Arsenic behavioral effects

No firm evidence has been seen that any of the anticholinergic test compounds surveyed produced long-range adverse human health effects in the doses used at Edgewood Arsenal. More intensive study is required to confirm this conclusion. The high frequency of uncontrolled variables makes evaluation of behavioral effects difficult. 

Ketchum JS, Kysor KP A model for predicting the effect of anticholinergic compounds on cognitive performance. In Berdjis, C (ed.) Proceedings of a Contractors Conference on Behavioral Sciences. Edgewood Arsenal Special Puhlication No. 100-11,... 

Whitworth, M.R., G.W. Pendleton, D.J. Hoffman, and M.B. Camardese. 1991. Effects of dietary boron and arsenic on the behavior of mallard ducklings. Environ. Toxicol. Chem. 10 911-916. 

Gallium arsenide s native oxide is found to be a mixture of nonstoichiometric galhum and arsenic oxides and elemental arsenic. Thus, the electronic band structure is found to be severely disrupted, causing a breakdown in normal semiconductor behavior on the GaAs surface. As a consequence, the GaAs MISFET (metal insulator semiconductor field-effect transistor) equivalent to the technologically important Si-based MOSFET (metal-oxide semiconductor field-effect transistor) is, therefore, presently unavailable. 

Returning to Figure 4, lead, like arsenic and antimony, shows a behavior similar to that of boron (Noll et al., 1993) indicating that it is extracted effectively from the slab through subsolidus metamorphic reactions and also beneath the volcanic front, presumably in a fluid However,... 

Many of the health and environmental problems caused by arsenic and selenium were not predicted until recently because the distribution and behavior of arsenic and selenium in the environment were not sufficiently well known. Recent improvements have been aided by cost-effective analytical techniques and more powerful data-processing techniques, which have made it easier to prepare high-resolution geochemical maps. Also, modem digital data sets of geochemical and hydrochemical data are used increasingly in studies designed to estimate element speciation, bioavailability, and risk. 

More recently, Peraniemi et al. [229] advocated the use of zirconium-loaded activated charcoal as an effective adsorbent for mercury (and especially for arsenic and selenium), the rationale being that the presence of active metal on an impregnated charcoal surface can greatly affect the adsorption affinity. They compared the pH effects on the uptakes by both a loaded and an unloaded commercial charcoal powder and concluded that the adsorption mechanism of mercury differs from that of the anionic arsenic and selenium species. They also noted the highly complicated behavior of mercury in aqueous solutions and did not attempt to explain the apparent absence of pH dependence of the uptakes. 

Arsonium ylides were discovered near the turn of the century, but their reactions with carbonyl compounds did not become elucidated until the 1960s. In a broad sense, arsonium ylides are midway in chemical behavior between ylides of phosphorus and those of sulfur. Stabilized arsonium ylides react with carbonyl compounds to afford alkenes, whereas the unstabilized analogs give rise to epoxides. More subtly, the nature of the substituents on either the ylide arsenic or carbon atom can alter the course of the reaction the choice of solvent can exert a similar effect. ... 

Arsenate has chemical behavior similar to that of phosphate in soils it is chemisorbed by Fe and A1 oxides, noncrystalline aluminosilicates, and, to a smaller extent, layer silicate clays. Being the anion of the strong acid, H3ASO4, with pKa values (2.24, 6.94, and 11.5) similar to those of phosphoric acid, arsenate adsorbs most effectively at low pH. Consequently, its mobility is fairly low in acid soils with high clay or oxide content. In neutral to alkaline soils, especially those that are sodic, As may be mobile in the soluble Na arsenate form. Soil microbes and Mn oxides are able to promote the oxidation of arsenite to arsenate under aerobic conditions. 

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