RETRACTED: Hydrogeochemical behavior of arsenic-enriched groundwater in the deltaic environment: Comparison between two study sites in West Bengal, India

Mukherjee-Goswami, Aishwaya; Nath, Bibhash; Jana, Joydev; Sahu, Sudip Jyoti; Sarkar, Mithun; Jacks, Gunnar; Bhattacharya, Prosun; Mukherjee, Abhijit; Polya, David A.; Jean, Jiin-Shuh; Chatterjee, Debashis

doi:10.1016/j.jconhyd.2008.04.004

Cited by 20 publications

(4 citation statements)

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“…For example, drinking water with ambient aluminum concentrations above 900 μg/L has been reported in the United States, according to the WHO [ 66 ]. Similarly, drinking water and potential drinking water supplies with ambient aluminum concentrations above 900 μg/L have been reported in Argentina [ 71 , 72 ], Bangladesh [ 79 ], Brazil [ 80 , 81 ], Ethiopia [ 76 ], Ghana [ 82 ], India [ 83 ], Iran [ 77 ], Kosovo [ 84 ], Lesotho [ 85 ], Sri Lanka [ 86 ], Sweden [ 87 ], Tanzania [ 88 ], Turkey [ 89 ], and Uganda [ 90 ]. The WHO noted that, “The concentration of aluminium in natural waters can vary significantly depending on various physicochemical and mineralogical factors.…”

Section: Introductionmentioning

confidence: 97%

Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water

2015

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The World Health Organization (WHO) has established guidelines for drinking-water quality that cover biological and chemical hazards from both natural and anthropogenic sources. In the most recent edition of Guidelines for Drinking-water Quality (2011), the WHO withdrew, suspended, did not establish, or raised guidelines for the inorganic toxic substances manganese, molybdenum, nitrite, aluminum, boron, nickel, uranium, mercury, and selenium. In this paper, we review these changes to the WHO drinking-water guidelines, examining in detail the material presented in the WHO background documents for each of these toxic substances. In some cases, these WHO background documents use literature reviews that do not take into account scientific research published within the last 10 or more years. In addition, there are instances in which standard WHO practices for deriving guidelines are not used; for example, rounding and other mathematical errors are made. According to published meeting reports from the WHO Chemical Aspects Working Group, the WHO has a timetable for revising some of its guidelines for drinking-water quality, but for many of these toxic substances the planned changes are minimal or will be delayed for as long as 5 years. Given the limited nature of the planned WHO revisions to the inorganic toxic substances and the extended timetable for these revisions, we suggest that governments, researchers, and other stakeholders might establish independent recommendations for inorganic toxic substances and possibly other chemicals to proactively protect public health, or at the very least, revert to previous editions of the Guidelines for Drinking-water Quality, which were more protective of public health.

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Section: Introductionmentioning

confidence: 97%

Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water

2015

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“…The present study focuses on red algae, which were specifically listed as an under-studied group in the report of a recent workshop on the future of the NSF-sponsored AToL project [27]. The red algae or Rhodophyta form one of the three major lineages of primary photosynthetic organisms that evolved after the enslavement of a cyanobacterium in a eukaryote cell to form a chloroplast more than 1.5 billion years ago [28,29] and the earliest fossil evidence for multicellular eukaryotic life, Bangiomorpha from the 1,200 Ma Hunting formation, is thought to be a red alga [30].…”

Section: Introductionmentioning

confidence: 99%

Data mining approach identifies research priorities and data requirements for resolving the red algal tree of life

et al. 2010

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BackgroundThe assembly of the tree of life has seen significant progress in recent years but algae and protists have been largely overlooked in this effort. Many groups of algae and protists have ancient roots and it is unclear how much data will be required to resolve their phylogenetic relationships for incorporation in the tree of life. The red algae, a group of primary photosynthetic eukaryotes of more than a billion years old, provide the earliest fossil evidence for eukaryotic multicellularity and sexual reproduction. Despite this evolutionary significance, their phylogenetic relationships are understudied. This study aims to infer a comprehensive red algal tree of life at the family level from a supermatrix containing data mined from GenBank. We aim to locate remaining regions of low support in the topology, evaluate their causes and estimate the amount of data required to resolve them.ResultsPhylogenetic analysis of a supermatrix of 14 loci and 98 red algal families yielded the most complete red algal tree of life to date. Visualization of statistical support showed the presence of five poorly supported regions. Causes for low support were identified with statistics about the age of the region, data availability and node density, showing that poor support has different origins in different parts of the tree. Parametric simulation experiments yielded optimistic estimates of how much data will be needed to resolve the poorly supported regions (ca. 103 to ca. 104 nucleotides for the different regions). Nonparametric simulations gave a markedly more pessimistic image, some regions requiring more than 2.8 105 nucleotides or not achieving the desired level of support at all. The discrepancies between parametric and nonparametric simulations are discussed in light of our dataset and known attributes of both approaches.ConclusionsOur study takes the red algae one step closer to meaningful inclusion in the tree of life. In addition to the recovery of stable relationships, the recognition of five regions in need of further study is a significant outcome of this work. Based on our analyses of current availability and future requirements of data, we make clear recommendations for forthcoming research.

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“…The release of arsenic from aquifers is favored in this region due to specific characteristics, such as adequate redox conditions and the occurrence of organic matter degradation. 10 The work by others 11 showed that the use of fertilizer could result in the presence of significant amounts of arsenic in the ecosystem. Arsenic contamination is not limited to ground water and may also occur due to the use of contaminated irrigation water, as observed by Dahal et al 12 Anthropogenic sources of arsenic contamination are also noteworthy.…”

Section: Introductionmentioning

confidence: 99%

Impairment of mice spermatogenesis by sodium arsenite

et al. 2011

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In order to assess the effect of arsenic on the male reproductive impairment in mice, 7-week-old animals were exposed to 7.5 mg sodium arsenite (NaAsO(2))/kg body weight, during 35 days (one spermatogenic cycle). One group of animals was sacrificed after exposure, while another group received distilled water for an additional period of 35 days, in order to study the spermatoxic effect and the recovery of spermatogenesis. In mice sacrificed after NaAsO(2) exposure, a decrease in testis/body weight ratio and reduction of tubular diameter were observed. Both groups of NaAsO(2)-exposed animals showed remarkable histopathological changes, such as sloughing of immature germ cells. Animals sacrificed after NaAsO(2) exposure showed decreased sperm motility, increased abnormal sperm morphology and decreased sperm viability. The effects of NaAsO(2) on sperm motility recovered to normal values after one spermatogenic cycle, while increased sperm abnormality was maintained. However, at this period, a decrease in acrosome integrity was detected. Concerning oxidative stress parameters, animals sacrificed after NaAsO(2) exposure showed a decreased selenium-dependent glutathione peroxidase activity, which was not detected after the recovery. Conversely, at this period, total glutathione peroxidase activity increased in exposed animals. These results demonstrate the toxic effects of NaAsO(2) on mice spermatogenesis and show the lack of recovery after one spermatogenic cycle.

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RETRACTED: Hydrogeochemical behavior of arsenic-enriched groundwater in the deltaic environment: Comparison between two study sites in West Bengal, India

Cited by 20 publications

References 40 publications

Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water

Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water

Data mining approach identifies research priorities and data requirements for resolving the red algal tree of life

Impairment of mice spermatogenesis by sodium arsenite

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