Lead In Hair Samples Research Articles

THE ROLE OF ANTHROPOGENIC DERMATOTOXICANTS IN THE FORMATION OF ACNE IN ADOLESCENTS

Abstract. Against the background of the steady pace of urbanization, the negative impact of anthropogenic toxic substances on human health is increasing every year. The most sensitive to the action of ecotoxicants is the child and adolescent organism. Given the acute reaction of the skin to the influence of toxic chemicals, aggravated by humoral changes in the body during puberty, the identification of criteria for the toxic etiology of acne is certainly relevant.
 The aim of the study was to determine the criteria of the predominantly toxicological mechanism of acne formation.
 To assess the effect of anthropogenic dermatotoxicants on the formation of acne, 595 children and various districts of the Moscow region were examined, of which 301 adolescents suffered from acne, and 294 practically healthy children made up the control group. The study used spectrometric, cytogenetic, biochemical and immunological research methods. The content of essential and toxic trace elements in adolescent hair samples was evaluated. A micronuclear test was performed in buccal epithelial cells. The testosterone level and the immunoregulatory index were evaluated.
 The results obtained in the study indicate at least two mechanisms of the formation of acne vulgaris in adolescents. The first is associated with a violation of the regulation of sex hormones, and the second with the dermatotoxicity of anthropogenic ecotoxicants. Adolescents with predominantly intoxicating etiology were characterized by low concentrations of selenium and zinc, high mercury and lead in hair samples, as well as an increase in the number of micronuclei in the buccal epithelium. Adolescents with predominantly hormonal etiology were characterized by an increase in testosterone levels and a decrease in the immunoregulatory index. At the same time, in adolescents with signs of genetic instability determined by the results of a micronucleus test, the clinical course of acne was significantly more severe than in children without pronounced karyopathology. Based on statistical processing of these data, prognostic algorithms were built to differentiate acne in adolescents by etiological factor.
 Thus, anthropogenic chemical toxicants, represented mainly by heavy metal salts, have an aggravating effect on the formation and course of acne in adolescents.

A pipette tip multiwalled-carbon nanotube solid-phase extraction of lead in water and hair samples: application of the statistical Taguchi method to optimise the experimental variables

A pipette tip multiwalled-carbon nanotube solid-phase extraction (PT-MWCNTs-SPE) coupled with flame atomic absorption spectrometry (FAAS) was developed for extraction and determination of lead in hair samples. In this study, PT-MWCNTs-SPE cartridge, assembled by packing MWCNTs as a sorbent into a 100-μL pipette tip. Taguchi’s method (L9 orthogonal array (OA)) as a statistical design of experiments was employed to optimise the factors and experiments that affected on the recovery of Pb(II). Under the optimum conditions, four parameters such as pH (P), volume of ligand (AL), sorbent amount (SA) and eluent concentrations of HNO3 (EC) were chosen as important affecting parameters. The limit of detection (LOD) of this method was 0.86 µg L−1 with relative standard deviations (RSD) ≤3% for Pb(II). Afterwards, the accuracy of proposed method was evaluated by TMDA 53.3 fortified water and NCS ZC 81002b human hair certified reference materials. The procedure was applied to lead contents of water and hair samples.

Metal doped keratin film standard for LA-ICP-MS determination of lead in hair samples

Lead doped keratin film standard was introduced as a new calibration standard for LA-ICP-MS determination of Pb along hair strands. The Pb doped keratin film standard was prepared by precipitation of hair protein solution casting in Pb standard solutions in the presence of trichloroacetic acid as a denaturant solution. Sulfur, which is a major matrix element in hair, was used as an internal standard element to normalize Pb intensity and to correct for variations in ablation efficiency and plasma condition. The method was applied to quantitatively determine Pb distribution along a single human hair strand obtained from workers in a battery manufacturing factory in Thailand who faced risk of Pb exposure. Single hair strands were analyzed along their length by LA-ICP-MS with a fixed spot size of 50 μm. The position of an analyzed hair sample on a strand was converted into time (hair closer to the scalp is newer) on the basis of an average hair growth rate of 0.33 mm per day. The patterns of Pb distribution of each worker in the same battery factory were different suggesting that these workers might either not be involved in the same activities or not work in the same room. This study demonstrated the applicability of LA-ICP-MS for rapid acquisition and tracking Pb concentrations along a single hair strand.

Use of aqueous slurry sampling for the determination of lead in human hair samples by electrothermal atomic absorption spectrometry

A method for the determination of lead in human hair slurries by electrothermal atomic absorption spectrometry was optimized. Particle size reduction was achieved with a vibrational mill ball equipped with zirconia cups, 20 min being sufficient grinding time to achieve an adequate particle diameter (<1 μm). The use of different thickening agents, namely glycerol, Triton X-100 and Viscalex HV30, was studied and glycerol was found to be the best. The use of Pd and Mg(NO 3) 2 at optimum concentrations of 20 and 25 mg l −1 respectively was found to be satisfactory for stabilizing lead at 1100 °C. A limit of detection of 0.21 mg kg −1 was obtained. The limit of detection can be reduced to 0.05 mg kg −1 without loss of analytical performance by increasing four-fold the amount of hair sample. Accuracy was studied by analysis of a CRM 397 human hair reference material with a certified lead content of 33.0 ± 1.2 mg Pb kg −1. The standard addition method was used for the determination of lead in hair samples from healthy people, the levels being between 2.3 and 35.5 mg kg −1.

Trace metal accumulation in hair and skin of the harbour seal, Phoca vitulina

Skin and hair samples of harbour seals ( Phoca vitulina) found dead along the west coast of northern Germany in 1988 were analysed for total mercury, cadmium and lead. Cadmium and lead concentrations were below the detection limit in most skin samples. The mercury content of the hair (median: 23.1 μg g −1 wet wt) was several magnitudes higher than the mercury content of the skin (0.27 μg g −1 wet wt). Mercury concentrations in hair samples were significantly higher than lead concentrations (0.54 μg g −1 wet wt), which significantly exceeded cadmium levels (0.09 μg g −1 wet wt). Female seals revealed lower cadmium concentrations in the hair than male seals. Accumulations of metals with age were observed for cadmium and lead in hair samples and for mercury in skin samples of male seals. A connection between metal accumulation and pigmentation or rather moult was clearly recognizable.

Heavy metals in hair samples of the Mediterranean Monk Seal ( Monachus monachus)

For the first time the concentrations of copper, zinc, mercury, cadmium and lead in hair samples of the Mediterranean Monk Seal, one of the world's rarest mammals, were determined. The hair samples were collected in the absence of the animals from six caves located in the Ionian Sea, Greece. Our data suggest the importance of hair analysis as a useful indicator for heavy metals in these rare animals.

Ｏｘｉｎｅ‐ＭＩＢＫ，ＡＰＤＣ‐ＭＩＢＫ抽出グラファイト・チューブ原子吸光法による毛髪中鉛の微量測定

Scalp hair samples were decomposed by the semimicro wet digestion method and transferred into test tubes (15 ml) equipped with face abraded exchangeable stoppers. To the test solution (5 ml), citric buffer was added and the pH was adjusted to 3.0, and water was added to make the solution 10 ml. Iron and other few ions are extracted with 1% oxine-MIBK solution (1 ml) and removed. Then, lead was extracted with APDC-MIBK solution (1 ml), and the upper layer (20 microliters) was injected immediately into graphite-tube. Atomic absorption was measured at 2,170 A corrected background by D2 lamp. Recovery tests of lead added to hair samples were satisfactory and interference by coexisting metals was not observed. With this method, the amount of lead in hair samples from healthy persons were determined, and the mean values of 4.90 ppm in male and 8.13 ppm in female were indicated.