Groundwater contamination by geogenic arsenic is a global problem affecting nearly 200 million people. In South and Southeast Asia, a cost-effective mitigation strategy is to use oxidized low ...

The natural, or geogenic, occurrence of arsenic in groundwater is a global problem with wide-ranging health effects for humans and wildlife. Because it is toxic and does not serve any beneficial metabolic function, inorganic arsenic (the species present in groundwater) can lead to disorders of the skin and vascular and nervous systems, as …

Elevated level of As in groundwater has been well documented in Chile, Mexico, China, Argentina, USA, and Hungary [ 1, 2] as well as in the Indian State of West …

Across all monitoring wells, seasonal variation in groundwater As concentration was positively correlated with Fe(II) concentration (Pearson_R = 0.83, 0.79, 0.73 and 0.78 in NH03 A, NH05 A, NH03B and NH05B, respectively, P < 0.01) (Fig. 2).Furthermore, corresponding trends between seasonal variation of groundwater level …

Arsenic Contamination in Groundwater: Geochemical Basis of Treatment Technologies. Sushil R. Kanel*, Tonoy K. Das., Rajender S. Varma., Sudarshan Kurwadkar., Sudip …

Arsenic concentrations in aquifers of S–SE Asia often span several orders of magnitude (~1 to >1000 μg L −1) over very small spatial scales (10–100 m). 9–14 Measurements of groundwater As are preferred to characterize exposure levels directly, but are exceedingly difficult to make for the millions of new wells installed ...

In this study, reducing conditions were exported from the small, sulfidic, organic-rich, clay lenses into the initially oxic aquifer sand. This promoted toxic levels of arsenic release to groundwater in the aquifer sand, effectively recruiting a much larger volume of aquifer to function as reducing arsenic-thiolating zones.

Similar oxidizing geochemical controls on arsenic levels in groundwater have been reported in Argentina, Chile and Spain (Garcia-Sanchez et al., 2005; ... The dashed rectangular area represents the average global oxidizing character of aquifers with respect to groundwater arsenic concentrations. The present study falls within the …

Water level and geochemistry of unconfined/updip and confined/downdip parts of the Edwards aquifer, Central Texas, respond differently to rainfall/recharge events and multiyear dry/wet cycles. ...

In California and Vietnam, research has linked rising arsenic levels in drinking water to land subsidence — when the ground sinks due to aquifer overpumping, which happens more during drought.

The occurrences of elevated Mn groundwater have often been discovered with high arsenic (As) groundwater and high iron (Fe) groundwater ... Hydrogeochemical evidences for targeting sources of safe groundwater supply in arsenic-affected multi-level aquifer systems. The Science of the Total Environment, 645 (2018), pp. 1159-1171.

Abstract. Confining clay layers typically protect groundwater aquifers against downward intrusion of contaminants. In the context of groundwater arsenic in Bangladesh, we challenge this notion ...

Groundwater wells in the Amman-Wadi Es Sir Aquifer (B2/A7) throughout Jordan are investigated for their arsenic (As) and element-by-element geochemical behavior. Groundwater wells are found to have total arsenic concentrations above the recommended levels designated by the Jordanian drinking water standard, the …

Groundwater contaminated with naturally occurring arsenic is a widespread problem affecting many alluvial and deltaic aquifer systems throughout the world. The human health toll from consuming groundwater with high levels of arsenic is staggering in its proportions. Furthermore, the use of arsenic contaminated groundwater for irrigation …

At Jianghan Plain of central Yangtze basins where the health of > 73, 000 people has been affected by long term intake of high arsenic groundwater, over 100 sediment samples from four boreholes at the field monitoring sites were collected and analyzed to delineate the distribution and speciation of As in the shallow aquifer …

In the San Joaquin Valley of California, approximately 1 million people rely on groundwater for drinking. This high reliance on groundwater has resulted in overpumping of this resource, which leads to subsidence, or massive compression of the ground and arsenic contamination of the water. Arsenic is deadly to human health; therefore, it is imperative …

The groundwater quality in a multi-level aquifer system can be influenced not only by geochemical processes, but also by inter-layer hydrodynamic exchange (Hsu et al., 2010 ... Near-surface wetland sediments as a source of arsenic release to ground water in Asia. Nature, 454 (2008), pp. 505-509. CrossRef View in Scopus Google …

Groundwater pumping can increase arsenic levels in irrigation and drinking water. Date: June 5, 2018. Source: Stanford University. Summary: Pumping an aquifer to the last drop squeezes out more ...

Highlights. •. Proportions of high arsenic groundwater increased with proximity to paleochannels. •. Redox sensitive components changed temporally evidently …

1. Introduction. Arsenic (As) is a toxic metalloid commonly found in groundwater in many regions of the world. Bangladesh, India, and China are known to have some of the most seriously As-affected groundwaters (Ahmad et al., 2017; Cromeans et al., 2005; Polizzotto et al., 2008).In China, elevated As in groundwater occurs mainly …

Elevated levels of arsenic (As) have been reported in groundwater from sandy aquifer systems in the Mannar Island, located in the northwest of Sri Lanka. As a result of serious health concerns, this study aims to investigate groundwater aquifers in order to trace the different As sources and mechanisms involved in its release from …

Vulnerability of deep groundwater in the Bengal Aquifer System to contamination by arsenic . W. G. Burgess, M. A. Hoque, H. A. Michael, C. I. Voss, G. N. Breit & K. M. Ahmed ... Arsenic levels in ...

Physicochemical parameters and arsenic, iron, and ion concentrations were measured in groundwater from wells reaching 23–82 m deep, revealing arsenic …

Moreover, natural contaminants such as arsenic that may be released from sandy aquifers can play an important role. Among natural contaminates in groundwater, arsenic in sedimentary aquifers has been extensively investigated (Ahmed et al., 2004, Bone et al., 2006, Wang et al., 2012). Arsenic is a ubiquitous element in the …

Here we find that recent groundwater pumping, observed through land subsidence, results in an increase in aquifer arsenic concentrations in the San Joaquin Valley of California. By comparison ...

22 May 2020. Vol 368, Issue 6493. pp. 845 - 850. DOI: 10.1126/science.aba1510. Dowsing for danger. Arsenic is a metabolic …

Arsenic, of particular importance due to its carcinogenicity, is present in elevated concentrations in groundwater in many regions; more than 5% of 6000 …

the distribution of groundwater arsenic in the major aquifers in Texas and assess linkages to populations using this water. Groundwater arsenic data were compiled from 10,489 wells sampled between 1992 and ... Groundwater arsenic levels exceeding the MCL are considered a health hazard. The form of arsenic determines the health impacts ...

The primary source of As is natural, derived mainly from the interactions between groundwater and aquifer sediments and hard rocks of minerals, particularly …

In a previous study in the valley, James found that lifetime exposure to low levels of inorganic arsenic in drinking water, between 10 and 100 micrograms per liter, or µg/L, was linked to a ...