Arsenic mitigation

About 20 million rural Bangladeshis continue to drink well water containing >50 μg/L arsenic (As). This analysis argues for reprioritizing interventions on the basis of a survey of wells serving a population of 380,000 conducted one decade after a previous round of testing overseen by the government. The available data indicate that testing alone reduced the exposed population in the area in the short term by about 130,000 by identifying the subset of low As wells that could be shared at a total cost of <US$1 per person whose exposure was reduced. Testing also had a longer term impact, as 60,000 exposed inhabitants lowered their exposure by installing new wells to tap intermediate (45−90 m) aquifers that are low in As at their own expense of US$30 per person whose exposure was reduced. In contrast, the installation of over 900 deep (>150 m) wells and a single piped-water supply system by the government reduced exposure of little more than 7000 inhabitants at a cost of US$150 per person whose exposure was reduced. The findings make a strong case for long-term funding of free well testing on a massive scale with piped water or groundwater treatment only as a last resort.

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization's reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the preferred options.

About 20 million rural Bangladeshis continue to drink well water containing >50 μg/L arsenic (As). This analysis argues for reprioritizing interventions on the basis of a survey of wells serving a population of 380,000 conducted one decade after a previous round of testing overseen by the government. The available data indicate that testing alone reduced the exposed population in the area in the short term by about 130,000 by identifying the subset of low As wells that could be shared at a total cost of <US$1 per person whose exposure was reduced. Testing also had a longer term impact, as 60,000 exposed inhabitants lowered their exposure by installing new wells to tap intermediate (45−90 m) aquifers that are low in As at their own expense of US$30 per person whose exposure was reduced. In contrast, the installation of over 900 deep (>150 m) wells and a single piped-water supply system by the government reduced exposure of little more than 7000 inhabitants at a cost of US$150 per person whose exposure was reduced. The findings make a strong case for long-term funding of free well testing on a massive scale with piped water or groundwater treatment only as a last resort.

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization's reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the preferred options.

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization's reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the preferred options.

This study seeks to understand factors that guide the decision-making process to adopt and implement the available arsenic-mitigation technologies in rural areas in the middle-Ganga Plain in India. A total of 340 households comprising 2500 people were surveyed. Socioeconomic and demographic factors, water and sanitation status, time spent and distance travelled to collect water, arsenic awareness, willingness to pay (WTP) for arsenic-free water, people's trust in others and in institutions, social capital in communities, and preferences for sustainable arsenic-mitigation options were investigated. Arsenic treatment units (filters) and piped water supply systems were the most preferred sustainable arsenic-mitigation options in the surveyed villages. Less preferred arsenic-mitigation options include deep tube wells, dug wells, and rainwater harvesting systems. Binary logistic regression models for each arsenic-mitigation option were produced. Arsenic awareness, WTP, trust in agencies, trust in institutions and social capital were found to be the most significant factors for decision-making for preferring one arsenic-mitigation technology over the others. We recommend a mixed model of two arsenicmitigation options for the studied individuals, which could be a sustainable arsenic-mitigation option for them, considering their socioeconomic and demographic conditions. Existing institutions should be strengthened, agencies empowered, and communities enlightened about arsenic problems.

This study presents a cost-effectiveness analysis and mapping requirements for three arsenic mitigation technologies sponsored by the government of India in the state of Bihar, offering recommendations for the technologies most likely to benefit 12 million at-risk people. The three arsenic mitigation technologies investigated in this paper are arsenic treatment (ATU) units, new hand pump (NHP) units, and new tube wells with stand post (NTWSP) units. For 100% coverage of arsenic mitigation in the arsenic-affected districts of Bihar, 314-5111 ATU and NHP and 16-256 NTWSP in Buxar and Jehanabad, respectively, are required. NHP and NTWSP units were found to be the most cost-effective arsenic mitigation interventions in the state, whereas ATU was found to be the dominant intervention. Installation of NHP could be the most efficient arsenic mitigation intervention in areas where the population is scarce and illiterate. NTWSP could be the most cost-effective arsenic mitigation intervention in regions having higher rates of literacy and of arsenic awareness among their communities. The cost-effectiveness of arsenic mitigation technologies should be carefully evaluated before designing and implementing arsenic mitigation policies.

This study evaluates state-of-the-art machine learning models in predicting the most sustainable arsenic mitigation preference. A Gaussian distribution-based Naïve Bayes (NB) classifier scored the highest Area Under the Curve (AUC) of the Receiver Operating Characteristic curve (0.82), followed by Nu Support Vector Classification (0.80), and K-Neighbors (0.79). Ensemble classifiers scored higher than 70% AUC, with Random Forest being the top performer (0.77), and Decision Tree model ranked fourth with an AUC of 0.77. The multilayer perceptron model also achieved high performance (AUC=0.75). Most linear classifiers underperformed, with the Ridge classifier at the top (AUC=0.73) and perceptron at the bottom (AUC=0.57). A Bernoulli distribution-based Naïve Bayes classifier was the poorest model (AUC=0.50). The Gaussian NB was also the most robust ML model with the slightest variation of Kappa score on training (0.58) and test data (0.64). The results suggest that nonlinear or ensemble classifiers could more accurately understand the complex relationships of socio-environmental data and help develop accurate and robust prediction models of sustainable arsenic mitigation. Furthermore, Gaussian NB is the best option when data is scarce.

This study seeks to understand factors that guide the decision-making process to adopt and implement the available arsenic-mitigation technologies in rural areas in the middle-Ganga Plain in India. A total of 340 households comprising 2500 people were surveyed. Socio-economic and demographic factors, water and sanitation status, time spent and distance travelled to collect water, arsenic awareness, willingness to pay (WTP) for arsenic-free water, people's trust in others and in institutions, social capital in communities, and preferences for sustainable arsenic-mitigation options were investigated. Arsenic treatment units (filters) and piped water supply systems were the most preferred sustainable arsenic-mitigation options in the surveyed villages. Less preferred arsenic-mitigation options include deep tube wells, dug wells, and rainwater harvesting systems. Binary logistic regression models for each arsenic-mitigation option were produced. Arsenic awareness, WTP, trust in agencies, trust in institutions and social capital were found to be the most significant factors for decision-making for preferring one arsenic-mitigation technology over the others. We recommend a mixed model of two arsenicmitigation options for the studied individuals, which could be a sustainable arsenic-mitigation option for them, considering their socio-economic and demographic conditions. Existing institutions should be strengthened, agencies empowered, and communities enlightened about arsenic problems.

This study presents a cost-effectiveness analysis and mapping requirements for three arsenic mitigation technologies sponsored by the government of India in the state of Bihar, offering recommendations for the technologies most likely to benefit 12 million at-risk people. The three arsenic mitigation technologies investigated in this paper are arsenic treatment (ATU) units, new hand pump (NHP) units, and new tube wells with stand post (NTWSP) units. For 100% coverage of arsenic mitigation in the arsenic-affected districts of Bihar, 314-5111 ATU and NHP and 16-256 NTWSP in Buxar and Jehanabad, respectively, are required. NHP and NTWSP units were found to be the most cost-effective arsenic mitigation interventions in the state, whereas ATU was found to be the dominant intervention. Installation of NHP could be the most efficient arsenic mitigation intervention in areas where the population is scarce and illiterate. NTWSP could be the most cost-effective arsenic mitigation intervention in regions having higher rates of literacy and of arsenic awareness among their communities. The cost-effectiveness of arsenic mitigation technologies should be carefully evaluated before designing and implementing arsenic mitigation policies.

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization&apos;s reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the...

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization&apos;s reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the...

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization&#39;s reference level of risk of 10-6 DALYs. A few dugwells and one pond-sand filter showed arsenic in excess of 50 microg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be...

The provision of alternative water sources is the principal arsenic mitigation strategy in Bangladesh, but can lead to risk substitution. A study of arsenic mitigation options was undertaken to assess water quality and sanitary condition and to estimate the burden of disease associated with each technology in disability-adjusted life years (DALYs). Dugwells and pond-sand filters showed heavy microbial contamination in both dry and monsoon seasons, and the estimated burden of disease was high. Rainwater was of good quality in the monsoon but deteriorated in the dry season. Deep tubewells showed microbial contamination in the monsoon but not in the dry season and was the only technology to approach the World Health Organization's reference level of risk of 10-6 DALYs. A few dugwells and one pondsand filter showed arsenic in excess of 50 µg/L. The findings suggest that deep tubewells and rainwater harvesting provide safer water than dugwells and pond-sand filters and should be the preferred options.

This study presents a cost-effectiveness analysis and mapping requirements for three arsenic mitigation technologies sponsored by the government of India in the state of Bihar, offering recommendations for the technologies most likely to benefit 12 million at-risk people. The three arsenic mitigation technologies investigated in this paper are arsenic treatment (ATU) units, new hand pump (NHP) units, and new tube wells with stand post (NTWSP) units. For 100% coverage of arsenic mitigation in the arsenic-affected districts of Bihar, 314– 5111 ATU and NHP and 16–256 NTWSP in Buxar and Jehanabad, respectively, are required. NHP and NTWSP units were found to be the most cost-effective arsenic mitigation interventions in the state, whereas ATU was found to be the dominant intervention. Installation of NHP could be the most efficient arsenic mitigation intervention in areas where the population is scarce and illiterate. NTWSP could be the most cost-effective arsenic mitigation intervention in regions having higher rates of literacy and of arsenic awareness among their communities. The cost-effectiveness of arsenic mitigation technologies should be carefully evaluated before designing and implementing arsenic mitigation policies.

This study presents a review of the arsenic contamination of drinking water, soil, and the food chain in the Middle-Gangetic Plain in India's Bihar state. We identify challenges for arsenic-mitigation and recommend solutions for this problem. Approximately 46% of the geographical regions, 72 of 532 community blocks, are arsenic contaminated. More than 10 million people in rural Bihar are exposed to elevated levels of arsenic through naturally contaminated drinking water. Arsenic levels exceed the United Nations Food and Agricultural Organization's standards for irrigation water. Arsenic contamination in soil and in the food chain could be potential threats to the area's inhabitants. Children are exposed to arsenic contaminated soil while playing in their backyards. Children who do not wash their hands thoroughly may unintentionally ingest soil, which over the long term may increase the risk of developing cancer. People with several stages of arsenicosis symptoms and suspected arsenic-induced cancers were found in the state. Recently discovered arsenic contaminated areas in Bihar are far from the River Ganges, which suggests that other River basins, such as the River Ghaghara and Gandak, are potential sources of arsenic. Katihar was the most vulnerable district because of the socioeconomic and biophysical conditions, followed by Vaishali, Samastipur, Khagaria, and Purnia. Munger was the only resilient district, as it had a greater adaptive capacity. Some of the foremost challenges of arsenic-mitigation are lack of guidelines for water sampling density, a common arsenic contamination data repository, coordination among research groups, and decision-making tools for arsenic-mitigation; uncontrolled and unregulated hand pump installations, and wide spatial variation in arsenic concentrations distribution. The state needs comprehensive arsenic-mitigation policies and decision-making tools to help prioritize, which arsenic contaminated areas to pursue. A decision-making tool, such as a composite vulnerability framework for assessing and mapping vulnerability to groundwater arsenic contamination, would be an absolute necessity.