Metallic profile of whole blood and plasma in a series of 106 healthy volunteers

Associations between prenatal exposure to metal mixtures and infant reproductive hormones during mini-puberty

BACKGROUND

The reproductive hormone homeostasis is crucial for child development. Exposure to metals during pregnancy may have adverse effects on offspring health. However, the association between prenatal exposure to metals and infant reproductive hormone levels remains unknown.

METHODS

This study involved 812 mother-infant pairs from Wuhan, China, assessing prenatal exposure to 13 metals in maternal plasma during early pregnancy and measuring five reproductive hormones in urine samples of one-month-old infants. Generalized linear models were employed to investigate the associations between individual metal exposures and urinary hormone levels in infants. Additionally, weighted quantile sum (WQS) regression and quantile g-computation were employed to evaluate the impact of metal mixtures.

RESULTS

Most of the detected metals in maternal plasma were associated with lower levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in infants. Each interquartile range (IQR) increase in manganese (Mn), barium (Ba), thallium (Tl), vanadium (V), cobalt (Co), nickel (Ni), and lead (Pb) was significantly associated with an approximately 9.87 % to 38.24 % decrease in FSH or LH. WQS and quantile g-computation models confirmed a significant association between prenatal metal mixtures and reduced FSH and LH in male infants, and WQS indicated a significant association between metal mixtures and decreased FSH in female infants.

CONCLUSIONS

Maternal exposure to mixed metals during early pregnancy was associated with lower levels of FSH and LH in infants, suggesting that prenatal exposure to metals may disrupt the balance of infant reproductive hormones. Further research is warranted to confirm these associations and explore the underlying mechanisms.

Reference values for plasma and urine trace elements in a Swiss population-based cohort

OBJECTIVES

Trace elements (TEs) are ubiquitous. TE concentrations vary among individuals and countries, depending on factors such as living area, workplaces and diet. Deficit or excessive TEs concentrations have consequences on the proper functioning of human organism so their biomonitoring is important. The aim of this project was to provide reference values for TEs concentrations in the Swiss population.

METHODS

The 1,078 participants to the SKiPOGH cohort included in this study were aged 18-90 years. Their 24-h urine and/or plasma samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine 24 TEs concentrations: Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Hg, I, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Se, Sn, Tl, V and Zn. Statistical tests were performed to evaluate the influence of covariates (sex, age, BMI, smoking) on these results. Reference intervals for the Swiss adult population were also defined.

RESULTS

TEs concentrations were obtained for respectively 994 and 903 persons in plasma and urine matrices. It was possible to define percentiles of interest (P50 and P95) for almost all the TEs. Differences in TEs distribution between men and women were noticed in both matrices; age was also a cofactor.

CONCLUSIONS

This first Swiss biomonitoring of a large TEs-panel offers reference values in plasma and in urine for the Swiss population. The results obtained in this study were generally in line with clinical recommendations and comparable to levels reported in other population-based surveys.

The smallest traces of crime: Trace elements in forensic science

BACKGROUND

Securing the evidence in various investigative situations is often associated with trace analysis, including fingerprints or blood groups. However, when classic and conventional methods fail, trace elements, such as copper, zinc, fluorine, and many others found in exceedingly insignificant amounts in organisms, may prove useful and effective.

METHODS

The presented work reviews articles published between 2003 and 2023, describing the use of trace elements and the analytical methods employed for their analysis in forensic medicine and related sciences.

RESULTS & CONCLUSION

Trace elements can be valuable as traces collected at crime scenes and during corpse examination, aiding in determining characteristics like the sex or age of the deceased. Additionally, trace elements levels in the body can serve as alcohol or drug poisoning markers. In traumatology, trace elements enable the identification of various instruments and the injuries caused by their use.

Association of Metal Cations with the Anti-PF4/Heparin Antibody Response in Heparin-Induced Thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is an antibody-mediated immune response against complexes of heparin and platelet factor 4 (PF4). The electrostatic interaction between heparin and PF4 is critical for the anti-PF4/heparin antibody response seen in HIT. The binding of metal cations to heparin induces conformational changes and charge neutralization of the heparin molecule, and cation-heparin binding can modulate the specificity and affinity for heparin-binding partners. However, the effects of metal cation binding to heparin in the context of anti-PF4/heparin antibody response have not been determined. Here, we utilized inductively coupled plasma mass spectrometry (ICP-MS) to quantify 16 metal cations in patient plasma and tested for correlation with anti-PF4/heparin IgG levels and platelet count after clinical suspicion of HIT in a cohort of heparin-treated patients. The average age of the cohort (n = 32) was 60.53 (SD = 14.31) years old, had a mean anti-PF4/heparin antibody optical density [OD405] of 0.93 (SD = 1.21) units, and was primarily female (n = 23). Patients with positive anti-PF4/heparin antibody test results (OD405 ≥ 0.5 units) were younger, had increased weight and BMI, and were more likely to have a positive serotonin release assay (SRA) result compared to antibody-negative patients. We observed statistical differences between antibody-positive and -negative groups for sodium and aluminum and significant correlations of anti-PF4/heparin antibody levels with sodium and silver. While differences in sodium concentrations were associated with antibody-positive status and correlated with antibody levels, no replication was performed. Additional studies are warranted to confirm our observed association, including in vitro binding studies and larger observational cohorts.

A Fast-Forward Dilute-and-Shoot Multielement Method for Analysis of 33 Elements in Human Whole Blood, Serum, and Urine by Inductively Coupled Plasma Mass Spectrometry: A Streamlined Approach for Clinical Diagnostic and Biomonitoring

The analysis of toxic and essential elements in human matrices is used in clinical diagnostics and for biomonitoring of different populations to study related health outcomes. This work aimed to develop fast and reliable methods for the analysis of a broad range of elements in liquid human matrices, such as whole blood, serum, and urine, with a similar setup for the three matrices and different analysis needs. An easy and fast-forward dilute-and-shoot method for 33 elements (i.e., Ag, Al, As, B, Ba, Be, Bi, Cd, Ce, Co, Cr, Cu, Hg, I, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Se, Sn, Sr, Te, Th, Tl, U, V, W, Zn, and Zr) was developed. 200 µL of either sample material was diluted with an alkaline reagent to a volume of 4 mL in total. Sample dilution and preparation of matrix-matched calibration standards were performed in 48-well plates by an automated liquid handler. Diluted samples were analyzed by inductively coupled plasma mass spectrometry on a Perkin Elmer NexIon 300D ICP-MS instrument equipped with an ESI-FAST SC2DX autosampler in kinetic energy discrimination mode with helium as cell gas at either 4.8 mL or 5.7 mL and 1600 W RF generator power. The method validation results showed good accuracy for fresh human samples from an external quality assessment scheme with measured concentrations within the assigned concentration ranges. Good precision and reproducibility for most elements were demonstrated with variation coefficients below or far below 8% and 15% for whole blood, 8% and 10% for serum, and 10% and 10% for urine, respectively. The developed reagent and instrumental setup were applicable to all three matrices. This minimizes the risk of human errors when switching between analyses of the different sample matrices and allows a rapid and easy analysis of whole blood, serum, and urine within one day if needed. The method demonstrated robustness over time, withstanding minor changes in the preparation of working solutions and samples, instrumental analysis, and setup. Analysis of human real samples showed the method's applicability for 33 toxic and essential elements in whole blood, serum, and urine and at concentrations relevant to clinical diagnostics as well as biomonitoring.

Negative Association of Cognitive Performance With Blood Serum Neurotoxicity and Its Modulation by Human Herpes Virus 5 (HHV5) Seropositivity in Healthy Women

Identification of early influences on cognitive decline is of paramount importance in order to stem the impacts of decrements in cognitive functioning and to potentially intervene. Thus, here we focused on 132 healthy adult women (age range 26-98 years) to (a) determine whether factors circulating in serum may exert neurotoxic effects in vitro, (b) evaluate associations between serum neurotoxicity and cognitive performance, and (c) assess the influence of human herpes virus (HHV) seroprevalence and other factors on apoptosis and cognitive performance. The results documented that the addition of serum from healthy adult women to neural cell cultures resulted in apoptosis, indicating the presence of circulating neurotoxic factors in the serum. Furthermore, apoptosis increased with age, and was associated with decreased cognitive performance. Stepwise regression evaluating the influence of 6 HHVs on apoptosis and cognitive function revealed that only HHV5 (cytomegalovirus; CMV) seropositivity was significantly associated with apoptosis and cognitive decline, controlling for age. These findings document neurotoxic effects of serum from healthy women across the adult lifespan and suggest a unique detrimental influence associated with CMV seropositivity.

Reference intervals of 24 trace elements in blood, plasma and erythrocytes for the Slovenian adult population

OBJECTIVES

The aim of the present study was to establish the population- and laboratory-specific reference intervals (RIs) for the Slovenian adult population for 24 trace elements (TEs) in blood, plasma and erythrocytes and to evaluate the impact of gender, age, seafood consumption, smoking habits and amalgam fillings on TEs levels.

METHODS

TEs (Mn, Co, Cu, Zn, Se and Mo, Li, Be, V, Cr, Ni, Ga, As, Rb, Sr, Ag, Cd, Sn, Cs, Au, Hg, Tl, Pb and U) were determined in 192 a priori selected blood donors (107 women and 85 men, aged 18-65 years), using inductively coupled plasma mass spectrometry (ICP-MS) with the Octopole Reaction System. Participants filled out a questionnaire, and RIs were established according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for TEs.

RESULTS

Uniform RIs for non-essential and gender-specific for essential TEs in blood, plasma and erythrocytes were established. In our population, higher blood and plasma Cu, and erythrocyte Mn levels in women were found. In men, blood Zn, plasma Zn, Mn and Se, and erythrocyte Cu levels were higher. Zn levels were higher in 30-39 years age group. Pb and Sr increased with age. Smoking positively affected Cd, Pb, Cs and Rb; seafood consumption increased As, Hg and Zn; and amalgam increased Hg, Ag and Cu levels.

CONCLUSIONS

Essential TEs were inside recommended levels, and the non-essential ones were far below critical levels. Established RIs will provide an important foundation for clinical diagnostics, safety erythrocyte transfusions assessment, toxicology and epidemiological studies.

A prototype of ultrasensitive time-resolved fluoroimmunoassay for the quantitation of lead in plasma using a fluorescence-enhanced europium chelate label for the detection system

This study describes the prototype of a novel ultra-sensitive time-resolved fluoroimmunoassay (TRFIA) for the quantification of lead (Pb) in plasma. The assay procedures were conducted in 96-microwell plates and involved the competitive binding format. The assay used a mouse monoclonal antibody, designated as 2C33, that specifically recognized the diethylenetriamine pentaacetic acid chelate of Pb (Pb-DTPA) but did not recognize Pb-free DTPA chelator. The antigen used for coating onto the inner surfaces of assay plate microwells was Pb-DTPA conjugated with bovine serum albumin protein (Pb-DTPA-BSA). The competitive binding reaction occurred between Pb-DTPA chelates, formed in the sample solutions by treating the samples with an excess DTPA, and the coated Pb-DTPA-BSA for a limited quantity of 2C33 antibody binding sites. The antigen-antibody complex formed in the plate wells was quantified by a europium-DTPA-labeled secondary antibody and a fluorescence enhancement solution. The conditions of the assay were refined, and its optimum procedures were established. The TRFIA was validated following the immunoassay validation guidelines, and all of the validation criteria were acceptable. The working range of the assay was 20-300 pg mL-1 and its limit of quantitation was 20 pg mL-1. Metals that are commonly encountered in blood plasma did not interfere with Pb in the analysis by the proposed TRFIA. The assay was applied to the quantitation of Pb in plasma samples with satisfactory accuracy and precision. The results were compared favorably with those obtained by atomic emission spectroscopy. In conclusion, the present study represents the first TRFIA for the quantitation of Pb in plasma. The assay is superior to the existing atomic spectrometric methods and other immunoassays for Pb in terms of sensitivity, convenience, and analysis throughputs. The proposed TRFIA is anticipated to effectively contribute to assessing Pb concentrations and controlling the exposure of humans to its potential toxicity.

Associations between plasma metal/metalloid mixtures and the risk of central obesity: A prospective cohort study of Chinese adults

Central obesity has increased rapidly over the past decade and posed a substantial disease burden worldwide. Exposure to metals/metalloids has been acknowledged to be involved in the development of central obesity through regulation of cortisol, insulin resistance, and glucocorticoid receptor reduction. Despite the importance, it is lack of prospective study which comprehensively evaluate the relations between multiple metals exposure and central obesity. We explored the prospective associations of plasma metal concentrations with central obesity in a prospective study of the Dongfeng-Tongji cohort. The present study included 2127 participants with a 6.87-year mean follow-up duration. We measured 23 plasma metal/metalloid concentrations at baseline. The associations between metals and incident central obesity were examined utilizing the Cox proportional hazard regression in single and multiple metals models. Additionally, we applied elastic net (ENET), Bayesian kernel machine regression (BKMR), plasma metal score (PMS), and quantile-based g-computation (Qgcomp) models to explore the joint associations of metal mixtures with central obesity. After adjusting potential confounders, we found significant associations of plasma manganese (Mn) and thallium (Tl) concentrations with a higher risk of central obesity, whereas plasma rubidium (Rb) concentration was associated with a lower risk of central obesity both in single and multiple metals models (all FDR <0.05). The ENET and Qqcomp models verified similar metals (Mn, Rb, and Tl) as important predictors for central obesity. The results of both BKMR model and PMS suggested cumulative exposure to metal mixtures was associated with a higher risk of central obesity. Our findings suggested that co-exposure to metals was associated with a higher risk of central obesity. This study expands our knowledge that the management of metals/metalloids exposure may be beneficial for the prevention of new-onset central obesity, which may subsequently alleviate the disease burden of late-life health outcomes.

Consequences of Disturbing Manganese Homeostasis

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

Lead, Mercury, and Cadmium Concentrations in Blood Products Transfused to Neonates: Elimination Not Just Mitigation

Lead (Pb), mercury (Hg), and cadmium (Cd) are identified as potent developmental neurotoxicants. Neonates are the main group receiving multiple blood transfusions. The exposure of neonates to these heavy metals (HMs) can occur through blood transfusions. This study aimed to determine the concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in various blood products (plasma, platelets, packed red blood cells (pRBCs), and whole blood (WB)) to explore the probability of concurrent exposure of these HMs and to identify the metal load per transfusion with risk assessment. Residual bloods from blood bank bags were collected after neonatal transfusion. Pb, Hg, and Cd concentrations were determined in 120 samples of blood products by inductively coupled plasma mass spectrometry (ICP-MS). Pb and Cd levels were over the normal levels in 19.2 and 5.9% of all blood units, respectively. In 35 and 0.8% of blood units, the Pb and Cd concentrations, respectively, were higher than that recommended for transfusions in premature neonates. The anticipated safe value was surpassed by 2.5% for Cd of all transfusions, primarily because of WB. However, Hg was detected only in 5.8% of all samples and their concentrations were within the normal range. The concurrent neonatal exposure to Pb, Hg, and Cd was statistically significant. Hazard quotients of Hg and Cr were >1 and Pb cancer risk was 2.41 × 10-4. To the best of our knowledge, this study is the first report examining Pb, Hg, and Cd in blood products other than WB and pRBCs using ICP-MS. This study demonstrated the exposure of neonates to Pb, Hg, and Cd during transfusion with a considerable amount of Pb. It confirms the significant concurrent exposure to the three HMs, which maximize their potential developmental neurotoxicity with a high probability of developing non-carcinogenic and carcinogenic health effects.

Association between whole blood essential trace elements and cognitive function in older adults

BACKGROUND

Essential trace elements (ETEs) are essential nutrients for keeping the nervous system functioning. Associations between ETEs and cognitive function are still inconclusive and limited.

OBJECTIVES

We aimed to investigate the individual and joint associations between ETEs and cognitive function among older adults.

METHODS

A population (N = 2181) at an average age≥ 65 from Yiwu cohort in China was available for this study. Whole blood chromium (Cr), selenium (Se), manganese (Mn), and copper (Cu) concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS). Cognitive function was assessed using the Mini-Mental State Examination (MMSE), consisting of five specific cognitive domains: orientation, registry, attention and calculation, recall, and language and praxis. Linear regression, restricted cubic spline (RCS) analysis, and Bayesian kernel machine regression (BKMR) were used to analyze the individual and joint associations between ETEs and cognitive function.

RESULTS

The association between Cr and MMSE score presented an inverted-U shape (Q3 versus Q1: β = 0.774, 95 % CI: 0.297, 1.250; Q4 versus Q1: β = 0.481, 95 % CI: 0.006, 0.956); and Cr was especially associated with the registry, recall, and language and praxis. Per IQR (36.32 μg/L) increase of Se was positively associated with the MMSE score (β = 0.497, 95 % CI: 0.277, 0.717) and all five cognitive domains. The BKMR showed that the dose-response association between Se and cognitive function increased initially and then decreased with increasing Se concentration when fixed the other ETEs in median. ETEs mixture was positively associated with cognitive function, and Se (posterior inclusion probabilities, PIPs = 0.915) was the most important contributor within the ETEs mixture.

CONCLUSIONS

The nonlinear association between Cr and cognitive function suggested further exploration of an appropriate concentration range for ETEs. A positive association between mixed ETEs and cognitive function is a reminder that their joint association should be considered. Further prospective studies or intervention studies are warranted to validate our findings in the future.

Assessment of barium diffusion from therapeutic mud wrapped in micro-perforated polyethylene bags towards the human organism

Barium is present within the clay-derived therapeutic mud packs deposed on the patient's skin for treating some rheumatologic conditions. We studied in twenty-four young healthy volunteers the diffusion of Ba from mud wrapped in micro-perforated polyethylene bags and soaked in mineral water. No significant systematic increase in plasma or urine Ba levels was evidenced when comparing pre- and post-treatment samples using inductively-coupled plasma mass spectrometry. These levels were markedly inferior to the recommended thresholds in nearly all the participants. Noticeably variability in blood and especially urine Ba concentrations was large and mainly explained by environmental exposure (alimentation). Interestingly, we evidenced an intense Ba accumulation within the therapeutic mud at the end of the regimen. Because we chose a clay with one of the highest Ba content available in France for medical therapy and participants with an optimal transcutaneous diffusion capacity (young individuals with low-fat mass), we conclude unambiguously that there is no risk of Ba overexposure in patients receiving pelotherapy according to the procedure used in French medical spas.

Investigation and monitoring of heavy metal poisoning

Historically, heavy metal measurement and interpretation has been a highly specialised area performed only in a handful of centres within the UK. However, recent years have seen a move to more local testing due to the repatriation of referred work into pathology networks and the increased availability of inductively coupled plasma mass spectrometry technology. While management of significant poisoning is still overseen by tertiary care poisoning specialists, management of milder cases may be undertaken locally.Non-specialist clinical scientists and clinicians need to know when heavy metal testing is appropriate, which samples are required (and any specific requirements around collection) and how to interpret and act on the results.This Best Practice article provides guidance on the investigation and monitoring of the toxic elements most frequently encountered in general medical practice; lead, mercury and arsenic. It is intended as a reference guide for the non-specialist and as a comprehensive summary for clinical toxicologists and clinical scientists.

Non-essential and essential trace element mixtures and kidney function in early pregnancy - A cross-sectional analysis in project viva

Some trace elements are established nephrotoxicants, yet their associations with kidney function remain understudied in the context of pregnancy, a time of substantial change in kidney physiology and function. We aimed to estimate the individual and joint associations of trace element mixtures with maternal kidney function during the 1st trimester of pregnancy (mean 9.7 gestational weeks). 1040 women from Project Viva contributed blood samples which were assessed for erythrocyte non-essential [arsenic (As), cadmium (Cd), cesium (Cs), mercury (Hg), lead (Pb)] and essential [barium (Ba), magnesium (Mg), manganese (Mn), selenium (Se), and Zinc (Zn)] trace elements, and plasma creatinine for kidney function. We estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration (eGFRCKD-EPI) equation without race-adjustment factors. We examined associations of eGFRCKD-EPI with individual trace elements using multivariable linear regression and their mixtures using quantile-based g-computation, adjusting for sociodemographics, pregnancy characteristics, and diet. Participants in our study were predominantly White (75%), college graduates (72%), and had household income >$70,000/year (63%). After adjusting for covariates, higher Pb (β -3.51 ml/min/1.73 m2; 95% CI -5.83, -1.18) concentrations were associated with lower eGFRCKD-EPI, while higher Mg (β 10.53 ml/min/1.73 m2; 95% CI 5.35, 15.71), Se (β 5.56 ml/min/1.73 m2; 95% CI 0.82, 10.31), and Zn (β 5.88 ml/min/1.73 m2; 95% CI 0.51, 11.26) concentrations were associated with higher eGFRCKD-EPI. In mixture analyses, higher non-essential trace elements mixture concentration was associated with reduced eGFRCKD-EPI (Ψ -1.03 ml/min/1.73 m2; 95% CI: 1.92, -0.14). Conversely, higher essential trace elements mixture concentration was associated with higher eGFR (Ψ 1.42; 95% CI: 0.48, 2.37). Exposure to trace elements in early pregnancy may influence women's kidney function although reverse causation cannot be eliminated in this cross-sectional analysis. These findings have important implications for long-term cardiovascular and postpartum kidney health that warrant additional studies.

Effects of Bismuth Exposure on the Human Kidney-A Systematic Review

The effects of bismuth toxicity on the kidney-the main organ responsible for blood filtration-were systematically reviewed. This review was motivated by availability of several sources of bismuth in contact with humans including environmental, medications, dental materials, and cosmetics, potentially leading to kidney filtration of this chemical. No previous studies have systematically reviewed the literature considering this association. A total of 22 studies with a total of 46 individuals met the inclusion criteria, 19 being case reports with only one patient enrolled. The included studies publication dates ranged from 1961 to 2021 and the countries of publication were the United States of America, United Kingdom, Germany, Turkey, Switzerland, and Canada. Bismuth sources affecting the kidneys were uniquely reported as from medical purposes and mostly associated to overdoses with several symptoms, apparently with dose-dependent consequences. Patient history of renal impairment seemed to affect the outcome of the case. Several therapies were conducted following bismuth intoxication, and few studies performed renal biopsies describing its histological findings. It is crucial to reconsider the nephrotoxicity of bismuth compounds, mainly in patients with previous history of renal impairment.

Association of copper exposure with prevalence of chronic kidney disease in older adults

BACKGROUND & AIMS

Metal exposure is suspected to be associated with the risk of chronic kidney disease (CKD). Copper (Cu) is an essential yet toxic trace element in humans. Epidemiological evidence on the association of Cu exposure with CKD remains inconsistent. This study aims to investigate the association of blood Cu and its co-exposure to other metals with CKD.

METHODS

A cross-sectional study was conducted among 3285 older participants in Zhejiang, China. The whole blood levels of Cu as well as other 10 metals were measured using the inductively coupled plasma mass spectrometry (ICP-MS). CKD events were defined as the presence of albuminuria or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². Multivariable logistic regression and linear regression models were applied to assess the association of Cu with kidney function. The Bayesian kernel machine regression (BKMR) was used to examine the association of metal interactions with CKD.

RESULTS

In logistic models, we found a dose-dependent positive association between blood Cu and the prevalence of CKD. Compared to the lowest quartile of blood Cu, the odds ratio (OR) of CKD in the highest quartile was 1.65 (95% confidence interval, CI: 1.25, 2.17), and the β of eGFR was -1.74 (95% CI: -3.15, -0.34) after adjusting for multiple covariates. The positive linear dose-response association was found between blood Cu and the OR of CKD, and negative linear association was found between Cu and the β of eGFR. The positive association between blood Cu and CKD risk was stronger at lower level of manganese (Mn) in the BKMR model.

CONCLUSION

The whole blood level of Cu was remarkably associated with the risk of CKD and showed positive dose-response relationships in the older Chinese population. The toxicity of Cu on kidney function could be antagonized by the exposure of Mn. These findings shed new light on the potential role of Cu in kidney health.

Individual and joint associations of co-exposure to multiple plasma metals with telomere length among middle-aged and older Chinese in the Dongfeng-Tongji cohort

Studies on associations of metals with leucocyte telomere length (LTL) were mainly limited to several most common toxic metals and single-metal effect, but the impact of other common metals and especially the overall joint associations and interactions of metal mixture with LTL are largely unknown. We included 15 plasma metals and LTL among 4906 participants from Dongfeng-Tongji cohort. Multivariable linear regression was used to estimate associations of individual metals with LTL. We also applied Bayesian kernel machine regression (BKMR) and quantile g-computation regression (Q-g) to evaluate the overall association and interactions, and identified the major contributors as well as the potential modifications by major characteristics. Multivariable linear regression found vanadium, copper, arsenic, aluminum and nickel were negatively associated with LTL, and a 2-fold change was related to 1.9%-5.1% shorter LTL; while manganese and zinc showed 3.7% and 4.0% longer LTL (all P < 0.05) in multiple-metal models. BKMR confirmed above metals and revealed a linearly inverse joint association between 15 metals and LTL. Q-g regression further indicated each quantile increase in mixture was associated with 5.2% shorter LTL (95% CI: -8.1%, -2.3%). Furthermore, manganese counteracted against aluminum and vanadium respectively (P_int<0.05). In addition, associations of vanadium, aluminum and metal mixture with LTL were more prominent in overweight participants. Our results are among the first to provide a new comprehensive view of metal mixture exposure on LTL attrition in the general population, including identifying the major components, metals interactions and the overall effects.

Trace elements repartition in body fluids, hair and organs in an autopsied population evaluated by ICP-MS high resolution

Exposure to metals and trace elements (TE) is universal and can cause toxicity in case of excessive exposure. We evaluated the concentrations and tissue distribution of 39 TE using high-resolution ICP-MS after total mineralization by microwave in twenty autopsied French subjects. We found a globally homogeneous distribution of TE in the body, with some accumulations in agents, involved in respiratory pathologies and classified as carcinogens, in the lungs. The liver, an organ of metabolism, appeared to concentrate Co, Fe, La, Mn, Mo, Pb and Zn. Fe seemed to accumulate in the spleen, the organ of hematopoiesis. The kidney showed high concentrations of some TE, which can cause nephrotoxicity. The use of microwave mineralization and high-resolution ICP-MS allowed accurate quantification and a very high sensitivity, without spectral interferences. The results obtained in this study could be used to support the interpretation of post-mortem metal concentrations in tissues.

Associations of multiple plasma metals with chronic kidney disease in patients with diabetes

As common contaminants, metals are non-negligible risk factors for diabetes and chronic kidney disease. However, whether there is an association between multiple metals exposure and incident chronic kidney disease (CKD) risk in patients with diabetes is unclear. We conducted a prospective study to evaluate these associations. In total, 3071 diabetics with baseline estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² from the Dongfeng-Tongji cohort were included. We measured baseline plasma concentrations of 23 metals and investigated the associations between plasma metal concentrations and CKD in diabetics using logistic regression, the least absolute shrinkage and selection operator (LASSO), and the Bayesian Kernel Machine Regression (BKMR) models. During average 4.6 years of follow-up, 457 diabetics developed CKD (14.9 %). The three models consistently found plasma levels of zinc, arsenic, and rubidium had a positive association with incident CKD risk in patients with diabetes, while titanium, cadmium, and lead had an inverse correlation. The results of BKMR showed a significant and positive overall effect of 23 metals on the risk of CKD, when all of the metals were above the 50th percentile as compared to the median value. In addition, potential interactions of zinc and arsenic, zinc and cadmium, zinc and lead, titanium and arsenic, and cadmium and lead on CKD risk were observed. In summary, we found significant associations of plasma titanium, zinc, arsenic, rubidium, cadmium, and lead with CKD in diabetes and interactions between these metals except for rubidium. Co-exposure to multiple metals was associated with increased CKD risk in diabetics.

NRF2 Genetic Polymorphism Modifies the Association of Plasma Selenium Levels With Incident Coronary Heart Disease Among Individuals With Type 2 Diabetes

Plasma selenium and NRF2 promoter variants (e.g., rs6721961) are associated with cardiovascular disease risk in the general population. However, epidemiological evidence on the interaction between plasma selenium and NRF2 genetic susceptibility in relation to incident coronary heart disease (CHD) risk remains scarce, especially among individuals with type 2 diabetes (T2D). Thus, we examined whether rs6721961 in the NRF2 gene might modify the association between plasma selenium levels and incident CHD risk among people with T2D. During a mean (SD) follow-up period of 6.90 (2.96) years, 798 incident CHD cases were identified among 2,251 T2D cases. Risk-allele carriers of rs6721961 had a higher risk of incident CHD among people with T2D (adjusted hazard ratio [HR] 1.17; 95% CI 1.02-1.35) versus nonrisk-allele carriers. Each 22.8-μg/L increase in plasma selenium levels was associated with a reduced risk of incident CHD among risk-allele carriers with T2D (HR 0.80; 95% CI 0.71-0.89), whereas no association was found in those without risk alleles (P for interaction = 0.004), indicating that the NRF2 promoter polymorphism might modify the association between plasma selenium levels and incident CHD risk among people with T2D. Our study findings suggest redox-related genetic variants should be considered to identify populations that might benefit most from selenium supplementation. More mechanistic studies are warranted.

Exposure to barium and blood pressure in children and adolescents: results from the 2003-2018 National Health and Nutrition Examination Survey

Barium (Ba) is ubiquitous in the environment, and humans are primarily exposed to it through ingestion of drinking water. Previous studies focused on the exposure to lead, cadmium, and arsenic, but have not focused on exposure to Ba. Recent studies found a significant association between Ba exposure and elevated blood pressure in pregnant women and adults. However, there are no studies regarding the effect of Ba exposure on blood pressure in children and adolescents, and the potential biological mechanisms remain unclear. We evaluated the associations between urinary Ba and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) among 8- to 17-year-old participants (n = 3707) of the 2003-2018 National Health and Nutrition Examination Survey. Furthermore, the potential roles of inflammation in these associations were explored. Weighted linear regression was used to analyze the association between urinary Ba and blood pressure, and mediation analyses were used to estimate the potential role of white blood cell count (WBC) in these associations. Quantile g-computation models were used to explore the effect of co-exposure to Ba and other metals on blood pressure. After adjusting for covariates, a two-fold increase in urinary Ba concentration was associated with a 0.41 (95% CI 0.12, 0.70) mmHg increase in SBP, a 1.04 (95% CI 0.55, 1.53) mmHg increase in PP, but a -0.63 (95% CI -1.04, -0.22) mmHg decrease in DBP. WBC significantly mediated 6% of the association between urinary Ba and SBP. Quantile g-computation models suggested that urinary Ba was the main contributor to the elevation of SBP and PP in the urinary metal mixture. Our findings revealed that exposure to Ba was associated with elevated SBP and PP among children and adolescents. Inflammation may play an important role in the associations of Ba exposure with SBP.

Magnesium for Implants: A Review on the Effect of Alloying Elements on Biocompatibility and Properties

An attempt is made to cover the whole of the topic of biodegradable magnesium (Mg) alloys with a focus on the biocompatibility of the individual alloying elements, as well as shed light on the degradation characteristics, microstructure, and mechanical properties of most binary alloys. Some of the various work processes carried out by researchers to achieve the alloys and their surface modifications have been highlighted. Additionally, a brief look into the literature on magnesium composites as also been included towards the end, to provide a more complete picture of the topic. In most cases, the chronological order of events has not been particularly followed, and instead, this work is concentrated on compiling and presenting an update of the work carried out on the topic of biodegradable magnesium alloys from the recent literature available to us.

Association between the blood manganese (Mn) and hemoglobin in patients undergoing maintenance hemodialysis

BACKGROUND AND AIMS

Manganese (Mn) and iron metabolism are closely related. Iron metabolism disorders often lead to anemia in patients undergoing maintenance hemodialysis (MHD). Here, we aimed to investigate the relationship between blood Mn and hemoglobin (Hb) in patients undergoing MHD.

METHODS

Patients undergoing MHD in September 2019 were included in a cross-sectional study. Clinical and demographic data and blood samples were collected before hemodialysis sessions, and blood levels of Mn were measured by inductively coupled plasma mass spectrometry. Both multivariable linear and binary logistic regression analyses were performed to study the relationship between the blood Mn and Hb.

RESULTS

A total of 144 patients undergoing MHD were enrolled in the study. The patients had a mean age of 64.33 ± 13.39 years, median vintage of 33.50 (16.25-57.50) months. Among them, 66 were females (45.8%). The median blood Mn level was 13.55 µg/L (IQR:9.92-17.48). Ninety-nine patients were anemic (68.8%). The mean Hb level was 99.83 ± 19.68 g/L. The patient group with high blood Mn had a high proportion of females, and these patients had high levels of RBC, hemoglobin, Hct, UIBC, serum TCHOL, and serum LDL, yet short dialysis vintage, low prevalence of anemia, low levels of serum ferritin, serum iron, and TSAT. Following adjustment for confounding factors, we found that low blood Mn level was independently associated with lower Hb level and anemia in patients undergoing MHD by multivariate linear and multivariate binary logistic regression, respectively, in different models.

CONCLUSION

Whilst our study showed that high levels of blood Mn were independently associated with high hemoglobin in patients undergoing MHD, further multicenter studies with large sample sizes are still required.

Multiple plasma metals, genetic risk and serum complement C3, C4: A gene-metal interaction study

Exposure to metals and metalloids is widely related with human health, and could affect the function of immune system. The complement system links innate and adaptive immunity, and is critically involved in the pathogenesis of inflammatory and immune diseases. The third and fourth components of complement (C3, C4) play key roles in the complement system. However, few studies have examined the relations between multiple metals and complement levels. In this study, based on a total of 2977 participants from the Dongfeng-Tongji cohort, China, we investigated 17 plasma metals and serum C3, C4 levels, and calculated C3/C4-associated genetic risk scores (GRSs) using established single nucleotide polymorphisms. We further explored the potential gene-metal interactions on C3 and C4. After multivariable adjustment, an increment of 10-standard deviation increase in natural log-transformed exposure concentrations of plasma copper was associated with 0.549 (0.489, 0.608) (FDR <0.0001), and 1.146 (0.999, 1.294) (FDR <0.0001) higher natural log-transformed serum C3 and C4 levels, respectively. While each increment of 10-standard deviation of natural log-transformed zinc was associated with a difference of 0.083 (0.024, 0.143) (FDR = 0.049) and 0.007 (-0.138, 0.152) (FDR = 0.935) in log-transformed C3 and C4 levels, respectively. Participants with higher GRS had higher C3 and C4 levels. Furthermore, we found a significant interaction between arsenic exposure and C3-GRS in relation to C3 level (P_interaction = 0.0096). Our results suggested that plasma arsenic would modify the association between C3 genetic predisposition and serum C3 level. We provide new insight into metals exposure on the human immune system. These findings require replication in future research.

Confirmation of the systematic presence of tin particles in fallopian tubes or uterine horns of Essure implant explanted patients: A study of 18 cases with the same pathological process

OBJECTIVE

To examine associations between local and systemic symptoms and the wear of the tin weld of Essure implants.

DESIGN

study of a series of cases.

SETTINGS

Two French hospitals.

PARTICIPANTS

Eighteen patients explanted by hysterectomy and salpingectomy for removal of their Essure implants between September 2019 and July 2020, have had a common anatomopathological process.

MAIN OUTCOME MEASURES

anatomopathological examination by optical microscopy and mineralogical analysis of the fallopian tube or uterine horn with scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX). Evaluation of local and systemic symptoms with a questionnaire. Examination of blood metal assays (nickel, chromium, and tin).

RESULTS

anatomopathological examination highlights foreign body granulomas, fibrosis, adenomyosis, nonspecific inflammation, cysts and myomas in the Fallopian tubes, uterine horns, or both and mentions the presence of foreign bodies in seven cases. SEM-EDX analyses showed, systematically, the presence of tin particles integrated in the wall near the weld, generally in clusters, and with a size ranging from about one micron to several dozen microns. The questionnaire shows that the most frequent local symptoms were pelvic pain, urinary disorders, bleeding, and pains during intercourse. The most common systemic symptoms were: asthenia, visual disturbances, amnesia, giddiness, dorsal pains, headaches, and joint pains. The majority of local and systemic symptoms decreased after explantation, but sometimes incompletely. Before explantation, high levels of nickel, tin and chromium were observed in 11/17, 1/7 and 2/17 patients. After explantation, tin levels were high in 3/11 patients.

CONCLUSIONS

our new anatomopathological process systematically demonstrates the presence of tin particles in tissue near the weld. These particles could be responsible for granulomatous inflammations as well as local symptoms. Many of the systemic symptoms are consistent with chronic organotin poisoning but further studies are needed to find out whether tin from the solder can be converted to organotin in the patients' bodies.

Associations of plasma metal levels with type 2 diabetes and the mediating effects of microRNAs

The present study aims to determine the associations of multiple plasma metal levels and plasma microRNAs (miRNAs) with diabetes risk, and further explore the mediating effects of plasma miRNAs on the associations of plasma metal with diabetes risk. We detected plasma levels of 23 metals by inductively coupled plasma mass spectrometry (ICP-MS) among 94 newly diagnosed and untreated diabetic cases and 94 healthy controls. The plasma miRNAs were examined by microRNA Array screening and Taqman real-time PCR validation among the same study population. The multivariate logistic regression models were employed to explore the associations of plasma metal and miRNAs levels with diabetes risk. Generalized linear regression models were utilized to investigate the relationships between plasma metal and plasma miRNAs, and mediation analysis was used to assess the mediating effects of plasma miRNAs on the relationships between plasma metals and diabetes risk. Plasma aluminum (Al), titanium (Ti), copper (Cu), zinc (Zn), selenium (Se), rubidium (Rb), strontium (Sr), barium (Ba), and Thallium (Tl) levels were correlated with elevated diabetic risk while molybdenum (Mo) with decreased diabetic risk (P < 0.05 after FDR multiple correction). MiR-122-5p and miR-3141 were positively associated with diabetes risk (all P < 0.05). Ti, Cu, and Zn were positively correlated with miR-122-5p (P = 0.001, 0.028 and 0.004 respectively). Ti, Cu, and Se were positively correlated with miR-3141 (P = 0.003, 0.015, and 0.031 respectively). In addition, Zn was positively correlated with miR-193b-3p (P = 0.002). Ti was negatively correlated with miR-26b-3p (P = 0.016), while Mo and miR-26b-3p were positively correlated (P = 0.042). In the mediation analysis, miR-122-5p mediated 48.0% of the association between Ti and diabetes risk. The biological mechanisms of the association are needed to be explored in further studies.

Associations of plasma metal concentrations with the risks of all-cause and cardiovascular disease mortality in Chinese adults

BACKGROUND

Exposure to metals/metalloids from both the natural environment and anthropogenic sources have a complex influence on human health. However, relatively few studies have explored the relations of exposure to multiple metals/metalloids with mortality. Therefore, this prospective study aims to examine the relations of multiple metal/metalloids exposures with all-cause and cardiovascular disease (CVD) mortality.

METHODS

A total of 6155 participants within the Dongfeng-Tongji (DF-TJ) cohort were involved in this analysis, which were followed for mortality until December 31, 2018. We applied inductively coupled plasma mass spectrometry (ICP-MS) to measure baseline plasma concentrations of 23 metals. We utilized Cox regression models to calculate the hazard ratios (HRs) for all-cause and CVD mortality associated with metal concentrations. We proposed plasma metal score to assess the simultaneous exposure to multiple metals through summing each metal concentration weighted by the regression coefficients with all-cause mortality.

RESULTS

During the follow-up (mean duration, 9.8 years), we ascertained 876 deaths, including 416 deaths of CVD (157 deaths of coronary heart disease and 259 deaths of stroke). In the multiple-metals model, after adjusting for potential confounders, plasma copper, molybdenum, and vanadium were positively associated with all-cause mortality, whereas manganese, selenium, and thallium were negatively associated with the risk of all-cause mortality, with adjusted HRs (95% Confidence Interval, CI) of the fourth quartiles were 1.73 (1.42-2.11, P-trend < 0.001) for copper, 1.33 (1.09-1.63, P-trend = 0.005) for molybdenum, 1.43 (1.16-1.77, P-trend < 0.001) for vanadium, 0.74 (0.58-0.94, P-trend = 0.005) for manganese, 0.68 (0.56-0.83, P-trend < 0.001) for selenium, and 0.74 (0.59-0.92, P-trend = 0.002) for thallium, respectively. Positive associations were observed between plasma copper, molybdenum, vanadium concentrations and CVD mortality, whereas negative associations were found for plasma selenium and thallium concentrations with CVD mortality in the multiple-metals model. Compared with the first quartiles, the HRs of fourth quartiles were 1.94 (1.45-2.58, P-trend < 0.001) for copper, 1.72 (1.26-2.35, P-trend < 0.001) for molybdenum, 1.81 (1.32-2.47, P-trend < 0.001) for vanadium, 0.67 (0.50-0.89, P-trend = 0.003) for selenium, and 0.58 (0.41-0.81, P-trend < 0.001) for thallium, respectively. The plasma metal score was significantly associated with higher risks of all-cause and CVD death in dose-response fashions. When compared with the first quartiles of plasma metal score, the HRs of fourth quartiles were 2.16 (1.76-2.64; P-trend < 0.001) for all-cause mortality and 3.00 (2.24-4.02; P-trend < 0.001) for CVD mortality.

CONCLUSIONS

The study indicated that several plasma metals/metalloids were key determinants and predictors of all-cause and CVD death in the Chinese population. Our findings highlighted the importance to comprehensively assess and monitor multiple metals/metalloids exposures.

Effects of storage conditions on the stability and distribution of clinical trace elements in whole blood and plasma: Application of ICP-MS

BACKGROUND

Knowledge of trace element stability during sample handling and preservation is a prerequisite to produce reliable test results in clinical trace element analysis.

METHOD

An alkaline dissolution method has been developed using inductively coupled plasma mass spectrometry to quantify eighteen trace element concentrations: vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, bromine, molybdenum, cadmium, antimony, iodine, mercury, thallium, lead, and bismuth in human blood, using a small sample volume of 0.1 mL. The study evaluated the comparative effects of storage conditions on the stability of nutritionally essential and non-essential elements in human blood and plasma samples stored at three different temperatures (4 °C, -20 °C and -80 °C) over a one-year period, and analysed at multiple time points. The distribution of these elements between whole blood and plasma and their distribution relationships are illustrated using blood samples from 66 adult donors in Queensland.

RESULTS

The refrigeration and freezing of blood and plasma specimens proved to be suitable storage conditions for many of the trace elements for periods up to six months, with essentially unchanged concentrations. Substantially consistent recoveries were obtained by preserving specimens at -20 °C for up to one year. Ultra-freezing of the specimens at -80 °C did not improve stability; but appeared to result in adsorption and/or precipitation of some elements, accompanied by a longer sample thawing time. A population sample study revealed significant differences between the blood and plasma concentrations of six essential elements and their relationships also varied significantly for different elements.

CONCLUSION

Blood and plasma specimens can be reliably stored at 4 °C for six months or kept frozen at -20 °C up to one year to obtain high quality test results of trace elements.

Exposure to e-cigarette aerosol over two months induces accumulation of neurotoxic metals and alteration of essential metals in mouse brain

Despite a recent increase in e-cigarette use, the adverse human health effects of exposure to e-cigarette aerosol, especially on the central nervous system (CNS), remain unclear. Multiple neurotoxic metals have been identified in e-cigarette aerosol. However, it is unknown whether those metals accumulate in the CNS at biologically meaningful levels. To answer this question, two groups of mice were whole-body exposed twice a day, 5 days a week, for two months, to either a dose of e-cigarette aerosol equivalent to human secondhand exposure, or a 5-fold higher dose. After the last exposure, the olfactory bulb, anterior and posterior frontal cortex, striatum, ventral midbrain, cerebellum, brainstem, remaining brain tissue and spinal cord were collected for metal quantification by inductively coupled plasma mass spectrometry and compared to tissues from unexposed control mice. The two-month exposure caused significant accumulation of several neurotoxic metals in various brain areas - for some metals even at the low exposure dose. The most striking increases were measured in the striatum. For several metals, including Cr, Cu, Fe, Mn, and Pb, similar accumulations are known to be neurotoxic in mice. Decreases in some essential metals were observed across the CNS. Our findings suggest that chronic exposure to e-cigarette aerosol could lead to CNS neurotoxic metal deposition and endogenous metal dyshomeostasis, including potential neurotoxicity. We conclude that e-cigarette-mediated metal neurotoxicity may pose long-term neurotoxic and neurodegenerative risks for e-cigarette users and bystanders.

High silver concentrations in biological samples following different exposures: Two case reports

BACKGROUND

Silver is used in various industrial applications, but also in confectioneries and for therapeutic use due to its antibiotic properties. Its toxicity is not well documented and most often only in the context of professional exposure.

AIM

Here we report two cases of high silver concentrations in biological samples in two women: the first patient presented grey marks around her cuticles, probably due to her consumption of silvered sweets and the second patient presented agranulocytosis and thrombocytopenia occurring within 24 h after the topical application of a cream containing sulfadiazine and silver to burns over a large surface area.

METHODS

Silver concentrations were determined in blood and urine samples and sweets using inductively coupled plasma- mass spectrometry (ICP-MS).

RESULTS

The silver concentrations were elevated compared to population reference values and confirmed the hypotheses for the patients: the significant consumption of sweets coated with silver nanoparticles and the topical application of a cream containing silver to burns over a large area.

DISCUSSION-CONCLUSION

After initial questioning by the dermatologist, Patient 1 explained that she consumed more than 30 bags of the sweets per year. She decreased her consumption of the sweets and the control performed one year later showed a plasma silver concentration of 1.5 μg/L. For Patient 2, the absorption of silver through burns over a large area appeared relatively significant, whereas it is very low through undamaged skin. The haematological cells counts returned to normal levels quickly and no other major effects were highlighted. To apply these findings to a larger population, further investigation to determine sulfadiazine and silver concentrations in plasma and urine have been initiated in a cohort of patients with burns over a large area.

Possible zinc deficiency in the Serbian population: examination of body fluids, whole blood and solid tissues

Studies indicate that the soil, water and consequently foodstuffs in Serbia are significantly poor in zinc (Zn), and thus, it is likely that there is a Zn deficiency in the Serbian population. This study examined the Zn status in multiple clinical samples, including body fluids (serum, cerebrospinal fluid), whole blood and Zn-rich solid tissues (thyroid and brain tissue). Differences between sex and age were also considered, and comparative analysis of Zn status with other world populations was performed. Serum samples from a large number of Serbian adults approximately had twofold lower Zn amounts when compared to other populations. A similar trend was obtained for whole blood. Males had significantly higher amounts of Zn in serum, whole blood and thyroid tissue samples than females. Higher amounts of Zn were observed in the group older than 50 years. Importantly, in thyroid and brain tissues, Zn was 10- and 20-fold lower, respectively, than reported in the literature. Our results indicate that the population in Serbia could be considered Zn deficient. Therefore, adequate oral Zn supplementation and/or foodstuff fortification should be considered to prevent the deleterious effects caused by Zn deficiency.

Distribution, metabolism, excretion, and toxicity of implanted silver: a review

Some implantable medical devices contain silver. We aimed to assess at what amount implanted silver becomes toxic. Silver was elevated in bodily fluids and tissues surrounding silver-containing implants. Silver released from implants also distributes to blood and other tissues; there is evidence to suggest silver can pass the blood-brain-barrier. Silver can be deposited as nano-sized particles in various tissues. Such particles, in addition to silver, often contain other elements too, e.g., selenium and sulfur. Silver released from implants seems to stay in the body for long periods (years). Reported excretion pathways following implantation are urinary and fecal ones. Reported toxicological effects were virtually all local reactions surrounding the implants. Argyria is a blue-gray discoloration of the skin due to deposited silver granules. Localized argyria has been described after the implantation of acupuncture needles and silver-coated prostheses, although the presence of silver was tested only for and shown in the former. Other toxicological effects include local tissue reactivity and examples of neurotoxic and vascular effects. We did not include genotoxicity studies in the present publication as we recently evaluated silver to be genotoxic. Carcinogenicity studies were absent. We conclude that local toxicity of implanted silver can be foreseen in some situations.

Molybdenum Occupational Study in a French Cohort of Workers

OBJECTIVES

Occupational exposure to molybdenum has been poorly documented to date. Here, we present a retrospective study evaluating urinary molybdenum concentration before and after shift over a period of 2 years in exposed workers.

METHODS

This retrospective study was conducted across eight industrial sites in France and included all workers undergoing medical follow-up for occupational molybdenum exposure. A mean of six sequential samples (before and after shift) was performed for each worker. The urinary molybdenum concentration was determined using a validated method of inductively coupled plasma-mass spectrometry. A mixed linear model was built and linear regression was used to verify the extent to which the urinary molybdenum concentration depends on the age of the workers and the sampling period. Additionally, an analysis based on individual trajectory was also performed.

RESULTS

Seventy-seven workers were included in the present study. Post-shift urinary molybdenum concentrations were significantly higher than pre-shift values [median (95th percentile) 37.9 (91.1), versus 60.6 (190.0) µg g-1 creatinine, respectively, P < 0.009]. No accumulation of molybdenum over time was observed. The urinary molybdenum concentrations were not influenced by age. Four workers presented high post-shift values as a result of not adhering to protection measures (maxima of 529.8, 359.7, 386.3, and 1459.7 µg g-1 creatinine, respectively).

CONCLUSIONS

To our knowledge, this is the first study of occupational molybdenum exposure in France to include an individual trajectory analysis. No accumulation of molybdenum was seen but high post-shift molybdenum urinary concentrations were observed for some workers. The study emphasizes the importance of molybdenum monitoring in exposed workers.

Lower Levels of Blood Zinc Associated with Intradialytic Hypertension in Maintenance Hemodialysis Patients

Intradialytic hypertension (iHTN) has been related with an increased risk of mortality, with imbalances in trace elements being frequent in maintenance hemodialysis (MHD) patients. The aim of this study was to analyze the relationships between the levels of blood trace elements and iHTN in MHD patients. A total of 144 MHD patients were enrolled in September, 2019 (66 females; 5616 hemodialysis treatments), with a mean age of 64.33 ± 13.39 years and median vintage of 33.50 (16.25-57.50) months. Patients exhibited an average peridialytic systolic blood pressure (SBP) change of - 4.18 ± 20.22 mm Hg in the next 3 months. Thirty-four (23.6%) patients had persistent iHTN (piHTN). These patients were characterized by older age, higher rate of hypozincemia, and modified Charlson comorbidity score, whereas lower blood zinc and hemoglobin, at the time of their recruitment. No significant difference in the levels of other blood trace elements was observed between groups. A general linear mixed (GLM) model showed that with every mg/L point lower mean blood zinc at baseline, the peridialytic SBP change was increased by 4.524 mm Hg (P < 0.001). Binary logistic model in modulate of the GLM model revealed that the lower level of blood zinc was associated with piHTN (OR = 0.433, 95 % CI 0.295 to 0.637, P < 0.001). Multivariate analysis confirmed both above results. Our study indicated that lower blood zinc was independently associated with piHTN in patients undergoing MHD, but prospective studies with larger population are still needed.

Associations Between Blood Trace Element Levels and Nutritional Status in Maintenance Hemodialysis

OBJECTIVE(S)

We aimed to investigate the associations between blood trace element levels and nutritional status in patients undergoing maintenance hemodialysis (MHD).

METHODS

This cross-sectional study included patients undergoing MHD who were treated at our center in September 2019. Clinical and demographic data and blood samples were collected before hemodialysis sessions, and the levels of manganese, lead, selenium, zinc, and copper were measured by inductively coupled plasma mass spectrometry. The Simplified Nutritional Appetite Questionnaire scale was used to assess patient appetite. Skinfold thickness, bicep circumference, upper arm muscle circumference, 7-point Subjective Global Assessment, Nutritional Risk Screening 2002 (NRS 2002), and Geriatric Nutritional Risk Index (GNRI) were used to assess patient nutritional status. Univariate and multivariate logistic regression analyses were performed to study the relationship between trace elements and nutritional indicators.

RESULTS

In total, 118 patients (64 males and 54 females) were included, with a median dialysis vintage of 34.0 months (16.0-54.5 months) and an average age of 63.20 ± 14.26 years. Malnourished patients, as defined by the GNRI, Subjective Global Assessment, and NRS 2002, accounted for 28.0%, 49.2%, and 26.3% of enrolled patients, respectively. The multivariate binary logistic regression showed that higher blood copper levels were independently associated with nutritional risk defined as GNRI ≤91.2 (odds ratio [OR] = 1.003, 95% confidence interval [CI] = 1.000-1.006; P = .020), whereas lower blood zinc levels (OR = 0.634, 95% CI = 0.439-0.916; P = .015), blood zinc < 4.220 mg/L (OR = 3.723, 95% CI = 1.274-10.879; P = .016), lower blood selenium levels (OR = 0.959, 95% CI = 0.929-0.990; P = .010), and blood selenium < 85 μg/L (OR = 5.568, 95% CI = 1.039-29.840; P = .045) were independently associated with a nutritional risk defined as NRS 2002 ≥ 3.

CONCLUSION(S)

Higher levels of blood copper and lower levels of blood zinc and selenium were independently associated with higher nutritional risk in MHD patients.

Single-cell transcriptomics uncovers phenotypic alterations in the monocytes in a Chinese population with chronic cadmium exposure

BACKGROUND

Cadmium is the most prevalent form of heavy metal contaminant globally and its exposure rises serious health concern. Chronic exposure to cadmium causes immune disturbances. However, few studies have addressed how it affects circulating immune cells, one of the most essential elements for the host defense system, at both population and molecular level. Therefore, this is the first single-cell transcriptomic analysis of the response of the human circulating immune system to plasma cadmium level.

METHODS

We conducted a cross-sectional study in Hunan province, which has the highest level of cadmium land contamination in China. A total of 3283 individuals were eligible for analyzing the association between plasma cadmium levels and the monocyte counts and its subgroups. Another 780 individuals were assigned for validation. Thirty propensity-matched individuals without chronic disease from the lowest- and highest-quartile groups according to serum cadmium levels were selected for single-cell RNA sequencing (scRNA-seq) and flow cytometry analyses. Moreover, the monocyte phenotypic alterations in the heavy metal-exposed population were validated with a cecal ligation and puncture sepsis mouse model.

RESULTS

From August 2016 to July 2017, we conducted a cross-sectional study to identify phenotypic alterations in peripheral immune cells in cadmium polluted areas in China. Monocyte percentages were negatively associated with plasma cadmium levels in multivariable linear regression analysis. Peripheral blood mononuclear cell scRNA-seq revealed that the CD14⁺ monocyte subset was dramatically reduced in the highest-quartile cadmium-exposed group. Moreover, we assessed different hallmarks of immune cell dysfunction-such as host defense capability, apoptotic signaling, cellular diversity and malignant gene expression in monocytes. Importantly, cadmium induced phenotypic alterations in the immune system were validated in the cecal ligation and puncture sepsis mouse model, in which chronic exposure to cadmium not only increased the death rate but also decreased monocyte numbers and the ability to clear bacterial infections.

CONCLUSION

This transcriptomic analysis provides molecular information about how the most important hallmarks of immune cell dysfunction are affected by plasma cadmium level. The significant phenotypic alterations in monocytes serving as early indicators of increased susceptibility to infectious and malignant diseases.

Trace Element Analysis in Whole Blood and Plasma for Reference Levels in a Selected Queensland Population, Australia

The levels of trace elements in whole blood and plasma have been widely used for assessing nutritional status and monitoring exposure and can vary widely in populations from different geographical regions. In this study, whole blood samples (n = 120) and plasma samples (n = 120) were obtained from healthy donors attending the Red Cross Blood Bank (Queensland Red Cross Blood Service), which provided information for age and sex. There were 71 males (age range: 19-73 years) and 49 females (age range: 18-72 years) for whole blood samples, and 59 males (age range: 19-81 years) and 61 females (age range: 19-73 years) for plasma samples. The main aim of the study was to provide information on blood reference levels of 21 trace elements (Ag, Al, As, Bi, Br, Cd, Co, Cr, Cu, Hg, I, Mn, Mo, Ni, Pb, Sb, Se, Tl, U, V, Zn) in Queensland. The study also aimed to assess differences in trace element blood levels between males and females and the effect of age. The trace element levels in blood samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and the standard reference materials of Seronorm (Trace Elements Whole Blood) and UTAK (Trace Elements Serum) were used for quality control and assurance. The study found wide variations of trace element levels in whole blood and plasma, and generally the levels were comparable to other countries. No detectable levels were found for Bi, Cr, U and V in whole blood, but V levels were found in plasma samples. There were significant differences between males and females for whole blood Cu (p < 0.001), I (p = 0.009), Tl (p = 0.016) and Zn (p = 0.016). Significant differences were also found for plasma Cu (p < 0.001) and Se (p = 0.003) between males and females. There were trends of increased levels of blood Pb, Se and Zn with age. The study has provided further information on a wide range of trace elements in blood as reference levels for Queensland and Australia which are currently lacking.

Levels of trace blood elements associated with severe sleep disturbance in maintenance hemodialysis patients

PURPOSE

Sleep disturbance is frequently observed in patients on maintenance hemodialysis (MHD), and this population usually presents imbalances in trace elements. We investigated the association between blood trace element levels and sleep quality in patients on MHD.

METHODS

This cross-sectional and single-center study was performed in September 2019. Patients regularly undergoing hemodialysis for > 3 months at our center were recruited, and demographic, clinical, and laboratory parameters were recorded. The Pittsburgh Sleep Quality Index (PSQI) was applied to define sleep disturbance. Blood trace element (zinc, manganese, copper, selenium, and lead) levels were measured using an inductively coupled plasma mass spectrometer.

RESULTS

In total, 121 patients on MHD (male/female = 68:53) were enrolled in the study (mean age 63.7 ± 13.9 years, median dialysis vintage 38.0 [20.0, 60.0] months). According to PSQI, 56 (46%) patients experienced severe sleep disturbance. These patients were characterized by older age, higher serum parathyroid hormone levels, and lower blood selenium levels (all P < 0.05). No significant differences in blood zinc, manganese, copper, and lead levels were observed between groups. Univariate binary logistic regression showed that lower blood selenium levels were associated with severe sleep disturbance (odds ratio = 0.976, 95% confidence interval: 0.954-0.999, P = 0.038). Multivariate analyses also confirmed the results after adjusting for confounding factors.

CONCLUSION

Our study indicated an association between lower blood selenium levels and the occurrence of severe sleep disturbances in patients on MHD. However, a prospective study with a larger sample size and assessing the importance of selenium supplementation are needed to confirm the results.

Human biomonitoring of 73 elements in blood, serum, erythrocytes and urine

BACKGROUND

Human biomonitoring studies of trace elements in biological fluids are mostly limited to a certain number of elements or biological materials. In this study, we describe the significant extension of a biomonitoring to 73 elements being present in concentration ranges from ng/L to g/L in clinically relevant specimens such as blood, serum, erythrocytes and urine.

METHODS

The samples were collected from 102 occupationally non-exposed inhabitants of northern Germany. The elements were determined either by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) in the low concentration range or by inductively coupled plasma optical emission spectrometry (ICP-OES) for essential trace elements and electrolytes.

RESULTS

Mean values and selected percentiles of element concentrations are presented for all sample materials. From the results, we calculated the distribution of elements between plasma and blood cells. Application of ICP-MS/MS improves selectivity and accuracy in the determination of elements that are strongly spectrally interfered, such as Cr, Ge, Pd or Ti in blood samples.

CONCLUSIONS

This publication provides very valuable information for occupational or environmental hygienists, toxicologists and clinical chemists due to the particularly high number of determined elements and presented concentration ranges.

Association of low blood arsenic exposure with level of malondialdehyde among Chinese adults aged 65 and older

High environmental arsenic exposure can increase chronic oxidative stress in experimental studies and in occupational epidemiology studies. Many regulatory agencies have put forth arsenic exposure limits, it is still unclear that whether low environmental arsenic exposure was associated with adverse health outcome in general population. This study aimed to explore the association of low blood arsenic with malondialdehyde in community-dwelling older adults. We used a cross-sectional study of 2384 older adult individuals aged ≥65 years (mean age: 85 years) from the Healthy Aging and Biomarkers Cohort Study in 2017. The median blood arsenic level was 1.41 μg/L. High oxidative stress was categorized according to the 95th percentile of MDA levels (7.47 nmol/mL). Restricted cubic spline models showed that blood arsenic levels were positively associated with malondialdehyde levels (P < 0.01); and the risk of high oxidative stress was no longer significantly increased when blood arsenic level up to 8.74 μg/L. After adjusting for potential confounders, the odds ratios of high oxidative stress for the second, third, and fourth quartiles of blood arsenic were 2.35 (1.11-4.96), 3.87 (1.90-7.91), and 4.18 (2.00-8.72) (P_trend < 0.01), compared with the first quartile. We concluded that even low arsenic exposure was associated with higher risk of oxidative stress, in a nonlinear dose-response.

Blood donation and heavy metal poisoning in developing nations: Any link?

Long term health effects of heavy metal exposure from both occupational and environmental settings involve multi-organ toxicities including but not limited to disturbances of neurological, cognitive, and metabolic processes, immune system dysregulation, carcinogenesis and sometimes permanent disabilities. Humans are exposed to toxic metals through various sources and routes of entry. The risk of heavy metal poisoning from donor blood has been the subject of many scientific investigations. In this review we highlight how the access to a safe and adequate blood transfusion with minimal risk of toxic metals to recipients is a public health challenge, especially in developing nations. For quality assurance purposes, blood donors are screened for various blood-borne pathogens, but screening for toxic metal levels is not routine. Evidence from scientific studies used in this review lends credence to the risk of heavy metal poisoning from donors with high blood concentrations of these heavy metals. The risk of toxicity is exceptionally high in vulnerable populations such as neonates and preterm infants, as well as in pregnant women and other individuals with conditions requiring multiple blood transfusions. This is worse in developing countries where some members of the population engage in illegal refining and artisanal mining activities. In order to reduce toxic metal exposure in vulnerable populations, blood meant for transfusion in vulnerable subjects, e.g. children, should be routinely screened for heavy metal concentrations. Patients receiving multiple blood transfusions should also be monitored for iron overload and its attendant toxicities.

Development and Validation of an ICP-MS Method and Its Application to Determine Multiple Trace Elements in Small Volumes of Whole Blood and Plasma

Essential and nonessential element concentrations in human blood provide important information on the nutritional status of individuals and can assist in the screening or diagnosis of certain disorders and their association with other causative factors. A simple and sensitive method, suitable for use with small sample volumes, for quantification of multiple trace element concentrations in whole blood and plasma has been developed using inductively coupled plasma-mass spectrometry. Method validation was performed using standard reference materials of whole blood and serum using varying sample treatments with nitric acid, water and hydrogen peroxide. The method was applied to quantify the trace element concentrations in whole blood and plasma samples (0.1 mL) from 50 adult blood donors in Queensland. The whole blood sample (5 mL) was collected in Vacutainer tubes with K2EDTA as anticoagulant. The developed method was able to quantify, in blood and plasma samples over a wide range of concentrations, several essential elements: cobalt, copper, zinc, iron, manganese and selenium; the nutritionally probably essential elements vanadium and strontium; and nonessential elements including lead, cadmium, arsenic, caesium, barium, thallium and uranium. Significant differences (P < 0.0001) were observed between whole blood and plasma concentrations for 13 elements; 5 of the measured elements, cobalt (0.49 vs. 0.36 μg/L), copper (1.0 vs. 0.75 mg/L), strontium (28 vs. 16 μg/L), barium (1.5 vs. 0.64 μg/L) and thallium (0.06 vs. 0.03 μg/L), had higher mean concentrations in plasma than in blood. Whole blood concentrations of nine trace elements were significantly correlated (P < 0.0001) with plasma concentrations. The distribution of the trace elements between human blood and plasma varied considerably for the different elements. These results indicate that, using a small sample volume, this assay is suitable for the evaluation of nutritional status as well as in monitoring human toxic elemental exposures.

Application of Lithium Assay kit LS for quantification of lithium in whole blood and urine

A commercially available kit for the quantitation of lithium, the Lithium Assay kit LS, was originally developed to measure lithium in serum or plasma using a conventional microplate reader. We investigated whether use of the kit could be extended to quantify lithium in whole blood and urine samples collected at autopsy. The calibration curve for whole blood showed good linearity ranging from 0.5 to 20 µg/mL with a coefficient of determination of 0.998 when samples were pretreated with methanol followed by acetonitrile. Moreover, for urine, we obtained excellent linearity with a coefficient of determination of 0.999 without any pretreatment. The accuracies and precisions were 106.3-174.7% and 1.9-18.1% for whole blood and 83.3-118.8% and 5.7-33.8% for urine. The values in the lower concentration range (0.5-1 µg/mL) were not satisfactory, whereas those in the higher range (2-20 µg/mL) were acceptable. The Lithium Assay kit LS was successfully applied to the measurement of lithium in whole blood and urine samples collected at autopsies. This method appears to be useful for forensic toxicological investigations because of its simplicity and speed.

Mercury level in biological samples of dentists in Iran: a systematic review and meta-analysis

Exposure to mercury is an important risk to dentists health. The aim of the present study was to assess the pooled mean mercury level (MML) in the urine, blood, nail, and hair of Iranian dentists (IDs) through the meta-analysis technique. Comprehensive and systematic searches were performed in main local databases including SID, Magiran, Iran medex, and ISC as well as internationally available databases including Embase, PubMed and Scopus for all the relevant studies up to 2018. In order to prevent bias in this study and identify eligible studies, various steps of the study was performed independently by two researchers. Out of 13 studies in the meta-analysis process which included 1499 IDs, the mean of the mercury level in the urine, nail, and blood was estimated to be 6.29 (95% CI: 2.61-9.97, I-square: 62.7%, P: 0.006), 3.54 (95% CI: 2.81-4.28, I-square: 0.0%, P: 0.968), 11.20 (95% CI: 2.28-20.13, I-square: 59.9%, P: 0.082), respectively. The mean mercury level (MML) in the biological samples of IDs was higher than the standard of World Health Organization (WHO). So, in accordance with Article 10 of the European Union Regulations (EUR), in the context of the Minamata Convention (MC) on Dental Amalgam (DA), in order to avoid the dangers of mercury exposure in dentists, it is necessary for Iran and other countries to approve laws and to implement a national plan to reduce mercury levels and replace the appropriate materials.

Association of plasma trace element levels with neovascular age-related macular degeneration

Although the triggers causing angiogenesis in the context of neovascular age-related macular degeneration (nAMD) are not fully understood, oxidative stress is likely involved. Oxidative stress in the eye can occur through exposure of macular tissues to sunlight and local or systemic exposure to oxidative stressors associated with environmental or lifestyle factors. Because trace elements have been implicated as regulators of oxidative stress and cellular antioxidant defense mechanisms, we hypothesized that they may play a role as a risk factor, modifying the progression toward nAMD. Herein, we determined whether levels of human plasma trace elements are different in 236 individuals with nAMD compared to 236 age-matched controls without AMD. Plasma levels of 16 trace elements including arsenic, barium, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, lead, antimony, selenium, vanadium and zinc were measured using inductively coupled plasma mass spectrometry. Associations of trace elements with demographic, environmental and lifestyle factors and AMD-associated genetic variants were assessed. Elevated levels of barium and cadmium and reduced levels of chromium were observed in nAMD patients compared to controls. Mean plasma concentrations of barium were 1.35 μg/L (standard deviation [SD] 0.71) in nAMD and 1.15 μg/L (SD 0.63) in controls (P = 0.001). Mean levels of chromium were 0.37 μg/L (SD 0.22) in nAMD and 0.46 μg/L (SD 0.34) in controls (P = 0.001). Median levels for cadmium, which were not normally distributed, were 0.016 μg/L (interquartile range [IQR] 0.001-0.026) in nAMD and 0.012 μg/L (IQR 0.001-0.022) in controls (P = 0.002). Comparison of the Spearman's correlation coefficients between nAMD patients and controls identified a difference in correlations for 8 trace elements. Cadmium levels were associated with the smoking status (P < 0.001), while barium levels showed a trend of association with the usage of antihypertensive drugs. None of the AMD-associated genetic variants were associated with any trace element levels. In conclusion, in this case-control study we detected elevated plasma levels of barium and cadmium and reduced plasma levels of chromium in nAMD patients. An imbalance in plasma trace elements, which is most likely driven by environmental and lifestyle factors, might have a role in the pathogenesis of AMD. These trace elements may be incorporated as biomarkers into models for prediction of disease risk and progression. Additionally, population-based preventive strategies to decrease Cd exposure, especially by the cessation of smoking, could potentially reduce the burden of nAMD. Future studies are warranted to investigate whether supplementation of Cr would have a beneficial effect on nAMD.

Comparison of Plasma Concentrations of Mercury, Cadmium, and Arsenic among Women in 2005 and 2012 in a Historically Contaminated Area in China

Mercury (Hg), cadmium (Cd), and arsenic (As) concentrations in women were measured and compared to evaluate the effects of environmental heavy-metal pollution control on internal exposure levels. In 2005 and 2012, 200 and 182 women, respectively, were enrolled in the study. Demographic and diet information were collected using a questionnaire. Fasting venous blood samples were collected, and plasma concentrations of Hg, Cd, and As were measured using inductive coupled plasma mass spectrometry. The median concentrations (P₂₅-P₇₅) of Hg, Cd, and As decreased from 0.56 (0.46-0.75) ng/mL, 0.14 (0.09-0.21) ng/mL, and 0.83 (0.66-1.09) ng/mL in 2005 to 0.39 (0.19-0.66) ng/mL, 0.09 (0.05-0.13) ng/mL, and 0.48 (0.29-0.72) ng/mL in 2012, respectively. The difference in plasma metal concentrations between measurements in 2005 and 2012 remained statistically significant after we adjusted for confounders. The adjusted ORs were 0.31 (0.16-0.60), 0.24 (0.12-0.48), and 0.25 (0.13-0.50) for Hg, Cd, and As concentrations, respectively, in 2012, relative to those in 2005. The levels of Hg, Cd, and As were 30% to 40% lower in 2012 than in 2005, indicative of lower human internal exposure to these contaminants due to the implementation of environmental pollution control. Engagement with agriculture and high-frequency water product consumption were associated with high Hg levels, and a high frequency of consumption of fresh fruit and eggs was negatively associated with lower levels of Cd in plasma.