Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

Comparative studies of hair shaft components between healthy and diseased donors

Globally, the rapid aging of the population is predicted to become even more severe in the second half of the 21st century. Thus, it is expected to establish a growing expectation for innovative, non-invasive health indicators and diagnostic methods to support disease prevention, care, and health promotion efforts. In this study, we aimed to establish a new health index and disease diagnosis method by analyzing the minerals and free amino acid components contained in hair shaft. We first evaluated the range of these components in healthy humans and then conducted a comparative analysis of these components in subjects with diabetes, hypertension, androgenetic alopecia, major depressive disorder, Alzheimer's disease, and stroke. In the statistical analysis, we first used a student's t test to compare the hair components of healthy people and those of patients with various diseases. However, many minerals and free amino acids showed significant differences in all diseases, because the sample size of the healthy group was very large compared to the sample size of the disease group. Therefore, we attempted a comparative analysis based on effect size, which is not affected by differences in sample size. As a result, we were able to narrow down the minerals and free amino acids for all diseases compared to t test analysis. For diabetes, the t test narrowed down the minerals to 15, whereas the effect size measurement narrowed it down to 3 (Cr, Mn, and Hg). For free amino acids, the t test narrowed it down to 15 minerals. By measuring the effect size, we were able to narrow it down to 7 (Gly, His, Lys, Pro, Ser, Thr, and Val). It is also possible to narrow down the minerals and free amino acids in other diseases, and to identify potential health indicators and disease-related components by using effect size.

Reference values for metal(loid)s concentrations in the urine samples of healthy Iranian adults: Results from the first nationally representative human biomonitoring study

BACKGROUND

This study measured the concentrations of arsenic (As), aluminum (Al), cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), and lead (Pb) in the urine samples of the Iranian adult population.

METHODS

This nationally representative study was conducted on 490 participants in six provinces of Iran who were selected based on the clustering method. Participants included healthy Iranian adults aged above 25 years without a history of illness and non-smokers. Fasting urine sampling, body composition, and demographic measurements were performed for each participant. Urine samples were analyzed by acid digesting method using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The analysis included descriptive statistics and multiple linear regression using Python programming language.

RESULTS

The geometrical mean (with corresponding reference values, µg/l) concentrations of metal(loid)s in urine for women, men, and both were 198.2 (625.3), 163.5 (486.1), and 192.5(570.4) for Al, 15.6(51.7), 28.8(71.1), and 21.9 (61.64) for As, 18.5(55.2), 20.7(56.5), and 19.22(55.75) for Pb, 17.9(57.6), 17.9 (53.9), and 17.9(56) for Ni, 13.95(47.5), 20.3(62.2) and 16(51.6) for Cr, 3.5(12.2), 2.9(11.5), and 3.3(12) for Hg, 0.74(2.7), 0.95 (3.6), and 0.81(3.1) for Cd. There was a direct relationship between the concentration of metal(loid)s and demographic indicators and body composition (P<0.05). Moreover, there was a direct relationship between the concentration of As, Cr, Hg, Ni, and Pb with age and wealth index (P<0.05).

CONCLUSIONS

The concentrations found could be used as the reference range for As, Al, Cd, Cr, Hg, Ni, and Pb for human biomonitoring studies on the Iranian adult population.

Individual, sociodemographic, and lifestyle influence on blood chromium, cobalt, and nickel levels in healthy population living in Belgrade, Serbia

The rapid trend of industrialization and urbanization can lead to greater exposure of the general population to chromium, cobalt, and nickel. Their total body burden from all routes of recent exposure, as well as interindividual variability in exposure levels, metabolism, and excretion rates, are reflected in the blood metal concentrations. The main goals in this study were as follows: observing the reference levels of chromium, cobalt, and nickel in the blood of the population living in Belgrade, identification of individual and sociodemographic factors that most affect their blood levels, and comprehension of recent exposure to chromium, cobalt, and nickel. Blood was sampled from 984 participants, voluntary blood donors, who agreed to participate in this study. Individual and sociodemographic data were collected using questionnaire adapted for different subpopulations. Blood metal analyses were measured using ICP-MS method (7700×, Agilent, USA). Our study provided reference values of chromium, cobalt, and nickel in blood for adult population (18-65 years) and confirmed that blood cobalt and nickel levels were mostly influenced by age and gender, and age, respectively. Furthermore, weight status affected blood chromium and cobalt levels, while national origin affected blood chromium levels. The present study highlighted the importance of human biomonitoring studies to monitor exposure status and identify subpopulations with increased exposure to chromium, cobalt, and nickel.

Direct Effects of Toxic Divalent Cations on Contractile Proteins with Implications for the Heart: Unraveling Mechanisms of Dysfunction

The binding of calcium and magnesium ions to proteins is crucial for regulating heart contraction. However, other divalent cations, including xenobiotics, can accumulate in the myocardium and enter cardiomyocytes, where they can bind to proteins. In this article, we summarized the impact of these cations on myosin ATPase activity and EF-hand proteins, with special attention given to toxic cations. Optimal binding to EF-hand proteins occurs at an ionic radius close to that of Mg²⁺ and Ca²⁺. In skeletal Troponin C, Cd²⁺, Sr²⁺, Pb²⁺, Mn²⁺, Co²⁺, Ni²⁺, Ba²⁺, Mg²⁺, Zn²⁺, and trivalent lanthanides can substitute for Ca²⁺. As myosin ATPase is not a specific MgATPase, Ca²⁺, Fe²⁺, Mn²⁺, Ni²⁺, and Sr²⁺ could support myosin ATPase activity. On the other hand, Zn²⁺ and Cu² significantly inhibit ATPase activity. The affinity to various divalent cations depends on certain proteins or their isoforms and can alter with amino acid substitution and post-translational modification. Cardiac EF-hand proteins and the myosin ATP-binding pocket are potential molecular targets for toxic cations, which could significantly alter the mechanical characteristics of the heart muscle at the molecular level.

Association between urinary cadmium level and subclinical myocardial injury in the general population without cardiovascular disease aged ≥ 50 years

Cadmium (Cd) is a toxic heavy metal linked to an increased risk of cardiovascular disease (CVD). But the relationship between urinary Cd (U-Cd) and electrocardiographic subclinical myocardial injury (SC-MI) in older people is unclear. This study evaluated the connection between U-Cd and SC-MI in people who did not have CVD. The study involved 4269 participants from the National Health and Nutrition Examination Survey III(NHANES III) aged ≥ 50 years and had no history of CVD. The relationship between U-Cd and cardiac infarction/injury score (CIIS) was assessed by multivariable linear regression. Whether U-Cd and SC-MI were correlated was determined by multivariate logistic regression, restricted cubic spline, and subgroup analysis. There was a significant association between U-Cd and CIIS (β, 1.04, 95% confidence interval (CI): 0.39-1.69; P = 0.003) in the highest quartile and fully adjusted model. After adjusting for relevant confounders, multivariable logistic regression showed that participants in the highest quartile of U-Cd had a greater chance of having SC-MI than those in the first ( OR (95% CI), 1.37(1.13,1.66), P for trend = 0.003), and this relationship was especially strong among hypertensive participants. And a positive linear correlation between U-Cd and the prevalence of SC-MI was shown by restricted cubic spline analysis. U-Cd may be a novel risk element for SC-MI because it is independently and linearly linked to CIIS and SC-MI.

Sex-dependent vascular effects of cadmium sub-chronic exposure on rats

Cadmium exposure is related to several cardiovascular diseases, such as hypertension, atherosclerosis and endothelial dysfunction. However, the toxic effect of cadmium can be dependent on the sex when examined sex in experimental models. The aim of this study was to analyze the effects of cadmium exposure on the cardiovascular system of male and female rodents. The experiments were carried out on both-sexes Wistar at 4 months of age, where from 3 months onwards, cadmium (CdCl2 100 mg/l in placed the drinking water for 30 days) or vehicle delivered (distilled water) was ingested. Before and after 30 days of exposure to cadmium, systolic blood pressure was regularly measured. After exposure, blood was collected to measure dosage of cadmium, in male and female, and estrogen in females. Vascular reactivity to phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP) was studied at respective isolated aortic segments. After the period to Cd-exposure, systolic blood pressure was increased only in the male rats. Males also had higher levels of plasma cadmium than those of female rats, and exposure to the metal did not affect the amount of estrogen produced in the female rats. Increased myeloperoxidase (MPO) activity was also observed in both the males and females that had been exposed to the metal. Moreover, exposure to the cadmium reduced the ACh relaxation and increased vascular reactivity to Phe, resulting in an imbalance between nitric oxide superoxide anion in the isolated aorta of male rats. In female rats, sub-chronic cadmium exposure did not modify the vascular reactivity to Phe and neither to the ACh. The present study revealed that the Cd exposure for 30 days induced sex-dependent cardiovascular abnormalities.

Concentrations of Transition Metal Ions in Rat Lungs after Tobacco Smoke Exposure and Treatment with His-Leu Dipeptide

Tobacco smoking is deleterious to the lungs because it exposes them to many toxic substances. These include transition metal ions, such as cadmium. However, there is a lack of information about the influence of endogenous metal-binding peptides, such as His-Leu (HL), on the lung distribution of transition metals in smokers. To address this, we administered HL subcutaneously to rats exposed to tobacco smoke for six weeks, then we measured the concentrations of transition metal ions in the lungs. We found that exposure to tobacco smoke elevates the concentrations of Cd(II) and Cu(II). Administration of the HL peptide, whose elevation is a consequence of angiotensin receptor blocker anti-hypertension therapy, increases the concentration of Fe in the lungs of rats exposed to smoke. These findings suggest that smoking is a risk factor for patients receiving angiotensin receptor blockers to treat hypertension.

Multi-matrix biomonitoring approach to assess exposure to metals and trace elements in the Lebanese population and associations with drinking water consumption

This study is the first attempt to assess exposure to metals and trace elements in subgroups of the Lebanese population using a multi-matrix biomonitoring approach. Concentrations of 11 metals and trace elements (aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), selenium (Se), uranium (U), zinc (Zn)) were measured in urine, hair and toenails. Biological levels were compared according to age, sex, smoking status, socioeconomic status, geographical area and drinking water source. While most urinary and toenail concentrations of metals and trace elements were not different between males and females, measured concentrations of several elements in hair were higher in females compared to males. Urinary concentrations of some metals (Al, Cu, Se and Zn) were higher in children compared to teenagers and adults. Hair and toenail concentrations of several elements (As, Cd, Pb, Mn, Se in hair and toenails plus Al, Fe in toenails) were also significantly higher in children compared to teenagers and/or adults. Smoking status had no influence on metal and trace element concentrations. Levels of Cd, Pb and Mn were also higher in samples from subgroups with lower economic status (Cd and Pb in the three matrices and Mn in hair and toenails). Very few correlations were identified between sources of drinking water and urine, hair, and toenail concentrations of metals and trace elements. However, a correlation was observed between hair and toenails levels of As, Cd and Pb. Overall, results highlight that a special attention should be given to metal and trace element exposure in this population (including Pb, As, Cd, Mn, and Se). It could be relevant to scale up this kind of investigation with a large human biomonitoring initiative in the Lebanese population in order to generalize results, and assess trends over time.

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.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

Biomonitoring of urinary metals in athletes according to particulate matter air pollution before and after exercise

Exposure to air pollution during physical exercise is a health issue because fine particulate matter (dimension < 10 μm; PM₁₀) includes several inhalable toxic metals. Body metal changes in athletes according to air pollution are poorly known. Urinary concentrations of 15 metals: beryllium (Be⁹), aluminum (Al²⁷), vanadium (V⁵¹), chromium (Cr⁵¹ + Cr⁵²), manganese (Mn⁵⁵), cobalt (Co⁵⁹), nickel (Ni⁶¹), copper (Cu⁶³), zinc (Zn⁶¹), arsenic (As⁷⁵), selenium (Se⁸²), cadmium (Cd¹¹¹ + Cd¹¹²), thallium (Tl¹²⁵), lead (Pb²⁰⁷), and uranium (U²³⁸) were measured before and after ten 2-h training sessions in 8 non-professional Italian American-football players (18-28 years old, body mass index 24.2-33.6 kg/m²). Collectively, post-training sessions, urinary concentrations of As, Cd, Co, Cu, Mn, Ni, Pb, Se, Tl, and Zn were higher than pre-training sessions; Al, Be, Cr, and U did not change; conversely, V decreased. Subdividing training sessions according to air PM₁₀ levels: low (< 20 μg/m³), medium (20-40 μg/m³), and high (> 40 μg/m³), pre-session and post-session urinary concentrations of Be, Cd, Cu, and Tl were significantly higher (p < 0.05) in more polluted days, whereas V concentrations were lower (p < 0.001). All the remaining metals were unaffected. We first showed that PM₁₀ levels modulate urinary excretion of some toxic metals suggesting an effect of air pollution. The effects of toxic metals inhaled by athletes exercising in polluted air need further studies.

Comparison of Urinary Heavy Metals and Pulmonary Function Test in Cafe Workers Based on Exposure to Secondhand Tobacco Smoke, Tehran 2021

Background

Secondhand tobacco smoke exposure is one of the morbidity causes but it is ignored occasionally. Various studies have shown that hookah and cigarette smoke contain significant volume of heavy metals. This study was designed aiming biological monitoring of the level of heavy metals in the urine samples of workers in smoking cafés and its association with their lung function and respiratory symptoms in Tehran City.

Methods

The list of cafés in Tehran was provided, and they were divided into water pipe cafés (WPC), cigarette smoking cafés (CSC), and non-smoking cafés (NSC); and then, 10 cafés were randomly selected from each group. Sampling was performed after explaining the study and obtaining the consent of the manager and staff. A check list of demographic data and smoking history was completed and analyzed.

Results

A total of 96 individuals were studied; there were 32 subjects in each group. All subjects were male. Six days a week, they worked about 10 h a day in café. The concentration of heavy metals in the groups of hookah and cigarettes was significantly higher and respiratory indices in these groups were significantly lower than non-smoking group.

Conclusions

Exposure to secondhand smoke increases the urinary level of heavy metals and reduces the respiratory capacity of people and this can be highly pathogenic in the future. Comprehensive informing on human rights should be provided in this regard and smoking bans in public places must be properly enforced.

Cadmium induces triglyceride levels via microsomal triglyceride transfer protein (MTTP) accumulation caused by lysosomal deacidification regulated by endoplasmic reticulum (ER) Ca2+ homeostasis

Cadmium (Cd) exposure induced lipid metabolic disorder with changes in lipid composition, as well as triglyceride (TG) levels. Liver is the main organ maintaining body TG level and previous studies suggested that Cd exposure might increase TG synthesis but reduce TG uptake in liver. However, the effects of Cd exposure on TG secretion from liver and underlying mechanism are still unclear. In the present study, the data revealed that Cd exposure increased TG levels in the HepG2 cells and the cultured medium by increasing the expression of microsomal triglyceride transfer protein (MTTP), which was abrogated by siRNA knockdown of MTTP. MTTP was synergistically accumulated after Cd exposure or treated with proteasome inhibitor MG132 and lysosome inhibitor chloroquine (CQ), which suggested the Cd increased MTTP protein stability by inhibiting both the proteasome and the lysosomal protein degradation pathways. In addition, our results demonstrated that Cd exposure inhibited the lysosomal acidic degradation pathway through disrupting endoplastic reticulum (ER) Ca²⁺ homeostasis. Cd-induced MTTP protein and TG levels were significantly reduced by pretreatments of BAPTA/AM chelation of intracellular Ca²⁺, 2-APB inhibition of ER Ca²⁺ release channel inositol 1,4,5-trisphosphate receptor (IP3R) and CDN1163 activation of ER Ca²⁺ reuptake pump sarcoplasmic reticulum Ca²⁺-ATPase (SERCA). These results suggest that Cd-induced ER Ca²⁺ release impaired the lysosomal acidity, which associated with MTTP protein accumulation and contributed to increased TG levels.

Comparison of serum concentrations of essential and toxic elements between cigarette smokers and non-smokers

The habit of smoking remains a severe public health problem. Heavy metals in cigarettes and mainstream smoke have been extensively investigated. This study has attempted to determine the essential and toxic elements in a biological sample of smokers and non-smokers. In this case-control study, 100 smokers were compared with 100 age- and gender-matched non-smoker healthy subjects. The smoker group was selected via the snowball sampling method. Serum concentrations of trace elements were determined using ICP-MS (Agilent 7900) for subsequent analysis. Data were analyzed by SPSS software using t test or Mann-Whitney U test along with chi-square test at the significant level of less than 0.05. The results of this study indicated that subjects in the smoker group compared with non-smokers had a significantly higher median of manganese (Mn) (11.5 [5.7-17.2] versus 6 [4-12.5] (μg/L), p = 0.003), copper (Cu) (40 [34-47.2] versus 34 [29-42] (μg/L), p = 0.005), arsenic (As) (39 [9-49.2] versus 12 [5-42] (μg/L), p = 0.007), thallium (Tl) (0.54 [0.27-0.68] versus 0.34 [0.11-0.66] (μg/L), p = 0.04), and lower iron (Fe) concentration (218 [156-508] versus 429 [192-573] (μg/L), p = 0.03). This study found that the concentrations of Mn, Cu, As, and TI in cigarette smokers were significantly higher than those obtained from the control group. These results can provide health policymakers with the necessary information to take public health measures towards preventive interventions in the community, though further studies are still warranted.

Semi-Automated Determination of Heavy Metals in Autopsy Tissue Using Robot-Assisted Sample Preparation and ICP-MS

The endoprosthetic care of hip and knee joints introduces multiple materials into the human body. Metal containing implant surfaces release degradation products such as particulate wear and corrosion debris, metal-protein complexes, free metallic ions, inorganic metal salts or oxides. Depending on the material composition of the prostheses, a systemic exposure occurs and may result in increasing metal concentrations in body fluids and tissues especially in the case of malfunctions of the arthroplasty components. High concentrations of Cr, Co, Ni, Ti and Al affect multiple organs such as thyroid, heart, lung and cranial nerves and may lead to metallosis, intoxications, poly-neuropathy, retinopathy, cardiomyopathy and the formation of localized pseudo tumors. The determination of the concentration of metals in body fluids and tissues can be used for predicting failure of hip or knee replacements to prevent subsequent severe intoxications. A semi-automated robot-assisted measurement system is presented for the determination of heavy metals in human tissue samples using inductively coupled plasma mass spectrometry (ICP-MS). The manual and automated measurement processes were similarly validated using certified reference material and the results are compared and discussed. The automation system was successfully applied in the determination of heavy metals in human tissue; the first results are presented.

An updated systematic review on the association between Cd exposure, blood pressure and hypertension

BACKGROUND

Since the first report by Perry et al. (1955), most studies affirmed the hypertensive effects of cadmium (Cd) in humans. Nonetheless, conclusions between studies remain inconsistent.

OBJECTIVE

The aim of this study was to reevaluate the evidence for a potential relationship between Cd exposure and altered blood pressure and/or hypertension, focusing on studies published between January 2010 and March 2020.

METHODS

We reviewed all observational studies from database searches (PubMed and SCOPUS) on Cd exposure and blood pressure or hypertension. We extracted information from studies that provided sufficient data on population characteristics, smoking status, exposure, outcomes, and design.

RESULTS

Thirty-eight studies met our inclusion criteria; of those, twenty-nine were cross sectional, three case control, five cohort and one interventional study. Blood or urinary Cd levels were the most commonly used biomarkers.

CONCLUSIONS

A positive association between blood Cd levels and blood pressure and/or hypertension was identified in numerous studies at different settings. Limited number of representative population-based studies of never-smokers was observed, which may have confounded our conclusions. The association between urinary Cd and blood pressure and/or hypertension remains uncertain due to conflicting results, including inverse relationships with lack of strong mechanistic support. We point to the urgent need for additional longitudinal studies to confirm our findings.

The Role of Antioxidants in the Prevention of Cadmium-Induced Endothelial Dysfunction

Background:

Cadmium is a worldwide spread toxicant that accumulates in tissues and affects many organs, mainly through oxidative damage. Oxidative stress is often associated with cardiovascular diseases and, when it affects vessels, it induces endothelial dysfunction, which, in turn, could precipitate atherosclerosis and hypertension. Therefore, it is reasonable to suggest antioxidant supplementation as a therapy against cadmiuminduced endothelial dysfunction.

Objective:

This literature review aims to present the mechanisms involving oxidative stress in which cadmium induces endothelial dysfunction and the benefits of antioxidant supplementation as a therapeutic strategy against its harmful effects.

Methods:

On PubMed Central, articles that contemplated studies on cadmium intoxication and associated oxidative stress with endothelial dysfunction as well as articles that reported the use of antioxidant supplementation in an attempt to prevent or avoid endothelial dysfunction induced by cadmium exposure were selected.

Results:

Most of the studies that associated cadmium intoxication with endothelial dysfunction suggested oxidative stress as the major mechanism for this damage. Furthermore, experimental studies also revealed that the administration of substances with antioxidant properties, such as ascorbic acid and curcumin, has beneficial effects on the prevention of such dysfunction, reducing reactive oxygen species within the vessels, preventing a reduction in the amount of glutathione and the increase in blood pressure observed in animals exposed to cadmium.

Conclusion:

Antioxidant therapy demonstrated to be a potential treatment to reduce cardiovascular injuries provoked by cadmium, but more studies are needed to determine the best antioxidant substance and dose to treat or avoid this complication.

Serum and urinary concentrations of arsenic, beryllium, cadmium and lead after an aerobic training period of six months in aerobic athletes and sedentary people

Aim

The aim of the present study was to evaluate the possible effect of a period of 6 months of aerobic physical training on serum and urinary concentrations of arsenic (As), beryllium (Be), cadmium (Cd) and lead (Pb), potentially toxic minerals.

Methods

Twenty-four well-trained, long distance runners (AG), were recruited at the start of their training period. They had been performing training regularly for the previous 2 years, recording an average volume of 120 km per week of rigorous aerobic exercise aimed at high-level competitions (1500 and 5000 m race modalities). Twenty-six untrained, sedentary participants constituted the control group (CG). All participants had been living in the same geographic area for at least 2 years before the start of the survey. Serum and urine samples were obtained from each participant at the beginning and at the end of the 6 months of the training program. The values of each mineral were determined by inductively coupled plasma mass spectrometry (ICP-MS). Additionally, the daily intake of each mineral was evaluated at both moments in time.

Results

The daily concentrations of trace elements in the diet were similar at the start and the end of the training period without differences between groups. In serum, significant differences between groups were observed in As, Cd and Pb (p < 0.05). Attending to time effects, a significant difference was obtained in Pb (p < 0.05). In urine, significant differences between groups were obtained in all minerals (p < 0.05). According to training period, significant differences were observed in As, Be and Pb (p < 0.05). Finally, the group x time interaction revealed significant differences in As and Be (p < 0.05).

Conclusions

Aerobic training may constitute a possibly effective method for increasing the elimination of Cd and Pb potentially toxic minerals from the body, especially among highly trained individuals.

Blood cadmium levels and sources of exposure in an adult urban population in southern Brazil

BACKGROUND

Cadmium (Cd) is a toxic metal that is widely present in the environment due to geologic and anthropogenic sources. Exposures to high Cd levels may cause nephrotoxicity, carcinogenicity, pulmonary and cardiovascular disease, among others. The goal of this study was to investigate in an adult urban population whether an association exists between sources and levels of Cd exposure and blood Cd concentrations.

METHODS

Using a census-based design, a total of 959 adults, aged 40 years or older, were randomly selected. Information on socio-demographics, dietary, and lifestyle background was obtained by household interviews. Blood Cd levels were measured by inductively coupled-plasma mass spectrometry. Geometric means (GM) (95% CI) and the 50th percentile were determined, stratified by sex, age, race, education, income class, smoking status, consumption of vegetables, red meat and milk, occupation and blood pressure. To assess the association between Cd exposure and the aforementioned variables, we estimated the geometric mean ratio (GMR) (95%CI) of blood Cd concentrations.

RESULTS AND CONCLUSION

The geometric mean (95%CI) of blood Cd levels in the total population was 0.25 (0.22, 0.27) ug/dL. In a univariate analysis, significantly higher blood Cd levels were found in men (p < 0.001), current and former smokers (p < 0.001), alcohol drinkers (p < 0.001), those who never or almost never consumed milk (p < 0.001), and in subjects with higher diastolic blood pressure (p = 0.03). Significant correlations were found between the number of cigarettes consumed daily and blood Cd levels. Multivariate analysis confirmed higher blood Cd concentrations were associated with alcohol consumption (GMR 95%CI = 1.28, 1.04-1.59) and in former and current smokers (GMR 95% IC = 1.33, 1.06-1.67 and 4.23, 3.24-5.52, respectively). Our results shed novel information on variables associated with blood Cd levels in an urban Brazilian population, and should encourage additional research to prevent environmental Cd exposure, both in Brazil and globally.

Human Biomonitoring of Trace Elements in Scalp Hair from Healthy Population of Pakistan

The present study deals with the assessment of essential trace and toxic elements in biological samples (scalp hair) of healthy smoker and non-smoker residents of Lahore (the second most populous city), Pakistan. Human biomonitoring of various trace elements like zinc (Zn), iron (Fe), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), lead (Pb), and arsenic (As) was evaluated in human hair samples of smokers and non-smokers (males and females) as per IFCC criteria. For the purpose of comparison, scalp hair samples of age- and sex-equivalent healthy persons were also analyzed. The results of this study show that the concentrations (P95 values) of As (0.17, 0.81, and 0.91 μg/g), Cd (2.80, 3.81, and 3.16 μg/g), Cr (4.1, 4.2, and 5.3 μg/g), Cu (20.0, 21.0, and 21.9 μg/g), Ni (3.9, 4.6, and 4.3 μg/g), Pb (4.0, 4.8, and 5.0 μg/g), and Fe (49.0, 49.0, and 59.3 μg/g) were significantly higher in scalp hair samples of smokers than in referents, for various age groups (16-32 years, 33-50 years, and 51-62 years), respectively. The concentrations of Zn (165, 163, and 173 μg/g various age groups, respectively) in similar age group were found lower in the scalp hair samples of smokers than referents. Exposure of high toxic metal level through smoking and deficiency of Zn could be synergistic with the risk factors associated with the use of tobacco. Correlation studies for the elements in cigarette with the elements in scalp hair of male smokers show a highly positive correlation between Cr-Cd, Cr-Ni, Cu-Fe, and Ni-Zn.

Toxicological and pharmacological assessment of a multiherbal phytopharmaceutical on Triton X-1339-induced hyperlipidemia and allied biochemical dysfunctions

This study investigated the safety and therapeutic effect of a multiherbal tea (MHT) on Triton X-1339-induced hyperlipidemia and associated biochemical and tissue dysfunctions. An infusion of the MHT was assessed for phytoconstituents, proximate and mineral composition, and antioxidant activity. Wistar rats administered 200 mg/kg Triton X-1399 were post-treated with MHT for 14 days followed by biochemical estimations in serum, heart, liver, and kidney of animals. Hematological and histopathological evaluations of the blood, and liver, respectively, were also performed. Different phytochemicals were detected in MHT, toxic metals were absent and antioxidant activity was appreciable. Disturbances in glucose level and redox homeostasis, alterations in liver, kidney, and heart function markers, and imbalances in hematological parameters precipitated by triton toxicity were mitigated by posttreatment with MHT. Multiherbal tea also ameliorated triton-induced hepatic histoarchitectural abnormalities. These results suggest that MHT is apparently an effective antilipemic tea with minimal or no side effects. PRACTICAL APPLICATIONS: Hyperlipidemia is one of the core risk factors for arteriosclerosis and a major contributor to other adverse health conditions. The prevalence of hyperlipidemia has increased drastically in the last few decades. Plant and plant products have been extensively used in the management of dyslipidemia and many plant-based antilipemic products with poorly defined toxicity and pharmacological profiles abound in the market. The results of this study demonstrated the protective effects of a MHT against triton-induced hyperlipidemia, atherogenic tendency, and dysfunction of key organs in rats and lent credence to its therapeutic relevance in the management of hyperlipidemia and related diseases.

Arsenic, Cadmium and Lead Erythrocyte Concentrations in Men with a High, Moderate and Low Level of Physical Training

The aim of the present study was to determine changes occurring in the erythrocyte concentrations of arsenic (As), cadmium (Cd) and lead (Pb) in highly trained males, moderately trained males and sedentary men living in the same area of Extremadura (Spain). Thirty sedentary subjects (24.34 ± 3.02 years) with no sports practice and a less active lifestyle formed the control group (CG). Twenty-four moderately trained subjects (23.53 ± 1.85 years), who practised sports at a moderate level between 4 and 7 h/week, without any performance objective and without following any type of systematic training, formed the group of subjects with a moderate degree of training (MTG). And 22 professional cyclists (23.29 ± 2.73 years) at the beginning of their sports season, who trained for more than 20 h/week formed the high-level training group (HTG). Erythrocyte samples from all subjects in a fasting stage were collected, washed and frozen at -80 °C until analysis. Erythrocyte analysis of the trace elements As, Cd and Pb was performed by inductively coupled plasma mass spectrometry (ICP-MS). As concentration was lower in CG (p < 0.01) and MTG (p < 0.01) than HTG. Cd (p < 0.001) and Pb (p < 0.05) concentrations were higher in CG than HTG. All results were expressed in μg/g Hb. Physical training produces a decrease in erythrocyte concentrations of Cd and Pb, as an adaptation in order to avoid their accumulation in the cells and preserve correct cellular functioning. The higher As concentration should be investigated in high-level sportsmen because of a possible negative effect on the cells.

Urinary metal/metalloid levels in relation to hypertension among occupationally exposed workers

Occupational exposure to metals can have an adverse effect on the cardiovascular system. However, epidemiological studies of the associations of metals expose with hypertension among occupationally exposed workers were limited. The aim of this study was to investigate the potential association between urinary metal levels and the risk of hypertension among molybdenum miners and iron and steel foundry workers. The cross-sectional study had 395 participants. Urinary metal levels were determined by inductively coupled plasma mass spectrometry. Log-binomial regression model and two-piece-wise regression model were applied to assess the dose-response relationship between metal exposure and hypertension. We observed that increased prevalence ratios for hypertension among the quartile of urinary concentrations of molybdenum, arsenic and lead were positive (all P for trend <0.05). Compared with the lowest quartiles, participants in the highest quartiles of molybdenum, arsenic and lead had a 2.58-fold, 4.30-fold and 4.85-fold increased probability of having hypertension, respectively. In the threshold effect analyses, we found the relationship was nonlinear between urinary molybdenum, cobalt, cadmium, arsenic and lead concentrations and the prevalence of hypertension. In addition, Pb, Mo, As and Co may have joint effect, and a strong positive correlation with the prevalence of hypertension. Conversely, the association between the joint effect of Cd, Pb and Mo versus the prevalence of hypertension is not significant. We provide reference levels of molybdenum, cobalt, cadmium, arsenic and lead that can be used to assess the effects of occupational metal exposure on hypertension.

Household Smoking Status and Heavy Metal Concentrations in Toenails of Children

There is limited evidence on the distribution of heavy metals and its association with secondhand smoking (SHS) within Pacific Island children living in New Zealand. Certain heavy metals such as cadmium (Cd), lead (Pb), and aluminum (Al) bioaccumulates in the body and can deteriorate health in both children and adults. Others, such as chromium (Cr) and nickel (Ni) in trace amounts are necessary but become toxic at high levels. Exposure routes of these elements include food, water, and air. The purpose of this study was to identify the distribution of toxic metal concentrations and its possible correlation with SHS within the Pacific Island children. A sub-sample of children within Pacific Island families longitudinal study, at the nine-year phase, who were living in the New Zealand city of Auckland were invited to participate, (n = 278). Toenails were used as a biomarker to determine Cr, Pb, Cd, Cu, Ni, and Al concentration using inductively coupled plasma mass spectrometry. Reliable and validated questionnaires were used for demographics, lifestyle, and health outcome variables. Significant differences between household smoking status and ethnicity, as well as parents' marital status, were observed (p < 0.05). There was no statistical difference in heavy metal concentrations in smoking versus non-smoking households. However, Cr, Pb, Cd, Cu, and Ni concentrations were all higher than the required optimal health value in both groups. A high concentration of heavy metals was observed in these children that exceeded the value required for optimal health, although no significant difference in heavy metals with regards to secondhand smoking was observed. SHS was associated with children's ethnicity and parental marital status, but not with household income levels or maternal education.

Metal nickel exposure increase the risk of congenital heart defects occurrence in offspring: A case-control study in China

BACKGROUND

Previous studies have investigated heavy metal exposure could increase the occurrence of congenital heart defects (CHDs). However, there are limited data regarding the relationship between exposure to nickel and CHDs occurrence in offspring. The aim of this study was to analyze the association between nickel exposure in mothers and the risk of CHDs in offspring.

MATERIALS AND METHODS

To explore the association of nickel exposure and occurrence of CHD, a case-control study with 490 controls and 399 cases with CHDs in China were developed. The concentrations of nickel in hair of pregnant woman and fetal placental tissue were measured and used a logistic regression analysis to explore the relationship between nickel exposure and risk of CHD.

RESULTS

The median concentrations of nickel were 0.629 ng/mg, P < .05 (adjusted odds ratio [aOR], 1.326; 95% CI, 1.003-1.757) and 0.178 ng/mg, P < .05 (aOR, 2.204; 95% CI, 0.783-6.206), in maternal hair and in fetal placental tissue in the CHD group, respectively. Significant differences in the level of nickel in hair were also found in the different CHD subtypes including septal defects (P < .05), conotruncal defects (P < .05), right ventricular outflow tract obstruction (P < .01), and left ventricular outflow tract obstruction (P < .05). Dramatically different nickel concentrations in fetal placenta tissue were found in cases with other heart defects (P < .05).

CONCLUSIONS

The finding suggested that the occurrence of CHDs may be associated with nickel exposure.

Chronic Cadmium Exposure Accelerates the Development of Atherosclerosis and Induces Vascular Dysfunction in the Aorta of ApoE-/- Mice

Cadmium exposure is related to cardiovascular diseases, including hypertension, atherosclerosis, increased oxidative stress, endothelial dysfunction, and specific biochemical changes induced by this metal. Thus, we aimed to investigate whether cadmium exposure induces endothelial dysfunction, accelerates atherosclerotic plaque formation in the aorta, and enhances oxidative stress in apolipoprotein E knockout (ApoE^-/-) mice. Experiments were performed in 14-week-old male wild-type and ApoE^-/- mice. ApoE^-/- mice received cadmium (CdCl₂ 100 mg/L in drinking water for 28 days) or vehicle (distilled water). After treatment, vascular reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was analyzed using isolated aorta. Bone marrow cells were isolated to assess the production of nitric oxide and reactive oxygen and nitrogen species. ApoE^-/- cadmium-treated mice had higher cholesterol levels than non-exposed mice. Cadmium exposure decreased the vasodilatation response to acetylcholine in aortic ring of ApoE^-/- mice, though no changes in phenylephrine or sodium nitroprusside responses were observed. L-NAME reduced vasodilator responses to acetylcholine; this effect was lower in ApoE^-/- cadmium-treated mice, suggesting reduction in nitric oxide (NO) bioavailability. Moreover, in bone marrow cells, cadmium decreased cytoplasmic levels of NO and increased superoxide anions, hydrogen peroxide, and peroxynitrite in ApoE^-/- mice. Morphological analysis showed that cadmium exposure increased plaque deposition in the aorta by approximately 3-fold. Our results suggest that cadmium exposure induces endothelial dysfunction in ApoE^-/- mice. Moreover, cadmium increased total cholesterol levels, which may promote the early development of atherosclerosis in the aorta of ApoE^-/- mice. Our findings support the hypothesis that cadmium exposure might increase the risk of atherosclerosis.

Blood cadmium determinants among males over forty living in Mexico City

BACKGROUND

Mexico City has air, water and food pollution problems; however, human exposure to cadmium and its sources have not been described.

OBJECTIVES

To determine the blood cadmium (BCd) level and its main exposure sources among males aged 40 years or older living in different areas of Mexico City.

METHODS

After receiving informed consent, we interviewed 702 males aged ≥40 years to collect data on their sociodemographic characteristics, lifetime occupation, smoking history, and dietary habits, using a validated questionnaire. The BCd level (μg/L) was determined by atomic absorption spectrophotometry.

RESULTS

The BCd mean level ± SD was 2.61 ± 0.82 μg/L, and 20% of men reported a potential cadmium occupational exposure. After adjusting for age and other potential confounders, the main determinants of the BCd level were the current smoking status at interview, with low (β_{≤8.5packs/year vs. non-smoker} = 0.46; 95% CI: 0.28-0.64 μg/L; p < 0.01) and high (β_{> 8.5 packs/year vs. non-smoker} = 0.71; 95% CI: 0.56-0.87 μg/L; p < 0.01) smoking intensity, and living in the Center (β_{Center vs. South} = 0.20; 95% CI: 0.02-0.37 μg/L; p = 0.02) or West area of the city (β_{West vs. South} = 0.40, 95% CI: 0.21-0.58 μg/L; p < 0.001). Moreover, the potential dietary sources of BCd included: liver (β_{Yes vs. No} = 0.13, 95% CI: 0.03-0.23 μg/L; p = 0.01), "Chorizo" (β_{>1-3servings/month vs. No} = 0.14, 95% CI: 0.01-0.26 μg/L; p < 0.001), sausage and ham.

CONCLUSIONS

The BCd levels observed in this population are high and only similar to those observed in workers from a sanitary landfill area in Southern Thailand. Potential environmental Cd exposure sources, such as industrial activity and previous land use, in the West and Center areas of the city should be explored in detail, especially in vulnerable population groups, such as children.

The NOAEL Metformin Dose Is Ineffective against Metabolic Disruption Induced by Chronic Cadmium Exposure in Wistar Rats

Previous studies have proposed that cadmium (Cd) is a metabolic disruptor, which is associated with insulin resistance, metabolic syndrome, and diabetes. This metal is not considered by international agencies for the study of metabolic diseases. In this study, we investigate the effect of metformin on Cd-exposed Wistar rats at a lowest-observed-adverse-effect level (LOAEL) dose (32.5 ppm) in drinking water. Metabolic complications in the rats exposed to Cd were dysglycemia, insulin resistance, dyslipidemia, dyslipoproteinemia, and imbalance in triglyceride and glycogen storage in the liver, muscle, heart, kidney, and adipose tissue. Meanwhile, rats treated orally with a No-observable-adverse-effect level (NOAEL) dose of metformin (200 mg/kg/day) showed mild improvement on serum lipids, but not on glucose tolerance; in tissues, glycogen storage was improved, but lipid storage was ineffective. In conclusion, metformin as a first-line pharmacological therapy must take into consideration the origin and duration of metabolic disruption, because in this work the NOAEL dose of metformin (200 mg/kg/day) showed a limited efficiency in the metabolic disruption caused by chronic Cd exposure.

Essential and Non-essential Elements in Scalp Hair of Diabetics: Correlations with Glycated Hemoglobin (HbA1c)

Essential elements (Ca, Mg, Zn, Cu, Fe, Cr, Mn and V) and non-essential elements (As, Cd, Hg and Pb) were measured in scalp hair samples of 45 diabetic subjects and 59 control subjects in Japan using inductively coupled plasma mass spectrometry. All diabetic subjects took insulin and/or antidiabetic agents, with glycated hemoglobin (HbA1c) ranging between 6.2 and 14.4%. The levels of Zn, Cu and Cr in the diabetic subjects (HbA1c>7) were significantly lower than those in the control subjects (p<0.05), and these concentrations decreased significantly with increases in HbA1c (p<0.01). The levels of Fe and Mg in the diabetic subjects were insignificantly lower, and the concentration of Fe decreased significantly with increases in HbA1c (p<0.05) and the concentration of Mn tended to decrease (p<0.10). In contrast, the concentration of As tended to increase with increases in HbA1c (p<0.10). The concentrations of other elements, such as Ca, Mn, V, Pb, Cd and Hg, in the diabetic subjects were similar to those of control subjects, and did not correlate with HbA1c. The average of estimated glomerular filtration rate (eGFR) in the diabetic subjects was 77.7±29.7 mL/min/1.73 m² with large variation (12.7-148 mL/min/1.73 m²), and previous study reported the increase of urinary excretion of Zn, Cr, Mn and Mg in diabetic subjects. The decreases of Zn, Cu, Cr, Fe and Mg concentrations in hair may reflect increased urinary excretion of these elements due to diabetic nephropathy.

Preliminary Studies of Acute Cadmium Administration Effects on the Calcium-Activated Potassium (SKCa and BKCa) Channels and Na+/K+-ATPase Activity in Isolated Aortic Rings of Rats

Cadmium is an environmental pollutant closely linked with cardiovascular diseases that seems to involve endothelium dysfunction and reduced nitric oxide (NO) bioavailability. Knowing that NO causes dilatation through the activation of potassium channels and Na⁺/K⁺-ATPase, we aimed to determine whether acute cadmium administration (10 μM) alters the participation of K⁺ channels, voltage-activated calcium channel, and Na⁺/K⁺-ATPase activity in vascular function of isolated aortic rings of rats. Cadmium did not modify the acetylcholine-induced relaxation. After L-NAME addition, the relaxation induced by acetylcholine was abolished in presence or absence of cadmium, suggesting that acutely, this metal did not change NO release. However, tetraethylammonium (a nonselective K⁺ channels blocker) reduced acetylcholine-induced relaxation but this effect was lower in the preparations with cadmium, suggesting a decrease of K⁺ channels function in acetylcholine response after cadmium incubation. Apamin (a selective blocker of small Ca²⁺-activated K⁺ channels-SK_Ca), iberiotoxin (a selective blocker of large-conductance Ca²⁺-activated K⁺ channels-BK_Ca), and verapamil (a blocker of calcium channel) reduced the endothelium-dependent relaxation only in the absence of cadmium. Finally, cadmium decreases Na⁺/K⁺-ATPase activity. Our results provide evidence that the cadmium acute incubation unaffected the calcium-activated potassium channels (SK_Ca and BK_Ca) and voltage-calcium channels on the acetylcholine vasodilatation. In addition, acute cadmium incubation seems to reduce the Na⁺/K⁺-ATPase activity.

Connecting gastrointestinal cancer risk to cadmium and lead exposure in the Chaoshan population of Southeast China

Cadmium (Cd) and lead (Pb) pose a serious threat to human health because of its carcinogenicity. China ranks first according to the Global Cancer Report for 2014 in newly diagnosed gastrointestinal cancers and cancer deaths. The aim of the present study was to evaluate the association of Cd and Pb burden with the risk of gastrointestinal cancers in a hospital-based case-control study from southern regions of China, Chaoshan area. A total of 279 hospitalized patients were recruited in this study, of which 167 were gastrointestinal cancer cases (70 esophageal cancer, 51 gastric cancer, and 46 colorectal cancer), and 112 controls were recruited from two hospitals in the Chaoshan area of southeast China. Basic clinical data and information on gender, age, and other demographic characteristics were collected from medical records. Blood Cd and Pb levels were detected by graphite furnace atomizer absorption spectrophotometry (GFAAS). Blood Cd/Pb levels and over-limit ratios between cases and controls were compared by Mann-Whitney U and Kruskal-Wallis H tests. We used logistic regression to estimate odds ratios (ORs) as measures of relative risk and explored the relationships between blood Cd/Pb levels and gastrointestinal cancer risk and clinicopathological characteristics. Median levels of blood Cd and Pb in cases (2.12 and 60.03 μg/L, respectively) were significantly higher than those of controls (1.47 and 53.84 μg/L, respectively). The over-limit ratios for Cd (≥ 5 μg/L) and Pb (≥ 100 μg/L) in the cases were both higher than that of controls. Blood Cd levels had a tendency to accumulate in the human body with gender, age, and tobacco smoking, while blood Pb levels only were associated with tobacco smoking. The logistic regression model illustrated that gastrointestinal cancers were significantly associated with blood Cd levels and blood Pb levels. The concentrations of Cd and Pb in patients with T3 + T4 stage were markedly higher than in patients with T1 + T2. On the other hand, blood Cd levels were dramatically increased in the distant -metastasis (M1). Blood Cd and Pb levels are significantly higher in gastrointestinal cancers compared to controls. Cd and Pb appear to be risk factors for gastrointestinal cancers in Chaoshan region, and higher levels of Cd and Pb may promote the occurrence and progression of gastrointestinal cancers.

Associations of environmental exposure to metals with the risk of hypertension in China

Hypertension contributes largely to the global burden of disease and mortality. Environmental exposure to metals might be a causative factor for hypertension, but the association remains unclear. The present case-control study of 502 hypertension patients and 502 healthy participants aimed to evaluate the potential relationships between the concentrations of 20 metal in urine and the risk of hypertension in a Chinese population. Multivariate logistic analyses adjusted for potential confounders were performed separately considering the effects of single and multi-metal. We found the increasing trends of urinary Fe, Co, Ni, Cu, Zn and Sr quartiles and the decreasing trends of urinary V and Rb quartiles with the ORs for hypertension. These dose-response associations were confirmed in the RCS models and remained robust in the multi-metal model. Urinary Hg quartiles were positively associated with the risk of hypertension in the models of single-metal and multi-metal. Urinary Cd quartiles were inversely associated with the risk of hypertension in the multi-metal model. Besides, modification effects of gender, BMI and smoking status on the associations of the exposure to various metals with the risk of hypertension were also suggested in the subgroup analysis. Our findings suggest that environmental exposure to V, Fe, Co, Ni, Cu, Zn, Rb, Sr, Cd and Hg might be related with the prevalence of hypertension. Further studies with prospective design should be conducted to confirm these findings.

Arsenic, cadmium, and mercury-induced hypertension: mechanisms and epidemiological findings

Arsenic (As), cadmium (Cd), and mercury (Hg) are toxic elements widely distributed in the environment. Exposure to these elements was attributed to produce several acute and chronic illnesses including hypertension. The aim of this review is to provide a summary of the most frequently proposed mechanisms underlying hypertension associated with As, Cd, and Hg exposure including: oxidative stress, impaired nitric oxide (NO) signaling, modified vascular response to neurotransmitters and disturbed vascular muscle Ca²⁺ signaling, renal damage, and interference with the renin-angiotensin system. Due to the complexity of the vascular system, a combination rather than a singular mechanism needs to be considered. In addition, epidemiological findings showing the relationship between various biomarkers of metal exposure and hypertension are described. Given the complex etiology of hypertension, further epidemiological studies evaluating the roles of confounding factors such as age, gender, and life style are still necessary.

The role of cadmium in obesity and diabetes

Multiple studies have shown an association between environmental exposure to hazardous chemicals including toxic metals and obesity, diabetes, and metabolic syndrome. At the same time, the existing data on the impact of cadmium exposure on obesity and diabetes are contradictory. Therefore, the aim of the present work was to review the impact of cadmium exposure and status on the risk and potential etiologic mechanisms of obesity and diabetes. In addition, since an effect of cadmium exposure on incidence of diabetes mellitus and insulin resistance was suggested by several epidemiologic studies, we carried out a meta-analysis of all studies assessing risk of prevalence and incidence of diabetes. By comparing the highest versus the lowest cadmium exposure category, we found a high risk of diabetes incidence (odds ratio=1.38, 95% confidence interval 1.12-1.71), which was higher for studies using urine as exposure assessment. On the converse, results of epidemiologic studies linking cadmium exposure and overweight or obesity are far less consistent and even conflicting, also depending on differences in exposure levels and the specific marker of exposure (blood, urine, hair, nails). In turn, laboratory studies demonstrated that cadmium adversely affects adipose tissue physiopathology through several mechanisms, thus contributing to increased insulin resistance and enhancing diabetes. However, intimate biological mechanisms linking Cd exposure with obesity and diabetes are still to be adequately investigated.

Metabonomics analysis of serum from rats given long-term and low-level cadmium by ultra-performance liquid chromatography-mass spectrometry

1. This study evaluated the toxicity of chronic exposure to low-level cadmium (Cd) in rats using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Forty male Sprague-Dawley rats were randomly assigned to four groups, namely, the control group, low-dose group (0.13 mg/kg·bw), middle-dose group (0.8 mg/kg·bw) and high-dose group (4.89 mg/kg·bw). The rats continuously received CdCl₂ via drinking water for 24 weeks. Serum samples were collected for metabonomics analysis. The data generated from the UPLC-MS was analysed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). PLS-DA model with satisfactory explanatory and predictive ability is capable of discriminating the treatment groups from the control group. 2. Finally, the 10 metabolites were identified and showed significant changes in some treatment groups compared with that in the control group (p < 0.0167 or p < 0.003). Exposure to Cd resulted in increased intensities of lysophosphatidic acid (P-16:0e/0:0), glycocholic acid, bicyclo-prostaglandin E2, lithocholyltaurine, sulfolithocholylglycine, lysophosphatidylethanolamine (20:5/0:0) and lysophosphatidylcholine (20:0), as well as decreased intensities of 3-indolepropionic acid, phosphatidylcholine (18:4/18:0) and 15S-hydroxyeicosatrienoic acid in rat serum. 3. Results suggest that exposure to Cd can cause disturbances in the lipid metabolism, amino acid metabolism, nervous system, antioxidant defence system, liver and kidney function.

One step hydrothermal synthesis and characterization of moss like MWCNT-Bi2S3 nanomaterial for solid phase extraction of copper

The present work was designed with the aim to one step simple hydrothermal synthesis of moss like MWCNT-Bi2S3 nanomaterial as solid phase extraction sorbent for separation, preconcentration and determination of copper in tobacco and food samples. Cu(II) ions was strongly retained on the MWCNT-Bi2S3 nanomaterial at the pH 7.0 and was successfully desorbed by using 1.5mL of 4M HNO3. The copper concentration in eluent was determined by flame atomic absorption spectrometer. The certified reference material (NC SZC 73033 Scallion) was analyzed for the verification and accuracy of the proposed method. This work was interpreted statistically and found the analytical performance of the proposed method which consist of preconcentration factor (20), limit of quantification (13.1µgL-1) and relative standard deviation (2.2%), respectively. It was concluded that this method was applied for the detection of copper from different types of tobacco and food samples successfully.

The impact of demographic factors, behaviors and environmental exposure to mercury content in the hair of the population living in the region of Lodz (central Poland)

The aim of this work was to access the influence of different factors such as sex, age, fish consumption, hair dyeing or smoking habit on the content of mercury in human hair samples. The research was carried on 444 samples (102 males and 342 females) collected from the population of people living in the region of Lodz (central Poland). The content of mercury in human hair samples was determined using the Mercury Analyzer MA 3000 (Nippon Instruments, Japan). The obtained results were elaborated using Statistica ver. 10.0 software. The mean value of mercury in investigated human hair samples was found to be 0.174±0.137mg/kg. We observed the statistically significant correlations (p<0.05) between the content of Hg in hair of the studied population and factors such as gender, age, and fish consumption. However, no statistically significant differences were found in relation to cosmetic treatment such as hair dyeing or smoking.

Cadmium and Cadmium/Zinc Ratios and Tobacco-Related Morbidities

Metals are one of five major categories of carcinogenic or toxic constituents in tobacco and tobacco smoke. Cadmium is highly volatile and a higher percentage of the total tobacco cadmium content is efficiently transferred to mainstream tobacco smoke than many other toxic metals in tobacco. Inhaled cadmium bioaccumulates in the lungs and is distributed beyond the lungs to other tissues, with a total body biological half-life of one to two decades. Chronic cadmium exposure through tobacco use elevates blood and urine cadmium concentrations. Cadmium is a carcinogen, and an inducer of proinflammatory immune responses. Elevated exposure to cadmium is associated with reduced pulmonary function, obstructive lung disease, bronchogenic carcinoma, cardiovascular diseases including myocardial infarction, peripheral arterial disease, prostate cancer, cervical cancer, pancreatic cancer, and various oral pathologies. Cadmium and zinc have a toxicologically inverse relationship. Zinc is an essential element and is reportedly antagonistic to some manifestations of cadmium toxicity. This review summarizes associations between blood, urine, and tissue cadmium concentrations with emphasis on cadmium exposure due to tobacco use and several disease states. Available data about zinc and cadmium/zinc ratios and tobacco-related diseases is summarized from studies reporting smoking status. Collectively, data suggest that blood, urine, and tissue cadmium and cadmium/zinc ratios are often significantly different between smokers and nonsmokers and they are also different in smokers for several diseases and cancers. Additional biomonitoring data such as blood or serum and urine zinc and cadmium levels and cadmium/zinc ratios in smokers may provide further insight into the development and progression of diseases of the lung, cardiovascular system, and possibly other organs.

Derivation of an oral toxicity reference value for nickel

Nickel (Ni) is in the earth's crust and can be found in environmental compartments such as water, soil, and air, as well as food. This paper presents an assessment of the oral nickel toxicity data in support of non-cancer health-based oral exposure limits or toxicity reference values (TRVs). This paper derives TRVs for three populations of interest: adults, toddlers, and people who have been dermally sensitized to nickel. The adult/lifetime TRV of 20 μg Ni/kg-day is based on post-implantation loss/perinatal mortality in a 2-generation reproductive study in rats. Several recent assessments by regulatory agencies have used the same study and endpoint, but the dose-response modeling conducted here was more appropriate for the study design. Toxicokinetic data from rats and humans indicate that the applied uncertainty factors are very conservative. Because the endpoint relates to fetal exposure and is not relevant to toddlers, a toddler TRV was derived based on decreased body weight in young rats; this TRV was also 20 μg Ni/kg-day. A separate TRV of 4 μg Ni/kg in addition to Ni in food was derived for protection of nickel-sensitized populations from flare-up of dermatitis, based on studies of single exposures in humans under conditions that maximize oral absorption.

Environmental Exposures and Cardiovascular Disease: A Challenge for Health and Development in Low- and Middle-Income Countries

Environmental exposures in low- and middle-income countries lie at the intersection of increased economic development and the rising public health burden of cardiovascular disease. Increasing evidence suggests an association of exposure to ambient air pollution, household air pollution from biomass fuel, lead, arsenic, and cadmium with multiple cardiovascular disease outcomes, including hypertension, coronary heart disease, stroke, and cardiovascular mortality. Although populations in low- and middle-income countries are disproportionately exposed to environmental pollution, evidence linking these exposures to cardiovascular disease is derived from populations in high-income countries. More research is needed to further characterize the extent of environmental exposures.

Association between blood arsenic levels and nasal polyposis disease risk in the Tunisian population

Although the pathophysiology underlying nasal polyposis (NP) formation is not fully understood, systemic, local, and environmental factors appear to contribute to NP disease development. This study aimed to explore the relationship between metal blood levels and NP risk. To the best of our knowledge, the current research represents the first scientific contribution reporting levels of Cr and As in blood of NP patients. In this context, 90 NP patients and 171 controls were recruited and blood samples were analyzed to determine the concentrations of As and Cr. Metal blood levels of As in patients (2.1 μg/L) were significantly higher than those of controls (1.2 μg/L). However, no significant difference in blood Cr levels was found between cases and controls. Arsenic blood levels of cigarette smokers were significantly higher than those of non-smokers. Environmental exposure and shisha consumption presented the most significant association with NP disease (OR = 10.1 and 14.1, respectively). High levels of blood As were significantly associated with NP disease (OR = 2.1). Cr blood levels were found to be associated with the four stages of polyps in both nasal cavities. This study found a strong association between nasal polyposis disease and As blood levels. These findings merit further investigation.

Acute Cadmium Exposure Reduces the Local Angiotensin I Converting Enzyme Activity and Increases the Tissue Metal Content

Cadmium exposure causes health problems that may result from increased oxidative stress and from changes in enzyme metalloproteases activities as angiotensin-converting enzyme (ACE). In fact, cadmium produces inhibition of serum ACE but is not known how cadmium acts on tissue ACE activity and whether following acute exposure tissue cadmium content is increased. In order to elucidate these issues, a cadmium bolus was injected intravenously in Wistar rats, and the cadmium content and the ACE activity were measured in the serum, lungs, aorta and kidneys. Moreover, in order to clarify if the cadmium affects directly tissue ACE activity, acute metal exposure in vitro was performed. Our results demonstrated that 120 min following cadmium administration, blood and organ cadmium content were both increased. Serum and lung ACE activity were reduced following acute cadmium exposure, but aortic and kidney ACE activities were not affected. The inhibitory effects induced by cadmium on ACE activity were also observed in the serum, as well as the lungs and the aorta, but not in the kidneys following in vitro exposure. Moreover, the inhibitory effects induced by cadmium on ACE activity were partially restored in vitro by zinc supplementation, suggesting a possible interaction or competition between cadmium and zinc by at the active site of ACE. Summarising, our results suggest that acute cadmium exposure promotes an increase in the tissue metal content that was accompanied by direct inhibition of serum, aorta and lung ACE activity, an effect that is cadmium concentration-dependent and is partially reversed by zinc.

Estimation of calcium, magnesium, cadmium, and lead in biological samples from paralyzed quality control and production steel mill workers

The determination of trace and toxic metals in the biological samples of human beings is an important clinical screening procedure. The aim of the present study was to compare the level of essential trace and toxic elements cadmium (Cd), calcium (Ca), lead (Pb), and magnesium (Mg) in biological samples (whole blood, urine, and scalp hair) of male paralyzed production (PPW) and quality control workers (PQW) of a steel mill, age ranged (35-55 years). For comparison purposes, healthy age-matched exposed referent subjects (EC), working in steel mill and control subjects (NEC), who were not working in industries and lived far away from the industrial areas, were selected as control subjects. The concentrations of electrolytes and toxic elements in biological samples were measured by atomic absorption spectrometry after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair, blood, and urine samples of PPW and PQW as compared to NEC and EC (p < 0.001), whereas the concentrations of Ca and Mg were found to be lower in the scalp hair and blood but higher in the urine samples of PPW and PQW. The results show the need for immediate improvements in workplace, ventilation, and industrial hygiene practices.