Hair Zn Research Articles

Effects of sex on the levels of metals and metalloids in the hair of a group of healthy Spanish adolescents (13 to 16years old).

Human biomonitoring can be a reliable tool to protect the health of the citizens of major urban environments. Human hair may be an invaluable specimen to determine chronic exposure to any environmental contaminant in an individual, especially in the young population. However, different factors including a lack of studies that have established reference values for metals and metalloids (trace elements) in human scalp hair make the use of this matrix controversial. A monitoring study was performed to establish possible normal or tentative reference values of Al, As, Be, Cd, Cr, Cu, Hg, Mn, Pb, Sn, Ti, Tl and Zn in adolescents' (aged 13-16) hair who have lived since birth in Alcalá de Henares, Madrid region (Spain). Strict inclusion criteria were followed to study the effect of sex on the hair metal content, and the levels of the above contaminants were also studied in park topsoils from Alcalá de Henares. Scalp hair samples were collected from 96 healthy adolescents (28 boys and 68 girls), and reference values were calculated following the recommendations of the International Union of Pure and Applied Chemistry. The levels of Cd, Cu, Pb, Sn and Zn in hair of adolescents from Alcalá de Henares show a sex dependency, being significantly higher in female participants. Sex should be a factor taken into account when developing future reference values and hair metal content. Soil metal contamination was not correlated with the levels found in hair. To conclude, the values of metals and metalloids here analysed and discussed could be considered as tentative reference values for Spanish adolescents aged 13-16years living in the Madrid region, and may be used to identify the level of exposure of adolescents in this Spanish region to the various metals and metalloids.

Distribution and health risk assessment to heavy metals near smelting and mining areas of Hezhang, China.

Mining and smelting areas in Hezhang have generated a large amount of heavy metals into the environment. For that cause, an evaluative study on human exposure to heavy metals including Co, Ni, Cu, Zn, Cr, As, Cd, Pb, Sb, Bi, Be, and Hg in hair and urine was conducted for their concentrations and correlations. Daily exposure and non-carcinogenic and carcinogenic risk were estimated. Sixty-eight scalp hair and 66 urine samples were taken from participants of different ages (6-17, 18-40, 41-60, and ≥65years) living in the vicinity of an agricultural soil near mine and smelting areas. The results compared to the earlier studies showed an elevated concentration of Pb, Be, Bi, Co, Cr, Ni, Sb, and Zn in hair and urine. These heavy metals were more elevated in mining than in smelting. Considering gender differences, females were likely to be more affected than male. By investigating age differences in this area, high heavy metal concentrations in male's hair and urine existed in age of 18-40 and ≥66, respectively. However, females did not present homogeneous age distribution. Hair and urine showed a different distribution of heavy metals in different age and gender. In some cases, significant correlation was found between heavy metals in hair and urine (P>0.05 and P>0.01) in mining area. The estimated average daily intake of heavy metals in vegetables showed a great contribution compared to the soil and water. Non-carcinogenic and carcinogenic risk values of total pathways in mining and smelting areas were higher than 1 and exceeded the acceptable levels. Thus, the obtained data might be useful for further studies. They can serve as a basis of comparison and assessing the effect of simultaneous exposure from heavy metals in mining and smelting areas, and potential health risks from exposure to heavy metals in vegetables need more consideration.

Essential trace elements in amyotrophic lateral sclerosis (ALS): Results in a population of a risk area of Italy.

Sardinian (Italy) island population has a uniquely high incidence of amyotrophic lateral sclerosis (ALS). Essential trace element levels in blood, hair, and urine of ALS Sardinian patients were investigated in search of valid biomarkers to recognize and predict ALS. Six elements (Ca, Cu, Fe, Mg, Se, and Zn) were measured in 34 patients compared to 30 age- and sex-matched healthy controls by a validated method. Levels of Ca and Cu in blood and of Se and Zn in hair were significantly higher in ALS than in controls, while urinary excretion of Mg and Se was significantly decreased. The selected cut-off concentrations for these biomarkers may distinguish patients with or without ALS with sufficient sensitivity and specificity. Many positive (as Se-Cu and Se-Zn) and negative associations (as Ca-Mg and Ca-Zn) between elements suggested that multiple metals involved in multiple mechanisms have a role in the ALS degeneration.

Serum and Hair Zinc Levels in Patients with Endemic Osteochondropathy in China: A Meta-analysis.

A large number of studies have shown growing interest in the zinc (Zn) levels of serum and hair samples collected from patients with Kashin-Beck disease (KBD), an endemic chronic osteochondral disease. However, inconsistent conclusions regarding the serum and hair Zn levels have been made. The aim of this study is to assess and to explore the change in serum and hair Zn levels among KBD patients. Multiple databases, including PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang database and Technology of Chongqing (VIP), were carefully searched for available studies up to January 13, 2017 in this integrated analysis. Standard mean difference (SMD) with a 95% confidence interval (95% CI) was calculated using STATA 11.0. A total of 18 studies, involving 978 KBD cases and 1116 healthy controls, were collected in this analysis. Pooled analysis found the KBD patients had a higher hair Zn level and a lower serum Zn level than the healthy controls (hair Zn (μg/g), SMD=0.030, 95% CI=-0.315, 0.376; serum Zn (mg/L), SMD=-0.069, 95%CI=-0.924, 0.785). Meta-regression method and sensitivity analysis were utilized to analyze the heterogeneity of data. Positive correlations were separately identified between hair Zn level in KBD patients (r=0.4639, P=0.032) and controls (r=0.4743, P=0.012) and the survey year. No evidence of publication bias was observed. The available results suggest that increased hair Zn level and decreased serum Zn level are commonly found in KBD patients; however, the role of Zn in the etiology and pathogenesis of KBD could not yet be confirmed.

Nanosized ion-imprinted polymer doped with Alizarin Red S for separation and quantification of zinc(II) prior to its determination by electrothermal AAS

The authors describe a nanostructured zinc(II)-imprinted polymer carrying Alizarin Red S as a ligand for separation and preconcentration of ultra-trace levels zinc(II). The adsorbent was obtained by bulk polymerization of a mixture of Zn(II) nitrate, Alizarin Red S, methacrylic acid, ethylene glycol dimethacrylate and 2,2′-azobis(isobutyronitrile). Zn(II) was then removed by treatment with ethanol and 2.0 mM HNO3. The imprinted nanoadsorbent was characterized by FT-IR spectroscopy and scanning electron microscopy. Following sorption of Zn(II) from the sample, it is desorbed with 3.0 M HCl and then quantified via electrothermal atomic absorption spectrometry. Under optimized conditions, the calibration plot is linear in the 3.0 to 250 ng L−1 Zn(II) concentration range, the detection limit is 0.7 ng L−1, and the relative standard deviation is ±4.0% (for n = 8). The method was successfully applied to the determination of Zn(II) in (spiked) water samples and hair, and in a certified reference material (MA-1b; reference gold ore) which corroborates the utility of the method.

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 Zinc and Severity of Symptoms Are Increased in Children with Attention Deficit and Hyperactivity Disorder: a Hair Multi-Element Profile Study

Determination of bioelement levels in hair is an emerging non-invasive approach for screening bioelement deposition. However, the role of essential bioelement levels in hair and attention deficit/hyperactivity disorder (ADHD) risk or severity is largely unknown. In this study, we have compared multi-element hair profiles between healthy and ADHD Thai children. In addition, the correlations between bioelements and ADHD symptoms according to Diagnostic and Statistical Manual of Mental Disorders, 5th edition, diagnostic criteria were identified. A case-control study was conducted in 111 Thai children (45 newly diagnosed ADHD and 66 matched healthy), aged 3-7years, living in Bangkok and suburban areas. Levels of 39 bioelements in hair were measured by ICP-MS. Among the analyzed bioelements, Cu/Zn and P/Zn ratios in ADHD children were significantly lower than those in healthy children. Indeed, increased hair Zn level was correlated with more symptoms of inattention, hyperactivity, and total ADHD symptoms. Higher Zn content was also associated with being female and older age. Furthermore, Zn in hair was positively correlated with levels of Ca, Mg, and P; however, it showed a negative correlation with Al, As, Fe, and Mo. These findings warrant further confirmation in a large-scale study. Thai Clinical Trials Registry (TCTR) study ID: 20151113001.

Copper and zinc concentrations in human hair and popular foodstuffs in China

ABSTRACTConcentrations of copper (Cu) and zinc (Zn) were determined in 383 human hair samples and in 445 food samples purchased in 11 Chinese cities. The concentrations of Cu were 7.91, 5.39, 2.27 and 2.20 mg kg−1 and those of Zn were 47.2, 24.8, 52.8 and 30.2 mg kg−1 in vegetables, cereals, meat and fish, respectively. The overall mean concentrations of hair Cu and Zn were 8.97 and 128 mg kg−1, respectively. Hair Cu and Zn concentrations were higher in females than in males, especially in the 13–19 and 20–50 year age groups. Hair Cu concentration increased with increasing age and these changes occurred mainly in males. In contrast, 51–65 years old females had the lowest hair Zn concentrations. Residents of rural areas had similar hair Cu or Zn concentrations to people in urban areas. There were no significant correlations between hair concentration and food intake in terms of Cu and Zn among the cities. The results indicate that hair Cu and Zn concentrations and their changes with biological and environmental factors cannot be explained satisfactorily by the estimated food intakes in the cities sampled.

Variations of Hair Trace Element Contents in Diabetic Females

Background: Alterations of trace elements, could induce metabolic disorders as they forthwith participating in the metabolic pathways and play different roles modulating it as well as many enzymes require trace elements for their activation and functions. Of these elements, selenium (Se), zinc (Zn), copper (Cu) and manganese (Mn) have been recognized as essentials for metabolism. Hyperglycemia and diabetes mellitus are important causes of mortality and morbidity worldwide, and their global prevalence are growing from 2.8% in 2000 projecting to be 4.4% in 2030. Diabetes is prevalent in Saudi Arabia with high incidence in urbanized areas and its prevalence is estimated to expand 3 times by 2030. Patients and Methods: In total, 75 diabetic women and 80 aberrantly healthy women were recruited. Clinical and familial history was recorded. Hair Se, Zn, Cu and Mn levels were analyzed as well as fasting blood sugar (FBS), glycated hemoglobin (HbA1c). Results: Our findings revealed a marked decrease of Zn and Mn levels in diabetic women hair compared to control group (p < 0.05, p <0.005 respectively). Otherwise, Se and Cu levels were significantly elevated in hair of diabetic patients (p < 0.005, p <0.05 respectively). Conclusion: Diabetes may disrupt the trace elements balance as well as their alterations can affect glucose metabolism and insulin action. Chronic hyperglycemia can cause disturbance of some trace elements which, in turn, can modulate glucose homeostasis. The metabolic dysregulation occurring in hyperglycemia may influence trace element status by increasing excretion, diminishing availability or redistribution of trace elements among different body pools. Hair trace elements can be useful long-term markers for metabolic disturbance; however, larger prospective studies are required to validate their role in diagnosis and follow up applications.

Alterations of Hair and Nail Content of Selected Trace Elements in Nonoccupationally Exposed Patients with Chronic Depression from Different Geographical Regions.

The aim of this study was to determine if altered levels of selected trace elements manifest themselves during chronic depression. To identify elements strongly associated with chronic depression, relationships between the elemental contents of hair and nails and the interelement correlations were checked. Inductively coupled plasma mass spectrometry and ion chromatography were used to evaluate the contents of Zn, Cu, Co, Pb, Mn, and Fe in hair and nail samples from a total of 415 subjects (295 patients and 120 healthy volunteers). The study included logistic regression models to predict the probability of chronic depression. To investigate possible intercorrelations among the studied elements, the scaled principal component analysis was used. The research has revealed differences in TE levels in the group of depressed men and women in comparison to the healthy subjects. Statistically significant differences in both hair and nails contents of several elements were observed. Our study also provides strong evidence that the intermediary metabolism of certain elements is age- and gender-dependent. Zn, Mn, Pb, and Fe contents in hair/nails seem to be strongly associated with chronic depression. We found no statistically significant residence-related differences in the contents of studied elements in nonoccupationally exposed patients and healthy subjects.

Characteristics of Heavy Metal Contents in Human Hairs of Mine Contaminated Areas in Nandan County

Nandan county is usually called "land of nonferrous metals". In order to discuss the impact of mining activities on the health of inhabitants in Nandan county, 200 human hair samples were collected from 4 villages (Liuzhai is a uncontaminated contrast areas, Chehe, Dachang and Zhanglao are contaminated areas) of Nandan and analyzed for contents of As, Sb, Cd, Pb, Cu and Zn. The results showed that the average contents of As, Sb, Cd and Pb were 1.260, 2.161, 2.466 and 20.92 μg·g-1 in the human hair samples from contaminated areas. They were 4.0, 20, 2.1 and 1.9 times higher than those in the contrast areas, and the Sb contents in human hair of Chehe and Dachang were higher than the recommended normal range. The contents of human hair Zn showed a negative correlation with the age of people (P<0.05), and contents of human hair Cd and Pb showed a weak negative correlation with the age of people in contaminated areas (P<0.1). The independent-samples t-test showed that Cd contents in male hair were apparently higher than those in female hair (P<0.05), however, Cu and Zn contents in female hair were apparently higher than those in male hair (P<0.05), in the contaminated areas. There were positive correlations between As and Sb, Cd and Pb, as well as As and Cd (P<0.01), while other elements showed no significant correlation between pairs. It was therefore concluded that contamination from the mining activities has exposed a serious threat to human health in the mine contaminated areas in Nandan county.

Evaluation of some factors influencing on variability in bioaccumulation of heavy metals in rodents species: Rombomys opimus and Rattus norvegicus from central Iran

In the present study, the effects of sex, age, nutritional status, and habitat use on hair and internal tissue concentrations of some trace metals (Zn, Cu, Ni, Pb and Cd) in brown rat (Rattus norvegicus) and great gerbil (Rhombomys opimus) from Aran-O-Bidgol City in Central Iran were investigated. Five sampling stations in different land-uses were selected for the study. Concentrations of Cd and Pb in liver and whole body concentration as well as concentration of Zn in hair of male rats were significantly higher than females. A significantly higher concentration was only observed for Pb in kidney of male gerbils than females. In numerous cases, age had significantly negative correlations with concentration of metals in different tissues of both species, and was only significantly (and positively) correlated with the concentration of Cd in kidney and Zn in liver of gerbils. This finding may indicate that the early neonatal age is a critical period for metals accumulation. The relationships between nutritional status and metal concentrations for both species were negative, which can be ascribed to the weight-specific metabolic rate that cause to a relatively low uptake of metals per unit of body weight. No significant differences were observed for soil metals concentrations in different sites. So, this suggests that the influence of life history, microhabitat use and foraging behavior did significantly influence on inter and intra specific variation of metals concentration in small mammals. Our observations suggest that hair cannot be used alone for monitoring exposure of metals.

Zinc supplementation modifies trace element status in exercised rats

PurposeInvestigation of the effect of exercise and zinc (Zn) supplementation on trace element status in rats. Methods24 male Wistar were divided into four groups: control, exercised, Zn-supplemented (15mg/kg weight Zn asparaginate), exercised Zn-supplemented. Zn was supplemented as Zn asparaginate. Serum lactate and creatinine levels, and creatine kinase activity were assessed. Tissue trace elements were estimated using inductively coupled plasma mass spectrometry. ResultsExercise significantly increased lactate, and creatinine levels. Exercise significantly decreased muscle, kidney, and hair Zn; liver, muscle and serum Co; serum Fe; myocardial and hair Cu; liver, heart, skeletal muscle and kidney Se levels. Oppositely, exercise results in elevation of liver Zn; heart and skeletal muscle, kidney and hair Fe; kidney Cu; liver and hair Mn; serum and hair Se content. Zn supplementation reduced exercise-induced increase in lactate and creatinine levels, and elevated liver, kidney, heart, and hair Zn content in exercised rats. Supplementation with Zn reversed exercise-induced decrease in Co levels and increased Fe and Se stores in animals with high physical activity. ConclusionsBeneficial effect of zinc supplementation in exercised organism may be associated not only with modulation of zinc status but regulation of other essential trace elements status and their biological effects.

Evaluating the effect of age and area of residence in the metal and metalloid contents in human hair and urban topsoils.

Monitoring the levels of trace elements in hair can allow estimating the effects of the geographical location and also can provide a notion of the metal body burden. However, the use of human hair is controversial due to the different confounding factors that could affect the presence of trace elements in hair. As a result, a comprehensive monitoring study was performed in Alcalá de Henares, one of the major cities in the Madrid region, Spain. Trace elements have been monitored in urban topsoils and in human hair of two well-defined and healthy groups of population: children (6-9years) and adolescents (13-16years). The city was divided into four areas or zones with different characteristics to assess the possible effect of area of residence and age in the presence of Al, As, Be, Cd, Cr, Cu, Hg, Mn, Pb, Sn, Ti, Tl and Zn in soils and hair. There is no current hypothesis that explains the possible effect of the area of monitoring in the distribution of Be, Cr, Ni, Sn and Ti found in these urban soils, maybe because urban soils receive high disturbance, and there are many factors involved. The presence of most of the trace elements monitored was significantly higher in the hair of the children population, except for Sn and Zn. This could be attributed mainly to dietary habits. Other factors influencing metal content in hair such as environmental factors would have had a minimal effect in the population groups here studied. Finally, none of the levels of trace elements studied in hair were significantly correlated with levels measured in the topsoils of public parks in Alcalá de Henares, with the exception of Pb in adolescent participants.

Trace Element Alterations in the Hair of Diabetic and Obese Women.

Alterations in the trace element content can induce metabolic disorders as these elements are involved in the regulation of metabolism. Obesity increases the likelihood of various diseases, particularly cardiovascular disease and type 2 diabetes, and is more prevalent in Saudi Arabia, especially in women. This study explored the potential of alterations in hair trace elements as long-term markers in diabetic and/or obese Saudi females. In total, 65 diabetic obese women, 47 non-diabetic obese women, and 70 normal-weight women were recruited. Clinical and familial history and anthropometric variables were recorded. Hair Se, Zn, Cu, Mn, and Fe levels were analyzed. Fasting blood sugar (FBS), glycated hemoglobin (HbA1c), and lipid profile were analyzed. Our findings revealed a marked decrease of hair Zn, Mn, and Fe and elevated Se and Cu levels in obese women. In addition, Zn and Fe levels were decreased in diabetic women. Thus, the metabolic distress occurring in obesity and hyperglycemia may affect trace element status by increasing the excretion and decreasing the bioavailability of trace elements or redistributing them among various pools. Hair trace elements can serve as important long-term markers for metabolic disorders; however, larger prospective studies are warranted to validate their diagnostic and follow-up utilities.

Trace elements in scalp hair from potentially exposed individuals in the vicinity of the Bayan Obo mine in Baotou, China.

Mining activities including mineral excavation and ore transportation produce and release large amounts of pollutants to the surrounding environment, raising concerns regarding the effects of environmental exposure to pollutants on human health. The concentration of elements in hair can be used as a biomarker of exposure to chemical elements. In the present study, hair samples from 89 relatively healthy volunteers aged 11-77 years old (57 living near Bayan Obo giant REE-Nb-Fe ore deposit and 32 in non-mining areas) from Baotou (Inner Mongolia, China) were analyzed to determine the contents of 25 chemical elements (Ag, Al, As, Ba, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mg, Mn, Mo, Ni, Pb, Rb, Se, Tl, U, V and Zn) with the aim of gaining insights about the potential exposure to chemical elements of the population living within the Bayan Obo opencast mining area. The effects of gender and living area on element concentrations in hair were also investigated. The results showed that the mean concentrations of the target elements (Ag, Al, Ba, Cd, Co, Li, Mn, Ni, Pb, Tl, V, Cs, Ga, Rb, U, Bi, Mo, As, Ca, Fe, Mg and Zn) in human hair from the mining area (MA) were primarily higher than that in non-mining areas (NMA). The area of residence had an influence on the presence of select trace elements (As, Cd, Mg, Pb, Tl, U and Zn) in human hair. In addition, the hair samples from MA showed statistically significant differences between males and females for a larger number of elements than those in NMA in which only Ag, Bi and Se were significantly different. This result implies a potential influence of mining activities on residents living in the vicinity. These findings confirm the need for competent authorities to act as early as possible and to implement strategies aimed to protect exposed populations and the entire ecosystem.

Trace elements in scalp hair samples from patients with relapsing-remitting multiple sclerosis.

BackgroundEpidemiological studies have suggested a possible role of trace elements (TE) in the etiology of several neurological diseases including Multiple Sclerosis (MS). Hair analysis provides an easy tool to quantify TE in human subjects, including patients with neurodegenerative diseases.ObjectiveTo compare TE levels in scalp hair from patients with MS and healthy controls from the same geographic area (Sicily).MethodsICP-MS was used to determine the concentrations of 21 elements (Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) in scalp hair of 48 patients with relapsing–remitting Multiple Sclerosis compared with 51 healthy controls.ResultsMS patients showed a significantly lower hair concentration of aluminum and rubidium (median values: Al = 3.76 μg/g vs. 4.49 μg/g and Rb = 0.007 μg/g vs. 0.01 μg/g;) and higher hair concentration of U (median values U: 0.014 μg/g vs. 0.007 μg/g) compared to healthy controls. The percentages of MS patients showing hair elemental concentrations greater than the 95th percentile of controls were 20% for Ni, 19% for Ba and U, and 15% for Ag, Mo and Se. Conversely, the percentages of MS patients showing hair elemental concentrations lower than the 5th percentile of healthy controls were 27% for Al, 25% for Rb, 22% for Ag, 19% for Fe, and 16% for Pb. No significant association was found between levels of each TE and age, disease duration or Expanded Disability Status Scale (EDSS) score. After stratification by gender, healthy subjects did not show any significant difference in trace element levels, while MS patients showed significant differences (p<0.01) for the concentrations of Ag, Cr, Fe, Ni and Sr. No significant differences were also found, at p<0.01, in relation to the use of cigarettes, consume of water, vegetables and place of living.ConclusionThe different distributions of TE in hair of MS patients compared to controls provides an additional indirect evidence of metabolic imbalance of chemical elements in the pathogenesis of this disease. The increase in U and decrease in Al and Rb levels in MS compared to controls require further assessments as well as the observed different distributions of other elements.

Human exposure to toxic metals via contaminated dust: Bio-accumulation trends and their potential risk estimation

We assessed the levels of potentially toxic trace metals, Zinc (Zn), Lead (Pb), Manganese (Mn), Copper (Cu), Nickel (Ni), Chromium (Cr), Cobalt (Co), and Cadmium (Cd), in dust, hair, nail and serum, sampled in rural, urban and industrial areas of Punjab, Pakistan. Trace metals occurrence in all samples, in descending order, was: Zn, Pb, Mn, Cu, Cr, Ni, Co, Cd. The samples from the urban areas showed significantly higher concentration of toxic trace metals (Zn, Ni, Cr, Co, Mn, and Cd) than those from industrial (which conversely had higher levels of Pb and Cu), and than samples from rural areas. Bioaccumulation patterns showed that dust exposure is one of the major routes into human body for Cd, Pb, Co, Mn and Cr, while the burden of Zn, Cu, and Ni can be more linked to dietary sources. The concentrations of trace metals in the samples from Punjab were comparable and/or higher than those reported worldwide. In many cases, the levels of Zn, Cr, Pb, Ni and Cd in hair and nail were beyond the ATSDR threshold guideline values that may cause some serious health effects. Hazard Index (HI) calculated for trace metal concentrations in the human population of Punjab points particularly to health risks from Cd (for children in urban and industrial areas) and from Pb (for all sub-groups).

Deficient zinc levels and myocardial infarction : association between deficient zinc levels and myocardial infarction: a meta-analysis.

The purpose of this study is to clarify the association between Zn levels and myocardial infarction (MI) using a meta-analysis approach. We searched articles in the PubMed, OVID, and ScienceDirect published as of November 2014. Thirteen eligible articles with 2886 subjects from 41 case-control studies were identified. Overall, pooled analysis indicated that subjects with MI had lower Zn levels than healthy controls (standardized mean difference (SMD) = -1.848, 95 % confidence interval (CI) = [-2.365, -1.331]). Further subgroup analysis found that subjects with MI had lower Zn levels than healthy controls in serum (SMD = -1.764, 95 % CI = [-2.417, -1.112]) and hair (SMD = -3.326, 95 % CI = [-4.616, -2.036]), but not in toenail (SMD = -0.396, 95 % CI = [-1.114, 0.322]). The subgroup analysis stratified by type of Zn measurement found a similar pattern in inductively coupled plasma-atomic absorption spectrometry (ICP-AAS) (SMD = -2.442, 95 % CI = [-3.092, -1.753]), but not in neutron activation analysis (NAA) (SMD = -0.449, 95 % CI = [-1.127, 0.230]). Lower Zn levels in MI patients were found both in male (SMD = -3.350, 95 % CI = [-4.531, -2.169]) and female (SMD = -2.681, 95 % CI = [-3.440, -1.922]). And the difference of Zn levels according to MI in Asia (SMD = -2.555, 95 % CI = [-3.267, -1.844]) was greater to that among the population in Europe (SMD = -0.745, 95 % CI = [-1.386, -0.104]), but no difference was found in Oceania (SMD = -0.255, 95 % CI = [-0.600, 0.089]). In conclusion, this meta-analysis indicates that there is a significant association between Zn deficiency and MI. We suggest that a community-based, long-term observation in a cohort design should be performed to obtain better understanding of causal relationships between Zn and MI, through measuring hair Zn at baseline to investigate whether the highest zinc category versus lowest was associated with MI risk.

Trace elements in scalp hair and fingernails as biomarkers in clinical studies

Context: There are accumulating evidences that the metabolism of several trace elements might have specific roles in clinical disorders and the pathogenesis of many diseases, such as diabetes mellitus (DM) and hypertension (HT). Objectives: To validate the analytical procedure and compare the levels of Cd, Cr, Cu, Pb, and Zn in scalp hair (SH) and fingernails (FN) of patients. Furthermore, to prove that human tissues such as hair and nails are useful in the studies pertaining to chronic body exposure and good biomarkers in clinical studies. Setting and Design: Inductively coupled plasma optical emission spectroscopy operating conditions were carefully selected and well-optimised in order to maximise the sensitivity for the desired elements and to obtain the best precision and accuracy. Factors affecting analytical and biological variability of the concentrations under study were discussed and carefully optimised. Materials and Methods: Totally, 160 samples of SH and 130 FN were collected from occupants of urban population from different districts adjacent to Taif city, Kingdom of Saudi Arabia. Different analytical procedures were investigated, and the most reliable one was developed and validated. Method Validity: The validity of the method was checked by standard addition method. The recoveries were in the range of 96.2-105.7%. Results: Cd, Cr, Cu, and Pb levels in SH were significantly higher in DM and HT compared to control groups, whereas, Zn was significantly lower. Cd and Pb levels in FN were significantly higher in DM and HT, whereas, Cr and Zn were lower, and Cu was in the same levels as compared to the control group. Conclusion: These findings may be consistent with those obtained in other studies, confirming that the deficiency and efficiency of trace elements play a role in clinical disorders and the pathogenesis of many diseases.