Environmental arsenic compounds arsenate

Thus, the literature is already well served with reviews of environmental arsenic compounds, so the chapter presented here will not endeavour to emulate them. Rather, we present a summary of the arsenic compounds relevant to discussions on arsenic s environmental chemistry, and, in so doing, hope to provide information that will complement the detailed material presented in the accompanying chapters dealing with specific aspects of this topic. 

Figure 1 Environmental arsenic compounds referred to in text and tables by name or acronym. The compounds are depicted in their fuUy protonated form.

II. ENVIRONMENTAL ARSENIC COMPOUNDS A. Arsenic-Containing Minerals... 

The commercial uses of arsenic compounds in 1988, measured in terms of elemental arsenic, are wood (qv) preservatives, 69% agricultural products (herbicides (qv) and desiccants (qv)), 23% glass (qv), 4% nonferrous alloys and electronics, 2% and animal feed additives and pharmaceuticals (qv), 2% (see Feeds AND feed additives). Chromated copper arsenate (CCA) [11125-95-4] is the most widely used arsenic-based wood preservative. The Environmental Protection Agency has, however, restricted the use of arsenical wood preservatives to certified appHcators. 

The most common toxic metals in industrial use are cadmium, chromium, lead, silver, and mercury less commonly used are arsenic, selenium (both metalloids), and barium. Cadmium, a metal commonly used in alloys and myriads of other industrial uses, is fairly mobile in the environment and is responsible for many maladies including renal failure and a degenerative bone disease called "ITA ITA" disease. Chromium, most often found in plating wastes, is also environmentally mobile and is most toxic in the Cr valence state. Lead has been historically used as a component of an antiknock compound in gasoline and, along with chromium (as lead chromate), in paint and pigments. 

To be useful as CVD precursors, a metallo-organic compound should be stable at room temperature so that its storage and transfer are not a problem. It should also decompose readily at low temperature, i.e., below 500°C. The compounds listed in Table 4.1 meet these conditions with the exception of the alkyls of arsenic and phosphorus, which decompose at higher temperatures. For that reason, the hydrides of arsenic and phosphorus are often preferred as CVD precursors (see Ch. 3). These hydrides however are extremely toxic and environmental considerations may restrict their use. 

The next eight chapters will be devoted to the ecotoxicology of groups of compounds that have caused concern on account of their real or perceived environmental effects and have been studied both in the laboratory and in the field. These are predominantly compounds produced by humans. However, a few of them, for example, methyl mercury, methyl arsenic, and polycyclic aromatic hydrocarbons (PAHs), are also naturally occurring. In this latter case, there can be difficulty in distinguishing between human and natural sources of harmful chemicals. 

Concerning anthropogenic sources, methyl arsenic compounds such as methyl arsonic acid and dimethylarsinic acid have been used as herbicides, and were once a significant source of environmental residues. Dimethyl-arsinic acid (Agent Blue) was used as a defoliant during the Vietnam War. 

Craig, PJ. (Eid.) (1986). Organometallic Compounds in the Environment—collection of detailed chapters on the environmental chemistry and hiochemistry of organometallic compounds. Environmental Health Criteria 18 Arsenic Environmental Health Criteria 85 Lead Environmental Aspects Environmental Health Criteria 86 Mercury, Environmental Aspects Environmental Health Criteria 101 Methylmercury Environmental Health Criteria 116 Tributyltin... 

The arsenic compounds most commonly found in environmental and biological materials, and in working places, are arsenite and arsenate ions [As(III) and As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsine, di- and tri-... 

Fendorf S, Eich MJ, Grossl P, Sparks DL (1997) Arsenate and chromate retention mechanisms on goethite. 1. Surface structure. Environ Sci Technol 31 315—320 Francesconi KA, Kuehnelt D (2002) Arsenic compounds in the environment. In Environmental chemistry of arsenic. In Frankenberger WT Jr (ed) Marcel Dekker, New York, Chapter 3, pp 51-94... 

But if we take into account the emerging pollutants and compounds, the choice of which is guided by environmental considerations (mainly risks for health), then surfactants, endocrine disruptors, pesticides, other industrial organics (PAH, aromatic amines,...) or inorganics (sulphides, arsenic,...) and microbiological indicators (pathogens) must also be considered. 

Similarly, legislation has been, or will be, introduced to deal with the disposal of treated wood waste at the end of a product lifetime. No longer will it be acceptable to dispose of treated wood waste by dumping in landfill. Proper disposal will require the incineration of treated wood waste in appropriate facilities that have the necessary equipment to prevent stack emissions of toxic compounds. This requires expensive investment to build plant that can meet the relevant environmental requirements. Such methods probably represent the best option for the permanent removal of these potential pollutants. The ash generated in these plants may contain high concentrations of arsenic, which will then have to be disposed of as hazardous waste. 

WHO (2001). Arsenic Compounds. Environmental Health Criteria, 224. World Health Organization, Geneva. 

WHO (2001) Arsenic and arsenic compounds. Environmental health criteria 224. The International Programme on Chemical Safety (IPCS). Available at http //www.inchem.org/documents/ehc/ ehc/ehc224.htm... 

For the determination of organotin compounds (tributyltin, triphenyltin, triethyltin, and tetra-ethyltin) a MAE is proposed before the normal phase (NP) HPLC/UV analysis [35], In organotin and arsenic speciation studies, hydride generation is the most popular derivatization method, combined with atomic absorption and fluorescence spectroscopy or ICP techniques [25,36], Both atmospheric pressure chemical ionization (APCI)-MS and electrospray ionization ESI-MS are employed in the determination of butyltin, phenyltin, triphenyltin, and tributyltin in waters and sediments [37], A micro LC/ESI-ion trap MS method has been recently chosen as the official EPA (Environmental Protection Agency) method (8323) [38] it permits the determination of mono-, di-, and tri- butyltin, and mono-, di-, and tri-phenyltin at concentration levels of a subnanogram per liter and has been successfully applied in the analysis of freshwaters and fish [39], Tributyltin in waters has been also quantified through an automated sensitive SPME LC/ESI-MS method [40],... 

The term heavy metal in environmental chemistry has traditionally been used to describe certain elements and compounds that are hazardous to the health of humans and other animals. Some elements included in this definition are arsenic, beryllium, cadmium, chromium, lead, and mercury. 

As with other specialty chemicals, which can impair human health and therefore need extensive and expensive testing prior to commercialization, R D in biocides is concentrating on formulations and applications, rather than on new chemical entities. NCEs are developed for substitution of old products with environmental hazards, such as the copper/arsenic compounds used in timber and wood preservation. 

Occupational and environmental poisoning with metals, metalloids, and metal compounds is a major health problem. Exposure in the workplace is found in many industries, and exposure in the home and elsewhere in the nonoccupational environment is widespread. The classic metal poisons (arsenic, lead, and mercury) continue to be widely used. (Treatment of their toxicities is discussed in Chapter 57.) Occupational exposure and poisoning due to beryllium, cadmium, manganese, and uranium are relatively new occupational problems, which present new and previously unaddressed problems. 

Swedish law requires that major retailers make an assessment of potential health and environmental hazards when deciding on which products to stock and sell. As a guide to which chemicals should be avoided, KEMI has published a list of especially hazardous chemicals ( OBS-listan ). The hazard profiles of the KEMI-listed substances differ widely, from decidedly toxic compounds, like arsenic salts and benzene, to practically innocuous substances, such as metallic zinc and many zinc compounds. (Like any other chemical, including table salt, zinc and its compounds should, of course, not be dumped in rivers in large quantities, but they are perfectly safe in most other contexts.)... 

Another intensively studied element in speciation analysis is arsenic. The biological and environmental effects of arsenic species and their transformation pathways have been studied in numerous papers.40- 42 Both arsenite and arsenate accumulate in living tissues because of their affinity for proteins, lipids and other cellular compounds.43 Arsenic species can undergo transformation via... 

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