Inorganic arsenic exposure

Several studies have suggested an association between inorganic arsenic exposure and increased risk of developmental effects (low birth weight and congenital malformations). ... 

Bolla-Wilson K, Bleecker ML Neuropsychological impairmenl following inorganic arsenic exposure. ] Occup Med 29 500-503, 1987... 

As(III), As(V), monomethyl arsonic acid, and dimethylarsenic acid, which gives a quick and reliable estimation of exposure to inorganic arsenic. 

There are no structure-activity relationships applicable to estimating acute exposure limits for arsine. The nature and rapidity of its toxicity are notably different from other inorganic arsenic compounds. 

Department of Labor Standard for exposure to inorganic arsenic. Fed Reg 40 3392-3404, 1975... 

The best recommendation is to avoid or reduce exposure to inorganic arsenic. 

Demethylation refers to the removal of methyls from organoarsenicals, which may ultimately transform the organoarsenicals into inorganic arsenic. Although exposure to ultraviolet radiation may demethylate arsenic (Cullen and Reimer, 1989), 741, the role of microorganisms in demethylation is especially important. Under sterile conditions, MMA(V) and DMA(V) are very stable in water (Cullen and Reimer, 1989), 749. However, bacteria can demethylate them and other methylarsenic species into inorganic arsenic (Frankenberger and Arshad, 2002), 364 (Cullen and Reimer, 1989), 749 (Santosa et al., 1996), 703. 

Minimal data are available from typical inhalation studies in laboratory animals to allow evaluation of extent or dose-dependency in inhaled arsenic absorption. Beck, Slayton and Farr (2002) reported a study in which rabbits were exposed to 0.05, 0.1, 0.22, or 1.1 mg m-3 of arsenic trioxide 8 hours/day, seven days/week for eight weeks. The particle size (mass median aerodynamic diameter, MMAD) ranged from 3.2 to 4.1pm. On the basis of minimal elevation of inorganic arsenic in plasma until exposure levels were at or above 0.22 mg m-3, the authors concluded that systemic uptake of arsenic trioxide following inhalation exposure was low and did not contribute significantly to body burden until relatively high levels of exposure were achieved. 

The discussion and studies cited previously generally reflect overall tissue distribution of total arsenic after acute exposure in the case of laboratory animals or unknown exposures in the case of humans. Advances in analytical technology in the last decade have facilitated the identification of tissue-specific patterns of metabolite distribution and accumulation in laboratory animals. Kenyon, Del Razo and Hughes (2005a) found that inorganic arsenic was the predominant form of arsenic in the liver and kidney up to two hours post administration of 10 or 100 p mol As kg-1 as inorganic As(V) to female mice, whereas... 

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