Hair Selenium Research Articles

Low hair selenium and plasma glutathione peroxidase in children with chronic renal failure

Selenium (Se) is a trace element that incorporates into the selenoenzyme glutathione peroxidase (GSH-Px). There are conflicting results regarding the Se levels and activity of GSH-Px in adult uremic patients. The aim of this study was to determine (1) the hair Se status, (2) the possible relation between the hair Se status and the antioxidant enzyme, GSH-Px, and (3) the influence of different treatment procedures on hair Se status and GSH-Px activity in children with CRI, those treated conservatively and those on HD and on CAPD. Ninety-three patients, including 32 patients with CRI, treated conservatively, 42 PD patients, 19 HD patients and 34 healthy children were enrolled in the study. The hair Se level was measured by the atomic absorption spectrophotometer method. Plasma GSH-Px activity was determined using a Randox test combination (RANSEL). Hair Se levels were significantly lower in the CRI, CAPD, and HD groups when compared to the control group (P=0.001, P=0.001, and P=0.001, respectively). Plasma GSH-Px activity was significantly lower in the CRI, CAPD, and HD groups when compared to the control group (P=0.001, P=0.001, and P=0.001, respectively). Plasma GSH-Px activity correlated with the GFR in patients with CRI and the control group (P=0.000; r(2)=0.60). There was no correlation between plasma GSH-Px and hair Se levels in the patient and control groups. These results revealed a decreased hair Se level and impaired antioxidative capacity in children with CRI on CAPD and HD. The lack of any relation between plasma GSH-Px and hair Se suggests that plasma GSH-Px is not a good marker of Se stores.

A preliminary analysis of trace elements in the scalp hair of patients with severe motor disabilities receiving enteral nutrition

The concentrations of essential trace elements (copper, zinc, selenium, manganese, chromium, molybdenum, cobalt, and iodine) in the scalp hair of 21 patients with severe motor disabilities receiving enteral nutrition were measured using inductively coupled plasma-mass spectrometry. Preliminary results show that copper, selenium, and molybdenum concentrations in the patients’ hair were significantly lower than those in an age-matched control group ( p < 0.01). This suggests that intake of these elements may be reduced in patients receiving restricted enteral nutrition, although the clinical significance of these results should be discussed.

Serum and Hair Levels of Zinc, Selenium, Iron, and Copper in Children with Iron-Deficiency Anemia

In the present study, the serum and hair levels of zinc, selenium, and copper were determined in children with iron-deficiency anemia (IDA). A total of 52 anemic children aged 1-4 yr constituted the study group. Forty-six healthy children acted as controls. The copper and zinc levels were measured with an atomic absorption spectrophometer. Serum and hair selenium was determined by a spectroflourometric method. The serum zinc and selenium concentrations in the IDA group were found to be significantly lower and serum copper significantly higher than those in the controls (p < 0.05). Lower iron, zinc, and selenium concentrations (p < 0.001) but not copper were found in hair (p > 0.05).

Simple Method for Simultaneous Determination of Selenium and Arsenic in Human Hair by Means of Atomic Fluorescence Spectrometry with Hydride Generation Technique

This study describes a simple, rapid and reliable method for simultaneous determination of selenium and arsenic in human hair by means of atomic fluorescence spectrometry combined with a hydride generation technique (HG-AFS). The procedure developed encompasses microwave digestion of a sample in the nitric acid environment only. The interferences caused by nitrous oxides are eliminated by removing a gas from above the digested solution with a stream of argon. The sample is then chemically treated in a flow-through hydride generation system and exposed to measurements in a double-channel atomic fluorescence spectrometer. The method permits determining both analytes in the linear range of 0.5–100 µg L−1 with a detection limit equal to 0.2 µg L−1, as well as with very good repeatability not exceeding 1% for Se and 2% for As. No mutual interferences from either of the analytes in the concentrations ranges matching the hair composition were found. The method was verified in terms of accuracy with the use of a reference material and then applied to the analysis of the natural samples of human hair.

Arsenic and Selenium in Human Hair: A Comparison of Five Countries With and Without Arsenicosis

The selenium (Se) content of the diet and/or selenium supplements might have an ameliorating effect on arsenic (As) toxicity as recently shown by Wang et al., Yang et al., and as reviewed by Spallholz et al.. The underlying principles of the ameliorating effect is the complexation of Se with As forming the seleno-bis (S-glutathionyl) arsinium ion excreted in bile and the complexation of Se with As in tissues forming nontoxic insoluble selenides. Additional protection afforded by Se supplementation from arsenicosis could be the elevation of glutathione peroxidase activity reducing the oxidative stress induced by As. The present study assessed the status of Se and As in hair by neutron activation analysis (NAA). Human hair samples were collected from the United States, Canada, The People's Republic of China (PRC), Bangladesh, and Nepal, the latter two countries now engaged in a struggle to find relief from human arsenicosis resulting from extensive domestic groundwater contamination by As. No statistically significant differences were observed in the samples between the Se and As content of hair from, Lubbock, Texas (USA) or Winnipeg, Canada. The concentration of As in all hair samples analyzed correlated (r = 0.960, p < 0.001) with the amount of As in the drinking water. Selenium levels in hair were highest from Nepal. The results demonstrate the viability of hair as a noninvasive biomonitor in assessing aspects of dietary Se and environmental As exposure. The hair data confirmed the known low intake of Se in the Keshan disease area of the PRC, the very high accumulation in hair of As from subjects consuming contaminated groundwaters, and an adequate Se status in subjects from North America consuming municipal water of low As content. The high As content of hair from people in Bangladesh is the result of a high As consumption from contaminated water compounded by a less than desirable intake of Se. From Nepal, the As content of hair corresponded to the known low and high intake of As from contaminated groundwater. The very high Se content found in all hair samples from Nepal might be the result of the use of henna.

Low levels of selenium in miscarriage

AbstractFew data are presented in the literature about selenium and miscarriage. The aim of this article was to study the relationship between the selenium status of pregnant women and miscarriage. A randomized, controlled trial was performed in Elazig State Hospital and Firat University Hospital. Serum and hair samples were obtained from 20 non‐pregnant women, 32 healthy mothers with normal newborns, and 16 women who miscarried. Serum selenium levels, as ng/mL, and hair selenium levels, as ng/g, were determined on a Perkin–Elmer 1000 spectrophotometer by fluorometry. The mean serum and hair selenium concentrations of the women who miscarried (42.8 ± 2.7 ng/mL, 276 ± 6.6 ng/g, respectively) were significantly lower than those of the control healthy mothers (50.2 ± 2.3 ng/mL, 300 ± 6.1 ng/g, respectively) and the non‐pregnant women (58.1 ± 3.1 ng/mL, 315 ± 7.6 ng/g, respectively). Maternal selenium deficiency during early gestation was thought to be one of the factors responsible in the pathogenesis of miscarriage. More studies on maternal selenium status during pregnancy are needed. J. Trace Elem. Med. 15:97–101, 2002. © 2002 Wiley‐Liss, Inc.

Removal of exogenously bound elements from human hair by various washing procedures and determination by inductively coupled plasma mass spectrometry

A review of the literature shows that a variety of washing procedures to remove external contamination from hair have been proposed, but as yet no standardised procedures are available. In this study, methods for the pre-treatment and determination of antimony, arsenic, cadmium, chromium, lead, mercury and selenium in human hair by inductively coupled plasma mass spectrometry (ICP-MS) are developed. Investigations of various washing procedures to remove external contaminants show that in unexposed hair samples cadmium, lead and mercury are significantly removed from hair using a 0.1 M HCl wash, with 87, 73 and 5%, respectively being washed-off. The removal of antimony, arsenic and chromium from unexposed hair is, however, more efficient with 1% (v/v) sodium lauryl sulphate (SLS), with 43, 40 and 13% of each element, respectively being washed-off. Selenium is not removed from the hair by any of the washing methods studied. For the digestion of hair samples a digestion mixture of nitric acid and hydrogen peroxide is used. Experiments with simulated sweat spiked with each of these elements show that exogenously bound chromium, cadmium and lead are removed after washing with 0.1 M HCl. In contrast, antimony, arsenic, selenium and mercury irreversibly bind and, thus, are not removed with any of the washing solutions investigated. This work also compares hair levels of these elements in an unexposed and exposed group using the method developed.

The selenium status of women with a history of recurrent miscarriage

Objective To assess the relationship between selenium levels in human blood and hair, and the risk of recurrent miscarriages. Design Case–control study. Participants Two groups of non-pregnant women: 18 women with one or more successful pregnancies and no history of miscarriage (control group); 26 women with a history of recurrent miscarriage (≥ 3) with no subsequent successful pregnancies (study group). Methods Samples of venous blood and scalp hair were collected and the selenium content analysed by inductively coupled plasma mass spectrometry. Results No significance difference was found between the level of selenium in the blood samples of the women in each group. There was a significant reduction in the mean hair selenium level in the recurrent miscarriage group compared with the control group (0.14μg/g vs 0.34μg/g). Further analysis of the recurrent miscarriage group revealed no relationship between levels of serum or hair selenium with parity. There was a significantly greater proportion of women in the control group who ate cereals, vitamin supplements, and liver or kidney. Conclusion There was evidence of selenium deficiency in women with recurrent miscarriages compared with a control group of women with a good reproductive performance. This difference was seen in hair samples but not serum samples and therefore may not represent a simple nutritional deficiency. The importance of selenium deficiency in miscarriage has still not been determined.

The selenium status of women with a history of recurrent miscarriage.

To assess the relationship between selenium levels in human blood and hair, and the risk of recurrent miscarriages. Case-control study. Two groups of non-pregnant women: 18 women with one or more successful pregnancies and no history of miscarriage (control group); 26 women with a history of recurrent miscarriage (> or = 3) with no subsequent successful pregnancies (study group). Samples of venous blood and scalp hair were collected and the selenium content analysed by inductively coupled plasma mass spectrometry. No significance difference was found between the level of selenium in the blood samples of the women in each group. There was a significant reduction in the mean hair selenium level in the recurrent miscarriage group compared with the control group (0.14 microg/g vs 0.34 microg/g). Further analysis of the recurrent miscarriage group revealed no relationship between levels of serum or hair selenium with parity. There was a significantly greater proportion of women in the control group who ate cereals, vitamin supplements, and liver or kidney. There was evidence of selenium deficiency in women with recurrent miscarriages compared with a control group of women with a good reproductive performance. This difference was seen in hair samples but not serum samples and therefore may not represent a simple nutritional deficiency. The importance of selenium deficiency in miscarriage has still not been determined.

Selenium, iodine and fungal contamination in Yulin District (People's Republic of China) endemic for Kashin-Beck disease.

We studied the status of selenium, iodine and fungal contamination in 353 school children (age 5-14 years) from four rural villages in the District of Yulin. In three villages Kashin-Beck disease (KBD) was endemic, whereas there were no cases of KBD in the fourth village. Clinical, biological and radiological examinations (right hand) were performed and KBD was established by X-ray diagnosis. The prevalence rate of KBD was 30.2%, 44.2% and 45.3% in the three endemic villages. Mean hair selenium and urine iodine concentrations were lower in affected than in unaffected children and fungal contamination in cereal grains stored in families with KBD was more elevated than in families without KBD. Low hair selenium concentration and presence of fungal cereal contamination were significantly associated with an increased risk of KBD, but low urine iodine was not.

Determination of mercury, selenium, bismuth, arsenic and antimony in human hair by microwave digestion atomic fluorescence spectrometry

A novel method for determination of Hg, Se, Bi, As and Sb based on microwave digestion followed by continuous flow vapour generation atomic fluorescence spectrometry was developed. The digestion for Hg was based on a two stage digestion involving HNO 3 and H 2O 2, whilst for the hydride forming elements a common digestion using HCl and H 2O 2 was found to be the most effective. The instrumentation and chemistry were optimised in order to provide the best accuracy and precision. The method detection limit for hair samples was found to be 0.2 ng g −1 for Hg and between 2 and 10 ng g −1 for the hydride forming elements. The atomic fluorescence detector showed excellent linearity over the concentration ranges studied with linear correlation co-efficients between 0.99984 and 0.99997. To validate the accuracy of the method a human hair certified reference material (GBW 0706) was analysed and excellent agreement with the certified value was obtained for all elements.

Determination of trace selenium in human plasma and hair with ternary inclusion compound-fluorescent spectrophotometry.

A method for determination of selenium in plasma and hair with ternary inclusion compound-fluorescent spectrophotometry has been developed. The determination of selenium in plasma and hair can be performed directly in aqueous solution. Blood and hair samples were destroyed by oxygen flask combustion. The linear range was 10-500 ng mL-1 for plasma and 10-100 ng mL-1 for hair. Within-day and day-to-day precisions for plasma ranged from 5.4% to 9.3% (n = 7) and from 3.5% to 14.5% (n = 7), respectively. Within-day precisions for hair ranged from 0.6% to 6.2% (n = 7). Recoveries ranged from 91.0% to 97.8% for plasma and from 95.0% to 102.0% for hair. The blood samples from 15 Hans and 20 Uygurs in Xinjiang Uygur automatic region and 23 Hans in Liaoning province were collected and determined. It was indicated that no statistically significant difference in plasma selenium concentration of the Hans between Xinjiang and Liaoning was found (F = 1.36, P > 0.05). However, there were statistically significant differences between the Hans and the Uygurs in Xinjiang (F = 1.01, P < 0.01) and between males and females in the two areas (P < 0.01). There was a low correlation between plasma selenium concentration and hair selenium concentration. The ratio of hair selenium concentration to plasma selenium concentration was 2.17, with a range of 1.63-2.88.

Long-term Zinc and Iron Supplementation in Children of Short Stature: Effect of Growth and on Trace Element Content in Tissues

We evaluated the effect of one year of supplementation with iron plus zinc (12 mg/day of Fe+++ and 12.5 mg/day of Zn++), zinc alone (12.5 mg/day of Zn++) and placebo on growth and on the iron, zinc, copper and selenium tissue contents in 30 well-selected children of short stature (16 M and 14 F; 4-11 years old). Before and after supplementation, we measured the concentrations of iron, transferrin, ferritin, zinc and copper in serum, of zinc in erythrocytes and leukocytes, and of zinc, copper and selenium in hair, as well as glutathione peroxidase activity in erythrocytes. Before supplementation, ferritin and serum, erythrocyte and hair zinc contents were significantly lower than in age-matched controls, while the other measured indices were in the normal range. Iron plus zinc supplementation caused an improvement in growth rate in all subjects, i.e., the median Z-score increased from -2.22 +/- 0.45 to -0.64 +/- 0.55; (p < 0.01). In the zinc-supplemented group, only the subjects whose ferritin levels were higher than 20 ng/L before supplementation showed a similar improvement of growth rate. Iron plus zinc supplementation could be a reasonable treatment in short, prepubertal children affected by marginal zinc and iron deficiency.

Correlation of mercury with selenium in human hair at a typical mercury-polluted area in China.

The levels of mercury (Hg) and selenium (Se) and their correlation in human scalp hair of 29 pairs of pregnant women and their newborns living at a high-Hg and low-Se area, the Second Song-Hua-Jiang River System, have been studied by instrumental neutron activation analysis. Our results indicate that the Hg level in infant hair samples are roughly close to that in their mothers, whereas the Se level in infants is much higher. Furthermore, the molar ratios of Se/Hg in newborns are also 40% higher than those in mothers. It demonstrates that infants are able to absorb more selenium from their mothers' bodies to protect against or alleviate the intoxication of Hg. This "autoprotective mechanism" likely plays a critical role during fetal development. The possible chemical species of Hg and Se in hair is also discussed.

Accuracy, precision and sensitivity in cyclic INAA with short-lived radionuclides

Repeated irradiation enhances the precision and sensitivity of INAA based on short-live radionuclides, but entail systematic losses due to dead time. The relative standard deviation in the net peak area decreases with the square root of the number of cycles while the systematic bias increases with it. The limits of decision, detection and determination decrease in a somewhat more complicated way with the number of cycles. The derived formulation is applied to the determination of selenium in hair by the 161.9 keV photopeak of77mSe,T1/2=17.8 s.

HAIR SELENIUM AS A MONITORING TOOL FOR OCCUPATIONAL EXPOSURES IN RELATION TO CLINICAL PROFILE

Nineteen workers exposed to low levels of selenium (0.047-0.202 mg/m3 air) along with 15 control subjects were studied for clinical, hematological, radiological, and neurobehav-ioral variables in relation to selenium concentration in hair. The levels of selenium in the hair of exposed subjects (1.44±0.37 µg/g) were significantly higher than those of control subjects (0.78±0.18 µg/g). The levels of selenium in the hair of 22 nonvegetarian subjects were found to be significantly higher as compared to 12 vegetarian subjects. Complaints of weakness and/or fatigue were found to be more prevalent in the exposed subjects. The study holds promise that hair selenium may be used as a monitoring tool for low-level occupational exposure to selenium.

The determination of mercury and selenium in maternal and neonatal scalp hair by inductively coupled plasma-mass spectrometry.

As part of a prospective study to evaluate maternal and neonatal scalp hair mineral profiles in normal and pathological pregnancy cases, the suitability of inductively coupled plasma-mass spectrometry (ICP-MS) was evaluated for the quantitation of mercury and selenium as part of a multi-element determination procedure. Treatment of hair samples included a closed-system microwave-assisted digestion in screw-capped PTFE vials of 10-mL capacity with concentrated nitric acid (2 mL) as the matrix solubilization medium. A digestion time of 10 min at 40% microwave power yielded limpid digestates, which, after appropriate dilution with deionized water to give a final acid concentration of 20% (v/v), were used for direct ICP-MS measurements within a rectilinear calibration range from 0 to 10 micrograms/L. Analytical recovery results for mercury ranged from 97 to 102%, whereas those for selenium ranged from 96 to 101%. Results from concurrent analyses of a human hair reference material showed a high degree of concordance with certified values. The results obtained suggest that the closed-system microwave-assisted digestion procedure described was effective in minimizing the risk of volatility-associated losses that can be encountered in the assays of both metals. The results also indicated that the ICP-MS system used in this study was suitable for including both metals as part of a multi-element quantitation procedure. Using this method, analytical results were obtained for mercury and selenium levels from 100 pairs of maternal and neonatal scalp hair samples collected at the postnatal ward of Hull Maternity Hospital, Hull, United Kingdom.

Selenium status of healthy Turkish children.

Selenium concentrations, in blood plasma, red blood cells, hair of 61 healthy children, ages 0-14 yr, were determined using hydride generation atomic absorption spectrometry. Starting from late lactation period, selenium concentrations in all these matrices were found to be increasing with age. A good correlation was found between erythrocyte and plasma, hair and plasma, and hair and erythrocyte selenium concentrations. Although plasma, erythrocyte, and hair selenium concentrations of girls seemed to be higher than that of boys (only in erythrocytes), selenium concentrations of girls were found to be significantly (p < 0.002) higher than that of boys, 71 +/- 9 ng/mL, vs 65 +/- 10 ng/mL, respectively. Selenium status of Turkish children is found to be lower than that found in the literature; marginal selenium deficiency could be important in the development of some selenium deficiency related diseases. There is a need for extension of this study to healthy children from different regions in Turkey and to different disease states.

A case-control study on selenium, zinc, and copper in plasma and hair of subjects affected by breast and lung cancer

The purpose of our study was to investigate the relationship between plasma and hair levels of Se, Zn, and Cu, and cancer. We selected a total of 66 patients affected by either breast (38) or lung (28) cancer. They entered into the study at the onset of disease, and before any chemical or radiotherapy. Controls were randomly selected among healthy people and were matched for sex, age, smoking habits, and residence. In the group of breast cancer, a significant decrease in hair Se was found compared to controls (p < 0.01), whereas plasma Se was only slightly decreased. No difference between cases and controls was detected in both hair and plasma levels of Zn and Cu. Subjects who developed lung cancer were significantly lower in hair Zn (p < 0.05) and Cu (p < 0.01) than controls, whereas there was no difference with regard to Se. In addition, plasma Cu of these patients was increased as compared to controls.

Determination of selenium in human hair and nail by electrothermal atomic absorption spectrometry

A microwave digestion procedure was used to prepare samples for determination of total Se by electrothermal atomic absorption spectrometry (ETAAS) with palladium modification. Conversion of organoselenium compounds to inorganic selenium was achieved by heating 100 mg hair with 0.5 ml concentrated nitric acid for 1 min and then, after the addition of 0.5 ml hydrogen peroxide (30 vols.), reheating for a further 8 min. The accuracy of the method was confirmed by analysis of certified hair reference materials containing 2.00 and 0.58 µg g–1 Se. The detection limit is 0.02 µg g–1 Se. A variation of the procedure was used to analyse nail samples. Digestion was achieved by heating 100 mg of nail with 1 ml nitric acid for 2 min and, after the addition of 1 ml hydrogen peroxide, for a further 33 (3 × 11) min. The detection limit for this procedure is 0.03 µg g–1 Se. Analysis of hair reference materials and both hair and nail samples by neutron activation analysis and ETAAS showed reasonable agreement between the techniques. The ETAAS procedure is more rapid and convenient. Analysis of 25 hair samples gave a range of 0.31–0.76 µg g–1 Se (mean value 0.52 ± 0.11 µg g–1) and for 27 nail samples a range of 0.17–0.66 µg g–1 Se (mean value 0.46 ± 0.16 µg g–1) was obtained.