Hair concentration of essential trace elements in adult non-exposed Russian population

Human Health Effects of Oral Exposure to Chromium: A Systematic Review of the Epidemiological Evidence

The toxicity and carcinogenicity of hexavalent chromium via the inhalation route is well established. However, a scientific debate has arisen about the potential effects of oral exposure to chromium on human health. Epidemiological studies evaluating the connection between ingested chromium and adverse health effects on the general population are limited. In recent years, a wealth of biomonitoring studies has emerged evaluating the associations between chromium levels in body fluids and tissues and health outcomes. This systematic review brings together epidemiological and biomonitoring evidence published over the past decade on the health effects of the general population related to oral exposure to chromium. In total, 65 studies were reviewed. There appears to be an inverse association between prenatal chromium exposure and normal fetal development. In adults, parameters of oxidative stress and biochemical alterations increase in response to chromium exposure, while effects on normal renal function are conflicting. Risks of urothelial carcinomas cannot be overlooked. However, findings regarding internal chromium concentrations and abnormalities in various tissues and systems are, in most cases, controversial. Environmental monitoring together with large cohort studies and biomonitoring with multiple biomarkers could fill the scientific gap.

Landmark native breed of the Orenburg goats: progress in its breeding and genetics and future prospects

This paper reviews information about a unique and iconic breed of the Orenburg Oblast, the homeland and the only place where the best herds of Orenburg down-hair goats in Russia are concentrated. Three types of these small ruminant animals are widespread on the territory of the region: Orenburg purebred gray goats, Orenburg purebred white goats, as well as crossbred white goats of F1 White Don × White Orenburg. Currently, at the farms of the Orenburg region, animals are selected according to their phenotype, with selected traits being color, weight and length of down hair. In recent years, the Orenburg goat breed has become an object of genetic research using various marker systems including immunogenetic, microsatellite, mtDNA and SNP markers. Overall, these studies evidence about the uniqueness of the allele pool in the landmark native breed of the Orenburg goats, which is a complex dynamic genetic system, prioritizing its further in-depth genome research and breeding applications.

Consequences of Disturbing Manganese Homeostasis

Manganese (Mn) is an essential trace element with unique functions in the body; it acts as a cofactor for many enzymes involved in energy metabolism, the endogenous antioxidant enzyme systems, neurotransmitter production, and the regulation of reproductive hormones. However, overexposure to Mn is toxic, particularly to the central nervous system (CNS) due to it causing the progressive destruction of nerve cells. Exposure to manganese is widespread and occurs by inhalation, ingestion, or dermal contact. Associations have been observed between Mn accumulation and neurodegenerative diseases such as manganism, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. People with genetic diseases associated with a mutation in the gene associated with impaired Mn excretion, kidney disease, iron deficiency, or a vegetarian diet are at particular risk of excessive exposure to Mn. This review has collected data on the current knowledge of the source of Mn exposure, the experimental data supporting the dispersive accumulation of Mn in the brain, the controversies surrounding the reference values of biomarkers related to Mn status in different matrices, and the competitiveness of Mn with other metals, such as iron (Fe), magnesium (Mg), zinc (Zn), copper (Cu), lead (Pb), calcium (Ca). The disturbed homeostasis of Mn in the body has been connected with susceptibility to neurodegenerative diseases, fertility, and infectious diseases. The current evidence on the involvement of Mn in metabolic diseases, such as type 2 diabetes mellitus/insulin resistance, osteoporosis, obesity, atherosclerosis, and non-alcoholic fatty liver disease, was collected and discussed.

A county-level spatial epidemiological study of hair selenium and Keshan disease

Background

No spatial analysis of hair selenium and Keshan disease (KD) on a nationwide county-level has been performed. Selenium deficiency is a recognized environmental risk factor for KD. Hair selenium is one of the recognized biomarkers of selenium nutrition. This study aimed to perform a geographically precise and visualized assessment of the achievement of KD prevention and control at the level of selenium nutrition in terms of etiology.

Methods

A spatial ecological study was conducted. The hair selenium content of the residents was assayed using an atomic fluorescence spectrometer. The spatial analysis was performed using ArcGIS.

Results

The median of the hair selenium levels of the 3,028 participants in the 1,174 counties was 0.38 mg/kg, and the content of inhabitants in KD endemic counties was significantly lower than that in KD non-endemic counties (0.34 vs. 0.39 mg/kg, z = −10.03, P < 0.0001). The proportion of Se-deficient and Se-marginal counties in KD endemic counties was significantly higher than that in KD non-endemic counties (59.4 vs. 29.0%, z = −7.45, P < 0.0001). The global autocorrelation analysis was not statistically significant (Moran's I = 0.0005, P = 0.68). Local autocorrelation analysis identified 174 low-low clusters of hair selenium levels, 83 (47.7%) of which are KD endemic counties located in KD endemic provinces of Henan, Gansu, Shaanxi, Inner Mongolia, Jilin, and Heilongjiang. The hair selenium featured a positive correlation with per capita GDP (rs = 0.20, P < 0.0001).

Conclusion

The median of the hair selenium levels of inhabitants living in KD endemic counties was significantly lower than that in KD non-endemic counties. All the 83 KD endemic counties with low-low clusters of hair selenium levels should be prioritized in KD precision prevention and control. These findings are geographically precise and visualized evidence of the assessment of the effectiveness of KD prevention and control at the level of selenium nutrition in terms of etiology.

High manganese and nickel concentrations in human hair and well water and low calcium concentration in blood serum in a pristine area with sulphide-rich bedrock

We report the trace element status of residents living in areas with naturally sulphide-rich bedrock and soil in two municipalities in Finland, Sotkamo and Kaavi. Altogether, 225 people from these sparsely populated regions participated voluntarily by providing hair and blood samples. The concentrations of calcium, zinc and copper in serum as well as selenium and cadmium in whole blood did not show correlation with those concentrations in hair samples. Calcium concentration in serum was slightly lower in the sulphide-rich areas (median value 91.4 mg/l, n = 103) than in the areas with adjacent sulphur-poor bedrock (median value 93.6 mg/l, n = 82). The concentrations of Ni and Mn in hair correlated with those in drinking water. The highest Mn and Ni concentrations in the water samples from private wells were 1620 µg/l and 51 µg/l and the highest concentrations in human hair samples 36.44 mg/kg and 12.3 mg/kg, respectively. The challenge with elevated trace element concentrations in some well waters is well documented. In northern countries (Finland, Sweden, Norway and Canada), only 10% of the population depend on private well water, and 90% have access to monitored municipal water supplies. Compared with data available from sulphide mine sites globally, the nickel and manganese concentrations in human hair samples were high in our sulphide-rich study area at Sotkamo representing the trace element status of residents under natural conditions.

Assessing oxidative stress resulting from environmental exposure to metals (Oids) in a middle Eastern population

Concentrations of metals and metalloids derived mainly from anthropogenic activities have increased considerably in the environment. Metals might be associated with increase reactive oxygen species (ROS) damage, potentially related to several health outcomes. This study has recruited 200 adult participants, including 110 males and 90 females in Shiraz (Iran), to investigate the relationship between chronic exposure to metals and ROS damage by analyzing malondialdehyde (MDA) and 8-Oxo-2'-deoxyguanosine (8-OHdG) concentrations, and has evaluated the associations between chronic metal exposure and ROS damage using regression analysis. Our findings showed participants are chronically exposed to elevate As, Ni, Hg, and Pb levels. The mean urinary concentrations of 8-OHdG and MDA were 3.8 ± 2.35 and 214 ± 134 µg/g creatinine, respectively. This study shows that most heavy metals are correlated with urinary ROS biomarkers (R ranges 0.19 to 0.64). In addition, regression analysis accounting for other confounding factors such as sex, age, smoking status, and teeth filling with amalgam highlights that Al, Cu, Si and Sn are associated with 8-OHdG concentrations, while an association between Cr and MDA and 8-OHdG is suggested. Smoking cigarettes and water-pipe is considered a significant contributory factor for both ROS biomarkers (MDA and 8-OHdG).

Biomarkers of environmental manganese exposure

We conducted a critical review on biomarkers of environmental manganese (Mn) exposure to answer the following questions: 1) are there reliable biomarkers of internal Mn exposure (Mn in biological matrices) associated with external metrics of Mn exposure (Mn in environmental media)? and 2) are there accurate reference values (RVs) for Mn in biological matrices? Three bibliographic databases were searched for relevant references and identified references were screened by two independent reviewers. Of the 6342 unique references identified, 86 articles were retained for data abstraction. Our analysis of currently available evidence suggests that Mn levels in blood and urine are not useful biomarkers of Mn exposure in non-occupational settings. The strength of the association between Mn in environmental media and saliva was variable. Findings regarding the utility of hair Mn as a biomarker of environmental Mn exposure are inconsistent. Measurements of Mn in teeth are technically challenging and findings on Mn in tooth components are scarce. In non-occupationally exposed individuals, bone Mn measurements using in vivo neutron activation analysis (IVNAA) are associated with large uncertainties. Findings suggest that Mn in nails may reflect Mn in environmental media and discriminate between groups of individuals exposed to different environmental Mn levels, although more research is needed. Currently, there is no strong evidence for any biological matrix as a valid biomarker of Mn exposure in non-occupational settings. Because of methodological limitations in studies aimed at derivation of RVs for Mn in biological materials, accurate RVs are scarce.

Essential Trace Elements in Scalp Hair of Residents across the Caspian Oil and Gas Region of Kazakhstan

Most of the country’s oil and gas fields are situated in West Kazakhstan, mainly on the Caspian Sea coast, causing significant damage to the local environment and contributing to an imbalance in the trace element composition of the human body. The study is aimed to evaluate the relationship between the concentration of essential trace elements in scalp hair of the western Kazakhstan adult population and the remoteness of their residence from oil and gas fields. The concentration of essential trace elements (Co, Cu, Fe, I, Mn, Se, Zn) in the hair of 850 individuals aged 18−60 years was determined by inductively coupled plasma mass spectrometry. In residents of settlements located at a distance of >110 km from oil and gas fields, the concentration of Cu and I in hair was significantly higher than in those closer to 110 km (p < 0.001). The content of Cu and I were associated with the distance to oil and gas fields (0.072 (95% CI: 0.050; 0.094)) and (0.121 (95% CI: 0.058; 0.185)), respectively. We detected a significant imbalance in the distribution of some essential trace elements in residents’ scalp hair from the Caspian region of western Kazakhstan, living near oil and gas fields. The concentrations of Cu and I were significantly interrelated with the distance to oil and gas fields. The level of copper in the hair of both inhabitants of the area most remote from oil and gas facilities and the entire population of western Kazakhstan as a whole remains significantly low. The data obtained provide evidence of the possible impact of pollutants generated by the oil and gas facilities on a shortage of essential trace elements and associated subsequent health risks.

Smoking is associated with altered serum and hair essential metal and metalloid levels in women

The objective of the study was to evaluate the association between smoking and essential metal (Co, Cr, Cu, Fe, Mn, V, Zn) and metalloid (Se) levels in hair and serum of adult women using inductively coupled plasma-mass spectrometry (ICP-MS). In this cross-sectional study, a total of 344 women 20-70 years old including 199 smokers and 145 non-smoking women were enrolled. Serum Cu, Fe, and Zn levels in smoking women were found to be 6%, 8%, and 3% lower of levels in non-smokers, respectively. In contrast, circulating Mn, V, and especially Cr concentrations in smoking women exceeded the respective values in non-smoking women by 5%, 14%, and 54%. Hair Fe and Se levels in smoking women were 17% and 23% lower as compared to non-smoking controls, respectively. In multiple regression models, smoking severity was inversely associated with serum and hair Se concentrations, whereas the relationship to serum and hair Cr was positive. In addition, serum Zn and hair Fe levels were found to be inversely associated with the number of cigarettes per day. These findings hypothesize that health hazards of smoking may be at least in part be mediated by alteration in essential metal and metalloid metabolism.

Direct digestion of human scalp hair on the substrate used for total reflection X-ray fluorescence analysis

It is important to determine the elemental content of scalp hair to evaluate human health and environmental contamination. Here, a new sample preparation method for total reflection X-ray fluorescence analysis was developed by directly digesting the human hair on the sample holder. A human hair sample was subjected to thermal nitric acid treatment for sample digestion and homogenization. The Zn concentration was estimated to be ~ 1.89 × 10² μg/g. We can evaluate other elements of human hair by using this method.

Associations between hair levels of trace elements and the risk of preterm birth among pregnant Wwomen: A prospective nested case-control study in Beijing Birth Cohort (BBC), China

Trace elements have various physiochemical functions in humans and are associated with the occurrence of preterm birth (PB). However, their mixed effects on PB risk have rarely been studied. We aimed to investigate the associations between hair levels of trace elements and PB risk among pregnant women. A nested case-control study with a prospective cohort was conducted in Beijing City, China. We included 82 women who had a PB [total PB (tPB)] as cases [including 40 with a spontaneous PB (SPB)] and 415 who had a term delivery as controls. Hair levels of the concerned trace elements were measured including endocrine disrupting metal(loid)s [EDMs; lead, mercury (Hg), arsenic, and cadmium] and nutritional trace metal(loid)s [NTMs; zinc (Zn), iron (Fe), copper, and selenium]. Logistic regression analysis was performed to estimate the odds ratios (ORs) for PB. Bayesian kernel machine regression (BKMR) was used to assess the associations between mixed exposure to the trace elements and PB risk. Significantly lower maternal hair concentrations of Zn and Fe were observed in the SPB cases than in the controls, whereas no differences for the other trace elements. Single-element modeling results suggested second-quartile Hg maternal hair concentrations, third-quartile Zn concentrations, and fourth-quartile Fe concentrations were associated with a reduced risk of tPB with adjusted ORs of 0.43 [95% confidence interval (CI): 0.21-0.87], 0.38 (95% CI: 0.18-0.82), and 0.48 (95% CI: 0.24-0.98), respectively, compared to first-quartile values. Similar results were obtained for SPB. According to the BKMR models, hair NTMs were significantly, monotonously, and inversely associated with the risk of SPB, after controlling for covariates and levels of the four EDMs. Fe and Zn contributed the most strongly to the association. We concluded that maternal higher levels of NTMs, especially Fe and Zn, may reduce the risk of PB.

Hair Selenium Content in Middle-Aged and Elderly Chinese Population

Selenium (Se) is an essential nutrient element for human health, and middle-aged and elderly people (age ≥ 45 years old) are at higher risk of nutrient deficiency including Se due to their physiological characteristics. This study investigated the hair Se content of middle-aged and elderly people in China with the purpose of providing a reference for prescription of hair Se normal range in this population. In this study, the hair Se content of 2155 middle-aged and elderly people was detected with atomic fluorescence photometry. The participants were recruited from 15 provinces or municipalities spreading from south to north of China with a diverse Se content in soil. Additionally, the relationships between hair Se content with sex, age, and BMI were analyzed. The results found that the median and 95% quantile of hair Se content were 0.36 μg/g and 0.60 μg/g respectively, with a range of 0.08 to 20.04 μg/g in middle-aged and elderly Chinese. The hair Se content mostly concentrated at 0.23~0.48 μg/g in 81.11% of participants. The participants in Guangdong and Hunan provinces had the highest hair Se levels (medians were 0.51 and 0.50 μg/g, respectively), while Henan and Shaanxi provinces had the lowest levels (medians were 0.30 and 0.29 μg/g, respectively). In addition, the Se content of males was higher than that of females (p < 0.05), whereas there was no significant difference between different ages and BMI (p > 0.05). In conclusion, this study found that the hair Se content of middle-aged and elderly Chinese ranges from 0.08 to 20.04 μg/g, with median and 95% quantile of 0.36 μg/g and 0.60 μg/g, respectively. Our results provide a reference for the establishment of hair Se content in this population and suggest that the differences of region and sex should be considered when setting up the range.

Bone Mineral Density in Population Long-Term Exposed to Rare Earth Elements from a Mining Area of China

This study aims to investigate the effects of individuals' exposure to rare earth elements (REEs) on bone metabolism. Adopting the inductively coupled plasma mass spectrometry, we measured REEs and eight other elements (Ca, Fe, Cu, Na, K, Zn, Mg, and P) in the hair of 53 miners exposed to REEs from Baiyunebo and 57 healthy farmers as the control group. Furthermore, bone mineral density (BMD) in both groups was assessed by dual-energy X-ray absorptiometry. Analysis of variance showed that the concentrations of La, Ce, Pr, Nd, Tb, Ho, Tm, and Yb in male hair of exposed group were significantly higher compared with the control group, whereas the concentrations of Ca and Fe in exposed group were significantly lower; the results of female hair, except for Ce, Tb, Ho, Tm, and Yb, were consistent with male hair. Student's t test showed that the BMD of exposed males at lumbar vertebrae, femoral neck, greater trochanter, and intertrochanter was significantly lower than that of controls, and exposed females reported lower BMD values at lumbar vertebrae and femoral neck. Multiple linear regression analysis showed that concentrations of differential REEs were inversely related to BMD in males, and concentrations of Ca and Fe were positively related to BMD both in males and females. Our study suggests that long-term environmental and occupational exposure leads to REE accumulation, and a low level of iron and calcium due to the competitive binding of REEs, which together induce bone metabolism disorders, and further reduce BMD.

The Reference Values of Hair Content of Trace Elements in Dairy Cows of Holstein Breed

The objective of this study was to assess trace element content in hair of Holstein dairy cows bred in the Leningrad Region of Russia and to calculate the site-specific reference intervals. Hair content of arsenic, boron, cadmium, cobalt, chromium, copper, iron, mercury, iodine, lithium, manganese, lead, selenium, silicon, tin, strontium, vanadium, and zinc in 148 cows during first (n = 50), second (n = 48), and third (n = 50) lactation periods of life was determined using inductively coupled plasma mass spectrometry. Dietary intake of trace elements corresponded to the adequate values according to national and international recommendations. Comparative analysis did not reveal any significant differences in hair content of main essential elements on the animals depending on the number of lactation. At the same time, the first-lactation cows had significantly (P < 0.05) lower concentration of lead in hair as compared to the third-lactation cows and a higher level of mercury as compared to the second-lactation cows. The reference intervals and 90% confidence intervals for the lower and upper limits were calculated in agreement with the American Society for Veterinary Clinical Pathology Quality Assurance and Laboratory Standard Guidelines.

Trace element biomonitoring in hair and blood of occupationally unexposed population residing in polluted areas of East Kazakhstan and Pavlodar regions

INTRODUCTION

Eastern and North-Eastern regions of Kazakhstan are considered to be environmentally disadvantaged due to industrial pollution and activity of the former Semipalatinsk Nuclear Test Site. Ferrous metallurgy is represented by the world's largest ferroalloy plant located in Aksu. In addition to a ferroalloy plant, Aksu is the home for the largest thermal power plant in Kazakhstan.

OBJECTIVE

Biomonitoring of 31 hair and blood trace elements (Ag, Ba, Be, Bi, Cs, Co, Ce, Cr, Cu, Eu, Gd, Hf, In, La, Li, Mn, Mo, Nb, Nd, Pb, Sc, Sn, Tl, Th, U, V, W, Y, Yb, Zn, and Zr) in non-occupationally exposed population residing in polluted areas of East Kazakhstan and Pavlodar regions.

METHODS

Five case groups, residing in the vicinity to the former Semipalatinsk Nuclear Test Site (Akzhar, Borodulikha, and Karaul) or in proximity to industrial plants (Aksu and Ust-Kamenogorsk) have been assessed vs. controls from a rural settlement in Kurchum. In total, 204 hair and blood samples were analyzed by inductively coupled plasma mass spectrometry.

RESULTS

The observed blood concentrations of trace elements were in agreement with earlier studies on residents of industrially polluted areas. Elevated levels of blood Ba, Mn, Pb, V, and Zn were detected in residents of Aksu and Ust-Kamenogorsk. The elemental composition of head hair was characterized by greater stability between the study sites.

CONCLUSION

Residency near the former Semipalatinsk Test Site could be considered as safe, while the environmental status of industrial settlements appears to be rather adverse.

Links between Cognitive Status and Trace Element Levels in Hair for an Environmentally Exposed Population: A Case Study in the Surroundings of the Estarreja Industrial Area

In the present study, trace elements (TE) levels were evaluated in scalp hair along the continuum from healthy subjects (HS) to patients suffering from subjective memory concerns (SMC), and/or mild cognitive impairment (MCI), and those with already installed dementia (DEM) in order to: (i) assess the effects of environmental and lifestyle factors on TE concentrations and (ii) evaluate the analyzed elements as possible diagnostic biomarkers for the disease. The study involved 79 mainly permanent residents, >55 years old, from the city of Estarreja (northern Portugal), a former industrial area. The health status of the participants was assessed by means of a complete socio-demographic questionnaire and through cognitive screening tests, namely the Mini-Mental State Examination (MMSE). The test scores were categorized and used in the statistical analysis. Hair samples were collected and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) ICP-MS for selected TE. Dementia appears to be associated with higher age, the female gender, lower education level, and longer residence time in the study area. In addition, most of the participants diagnosed with dementia frequently consume home-grown foodstuffs, some irrigated with contaminated well water. The calculation of the TE enrichment factors of soil samples collected in kitchen gardens/small farms in the vicinity of the Estarreja Chemical Complex (ECC) reinforces the degree of Hg soil contamination in the area, due to anthropogenic sources that can be a source for the population Hg exposure route among others. Mercury levels in hair differed significantly between the four individual groups (HS, SMC, MCI, and DEM), increasing from healthy to dementia participants. Improved diagnostic results can be obtained using hair TE signatures coupled with MMSE scores. This strategy may prove useful for predictive diagnosis in population screening for cognitive impairment.

Assessment of Gender Effects and Reference Values of Mane Hair Trace Element Content in English Thoroughbred Horses (North Caucasus, Russia) Using ICP-DRC-MS

The objective of the present study was assessment of gender differences in hair trace element content in English Thoroughbred horses (North Caucasus, Russia) using ICP-DRC-MS and calculation of the reference values. Trace element content in mane hair of 190 stallions and 94 mares (3-7 years old) bred in North Caucasus (Russia) was assessed using inductively coupled plasma mass spectrometry. Mane hair Co, Cr, Mn, Li, Si, and Sr levels in mares exceeded those in stallions by 77%, 63%, 64%, 42%, 39%, and 64%, respectively. Hair Fe and Si content was nearly twofold higher in female horses as compared to the males. Only hair Zn content was 5% higher in stallions as compared to mares. In addition, mares were characterized by 63%, 65%, 29%, and 40% higher levels of As, Pb, Sn, and Ni levels in hair as compared to the respective values in stallions. In turn, hair Al and Hg were more than twofold higher in mares than in stallions. The reference intervals of mane hair content (μg/g) for Co (0.006-0.143), Cr (0.028-0.551), Cu (4.17-6.84), Fe (10.11-442.2), I (0.026-3.69), Mn (0.551-12.55), Se (0.108-0.714), Zn (97.43-167), Li (0.011-0.709), Ni (0.060-0.589), Si (0.665-29.12), V (0.006-0.584), Al (1.98-168.5), As (0.006-0.127), Cd (0.002-0.033), B (0.494-16.13), Pb (0.018-0.436), Sn (0.002-0.144), Sr (1.0-9.46), and Hg (0.0018-0.017) in the total cohort of horses were estimated using the American Society for Veterinary Clinical Pathology Quality Assurance and Laboratory Standard Guidelines. The reference intervals were also estimated for stallions and mares bred in North Caucasus (Russia) and may be used for interpretation of the results of hair trace element analysis in horses.

Geographic variation of environmental, food, and human hair selenium content in an industrial region of Russia

The objective of the present study was investigation of the selenium (Se) levels in environmental samples, main consumed food products, as well as human hair in the areas of the Orenburg region. Se levels in the environmental objects (water, soil, wheat), frequently consumed food products (wheat bread, ryebread, beef, pork, chicken, milk, cottage cheese), as well as human hair samples in the western (n = 210), central (n = 195), and eastern (n = 120) areas were assessed using inductively-coupled plasma mass-spectrometry and atomic absorption spectrometry (soil). The obtained data demonstrate that water (87% and 89%), soil (41% and 48%), and wheat (11% and 11%) Se levels Central and Eastern areas were significantly higher than those in the Western area. The level of Se in foods was found to be the highest in the Eastern (wheat bread and beef), Central and Eastern (ryebread and pork), or Central (milk and cottage cheese) areas of the Orenburg region. Hair Se content (0.298 (0.233-0.591) μg/g) as well as dietary Se intake (84.3 (73.7-95.8) μg/day) did not differ significantly between the studied areas. At the same time, regression analysis demonstrated that Se intake with wheat bread (β = 0.634; p = 0.042) was the strongest predictor of hair Se. The revealed associations between environmental and food Se content and Se status of the population underline the necessity of continuous monitoring of Se intake and exposure in order to prevent potential health effects associated with both deficiency and overload.

Hair Mineral and Trace Element Content in Children with Down's Syndrome

The objective of the present study was to assess the level of minerals and trace elements in 40 children with Down's syndrome and 40 controls aged 1-2 years old. Hair mineral and trace element analysis was performed using inductively coupled plasma mass spectrometry. The obtained data demonstrate that hair levels of Mg, P, I, Cr, Si, Zn, and Pb in Down's syndrome patients exceeded the respective control values by 36, 36, 93, 57, 45, 28, and 54%, whereas hair mercury was more than twofold lower in children with Down's syndrome. The observed difference in the levels of trace elements was age-dependent. In particular, in 1-year-olds, major differences were observed for essential elements (Cr, Si, Zn), whereas in 2-year-olds-for toxic elements (Hg, Pb). At the same time, hair P levels in Down's syndrome patients were 14 and 35% higher at the age of 1 and 2 years in comparison to the respective controls. Multiple regression analysis demonstrated that a model incorporating all elements, being characterized by a significant group difference, accounted for 42.5% of status variability. At the same time, only hair phosphorus was significantly interrelated with Down's syndrome status (β = 0.478; p < 0.001). Principal component analysis (PCA) used As, Ca, Cr, Fe, Hg, I, Mg, P, Pb, Se, Si, Sn, and Zn as predictors, with the resulting R² = 0.559. The OPLS-DA models also separated between Down's and health control groups. Therefore, 1-2-year-old patients with Down's syndrome are characterized by significant alterations of mineral and trace element status.

Statistical resolutions for large variabilities in hair mineral analysis

Measuring biomaterials is usually subject to error. Measurement errors are classified into either random errors or biases. Random errors can be well controlled using appropriate statistical methods. But, biases due to unknown, unobserved, or temporary causes, may lead to biased conclusions. This study describes a verification method to examine whether measurement errors are random or not and to determine efficient statistical methods.

A number of studies have dealt with associations between hair minerals and exposures such as health, dietary or environmental conditions. Most review papers, however, emphasize the necessity for validation of hair mineral measurements, since large variations can cause highly variable results. To address these issues, we answer the following questions:

How can we ascertain the reliability of measurements?

How can we assess and control the variability of measurements?

How do we efficiently determine associations between hair minerals and exposures?

How can we concisely present the reference values?

Since hair minerals all have distinctive natures, it would be unproductive to examine each mineral individually to find significant and consistent answers that apply to all minerals. To surmount this difficulty, we used one simple model for all minerals to explore quantitative answers. Hair mineral measurements of six-year-old children were analyzed based on the statistical model. The analysis verified that most of the measurements were reliable, and their inter-individual variations followed two-parameter distributions. These results allow for sophisticated study designs and efficient statistical methods to examine the effects of various kinds of exposures on hair minerals.

Evaluation of the status and the relationship between essential and toxic elements in the hair of occupationally exposed workers

Lead poisoning is a common disease in lead-acid battery manufacturing industries. Workers can be also exposed to various toxic elements present as contaminants or used as catalysts to enhance batteries' performances. In the present study, levels of essential and toxic elements and their relationship were assessed by analyzing scalp hair samples of 52 workers in a Pb battery manufacturing plant. The impact of some confounding factors on hair mineral contents was also investigated. For comparative purposes, nonoccupationally exposed subjects were selected as controls. All elements were determined by triple quadrupole ICP-MS. The results indicated significantly higher levels of Pb, Sb, As, and Cd in the hair of workers when compared to controls (p < 0.01). The Spearman correlation test revealed significant correlations between Pb/Cr, Pb/Mn, Pb/Ni, Pb/As, Pb/Se, Pb/Sb, Hg/As, Hg/Sn, Hg/Sb, Sb/Cr, Sb/As, Sb/Se, Sb/Cd, Sb/Sn, Sn/Cr, Sn/As, Sn/Cd, Cd/As, Se/Ni, As/Cr, Ni/Cr, Ni/Mn, and Mn/Cr in the hair of workers and Pb/Cr, Pb/Mn, Pb/Ni, Pb/Cd, Mn/Ni, Mn/Cd, Cd/Ni, As/Ni, Sn/Ni, Sb/Sn, and Hg/Sn in the hair of controls. Multiple linear regression analysis revealed linear dependence including Cr = f(Pb, Ni, Sb), Mn = f(Ni, Sb), Ni = f(Mn, Cr, -Cd) (Cd was negatively correlated, β < 0), As = f(Sn, Sb, Hg), Se = f(Ni); Sn = f(As), Sb = f(As, Mn, -Hg, Sn, Se, -Ni) (Hg and Ni were negatively correlated), Hg = f(As, -Sb, Sn) (Sb was negatively correlated), and Pb = f(Cr). The result of this study can be very useful to explain the interactions between elements or for comparison studies when establishing reference ranges or monitoring elements in workplaces.

Copper and zinc levels in soil, water, wheat, and hair of inhabitants of three areas of the Orenburg region, Russia

The objective of the present study was to assess the level of zinc and copper in soil, water, wheat and hair of inhabitants of the western, central, and eastern areas of the Orenburg region. A total of 525 water, soil, and wheat samples, as well as 420 hair samples were assessed using atomic absorption spectrometry (water, soil, wheat) and inductively-coupled plasma mass spectrometry (hair). The highest levels of Zn and Cu in water (4.9(4.2-5.1) and 1.0(0.9-1.1) mg/l), soil (23.8(20.7-27.0) and 2.6(1.9-3.1) mg/kg), and wheat (24.7(20.5-31.0) and 4.8(4.2-5.5) mg/kg) were observed in the eastern area (p < 0.001). Hair zinc levels in inhabitants of the western (184(165-198) µg/g) and eastern (224(211-253) µg/g) areas of the region exceeded the respective values from the central area by 32% and 61% (p < 0.001). In turn, hair Cu levels in the central (16.4(14.3-17.8) µg/g) and eastern (17.9(16.4-19.0) µg/g) areas exceeded the values from the western area by 10% and 20%, respectively. Correlation analysis demonstrated that hair Zn levels were positively correlated with water and soil content, whereas wheat Zn levels were associated with soil and water content. For copper significant direct correlation was observed only between soil and water Cu content. In multiple regression models, only water zinc level was significantly associated with hair Zn content, although the general model accounted for 55% of variability of hair Zn content. Higher zinc and copper exposure in the eastern area is presumably associated with higher activity of metal-processing industry.

Comparative Hair Trace Element Profile in the Population of Sakhalin and Taiwan Pacific Islands

The objective of the current study is to perform a comparative analysis of hair trace element content in 393 apparently healthy adults living in Taipei, Taiwan, Republic of China (94 women and 46 men) and Yuzhno-Sakhalinsk, Sakhalin, Russia (186 women and 67 men). The obtained data indicate that Yuzhno-Sakhalinsk inhabitants were characterized by significantly higher hair Co, Cr, Mn, and V levels, exceeding the respective Taipei values by a factor of 3, 2, 7, and 5, respectively (all p < 0.001). Hair Cu, Fe, and Si levels were also higher in examinees from Yuzhno-Sakhalinsk than those from Taipei by 10% (p = 0.001), 61% (p < 0.001), and 68% (p < 0.001), respectively. It is notable that the only essential element, being significantly higher (+ 30%; p < 0.001) in Taipei inhabitants, is selenium. Yuzhno-Sakhalinsk inhabitants were characterized by 60% higher levels of hair Sn, and nearly two- and threefold higher scalp hair content of Be and Cd in comparison to Taipei values, respectively (all p < 0.001). Oppositely, the examinees from Taipei had 14% (p = 0.040) and 47% (p = 0.001) higher levels of hair As and Hg as compared to Yuzhno-Sakhalinsk inhabitants. Further analysis demonstrated that men from both Yuzhno-Sakhalinsk and Taipei were characterized by significantly higher hair Mn, As, and Pb levels in comparison to women. The intensive development of heavy industry in Yuzhno-Sakhalinsk may result in increased metal emissions, whereas fish consumption may result in elevation of hair Hg, As, and Se levels in Taiwan inhabitants.

Hair Trace Element and Electrolyte Content in Women with Natural and In Vitro Fertilization-Induced Pregnancy

The objective of the present study was to perform comparative analysis of hair trace element content in women with natural and in vitro fertilization (IVF)-induced pregnancy. Hair trace element content in 33 women with IVF-induced pregnancy and 99 age- and body mass index-matched control pregnant women (natural pregnancy) was assessed using inductively coupled plasma mass spectrometry. The results demonstrated that IVF-pregnant women are characterized by significantly lower hair levels of Cu, Fe, Si, Zn, Ca, Mg, and Ba at p < 0.05 or lower. Comparison of the individual levels with the national reference values demonstrated higher incidence of Fe and Cu deficiency in IVF-pregnant women in comparison to that of the controls. IVF pregnancy was also associated with higher hair As levels (p < 0.05). Multiple regression analysis revealed a significant interrelation between IVF pregnancy and hair Cu, Fe, Si, and As content. Hair Cu levels were also influenced by vitamin/mineral supplementation and the number of pregnancies, whereas hair Zn content was dependent on prepregnancy anthropometric parameters. In turn, planning of pregnancy had a significant impact on Mg levels in scalp hair. Generally, the obtained data demonstrate an elevated risk of copper, iron, zinc, calcium, and magnesium deficiency and arsenic overload in women with IVF-induced pregnancy. The obtained data indicate the necessity of regular monitoring of micronutrient status in IVF-pregnant women in order to prevent potential deleterious effects of altered mineral homeostasis.

Hair biomonitoring and health status of a general population exposed to Nickel

An epidemiological cross-sectional study was conducted in a Greek population, being orally exposed to Ni via food consumption, in order to investigate possible health effects and to evaluate hair Ni concentration as a biomarker of exposure. The study population consisted of 139 men and 155 women, aged 25-69. Socio-demographics, lifestyle, dietary habits, occupational and medical history data were recorded through a personal interview. Hematological and biochemical examinations were conducted in blood specimens. Metals - Ni, Cr, Cd, Pb, Hg, Cu and Zn - were determined in hair samples. Women were characterized by higher Ni and Cu hair concentrations, while men by higher Cr and Hg. Factors affecting hair metal concentrations were identified to be dietary habits, consumption of local crops, occupation and smoking. Hair element content in the study population was comparable to the "reference ranges" reported in Europe, except for Ni, found higher in a fraction of our population. Men in the upper quartile of hair Ni distribution are at higher risk for abnormal high cholesterol, LDL, albumin and calcium, with odds ratios (OR) varying between 3.5 and 6.2. Accordingly, high hair Ni content in women is associated with abnormal glucose (OR=3.9), triglycerides (OR=3.1) and low abnormal sodium (OR=4.3). The study provides evidence of the suitability of hair analysis in assessing environmental exposure to Ni and supports the use of hair Ni content as a valuable and relatively inexpensive tool of biomonitoring, to identify people at risk for certain biochemical alterations.

The level of toxic and essential trace elements in hair of petrochemical workers involved in different technological processes

The objective of the investigation is comparative analysis of hair trace element content in workers of different departments of petrochemical plant. A total of 75 men working in office (engineers), and departments 1 (D₁), 3 (D₃), and 4 (D₄) of the petrochemical plant, as well as occupationally non-exposed persons, were examined. Hair trace element levels were analyzed using inductively coupled plasma mass spectrometry. The office workers were characterized by the highest hair As, Hg, Sn, I, and Si content as compared to the workers of other departments, whereas the level of those elements did not differ significantly from the control values. It is notable that hair Be levels in all employees of petrochemical plant were significantly lower, whereas Se content was significantly higher than that in unexposed controls. Hair toxic trace element content in workers directly involved in industrial processes did not differ significantly or was lower than that in the control group. At the same time, the highest levels of essential trace elements (Cr, Fe, and I) were observed in employees working in primary oil refining (D₁). Hair levels of Co, I, and Li were maximal in persons of sulfur and bitumen-producing division (D₄). The lowest levels of both essential and toxic trace elements in hair were detected in employees involved in production of liquefied gas, kerosene, and diesel fuel (D₃). The obtained data demonstrate that involvement in different technological processes in petrochemical complex differentially affect hair trace element content in workers.

High concentrations of lead and barium in hair of the rural population caused by water pollution in the Thar Jath oilfields in South Sudan

In the oil fields of Thar Jath, South Sudan, increasing salinity of drinking water was observed together with human incompatibilities and rise in livestock mortalities. Hair analysis was used to characterize the toxic exposure of the population. Hair samples of volunteers from four communities with different distance from the center of the oil field (Koch 23km, n=24; Leer 50km, n=26; Nyal 110km, n=21; and Rumbek 220km, n=25) were analyzed for altogether 39 elements by inductively coupled plasma-mass spectrometry. Very high concentrations and a toxic health endangerment were assessed for lead and barium. The concentration of lead increased steadily with decreasing distance from the oil field from Rumbek (mean 2.8μg/g) to Koch (mean 18.7μg/g) and was there in the same range as in highly contaminated mining regions in Kosovo, China or Bolivia. The weighting materials in drilling muds barite (BaSO₄) and galena (PbS) were considered to be the sources of drinking water pollution and high hair values. The high concentrations of lead and barium in hair demonstrate clearly the health risk caused by harmful deposition of toxic industrial waste but cannot be used for diagnosis of a chronic intoxication of the individuals.