agua de la laguna reduce los sitios de sorción para remover el As(V) en las partículas de OFH. Además, se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos As-materia orgánica. Estos complejos son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
En un ensayo de lecho-fijo se observó que AsT alcanza 10 g/L luego de tratar aproximadamente 2500 volúmenes de lecho y 50 g/L después de hacer pasar 15000 volúmenes de lecho de agua contaminada con As proveniente del embalse de la EMAAP-Q. El quitosano impregnado con OFH muestra una capacidad de remoción significativa por el As y los aniones competidores no influencian en su sorción. Igualmente se comprueba que la materia orgánica natural dificulta la remoción de los compuestos arsenicales al inducir la formación de complejos, los que son muy solubles en agua y arrastran el arsénico fuera de la zona de reacción de las partículas de OFH dispersas en las esferas de quitosano.
La regeneración del Q-OFH es buena y se requieren únicamente 15 volúmenes de lecho para recuperar más del 75 % de arsénico retenido en el sorbente. Del balance de masa se calcula que la recuperación del AsT desde el sorbente es alrededor de 179.7µgAsT/g quitosano modificado. Igual que en la regeneración de columnas de lecho-fijo usando agua sintética, la red de poros es accesible al regenerante, produce un incremento de pH en la fase sólida y líquida y promueve la formación de los oxianiones de As y la desprotonización de la superficie de los óxidos de Fe(III), facilitando de esta manera la desorción de los compuestos arsenicales.
Water is the source of all life on earth. Water has many unique properties that allow it to be such a universal material. One special characteristic of water is its ability to change state very easily under earth conditions. These forms play a great part in the hydrologic cycle. For irrigation, a typical characteristic of water (termed as “water quality”) is important. This “characteristic” feature influences the suitability of water for an intended use. To irrigate in a sustainable fashion, it is important to assess the water quality characteristics, land suitability, and crop limitations. Even water of reasonable quality may negatively affect the soil if salinity levels concentrate over time.
The aim of this study was to estimate both the contribution of drinking water and food (raw and cooked) to the total (t-As) and inorganic (i-As) arsenic intake and the exposure of inhabitants of Socaire, a rural village in Chile´s Antofagasta Region, by using urine as biomarker. The i-As intake from food and water was estimated using samples collected between November 2008 and September 2009. A 24-hour dietary recall questionnaire was given to 20 participants. Drinking water, food (raw and cooked) and urine samples were collected directly from the homes where the interviewees lived. The percentage of i-As/t-As in the drinking water that contributed to the total intake was variable (26.8-92.9). Cereals and vegetables are the food groups that contain higher concentrations of i-As. All of the participants interviewed exceeded the reference intake FAO/OMS (149.8 µg∙i-As·day-1) by approximately nine times. The concentration of t-As in urine in each individual ranged from 78 to 459 ng·mL-1. Estimated As intake from drinking water and food was not associated with total urinary As concentration. The results show that both drinking water and food substantially contribute to i-As intake and an increased exposure risk to adult residents in contaminated areas.
In India, demand for water has increased due to population growth and the competition induced by economic aspirations for developmental activities. Despite abundant rainfall, a few crucial issues for the water crisis are as follows: erratic rainfall and zonal disparity in the distribution of the available water and its inefficient use across different regions, unregulated groundwater extraction, worsening water quality, inefficient management and implementation of the regulations, lack of an ethical framework, and so on. Over 70% of the surface water is polluted and is unsafe for drinking/farming. More than 65% of irrigated agriculture and 80-85% of the rural and urban water supply and drinking water supply depend on groundwater. However, people have inadequate knowledge and awareness and different perceptions of this vital natural resource and how vulnerable it is. Geoscientists have a significant role to play to increase public awareness on the topic of 'groundwater ethics' and its interaction with people, their habits and the water in order to control indiscriminate water extraction and its wasteful utilization. To protect groundwater from depletion, emphasis should be placed on community-focused groundwater use, the price of water extraction and the costs and benefits of water allocation for irrigation needs where consumptive use is high compared to all other uses with relatively smaller water needs.
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