Arsenic (As) contamination in the groundwater of Bangladesh is one of the major public health concerns. It has become a challenge to remove As from groundwater and a great deal of efforts employed in this regards with limited success. Cerium oxide is one of the important medias of arsenic removal techniques. Nine units of cerium-based arsenic technology were tested with seven different well wat...

The objectives of this study were to conduct batch and column studies to (i) assess the effectiveness of zero-valent iron for arsenic remediation in groundwater, (ii) determine removal mechanisms of arsenic, and (iii) evaluate implications of these processes with regard to the stability of arsenic and long-term remedial performance of the permeable reactive barrier (PRB) technology. A high conc...

For the past 60 yr, chromate-copper-arsenate (CCA) has been used to pressure-treat millions of cubic meters of wood in the United States for the construction of many outdoor structures. Leaching of arsenic from these structures is a possible health concern as there exists the potential for soil and groundwater contamination. While previous studies have focused on total arsenic concentrations le...

Arsenic is one of the heavy metals and nearly all its compounds, especially organic compounds, are toxic. The wide spectrum of diseases caused by this element has led to evaluation of the toxicity of different arsenic species and identification of the major natural and anthropogenic pollution sources of it in the nature. Mining activities are among the main sources of anthropogenic pollution of...

An analytical speciation method, capable of separating inorganic arsenic (As (V), As (III] and its methylated metabolites (MMAA, DMAA) from common, inert, dietary organoarsenicals, was applied to the determination of arsenic in urine from a variety of workers occupationally exposed to inorganic arsenic compounds. Mean urinary arsenic (As (V) + As (III) + MMAA + DMAA) concentrations ranged from ...

In this article, a mechanism of arsenite [As(III)]resistance through methylation and subsequent volatization is described. Heterologous expression of arsM from Rhodopseudomonas palustris was shown to confer As(III) resistance to an arsenic-sensitive strain of Escherichia coli. ArsM catalyzes the formation of a number of methylated intermediates from As(III), with trimethylarsine as the end prod...

Arsenic (As) is a widely distributed toxic element in the environment and microorganisms have developed resistance mechanisms in order to tolerate it. The cellular response of the chemoorganotrophic arsenite (As[III])-oxidizing α-Proteobacteria, Sinorhizobium sp. strain A2, to arsenic was examined in the present study. Several proteins associated with arsenite oxidase and As resistance were sho...

Arsenic in drinking water, a mixture of arsenite and arsenate, is associated with increased skin and other cancers in Asia and Latin America, but not the United States. Arsenite alone in drinking water does not cause skin cancers in experimental animals; therefore, it is not a complete carcinogen in skin. We recently showed that low concentrations of arsenite enhanced the tumorigenicity of sola...

Accumulation of arsenic has potential health risks through consumption of food. Here, we inserted the arsenite [As(III)] S-adenosylmethionine methyltransferase (ArsM) gene into the chromosome of Pseudomonas putida KT2440. Recombinant bacteria methylate inorganic arsenic into less toxic organoarsenicals. This has the potential for bioremediation of environmental arsenic and reducing arsenic cont...

An arsenic-chelating metallothionein (fMT) from the arsenic-tolerant marine alga Fucus vesiculosus was expressed in Escherichia coli, resulting in 30- and 26-fold-higher As(III) and As(V) binding, respectively. Coexpression of the As(III)-specific transporter GlpF with fMT further improved arsenic accumulation and offered high selectivity toward As. Resting E. coli cells coexpressing fMT and Gl...