Water Arsenic Concentrations Research Articles

DISTRIBUCIÓN DE ARSÉNICO EN AGUA SUPERFICIAL Y SEDIMENTO EN LA CUENCA DEL RÍO CARRIZAL, MANABÍ - ECUADOR

En diversas fuentes naturales de agua superficial de Ecuador, así como en otras a nivel mundial, la concentración de arsénico supera los límites permisibles (10 μg/L) establecidos por la Organización Mundial de la Salud. El objetivo de la presente investigación fue determinar los niveles de arsénico en agua superficial y sedimentos en la cuenca del río Carrizal (Manabí, Ecuador), zona que posee una importante actividad agropecuaria. Se monitorearon 21 estaciones en tres zonas, cubriendo una extensión de 51 km. Las concentraciones de arsénico en agua y sedimento se evaluaron mediante espectrometría de absorción atómica con el equipo PerkinElmer® AAnalyst™ 200, de acuerdo con los lineamientos del Standard Methods Edición 2015, por la metodología APHA AWWA WEF 3114-B. Se utilizó el diseño experimental de bloques al azar, con arreglo factorial de las tres zonas de muestreo. Los resultados indican que se encontraron concentraciones de arsénico de hasta 35,64 mg/L en agua superficial y de 47,41 mg/kg en sedimentos. Se concluye que estos altos niveles de arsénico en la cuenca del río Carrizal podrían ser de origen antrópico.

Seasonal variations in arsenic mobility and bacterial diversity: The case study of Huangshui Creek, Shimen Realgar Mine, Hunan Province, China

Rivers throughout the world have been contaminated by arsenic dispersed from mining activities. The biogeochemical cycling of this arsenic has been shown to be due to factors such as pH, Eh, ionic strength and microbial activity, but few studies have examined the effects of both seasonal changes and microbial community structure on arsenic speciation and flux in mining-affected river systems. To address this research gap, a study was carried out in Huangshui Creek, Hunan province, China, which has been severely impacted by long-term historic realgar (α-As4S4) mining. Water and sediment sampling, and batch experiments at different temperatures using creek sediment, were used to determine the form, source and mobility of arsenic. Pentavalent (AsO43) and trivalent arsenic (AsO33−) were the dominant aqueous species (70–89% and 30–11%, respectively) in the creek, and the maximum concentration of inorganic arsenic in surface water was 10,400 μg/L. Dry season aqueous arsenic concentrations were lower than those in the wet season samples. The sediments contained both arsenate and arsenite, and relative proportions of these varied with season. 8.3 tons arsenic per annum were estimated to be exported from Huangshui Creek. Arsenic release from sediment increased by 3 to 5 times in high water temperature batch experiments (25 and 37 °C) compared to those carried out at low temperature (8 °C). Our data suggest that the arsenic-containing sediments were the main source of arsenic contamination in Huangshui Creek. Microbial community structured varied at the different sample sites along the creek. Redundancy analysis (RDA) showed that both temperature and arsenic concentrations were the main controlling factors on the structure of the microbial community. Protecbacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Verrucomicrobia, and Planctomycetes were the stable dominant phyla in both dry and wet seasons. The genera Flavobacterium, Hydrogenophaga and Sphingomonas occurred in the most highly arsenic contaminated sites, which removed arsenic by related metabolism.Our findings indicate that seasonal variations profoundly control arsenic flux and species, microbial community structure and ultimately, the biogeochemical fate of arsenic.

Arsenic exposure-related hyperglycemia is linked to insulin resistance with concomitant reduction of skeletal muscle mass

BackgroundAlargebodyof evidence has shown a link between arsenic exposure and diabetes, but the underlying mechanisms have not yet been clarified. ObjectiveWe explored the association between arsenic exposure and the reduction of skeletal muscle mass as a potential mechanism of insulin resistance for developing arsenic-related hyperglycemia. MethodsA total of 581 subjects were recruited from arsenic-endemic and non-endemic areas in Bangladesh and their fasting blood glucose (FBG), serum insulin, and serum creatinine levels were determined. Subjects’ arsenic exposure levels were assessed by arsenic concentrations in water, hair, and nails. HOMA-IR and HOMA-β were used to calculate insulin resistance and β-cell dysfunction, respectively. Serum creatinine levels and lean body mass (LBM) were used as muscle mass indicators. ResultsWater, hair and nail arsenic concentrations showed significant positive associations with FBG, serum insulin and HOMA-IR and inverse associations with serum creatinine and LBM in a dose-dependent manner both in males and females. Water, hair and nail arsenic showed significant inverse associations with HOMA-β in females but not in males. FBG and HOMA-IR were increased with the decreasing levels of serum creatinine and LBM. Odds ratios (ORs)of hyperglycemia were significantly increased with the increasing concentrations of arsenic in water, hair and nails and with the decreasing levels of serum creatinine and LBM. Females’ HOMA-IR showed greater susceptibility to the reduction of serum creatinine and LBM, possibly causing the greater risk of hyperglycemia in females than males. Path analysis revealed the mediating effect of serum creatinine level on the relationship of arsenic exposure with HOMA-IR and hyperglycemia. ConclusionArsenic exposure elevates FBG levels and the risk of hyperglycemia through increasing insulin resistance with greater susceptibility in females than males. Additionally, arsenic exposure-related reduction of skeletal muscle mass may be a mechanism underlying the development of insulin resistance and hyperglycemia.

376 Estimation of cutaneous squamous cell carcinoma incidence attributable to arsenic in U.S. water supplies

Arsenic in water supplies potentially exposes millions of people to increased disease risk worldwide. Despite strengthened regulation, arsenic concentrations commonly found in U.S. water supplies may increase the incidence of cutaneous squamous cell carcinoma (cSCC). We estimated cSCC incidence attributable to arsenic in water supplies among U.S. non-Hispanic whites, a demographic with disproportionately high skin cancer incidence. We determined the number of people exposed to various concentrations of arsenic in water supplies by analyzing three datasets: urine samples from the National Health and Nutrition Examination Survey (2015–2016), public water supply data from the Environmental Protection Agency (EPA) Six-Year Review 3 (2006–2011), and private well user data from Ayotte et al. (2017). Among 743 representative patients, total arsenic concentrations in urine had a median (interquartile range) of 3.00 μg/l (2.25–4.02). Public water supplies serving 10 million out of 151 million non-Hispanic white users had detectable levels of arsenic. An estimated 1.6 million out of 33 million non-Hispanic white private well users had water arsenic concentrations above 10 μg/l (EPA limit for public water). These data were combined with published odds ratios for cSCC incidence with arsenic exposure, assuming that total arsenic concentrations in urine less than 4.76 μg/l do not affect cSCC risk. Based on urinary arsenic data, 32,512 out of 2,548,845 cSCCs annually in the U.S. are attributable to arsenic in water supplies. This estimate includes 26,228 cSCCs among public water users and 6,284 among private well users. Separately, water supply data suggest that at least 10,361 and 4,380 cSCCs are attributable to arsenic in public water supplies and in private wells, respectively. Overall, up to 1.3% of cSCC incidence in the U.S. may be attributed to arsenic in current water supplies. Thousands of cSCCs may be prevented by further restricting arsenic in U.S. water supplies.

Arsenic in US correctional facility drinking water, 2006–2011

BackgroundLittle is known about the quality of drinking water in US correctional facilities (e.g. detention centers, prisons, jails, etc.). Our objective was to determine if incarcerated persons are at risk for chronic, elevated arsenic exposure relative to the non-incarcerated US population, particularly in the Southwestern US where public water and groundwater arsenic concentrations are high compared to the rest of the US. MethodsWe analyzed 230,158 arsenic monitoring records from 37,086 community water systems (CWSs) from the Environmental Protection Agency's (EPA) Third Six Year Review of Contaminant Occurrence dataset (covering 2006–2011). We compared six-year average arsenic concentrations and the odds of exceeding the EPA's 10 μg/L maximum contaminant level (MCL) for CWSs exclusively serving correctional facilities versus all other CWSs in the Southwestern US, where groundwater arsenic concentrations are high. ResultsAverage six-year water arsenic concentrations were higher for Southwestern correctional facility CWSs (6.41 μg/L, 95% CI 3.48, 9.34) compared to all other Southwestern CWSs (3.11 μg/L, 95% CI 2.97, 3.24) and to other CWSs across the rest of the US (1.39 μg/L, 95% CI 1.35, 1.42). In the Southwest, 26.1% (N = 6) of correctional facility CWSs versus 5.8% (509) of other CWSs reported six-year arsenic averages exceeding 10 μg/L, corresponding to an odds ratio of 5.70 (95% confidence interval 2.24, 14.52). Correctional facility CWSs in the Southwest were also more likely to report six-year averages exceeding 5 μg/L (the MCL for New Jersey and New Hampshire, N = 8, odds ratio 2.77, 95% CI 1.17, 6.54). DiscussionPersons incarcerated in the Southwestern US were at disproportionate risk of elevated drinking water arsenic exposure and related disease from 2006 to 2011. Strict enforcement of EPA regulations and additional technical and financial support for CWSs serving correctional facilities in the Southwest is necessary to protect the health and human rights of incarcerated persons.

Arsenic in agro-ecosystems under anthropogenic pressure in Germany and France compared to a geogenic As region in Finland

Arsenic concentrations in soil and water were examined at the European level via a literature review and data inventory in the first phase of the AgriAs European Water JPI project. Arsenic in soil can be derived from both natural and anthropogenic sources. At the European scale, the distribution of arsenic in agricultural topsoil can mostly be explained by geology. In the next step, the AgriAs project investigated arsenic concentrations in soil and water in two regions: Saxony in Germany and Verdun in France. The results were compared with arsenic data from a geogenic arsenic region around the city of Tampere in Finland. In Saxony, arsenic is partly natural and partly derived from the widespread mining and ore processing activities in the area that have lasted for centuries. Areas contaminated with As were found to cover 970 km2 in Saxony. The soil baseline for As is only 20–40 mg/kg but the highest concentrations in soil are up to 5000 mg/kg. The large number of investigations in Saxony has given a possibility to evaluate As transfer into plants, fodder and food and to develop guidelines for farmers. In Verdun, arsenic is derived from a former chemical ammunition destruction facility that operated in the interwar period. Today, there are hot spots of As in topsoil with concentrations ranging from 100 to 1000 mg/kg, while the baseline concentration in soil is 18 mg/kg. In the Tampere region, baseline concentrations of As in glacial till forest soils are relatively high (30 mg/kg) over an area of 7400 km2, with hot spots of 1050 mg/kg in topsoil. However, agricultural soils contain clearly lower As concentrations. In all three regions, As concentrations in surface waters and in groundwater were found to be relatively low, and the As concentration in topsoil could not be linked to irrigation with As-containing water. Fortunately, As transfer from soil into plants via root systems is generally low in aerated soil, but As-containing dust can affect fodder plants. Especially in the Freiberg area of Saxony, As is usually associated with Cd contamination in topsoil, and guidelines for farmers based on Cd concentrations are also a good risk management method for As.

Health risk analysis of phenol and arsenic exposure among kokoda communities village Sorong, West Papua

This study aims to determine the level of risk management and reduction of health risks from exposure to phenol and arsenic in drinking water, environmental management improvement the quality of health Kokoda communities. This observational study analysis of environmental health risks. The sample was 100 people who have been based on the specified criteria. Data collected through environmental observation, an examination of water samples and questionnaires. Determination of phenol and arsenic using AAS methods. Phenol concentration in surface waters is 0.193mg/L, the average concentration of phenol in the underground water 0.1268mg/L while the concentration of arsenic in surface water and underground water is 0.01mg/L. Risk level of non-carcinogenic effect suggests that the rate of water consumption as well as the duration of exposure is very influential on the level of public health risk.

MACRO-ZOOPLANKTON ABUNDANCE IN RELATION TO METAL ACCUMULATION AND WATER QUALITY IN TRUC BACH LAKE

Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in Truc Bach lake and levels of two essential metals: copper (Cu), and zinc (Zn) and of three non-essential metals: arsenic (As), and lead (Pb) in water samples were determined. The results showed that Cladocerans and copepods are macro-zooplankton dominant species in Truc Bach Lake. Water temperature significantly affects the variety of copepod blooming. Arsenic concentration in water collected from the lake exceeded the safety level of current Vietnamese regulation. As concentration in macro-zooplankton positively correlated with metal concentrations in the water (p < 0.05) while the concentration of Cu, Zn, and Pb in water has no significant correlation with the metal in zooplankton’s body. The relative abundance of adult copepods in Truc Bach lake had a negative correlation with As concentration in water (p = 0.01). The higher As concentration in water, the lower relative abundance of copepods was found in the sample.

Reduction in drinking water arsenic exposure and health risk through arsenic treatment among private well households in Maine and New Jersey, USA

Over 2 million mostly rural Americans are at risk of drinking water from private wells that contain arsenic (As) exceeding the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) of 10 micrograms per liter (μg/L). How well existing treatment technologies perform in real world situations, and to what extent they reduce health risks, are not well understood. This study evaluates the effectiveness of household As treatment systems in southern-central Maine (ME, n = 156) and northern New Jersey (NJ, n = 94) and ascertains how untreated well water chemistry and other factors influence As removal. Untreated and treated water samples, as well as a treatment questionnaire, were collected. Most ME households had point-of-use reverse-osmosis systems (POU RO), while in NJ, dual-tank point-of-entry (POE) whole house systems were popular. Arsenic treatment systems reduced well water arsenic concentrations ([As]) by up to two orders of magnitude, i.e. from a median of 71.7 to 0.8 μg/L and from a mean of 105 to 14.3 μg/L in ME, and from a median of 8.6 to 0.2 μg/L and a mean of 15.8 to 2.1 μg/L in NJ. More than half (53%) of the systems in ME reduced water [As] to below 1 μg/L, compared to 69% in NJ. The treatment system failure rates were 19% in ME (>USEPA MCL of 10 μg/L) and 16% in NJ (>NJ MCL of 5 μg/L). In both states, the higher the untreated well water [As] and the As(III)/As ratio, the higher the rate of treatment failure. POE systems failed less than POU systems, as did the treatment systems installed and maintained by vendors than those by homeowners. The 7-fold reduction of [As] in the treated water reduced skin cancer risk alone from 3765 to 514 in 1 million in ME, and from 568 to 75 in 1 million in NJ.

Seasonal variation of arsenic concentrations in tubewells in west Bengal, India.

This study was conducted to monitor the changes in arsenic concentration during different seasons in a one-year period during 2002-2003 in selected tubewells in an arsenic-affected area in the district of South 24 Parganas in West Bengal, India, and to map the location of the wells. Seasonal variations in concentrations of arsenic in water were measured from 74 selected tubewells, ranging in depth from 40 to 500 feet. Water samples were collected from these wells during winter, summer, monsoon, and the following winter in 2002-2003. A global positioning system was used for locating the tubewells, and a geographic information system was used for mapping. There was evidence of seasonal variation in concentrations of arsenic in water (p=0.02) with the minimum average concentration occurring in the summer season (694 microg/L) and the maximum in the monsoon season (906 microg/L). From the winter of 2002 to the winter of 2003, arsenic concentrations increased, irrespective of the depth of the tubewells, from an average of 464 microg/L to 820 microg/L (p<0.001). This extent of variation in arsenic concentration, if confirmed, has important implications for both epidemiological research and mitigation programmes.

Human health risk-based life cycle assessment of drinking water treatment for heavy metal(loids) removal

A human health risk-based life cycle assessment (LCA) framework was developed for selecting low-impact water treatment systems with a focus on heavy metal(loids) removal. The framework comprises three phases, including pilot-scale water treatment, human health risk assessment (HRA), and LCA. The application of the framework was demonstrated by a case study. Two water treatment systems employing ozonation-greensand-ferric hydroxide-based sorbent (OGF) and Birm-ferric hydroxide-based sorbent (BF) processes were used to reduce arsenic and manganese concentrations in the source water of a small municipality in southwestern Canada. The heavy metal(loids) concentration as well as material and energy use data of the two systems were collected to perform HRA and LCA. The results showed that both systems can reduce arsenic and manganese concentrations; however, the removal efficiencies of OGF and BF processes decreased with the increase of treatment volume. At a constant inflow rate, the ferric hydroxide-based sorbent needed to be replaced every 31 and 25 days in the OGF and BF processes, respectively, to ensure that arsenic concentration in the effluent would not pose any significant human health risk. The LCA results indicated that the system using the OGF process generated lower life cycle environmental impacts than the system using the BF process throughout ten years’ operation. It was also found that the arsenic removal process was the largest impact contributor in both systems. The manufacturing of ferric hydroxide-based sorbent and disposal of arsenic-contaminated treatment waste accounted for the highest impact in water treatment.

Vitamin B-6 Intake Is Modestly Associated with Arsenic Methylation in Uruguayan Children with Low-Level Arsenic Exposure

Background:Detoxification of inorganic arsenic (iAs) occurs when it methylates to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of urinary iAs and MMA, and higher proportions of DMA indicate efficient methylation. The role of B-vitamins in iAs methylation in children with low-level arsenic exposure is understudied. Objectives:Our study objective was to assess the association between B-vitamin intake and iAs methylation in children with low-level arsenic exposure (<50 µg/L in water; urinary arsenic 5–50 µg/L). Methods:We conducted a cross-sectional study in 290 ~7-y-old children in Montevideo. Intake of thiamin, riboflavin, niacin, vitamin B-6, and vitamin B-12 was calculated by averaging 2 nonconsecutive 24-h recalls. Total urinary arsenic concentration was measured as the sum of urinary iAs, MMA, and DMA, and adjusted for urinary specific gravity; iAs methylation was measured as urinary percentage As, percentage MMA, and percentage DMA. Arsenic concentrations from household water sources were assessed. Linear regressions tested the relationships between individual energy-adjusted B-vitamins and iAs methylation. Results:Median (range) arsenic concentrations in urine and water were 9.9 (2.2–48.7) and 0.45 (0.1–18.9) µg/L, respectively. The median (range) of urinary percentage iAs, percentage MMA, and percentage DMA was 10.6% (0.0–33.8), 9.7% (2.6–24.8), and 79.1% (58.5–95.4), respectively. The median (range) intake levels of thiamin, riboflavin, niacin, and vitamin B-6 were 0.81 (0.19–2.56), 1.0 (0.30–2.24), 8.6 (3.5–23.3), and 0.67 (0.25–1.73) mg/1000 kcal, respectively, whereas those of folate and vitamin B-12 were 216 (75–466) and 1.7 (0.34–8.3) µg/1000 kcal, respectively. Vitamin B-6 intake was inversely associated with urinary percentage MMA (β = –1.60; 95% CI: –3.07, –0.15). No other statistically significant associations were observed. Conclusions:Although vitamin B-6 intake was inversely associated with urinary percentage MMA, our findings suggest limited support for a relation between B-vitamin intake and iAs methylation in children exposed to low-level arsenic.

Constraints of major ions and arsenic on the geological genesis of geothermal water: Insight from a comparison between Xiong'an and Yangbajain, two hydrothermal systems in China

Hydrochemical similarities are shared by the geothermal waters from Xiong'an, a typical non-magmatic hydrothermal system, and Yangbajain, a typical magmatic hydrothermal system. Both systems are primarily discharging chloride- and sodium-rich geothermal waters with similar TDS values. However, the hydrochemical investigations made in this study show that the chloride in the Xiong'an geothermal waters originates mainly from the mixing of deep saline waters, while that in the Yangbajain geothermal waters is basically of magmatic origin, like many other magmatic hydrothermal systems hosted by felsic rocks worldwide. In contrast to chloride, the concentrations of arsenic in the geothermal waters from Xiong'an and Yangbajain differ greatly. The higher arsenic concentrations of the Yangbajain geothermal waters are attributable to the much greater reservoir temperatures in Yangbajain, and possibly, the input of magmatic fluids to the Yangbajain reservoirs. The contents of arsenic in reservoir rocks, instead, don't seem to be an important factor controlling the geothermal arsenic concentrations. Leaching of arsenic from arsenic-rich sandstone or carbonate rocks at relatively low Xiong'an reservoir temperatures should be much less than that from arsenic-poor granitic rocks at higher Yangbajain reservoir temperatures. The results obtained in this study indicate that arsenic coupled with other hydrochemical constituents can be used as a useful tool to identify the geological geneses of geothermal waters.

Arsenic transport in canal water and across rice fields in district Badin

Background/Objectives: Irrigation water at Phuleli and Akram canals carry the waste of Hyderabad city and other places on the way to rice fields at lower part of Indus Plain. The long term use of arsenic contaminated irrigation water can accumulate arsenic in rice soils. This study evaluated total arsenic in irrigation water and transported load to rice sites, in addition to the arsenic concentration in main canals and waste sites on the way to Badin. Methods: Atomic absorption spectrophotometer equipped with hydride vapor assembly was used to analyze the arsenic concentrations in irrigation water. Findings: Currently, the irrigation water quality was generally within the permissible limits of FAO for rice. All types of wastes (14.62-37.2 µg L-1) entering the Phuleli and Akram canals (7.08 µg L-1) on the way contributed to total arsenic (6.30-57.12 µg L-1) in irrigation water at the entrance of rice sites. However, higher arsenic contamination in irrigation water was due to sugar industry waste (37.2 µg L-1) and lowest due to city waste of Badin (14.62 µg L-1). The data indicated that mean total arsenic concentration from irrigation water would load 0.12 and 0.14 mg kg-1 of arsenic annually in soils on the basis of net 1000 and 1300 mm a-1 water application to rice, respectively. Applications/Improvements: The results clearly indicated that waste added from different sources may aggravate the arsenic contamination of canal water and yet the accumulation in rice fields will keep on increasing. It is suggested that waste must be treated before releasing to prevent contamination of rice field. Keywords: Arsenic load, City waste, Contamination, Industrial waste

Carcinogenic and non-carcinogenic health risks of arsenic exposure in drinking water in the rural environment

Carcinogenic and systemic health effects of arsenic exposure in drinking water are well documented. This study estimated the risk associated with chronic consumption of water with high concentrations of arsenic in children and adults living in six Andean locations, in Chile. Concentrations of arsenic in the drinking water were analyzed between 2014 and 2017 based on health authority reports and data collected during this study. Average daily arsenic intake was estimated, and systemic (HQ) and deterministic carcinogenic risk (CR) indices were calculated using U.S. Environmental Protection Agency methodology. Threshold values ​​of HQ>1 and CR> 1 x 10–4 were considered to indicate high risk of adverse health effects. Four of the locations (Chucuyo > Putre > Humapalca = Visviri) had high concentrations of arsenic in the water, at levels 6.3–57.6 times the norm of 0.01 mg/L, Zapahuira and Belen, had values just below the threshold. Extremely high HQ values were estimated in children, at 1.3–119.8 times the threshold. Furthermore, CR values were several orders of magnitude (3.06–10790.6) above the tolerable value among all age strata. The locations studied have a high risk of adverse health effects from exposure to arsenic in drinking water. It is urgent to implement mitigation measures to improve water quality in these communities and to carry out probabilistic studies to provide more accurate assessment of exposure.

Removal of Arsenic Contamination from Gomti River Water by using Activated Charcoal Absorbent Integrated with Solar Distillation Unit

Arsenic is a ubiquitous and short-term poisoning element, which affects living things. In this study, the removal of arsenic from Gomti river water, Lucknow, Uttar Pradesh integrated modified double slope solar still with activated adsorption bed has been applied. Arsenic contamination in Gomti river at five places were found in the river water in the range of 55.70 ppb to 681.60 ppb, which exceed the maximum permissible limit of 10 ppb as recommended by WHO. Maximum concentration of arsenic in water was found in Mohan Maekins (681.60 ppb). However, mean arsenic concentration in water followed the order: Gaughat (115.37 ppb) &lt; Hanuman setu (297.80 ppb) &lt; Barrage (302.62 ppb) &lt;Kukrail (336.27 ppb) &lt; Mohan Maekins (481.89 ppb). The amount of adsorbed arsenic was increased with increasing initial concentration of arsenic. The aim of this study is to develop a low-cost process for the removal of arsenic effectively including the production of potable water. After results, data were analyzed with ICP-MS method and also verified with Langmuir and Freundlich adsorption isotherm models.

Chromium, Cadmium, Lead, and Arsenic Concentrations in Water, Vegetables, and Seafood Consumed in a Coastal Area in Northern Vietnam.

Background:Heavy metal contamination and related risks for the environment and human health are matters of increasing concern.Methods:The levels of 4 heavy metals (Cr, Cd, Pb, and As) were evaluated in 2 water types (surface and well), 4 types of seafood (tiger shrimp, stuffed snail, snake-head fish, and catfish), and 27 types of vegetables (12 leafy vegetables, 4 pea plants, 4 tuber vegetables, and 7 herbs) that are commonly consumed in northern coastal communes located in Vietnam. Atomic absorption spectrometry was employed for quantification.Results:The mean concentrations of heavy metals detected in water, seafood, and vegetable samples exceeded the national permitted standards and World Health Organization (WHO) recommendation values by at least 2-fold, 2.5-fold, and 5-fold for surface water, vegetables, and well water, respectively. The concentrations of all 4 heavy metals detected in seafood samples were higher than the standards. The levels of heavy metals decreased with increasing distance between the sample collection point and the pollution source.Conclusions:This is the first report of heavy metal contamination of common sources of food and water in the northern coastal area of Vietnam. Significantly, the concentrations of heavy metals detected in study samples exceeded the regulatory limits. These results underscore the importance of continued monitoring and the development of intervention measures to ensure that the quality of food and water meets established standards and protects the health of the local population.

Towards a Sustainable Solution: Factors and Prerequisites of Improving the Kanchan Arsenic Filters used in the Terai of Nepal. A Review

The issue dealing with the high arsenic (As) concentrations in ground water used as drinking water in Nepal was neglected for a long time. Whereas Bangladesh received much international attention and appropriate filters to remove As were installed, the distribution of the so-called Kanchan filters in Nepal only began in the early nineties. Arsenic itself can be readily released into ground water depending on pH, redox conditions, temperature, and solution composition. However, there is an obvious de-coupling of As and Fe concentrations in ground water. In this regard, the partial low removal efficiency of the installed Kanchan filters can tentatively be explained by the ratio of main and trace elements (particularly Fe and As), pH, flow rates, contact time with the nails, and filter maintenance. This review paper summarizes the identified geological background, origin of the As, the established mitigation option and future improvements of the filters. In that regard, the approach of building the filters with locally available material is still imperative for a country like Nepal where industrial jobs are relatively in scarce.

Determination of Arsenic Concentration in Ground Water and its Effects on Children: A Case Study of Sonarpur and Baruipur Block, South 24 Parganas, West Bengal

Determination of Arsenic Concentration in Ground Water and its Effects on Children: A Case Study of Sonarpur and Baruipur Block, South 24 Parganas, West Bengal

Assessment of arsenic concentration along a surface water flow path from Zarshuran gold mine to the downstream residential area

Arsenic is one of the most important toxic metalloids that can be mainly found in gold mining areas. As a significant zone in the Takab mining area, Zarshuran gold mine has a drastic effect on the environment because of arsenic contamination. This study evaluated the arsenic concentrations in different parts of a water flow path from the mine to the residential area. Different factors that have a possible impact on arsenic content in water and soil were also evaluated. Water and sediment samples were taken throughout the water flow path, and the locations of the samples were recorded by a global positioning system. The arsenic and iron contents of the samples were determined using inductively coupled plasma mass spectrometry. Results indicated a high amount of arsenic in all samples, especially in those taken near the mine (originated place). In most of the samples, the concentration of arsenic was hundreds of times more than the allowed limit. Arsenic content was decreased throughout the water path, and a high amount of iron was found, where the total arsenic of soil was high.