Chronic exposure to arsenic

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. 

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... 

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. 

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. 

Liquid, bp 105°C. Said to be produced by the mould Penicillium brevicaule growing on wallpaper coloured green with arsenical green pigments. Causes chronic exposure to arsenic. 

Arsenic metabolismandthioarsenicals. 2012. Afeffl//om cs4,p. 881. DOI 10.1039/c2mt00181k. ... Leishmania parasites are susceptible to treatments with the element antimony. .. M. R. Perry et al. Chronic exposure to arsenic in drinking water can lead to resistance to... 

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. ... 

Lung damage after chronic exposure to fumes in industry has not been described. The higher incidence of respiratory cancer reported in copper smelters is due to the presence of arsenic in the ore. ... 

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). 

Conducting studies under controlled conditions with appropriate aquatic and terrestrial indicator organisms to determine the effects of chronic exposure to low doses of inorganic and organic arsenicals on reproduction, genetic makeup, adaptation, disease resistance, growth, and other variables... 

Both acute and chronic exposure to lead became more common with the advent of the Industrial Revolution and there were as many as a thousand cases per year of lead poisoning in the UK at the end of the nineteenth century. During the nineteenth century there were also many cases of lead poisoning due to contamination of domestic drinking water in areas such as the north of England where slightly acidic water was delivered to houses in lead pipes. Lead was also used in fungicides in the form of lead arsenate. 

After initial contradictory reports it is now established that arsenic can cross the blood-brain barrier and produces alternations in whole rat brain biogenic amines levels in animals chronically exposed to arsenite (Tripathi et al, 1997). The neurological effects are many and varied. Usually, peripheral neuropathy, sensory neuropathy (Hafeman et al, 2005), and encephalopathy are the initial complaints associated with acute arsenic poisoning. Acute exposure to arsenic in humans has been shown to result in problems of memory, difficulties in concentration, mental confusion, and anxiety (Hall, 2002 Rodriguez et al, 2003). Other neurological symptoms arising due to arsenic are primarily those of a peripheral sensory neuritis, predominantly numbness, severe paresthesia of the distal portion of the extremities, diminished sense of touch, pain, heat and cold, and symmetrically reduced muscle power (Menkes, 1997). 

Kojima, C., Qu, W., Waalkes, M.P., Himeno, S., Sakurai, T. (2006). Chronic exposure to methylated arsenicals stimulates arsenic excretion pathways and induces arsenic tolerance in rat liver cells. Toxicol. Sci. 91 70-81. 

Arsenic in aquatic environments is usually more concentrated in sediments and pore water than in the overlying water column (Ahmann et al., 1997 Smedley and Kinniburgh, 2002 Williams, 2001). The most abundant forms of arsenic are arsenate [As(V)] and arsenite [As(III)], but methylated forms can occur in mine-impacted environments (i.e., methylarsenic acid and dimethylarsenic acid) (Smedley and Kinniburgh, 2002) see Chapter 9.02. The principal pathway of arsenic toxicity is through dietary exposure to sediment and suspended particulates by fish, followed by human consumption. Environmental exposure to arsenic is a causal factor in human carcinogenous and other related health issues. Chronic exposure symptoms in humans include hyperkeratosis, hyperpigmentation, skin malignancies, and peripheral arteriosclerosis. Water provides the dominant pathway for arsenic exposure in humans (Williams, 2001). 

This patient had both idiopathic portal hjrpertension and hepatic angiosarcoma, in which the common causative factor was the chronic nse of arsenical salts for the treatment of psoriasis. In a review of the Uteratnre the authors found only five other cases in which both diseases were associated, while exposure to arsenical salts was found in only one of them. 

Gerdsen R, Stockfleth E, Uerlich M, Fartasch M, Steen KH, Bieber T. Papular palmoplantar hyperkeratosis following chronic medical exposure to arsenic human papillomavirus as a co-factor in the pathogenesis of arsenical keratosis Acta Derm Venereol 2000 80(4) 292-3. 

Chronic exposure to silver produces a bluish skin discoloration known as argyria. Gold poisoning has resulted from the use of gold salts for treatment of arthritis. Poisoning from antimony, arsenic, bismuth, mercury, and thallium is well known. 

Chronic inhalation exposure to arsenic compounds occurs most frequently in occupational settings. The resulting symptoms have been reported to occur in three phases, with the initial appearance of weakness, loss of appetite, nausea, and diarrhea. 

Induction of cancer appears to be the most striking long-term effect of chronic exposure to inorganic arsenic. Epidemiological studies have demonstrated an evident causal relationship between environmental, occupational, and medicinal exposure of man to inorganic arsenic and cancer of the skin and lungs (NAS 1977, Fowler 1977, Leonard 1984, lARC 1987, Cantor 1997, Hayes 1997). 

Lung cancer is probably the most lethal manifestation of toxic effect from chronic exposure to certain chemicals. Asbestos fibers, coke oven emissions, arsenic, chromates, nickel and the radioactive gas, radon, are some of the substances known to cause lung cancer. For a detailed discussion of carcinogenesis, see Part A, Section VI, while specific compounds are discussed in Part B of this text. Acute and chronic effects of some common pulmonary toxicants are presented in Table V.3. 

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