Nails arsenic concentrations

Ingested arsenic is known to be not only excreted by urine, but also to be stored in sulfydryl rich tissue like hair, nails or skin. A method of extracting arsenic species from hair and nail samples has been developed for the analysis of the total arsenic concentration, inorganic As ( ) and As... 

One of the most famous applications in forensic science is the analysis of Napoleon s hair by ICP-MS after mineralization in concentrated nitric acid whereby an arsenic concentration about 40 times higher than normal (about 40p,gg 1) was measured (see Section 9.5). Ingested arsenic is known to be stored in sulfydryl rich tissue, like hair, nails or skin. ETV-ICP-MS combined with isotope dilution has been employed to measure thallium in human scalp hair from a person poisoned by thallium compared to control subjects, whereby several longitudinal concentration gradients for the analyzed segments (length 10 mm) were obtained.28... 

Human exposure to arsenic has been mainly assessed in the past by the determination of the total arsenic concentration in blood, hair, nails, and urine. In cases of suspected arsenic poisoning gastric juice has also been analyzed. In order to obtain meaningful data, however, it is important to determine the chemical form of arsenic, at least in body fluids. Depending on the source and length of exposure, these indicators have a different meaning and different significance as well (Foa et al., 1987 Vahter, 1988). 

Arsenic concentrations in hair and nails have been used as indicators of exposure to inorganic arsenic (112,113,121,122). However, arsenic in hair might be influenced by surface contamination via dust, water, soaps, and shampoos. Data on arsenic speciation in hair and nails is sparse. Only two studies reported the presence of dimethylated arsenic species in hair and nails (119,120). 

Chen, K.-L. B., Amarasiriwardena, C. J., and Christiani, D. C. (1999). Determination of total arsenic concentrations in nails by inductively coupled plasma mass spectrometry. Biol. Trace Elem. Res. 67(2), 109. 

Animal tissues usually contain low levels (<0.3 mg As/kg fresh weight) of arsenic. After the administration of arsenicals, these levels are elevated, especially in liver, kidney, spleen, and lung and several weeks later, arsenic is translocated to ectodermal tissues (hair, nails) because of the high concentration of sulfur-containing proteins in these tissues. 

Arsenic is concentrated in the liver, spleen and kidney and is bound preferentially to sulphydryl groups in skin, hair and nails. Urine and gastric contents should also be obtained. The sequential analysis of hair sections has been shown to be of value in the examination of prolonged exposure to arsenic [8]. 

WHO (1986) especially mentions degeneration in the inner ear caused by arsenicals. Should the patient recover, axonal regeneration can occur and semilunar strips, which contain a very high concentration of arsenic, will appear across the entire base of the nails ( Mees lines Cavanagh 1979, Wong etal. 1998). 

Creatine SH groups of the skin retain up to 30% of the absorbed arsenic. Parts of this are later located in hair and nails. Periods of higher arsenic intake cause higher concentrations of arsenic in limited areas of the hair. Controls in the hair of infants during the first year of infancy demonstrated that the levels of arsenic in hair depend first on the arsenic content of food [56]. Four weeks after ingestion As is localized mainly as As(V) in bone substituting for phosphate [9,12,19]. 

The highest concentrations were measured in hair and nails. Hair analysis does not discriminate between externally and internally deposited arsenic (see also Chap. 15) [9]. The contents in hair vary between 8 and 600 p.g/kg [3,4,13,15,18,28,31,70,78-81]. Of arsenic found in hair, 73% is inorganic and 27% is DMAA [70]. Concentrations in nails range between 280 and 1200 p-g/kg [4,31,73,78]. 

Blood levels decrease within a few hours. They do not lend themselves to the detection of chronic exposure [29,58,73]. But during spraying season the blood levels of workers who applied arsenic herbicides were significantly elevated [60]. Increased serum contents of 78-180 p.g/liter of Indian opium eaters are exotic [88]. More information is available from hair. Children living near a coal power plant showed a mean level of 3260 (ig As/kg in comparison to unexposed children with 152 p.g/kg [15]. Similar results were evoked by smelter emission high exposure led to 182600 p,g As/kg low exposure to 8900 p-g/kg [78], 5500 p.g/kg [18] or 2600 p.g/kg [13]. Significantly lower are the concentrations caused by arsenic in well water (450-1240 p.g/kg) [31,80,89]. Nails also contain remarkably high contents of arsenic compared with normal levels 21100-72800 p,g As/kg in smelter workers [78] and 4550 p.g/kg in persons exposed to arsenic well water [31],... 

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