Mercury in hair

Cumbie PM. 1975a. Mercury in hair of bobcats and raccoons. J Wild Manage 39 419 25. 

Nielsen JB, Andersen O, Grandjean P. 1994. Evaluation of mercury in hair, blood and muscle as biomarkers for methylmercury exposure in male and female mice. Arch Toxicol 68 317-321. 

Bom, E.W., A. Renzoni, and R. Dietz. 1991. Total mercury in hair of polar bears (Ursus maritimus) from Greenland and Svalbard. Polar Res. 9 113-120. 

Stevens, R.T., T.L. Ashwood, and J.M. Sleeman. 1997. Mercury in hair of muskrats (Ondatra zibethicus) and mink (Mustela vison) from the U.S. Department of Energy Oak Ridge Reservation. Bull. Environ. Contam. Toxicol. 58 720-725. 

Human pharmacokinetic studies indicate that methylmercury has a half-life in blood and the whole body of about 50 days (CDC 2005). Hair grows at about 1 cm/month with a delay of around 20 days between current blood concentration and appearance of mercury in hair (Myers et al. 2003). Thus, postnatal maternal hair can be analyzed sequentially to evaluate timing of methylmercury exposure during pregnancy. However, the potential that this affords to document critical periods of prenatal methylmercury exposure has yet to be realized. 

G. R. Boaventura, A. C. Barbosa, G. A. East, Multivessel system for cold-vapor mercury generation determination of mercury in hair and Psh, Biol. Trace Elem. Res., 60(1997), 153D161. 

Studies from New Zealand and the Faroe Island indicate that adverse effects in children can be correlated with maternal hair levels as low as 10-20 pg/g [44]. Mercury analyses conducted on a single human hair can be used to monitor daily variations in methyl mercury exposure among fish eaters [45,46], and have been utilized to track maternal fish consumption and risk of preterm delivery [47]. Other investigators [48] have utilized measurements of total mercury in hair, toenails and urine to assess exposures in a group of non-occupationally exposed women in relation to renal tubular effects. 

Methylmercury is rapidly and nearly completely absorbed from the gastrointestinal tract 90-100% absorption is estimated. Methylmercury is somewhat lipophilic, allowing it to pass through lipid membranes of cells and facilitating its distribution to all tissues, and it binds readily to proteins. Methylmercury binds to amino acids in fish muscle tissue. The highest methylmercury levels in humans generally are found in the kidneys. Methylmercury in the body is considered to be relatively stable and is only slowly transformed to other forms of mercury. Methylmercury readily crosses the placental and blood/brain barriers. Its estimated half-life in the human body ranges from 44 to 80 days. Excretion of methylmercury is via the feces, urine, and breast milk. Methylmercury is also distributed to human hair and to the fur and feathers of wildlife measurement of mercury in hair and these other tissues has served as a useful biomonitor of contamination levels. 

Hair has been used in the biomonitoring of various elements, for example, arsenic, thallium, and zinc, and has been used in the monitoring of drugs and biological substances. The level of mercury in hair is widely used as a biological indicator for exposure to methyl mercury (MeHg). In addition, hair samples have been utilized to evaluate environmental exposure to pollutants such as lead, and occupational exposures to metals such as nickel and chromium. However, the ATSDR has stated ... 

Nakagawa (1995) analyzed total mercury in hair samples from 365 volunteers in Tokyo, and reported higher mercury levels in those who preferred fish in their diet, compared to those who preferred other foods (preference choices were fish, fish and meat, meat, and vegetables). The mean hair mercury levels were 4 ppm in men who preferred fish and 2.7 ppm in women who preferred fish. The lowest hair mercury levels were seen in men and women who preferred vegetables, 2.27 and 1.31 ppm, respectively. The mean hair level for the whole group was 2.23 ppm (median 1.98). 

People who are concerned that their mercury exposure may be causing adverse effects can be tested for allergies to mercury or to other metals, or for the amount of mercury in their body. Tests that measure the amounts of mercury in hair and urine are available and provide some indication of the potential for adverse effects from mercury. For more information about the tests that are available, see Section 2.7, Biomarkers of Exposure and Effects. 

Recent reference values for mercury levels in hair from non-exposed individuals in the general U.S. population are very limited. A summary of mercury concentrations in hair from residents (adults, men, women, and children) of several U.S. communities is presented in Table 5-18. Most of the these studies, however, with the exception of Fleming et al. (1995) were conducted from 7 to 20 years ago. For populations studied in the United States, the range in mean hair concentrations was 0.47-3.8 ppm for adults (maximum value of 15.6 ppm) and 0.46-0.77 ppm for children (maximum value of 11.3 ppm). The mean concentration of mercury in hair based on a review of existing data from other countries is 2 g/g (ppm) (WHO 1990), and the WHO advisory maximum tolerable level for hair is 6 ppm. 

Blood, urine, hair, fish (total, methyl Hg) Total digestion of sample with nitric, perchloric, and sulfuric acids Methyl mercury in hair digestion with HCI and extraction into benzene. Methyl mercury in blood, fish, and urine digestion with KOH and extraction into dithizone solution, cleaned up via extractions. Total CVAAS, methyl mercury GC/ECD 0.5 ng No data Akagi et al. 1995... 

A1-Shahristani J, Shihab KM, Al-Haddad JK. 1976. Mercury in hair as an indicator of total body burden. Bull World Health Organ (Suppl) 53 105-112. 

Lasora BK, Cittemam. 1991. Segmental analysis of mercury in hair in 80 women of Nome, Alaska. 

Nakagawa R. 1995. Concentration of mercury in hair of Japanese people. Chemosphere 30( 1) 127-133. 

Suo Y, Yi F, Huang Y. 1992. Determination of trace mercury in hair, urine and nail by flameless nondispersive atomic fluorescence spectrometry. Fenxi Huaxue 20(3) 335-338. 

Since the 1970s, hair has been analyzed for trace metals for purposes of assessing nutritional status. However, (1) lack of standardized procedures (collection, preparation, and analysis), (2) lack of reference limits, and (3) problems due to environmental contamination have limited the success of hair analysis for this purpose. However, the analysis of lead, arsenic, and mercury in hair is an established and accepted method of assessing prior toxic exposure to these metals (see Chapter 35). 

Batista, J., M. Schuhmacher, J.L. Domingo, and J. Corbella. 1996. Mercury in hair for a child population from Tarragona Province, Spain. Sci. Total Environ. 193(2) 143-148. 

Pellizzari, E.D., R. Fernando, G.M. Cramer, G.M. Meabum, and K. Bangerter. 1999. Analysis of mercury in hair of EPA region V population. J. Expo. Anal. Enviroir Epidemiol. 9... 

The determination of mercury in hair by flameless atomic absorption spectroscopy (Association of Official Analytical Chemists, International, Method 971.21, 16th ed., modified for hair)... 

Hair is rich in -SH groups, and the concentration of mercury in hair is about 300 times that in blood. Human hair grows about 20 cm/year, and a history of exposure may be obtained by analysis of different segments of hair. 

Campe, A., Velghe. N. and Claeys, A. (1982) Determination of inorganic, phenyl, and alkyl mercury in hair. Atom. Spectrosc., 3,122-125. 

Giovanoli-Jacubzak, T., Greenwood, M.R., Crispin-Smith, J. and Clarkson, T.W. (1974) Determination total and inorganic mercury in hair by flamless AAS and of methylmercury by GC. Clin. Chem., 20, 222-229. 

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