Uranium in hair

Laser ablation coupled to ICPMS has been used to determine the concentration of uranium in hair samples (Rodushkin and Axelsson 2003) and even along a... 

Alpha spectrometry was deployed to determine the concentration of uranium in hair samples collected from 10 Greek monks (Kehagia et al. 2010). The samples were collected from the nape of the neck, rinsed with water and acetone, and air-dried prior to digestion in a microwave oven. The uranium was purified and preconcentrated on an anion exchange resin column, and finally electrodeposited on a stainless steel plate for alpha spectrometry. The detection limit in hair was reported as 5 ng g for 7200 min counting time. The measured uranium concentration among these subjects varied from 12.1 to 170 ng U g hair compared to that measured for staff members that was around 30 ng g . ... 

Karpas et al. reported on the determination of the 234U/238U isotope ratio (54.9 x 10-6) by MC-ICP-MS and ICP-QMS compared to a-spectrometry in hair, nail and water samples.46 A correlation of 0.99 was found between the two ICP-MS methods and of 0.98 with a-spectrometry for the water sample. The measurement time of the water sample after dilution for ICP-MS was 1 min and 1000 min (including uranium separation and counting time) for a-spectrometry.46... 

Bentley KW, Wyatt JH, Wilson DJ, et al. 1982. Uranium and plutonium in hair as an indicator of body burden in mice of different age and sex. Bull Environ Contam Toxicol 28 691-696. 

In Chapter 4, we discuss the effects of uranium on human life and well-being with a detailed survey of the methods and means of estimating internal exposure to uranium on the basis of bioassays (urine, feces, blood, hair, nails, and some nonstandard assays). We also present a detailed review of the analytical methods used to assess the amount of uranium in food products and drinking water that are the main pathways of exposure to uranium of the general population. 

The extent of the disequilibrium can serve as a natural isotopic tracer for proving exposnre pathways as seen in Figure 1.2 that shows the correlation of the 234U/238U ratio in drinking water and bioassays (hair and nails) of residents of sonth Finland that consnme elevated levels of uranium in their drinking water (Karpas et al. 2006). For some samples, the ratio was more than double the ratio calculated for secular equilibrium. 

In these models, the bloodstream is in contact (directly or indirectly) with each compartment and equilibrium exists between the uranium content of the compartment and the uranium couceutration in the blood. Elevated levels of uranium in the bloodstream would lead to deposition of uranium in the compartment. The exchange rate of this process is shown in the model of Eigure 4.7. If the uranium concentration in the blood is low, then uranium could be transported from the compartment (body organ) to the blood and eventually be ranoved from the body (excreted) either by the kidneys and bladder (urine), the intestine (feces), contained in keratin of the hair or nails, or even through exhaled breath or perspiration. 

Once equilibrium is attained between uranium in the blood and the other organs (skeleton and soft tissues), it is gradually excreted in the urine and feces. As mentioned earlier, excretion of ingested uranium is mainly (around 98%) through the feces, but removal of the uranium fraction that has entered the bloodstream is distributed between urine, feces, hair, nails, and perspiration (Figure 4.1). The rate of removal of uranium through urine depends in part on the pH of tubular urine. The uranyl hydrogen carbonate complex is stable under alkaline conditions and is excreted in the urine but low pH values would induce dissociation of this complex and the uranyl ion may then bind to cellular proteins in the tubular wall, which may then impair tubular function (Berlin 1986). 

Table 4.8 summarizes the findings of some of the major studies that were carried out in Sweden by Rodnshkin et al., where reference valnes for the concentration of uranium in urine, whole blood, sernm, hair, and nails are given for populations that are not occnpationally exposed to nraninm componnds. 

Blood Neutron activation analysis was used to determine the level of uranium in samples of blood, urine, and hair of exposed people (woikers in uranium production facilities in Slovenia) and unexposed population (Byrne and Benedik 1991). Blood samples were collected by venipuncture from the arm. The samples were freeze-dried and powdered and well mixed before encapsulation in polythene vials that were heat-sealed. The samples were irradiated with a 4 10 n cm s neutron flux for up to 30 min and rapidly ashed with 50 mg of uranium that served as a carrier. The uranium was then extracted with TBP in toluene and after cleaning the organic phase by acid washing the samples were counted with a HPGe gamma detector for 20 min. The 74.7 keV peak formed by neutron irradiation and the 185.7 keV peak (from the... 

The uranium level in blood, urine, and hair of workers in phosphate mines in Syria was determined by fluorimetry (Othman 1993). The preparation of the blood samples included addition of an anticoagulant, nitric acid, and hydrogen peroxide, followed by centrifugation. The samples were then heated on a platinum plate and the flux mixture was added. Finally, the fluorescence of the samples was recorded. A correlation was found between the level of uranium in the bioassays and the number of years of employment in the mines (Othman 1993). 

The uranium concentration in hair samples of Brazilian residents (18 young females and 4 males) was determined by ENAA (Akamine et al. 2007). Hair samples were collected from the occipital part of the head, cut into 2 mm sections, rinsed to remove external contamination, and placed on filter paper for drying. The hair samples, and samples spiked with uranium standards, were placed in thin cadmium capsules and irradiated for 16 h. After 4 days, to allow for decay of interfering radionuclides, the gamma activity of the samples was measured for 50,000 s, and the uranium content was determined from the intensity of the 106 and 278 keV peaks of Np. Method validation was based on measur ent of CRM (NIST 1575—pine needles). The uranium concentration was 2.1-49.8 ngU g hair, with mean and median values of 15.4 and 10.7 ng g , respectively. 

Akamine, A.U., Silva, M.A.D., Saiki, M. et al. (2007). Determination of uranium in human head hair of a Brazilian populational group by epithermal neutron activation analysis,... 

Alaani, S., Tafash, M., Busby, C. et al. (2011b). Uranium and other contaminants in hair from the parents of children with congenital anomalies in Fallujah, Iraq, Confl. Health 5, 15. 

DTlio, S., Violante, N., Senofonte, O. et al. (2010). Determination of depleted uranium in human hair by quadrupole inductively coupled plasma mass spectrometry Method development and validation, A a/. Methods 2, 1184-1190. 

Gonnen, R., Kol, R., Laichter, Y. et al. (2000). Determination of uranium in human hair by acid digestion and FIAS-ICPMS, J. Radioanal. Nucl. Chem. 243, 559-562. 

Li, W.B., Karpas, Z., Salonen, L. et al. (2009). A compartmental model of uranium in human hair for protracted ingestion of natural uranium in drinking water. Health Phys. 96, 636-645. 

Determination of depleted uranium in human hair by quadmpole inductively coupled plasma mass... 

Figure 9.30 (a) Changes in uranium concentrations along a single hair strand collected from an indi-... 

Radioactivity was a sensation in the first decade of this century. The very concept of rays that could go right through you without you feeling a thing caused shivers of schadenfreud and for some the exposure of ones skeleton to outside view was uneasily akin to the exposure of ones soul. Conversely, the hair-loss associated with exposure to X-rays or radioactivity led to at least one clinic being set up, to which women flocked, using uranium salts as depilatory treatment. 

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