Arsenic, bioaccumulation

Dushenko W. T., Bright D. A., and Reimer K. J. (1995) Arsenic bioaccumulation and toxicity in aquatic macrophytes exposed to gold-mine effluent relationships with environmental partitioning, metal uptake and nutrients. Aquat. Bot. 50, 141-158. 

TABLE 2. Effects of arsenic acclimation on the arsenic bioaccumulation by C. vulgaris [28]. 

Mercury, tin, lead, arsenic, and antimony form toxic lipophilic organometallic compounds, which have a potential for bioaccumulation/bioconcentration in food chains. Apart from anthropogenic organometallic compounds, methyl derivatives of mercury and arsenic are biosynthesized from inorganic precursors in the natural environment. 

Mason RP, Laporte J, Andres S. 2000. Factors controlling the bioaccumulation of mercury, methyhnercury, arsenic, selenium, and cadmium by freshwater invertebrates and fish. Arch Environ Contam Toxicol 38 283-297. 

Weis, P., J.S. Weis, and J. Couch. 1993a. Histopathology and bioaccumulation in oysters Crassostrea virginica living on wood preserved with chromated copper arsenate. Dis. Aquat. Organ. 17 41 -46. 

Fowler, S.W. and M.Y. Unlu. 1978. Factors affecting bioaccumulation and elimination of arsenic in the shrimp Lysmata seticaudata. Chemosphere 9 711-720. 

Maeda, S., S. Nakashima, T. Takeshita, and S. Higashi. 1985. Bioaccumulation of arsenic by freshwater algae and the application to the removal of inorganic arsenic from an aqueous phase, n. By Chlorella vulgaris isolated from arsenic-polluted environment. Separation Sci. Technol. 20 153-161. 

The chemical form of arsenic in marine environmental samples is of interest from several standpoints. Marine organisms show widely varying concentrations of arsenic [4-6] and knowledge of the chemical forms in which the element occurs in tissues is relevant to the interpretation of these variable degrees of bioaccumulation and to an understanding of the biochemical mechanisms involved. Different arsenic species have different levels of toxicity [7] and bioavailability [8] and this is important in food chain processes, while physicochemical behaviour in processes such as adsorption onto sediments also varies with the species involved [9]. It has... 

It is of interest that arsenobetaine is accumulated so much more readily than other similar arsenic species. The cationic nature of the compounds may be significant those compounds not bioaccumulated by the mussel are all anionic or neutral at seawater pH, whereas those accumulated all contain a positive charge. The zwitterionic nature of arsenobetaine may also be a factor, and recent experiments with C-3 and C-4 arsenic containing betaines (compounds 42 and 43) support this view. Preliminary results (164 ) show that mussels bioaccumulate these compounds readily the relative bioaccumulation efficiency was C-2 betaine (arsenobetaine) 100, C-3 betaine 65, and C-4 betaine 6 (Table VII). These results also suggest that the distance between the charges in the molecules may be an additional factor. Expansion of studies on arsenic uptake from water may elucidate the actual processes of absorption of arsenobetaine, which may involve a specific ion channel. 

Metals frequently occurring in the state s waste streams include cadmium, chromium, lead, arsenic, zinc, copper, barium, nickel, antimony, beryllium, mercury, vanadium, cobalt, silver, and selenium. These metals are toxic to humans and other organisms, are persistent in the environment, and can bioaccumulate in food chains. They are typically used by businesses in many industrial categories, as shown in Table 2.1-1. 

Phytoremediation The use of living plants, plant parts, or plant extracts to treat contaminated sites. Certain plants have the ability to bioaccumulate arsenic and detoxify their surroundings. 

Cullen, W.R., Harrison, L.G., Li, H. and Hewitt, G. (1994) Bioaccumulation and excretion of arsenic compounds by a marine unicellular alga, Polyphsa peniculus. Appl. Otganomet. Chem., 8, 313—324. 

Lewisite in soil may rapidly volatilize or may be converted to lewisite oxide due to moisture in the soil (Rosenblatt et al, 1975). The low water solubility suggests intermediate persistence in moist soil (Watson and Griffin, 1992). Both lewisite and lewisite oxide may be slowly oxidized to 2-chlorovinylarsonic acid (Rosenblatt et al, 1975). Possible pathways of microbial degradation in soil include epoxidation of the C=C bond and reductive deha-logenation and dehydrohalogenation (Morrill et al, 1985). Due to the epoxy bond and arsine group, toxic metabolites may result. Additionally, residual hydrolysis may result in arsenic compounds. Lewisite is not likely to bioaccumulate. However, the arsenic degradation products may bioaccumulate (Rosenblatt et al, 1975). 

The metalloregulatory protein arsR was overexpressed in Escherichia coli and resulted in both elevated levels of arsenite bioaccumulation leading to severe reduction in cellular growth (Kostal et al, 2004), and the efficacy of this strain at low arsenic levels. Equivalent strains overexpressing PC synthase genes and arsR could be developed to have arsenic hypertolerant strains with higher bioaccumulation, valuable for the bioremediation of arsenic. 

Apart from their pharmaceutical applications, the organic arsenicals are also used as herbicides. The main compounds are monosodium methanarsonate (MSMA) and hydroxydimethylarsine oxide (cacodylic acid). The relatively wide use of these agents is one of the main reasons for concern about their potential hazard to public health. Additionally, bioaccumulation of organic arsenicals in aquatic organisms such as seaweeds, freshwater algae and Crustacea plays a major role in the evaluation of the toxicity of these materials. Consequently, human exposure to organic arsenicals due to the combination of environmental and therapeutic applications is the main cause of the variety of toxic manifestations of these compounds. 

Maeda, S., Ohki, A., Kusadome, K., Kuroiwa, T., Yoshifuku, 1., and Naka, K., 1992, Bioaccumulation of arsenic and its fate in a freshwater food chain Applied Organometallic Chemistry, v. 6, p. 213-219. 

Many environmental problems in water result from chemical species that are present in only trace quantities. Consequently, chemical analysis and detection have made major contributions to discovering and understanding these problems. Examples include the problems of bioaccumulation of certain chemicals, persistent organic pollutants, pesticide residues, and the health effects of arsenic and lead as well as other trace metals. 

Groundwater remediation bioaccumulation and persistent organic pollutants (2) detection of pesticides (1) human and eco-health effects of arsenic and mercury... 

PROBABLE FATE photolysis not an important process oxidation under reducing conditions, it is a stable solid, dissolved arsenic is present in oxygenated water hydrolysis all arsenic halides hydrolyze in presence of water hydrolyzed to arsenious and arsenic acid forms (soluble) volatilization not important under natural redox conditions sorption removed by clays, iron oxides, manganese oxides, and aluminum biological processes bioaccumulated, but not biomagnified, biotransformed to organic arsenicals... 

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