Exposure to arsenic

Current and past uses of arsenic include pesticides, wood preservatives, munitions, semiconductors, antimicrobials for growth promotion in animals, and anticancer agents (Table 4.2 Chapter 5). Although production of arsenic ceased in the United States in 1985, it was the world s largest consumer of arsenic in 2003 (ATSDR, 2007). People are exposed to arsenic from its use today as well as from its use years ago. 

Arsenicals of recent interest include the wood preservatives chromated copper arsenate (CCA) (Chapter 5). Because of the concern over the potential toxic effects of arsenic in the preservative, in an agreement with the US Environmental Protection Agency (EPA), the wood preservative industry voluntary phased out the use of CCA in wood for residential use in 2003 (Katz and Salem, 2005). However, CCA-treated wood can still be used in industrial applications. A problem in the future will be how to safely dispose of CCA-treated wood (Chapter 7). 

A unique use of arsenic, in the form of arsenic trioxide (AS2O3), is for the treatment of cancer. Relapsed or refractory cases of acute promyelocytic leukemia have been successfully treated with this arsenical. Its use in the United States was approved by the US Food and Drug Administration (FDA) in 2000 (Antman, 2001). 

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Lantz RC, Petrick JS, Hays AM. Altered protein expression following in utero exposure to arsenic. Society of Toxicology, 2005. 

BAL is the standard treatment for poisoning by arsenic compounds and will alleviate some effects from exposure to arsenic vesicants. It may also decrease the severity of skin and eye lesions if applied topically within minutes after decontamination is complete (i.e., within 2-5 minutes postexposure). Additional chelating agents for the treatment of systemic arsenic toxicity include meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-l-propanesulfonic acid (DMPS). 

Chronic exposure to arsenicals by way of the air, diet, and other routes has been associated with liver, kidney, and heart damage, hearing loss, brain-wave abnormalities, and impaired resistance to viral infections. 

Exposure to arsenic has been associated with different types of human cancers such as respiratory cancers and epidermoid carcinomas of the skin, as well as precancerous dermal keratosis. The epidemiological evidence of human carcinogenicity is supported by carcinogenesis in experimental animals (Deknudt et al. 1986). 

For maximum protection of human health from the potential carcinogenic effects of exposure to arsenic through drinking water or contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for arsenic. But a zero level may not be attainable. Accordingly, the levels established are those that are estimated to increase cancer risk over a lifetime to only one additional case per 100,000 population. These values are estimated at 0.022 pg As/L for drinking water and 0.175 pg As/L for water containing edible aquatic resources (USEPA 1980 Table 28.7). 

Hanlon, D.P. and V.H. Ferm. 1986b. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate using constant rate administration. Environ. Res. 40 372-379. 

Kurttio, R, H. Komulainen, E. Hakala, and J. Pekkanen. 1998. Urinary excretion of arsenic species after exposure to arsenic present in drinking water. Arch. Environ. Contam. Toxicol. 34 297-305. 

McGeachy, S.M. and D.G. Dixon. 1992. Whole-body arsenic concentrations in rainbow trout during acute exposure to arsenate. Ecotoxicol. Environ. Safety 24 301-308. 

This chapter presents specific information with regard to the effects of environmental and occupational exposure to arsenic on inflammatory processes, the immune system, and host defense. While the focus is on the in vivo and in vitro effects of arsenic on host immune responses (e.g., immunotoxicity and hypersensitivity) and their relationship to clinically observed manifestations of arsenic toxicity (e.g., inflammation and skin cancer), information on the potential mechanisms through which arsenic may exert its biological effects is also provided. 

Ingested arsenic localizes to the skin [2, 7], where it may alter cutaneous immune responses. The delayed type hypersensitivity (DTH) response to 2,4-dinitrochlorobenzene (DNCB) was suppressed in Bowen s disease patients [8], Langerhans cells (LC) in skin lesions and perilesioned skin from arsenic-induced Bowen s disease and carcinomas were reduced in number and were morphologically altered, having a notable loss of dendrites [9], These data suggest that chronic exposure to arsenic in drinking water may... 

Toxicology. Arsenic compounds are irritants of the skin, mucous membranes, and eyes gastrointestinal effects, peripheral neuropathy, vascular lesions, skin diseases, and various cancers are reported risks of exposure to arsenic compounds. 

Acute inhalation exposures have resulted in irritation of the upper respiratory tract, even leading to nasal perforations. Occupational exposure to arsenic compounds results in hyperpigmentation of the skin and hyperkeratoses of palmar and plantar surfaces, as well as dermatitis of both primary irritation and sensitization types. Impairment of peripheral circulation and Raynaud phenomenon have been reported with long-term exposure. ... 

Lee-Eeldstein A Cumulative exposure to arsenic and its relationship to respiratory cancer among copper smelter employees, f Occup Med 28 296-302, 1986... 

Inhaled arsine is oxidized to form elemental trivalent arsenic (As ) and arsenous oxide (AS2O3), two human carcinogens. Excess cancers from trivalent arsenic and arsenic trioxide have been associated with cumulative lifetime arsenic exposure. Exposure to arsine above 0.004ppm is associated with increased urinary arsenic excretion, indicating exposure to arsenic. Current exposure limits may not prevent potential chronic toxicity. ... 

The toxicity of chronic exposure to arsenic is well established and the best recommendation is to avoid arsenic exposure. The most common home exposure is from contaminated drinking water and arsenic-treated lumber. Certain areas of the country have higher levels of arsenic in water. The EPA has lowered arsenic drinking water standards, but water providers have until 2006 to meet the new standards. Avoid inhalation of sawdust from arsenic-treated lumber or inhalation of smoke from burning arsenic-treated wood. And of course always wash your hands. This is particularly important if a young child is playing on arsenic-treated wood. 

Chemically, arsenic is complex in that it can exist in a variety of forms including trivalent and pentavalent or as arsenic trioxide (computer chip manufacture) and arsenic acid. Arsenic is excreted in skin cells, sweat, hair, and fingernails, which can be seen as white transverse bands. Acute exposure to arsenic results in gastrointestinal pain, sensory loss, cardiovascular failure, and death. Chronic exposure or survival of acute exposure can cause loss of peripheral sensory function and loss of central nervous system function. Chronic arsenic exposure can also cause cancer of the lung and skin (see the chapter on arsenic). 

Since 1960, it has been demonstrated by various analytical procedures that high concentrations of arsenic were present in Napoleon s hair.88 Multi-element analysis of two specimens of Napoleon s hair by ICP-MS after mineralization in concentrated nitric acid resulted in arsenic concentrations (42.1 and 37.4(xgg-1) about 40 times higher than normal values, confirming the hypothesis of a significant exposure to arsenic. However, mercury (3.3. and 4.7(xgg 1), antimony (2.1 and 1.8(xgg 1) and lead (229 and 112p,gg-1) were also detected at elevated levels. The elevated concentrations of Sb and Hg are in agreement with the data already known about the therapeutic treatments given to Napoleon (calomel and tartar emetic are compounds of mercury and antimony, respectively).88... 

Paulu, C.A., Moll, D.M., Backer, L.C. et al. (2002) Exposure to Arsenic Via Bathing and Other Contact in Households that Use Bottled Water or Point-of-Use Treatment Devices for Drinking Water. Arsenic in New England A Multidisciplinary Scientific Conference, May 29-31, 2002, National Institute of Environmental Health Sciences, Superfund Basic Research Program, Manchester, MA. 

Many organ systems in the human body can be affected by chronic exposure to arsenic (Agency for Toxic Substances and Disease Registry (ATSDR), 2007 World Health Organization (WHO), 2001 National Research Council (NRC), 1999, 2001). These include the skin, developing fetus, liver and the cardiovascular, pulmonary, nervous, and endocrine systems. These effects are dose-related and primarily arise from oral exposure to arsenic, although inhalation of arsenic may also result in adverse health effects. The chronic effects from dermal exposure to arsenic are not known. 

Atherosclerosis is a pathogenic response of the intima of the arterial vessel walls to noxious stimuli. It is characterized by lipids depositing in the vessel walls, which leads to wall narrowing. This can progress to IHD. Exposure to arsenic in drinking water is associated with an increased prevalence of carotid atherosclerosis in a dose-response relationship. In a cross-sectional study, Wang et al. (2002) assessed... 

There does not appear to be one specific cell type of lung cancer in the exposed-workers (Agency for Toxic Substances and Disease Registry (ATSDR), 2007). Several tumor types (such as epidermoid carcinomas, small carcinomas, and adenocarcinomas) have all been found to increase following exposure to arsenic by inhalation. 

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