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The metal/metal alloy-based implants and prostheses are in use for over a century, and the rejections, revisions, and metal particle-based toxicities were reported concurrently. Complications developed due to metal ions, metal debris, and organo-metallic particles in orthopedic patients have been a growing concern in recent years. It was reported that local and systemic toxicity caused by such released products from the implants is one of the major reasons for implant rejection and revision. Even though the description of environmental metal toxicants and safety limits for their exposure to humans were well established in the literature, an effort was not adequately performed in the case of implant-based metal toxicology. Since the metal ion concentration in serum acts as a possible indicator of the systemic toxicity, this review summarizes the reported human serum safe limits, toxic limits, and concentration range (μg/L, ppb, etc.) for mild to severe symptoms of six (cardiac, hepatic, neuro, nephron, dermal and endocrine) systemic toxicities for twelve most commonly used metallic implants. It also covers the widely used metal ion quantification techniques and systemic toxicity treatments reported., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2021. Published by Elsevier B.V.)

Globally, human exposure to environmental pollutants causes an estimated 9 million deaths per year and it could also be implicated in the etiology of diseases that do not appear to have a genetic origin. Accordingly, there is a need to gain information about the biomolecular mechanisms that causally link exposure to inorganic environmental pollutants with distinct adverse health effects. Although the analysis of blood plasma and red blood cell (RBC) cytosol can provide important biochemical information about these mechanisms, the inherent complexity of these biological matrices can make this a difficult task. In this perspective, we will examine the use of metalloentities that are present in plasma and RBC cytosol as potential exposure biomarkers to assess human exposure to inorganic pollutants. Our primary objective is to explore the principal bioinorganic processes that contribute to increased or decreased metalloprotein concentrations in plasma and/or RBC cytosol. Furthermore, we will also identify metabolites which can form in the bloodstream and contain essential as well as toxic metals for use as exposure biomarkers. While the latter metal species represent useful biomarkers for short-term exposure, endogenous plasma metalloproteins represent indicators to assess the long-term exposure of an individual to inorganic pollutants. Based on these considerations, the quantification of metalloentities in blood plasma and/or RBC cytosol is identified as a feasible research avenue to better understand the adverse health effects that are associated with chronic exposure of various human populations to inorganic pollutants. Exposure to these pollutants will likely increase as a consequence of technological advances, including the fast-growing applications of metal-based engineering nanomaterials.

Purpose: Cobalt exposure is known to cause adverse effects on health. A major use of cobalt is in the manufacture of hard metal. Exposure can lead to asthma, hard metal lung disease, contact allergy and increased risk of cancer. Cobalt is mainly absorbed from the pulmonary tract, however penetration through skin may occur. The relationships between exposure to inhalable cobalt in air and on skin and the uptake in blood and urine will be investigated, as well as the association between dermal symptoms and dermal exposure., Methods: Cobalt exposure in 71 workers in hard metal production facilities was measured as inhalable cobalt in the breathing zone and cobalt found on skin with acid wash. Uptake of cobalt was determined with concentrations in blood and urine. Correlations between exposure and uptake were analysed., Results: Inhalable cobalt in air and cobalt in blood and urine showed rank correlations with coefficients 0.40 and 0.25. Cobalt on skin and uptake in blood and urine presented correlation coefficients of 0.36 and 0.17. Multiple linear regression of cobalt in air and on skin with cobalt in blood showed regression coefficients with cobalt in blood (β = 203 p < 0.0010, and β = 0.010, p = 0.0040) and with cobalt in urine (β = 5779, p = 0.0010, and β = 0.10, p = 0.60)., Conclusions: Our data presents statistically significant correlations between exposure to cobalt in air with uptake of cobalt in blood and urine. Cobalt on skin was statistically significant with cobalt in blood but not with urine., Competing Interests: The authors have declared that no competing interests exist.

Background: Laboratory testing for trace and toxic elements is important to diagnose metal toxicity and nutritional deficiency. There are several essential elements that are necessary for biological function and non-essential elements that can pose risk from exposure. Both essential and nonessential elements can be toxic if concentrations exceed a certain threshold., Methods: An aliquot of serum was diluted in a diluent solution, which contained iridium (Ir) as the internal standard, gold (Au), 0.05% Triton X-100, and 1% nitric acid (HNO3). The diluted specimen was aspirated into an inductively coupled plasma-mass spectrometer for quantitative elemental analysis of chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), selenium (Se) and zinc (Zn). The sample was introduced into the instrument spray chamber to form aerosol droplets, then atomized and ionized in argon plasma. The ions exited the plasma, passed through the interface of the instrument, then arrived at the entrance of the collision cell where helium gas was introduced to remove polyatomic interferences by kinetic energy discrimination (KED). After exiting the collision cell, the ions were filtered by a quadrupole mass spectrometer., Results: The analytical measurement range was determined specifically for each element. Imprecision was <20% CV for the lowest limit of quantification for each element and accuracy was within ±15%., Conclusions: This method was validated for the quantification of seven elements in serum to assess nutritional deficiency and toxicity. The multi-element panel by ICP-MS met the validation criteria for biological monitoring of trace and toxic elements in patient specimens., (Copyright © 2020 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The hazard of hexavalent chromium (Cr(VI)) from environmental pollution and medical implanted metal has been recognized widely. However, removal of trace amount of Cr(VI) in the blood circumstance faces tremendous difficulties for that most of Cr(VI) located in erythrocytes, thus there is almost no literature to report the removal of Cr(VI) in blood. Herein, a removal strategy, named as reduction-adsorption-separation, is proposed to realize the removal of Cr(VI) in blood. First, magnetic core-shell mesoporous nanocomposite is fabricated by using Fe 3 O 4 nanoparticles as magnetic core and mesoporous silica (MS) as shell, hyperbranched polyamide (HPA) as mesoporous channel modifier and ascorbic acid (ASC) as the reductant drug loaded in the mesoporous channels, which is also denoted as Fe/MS/HPA/ASC. Then, on the basis of the bionic idea, the erythrocyte membrane (EM)-wrapped Fe/MS/HPA/ASC to protect ASC from deactivation is obtained and named as the therapeutic agent (Fe/MS/HPA/ASC@EM). During removal process, the therapeutic agent can enter in erythrocytes to use ASC to reduce Cr(VI) to Cr(III) and HPA in mesoporous channels to adsorb Cr(III) and can then be recollected from blood by magnetic separation. Finally, an animal model of blood Cr(VI) poisoning is constructed and used to test the removal ability of Cr(VI) from pig blood in vivo, verifying the effectiveness of this blood Cr(VI) removal strategy, providing a possible way to design more efficient and biosafe therapeutic agents for blood purification.

Background: Heavy metals were related to increased risk of atherosclerotic cardiovascular disease (ASCVD). However, potential mechanisms under such associations remain unclear. We aimed to investigate the mediating role of mean platelet volume in the associations between heavy metals exposure and 10-year ASCVD risk., Method: Urinary heavy metals and mean platelet volume were measured in 3081 adults from the Wuhan-Zhuhai cohort in China. The associations between urinary heavy metals, mean platelet volume and 10-year ASCVD risk were separately analyzed through generalized linear models and logistic regression models. Mediation analyses were conducted to assess the role of mean platelet volume in the associations between urinary heavy metals and 10-year ASCVD risk., Results: After adjusting for potential confounders, 10-year ASCVD risk was positively associated with urinary iron (odds ratio (OR) = 1.142, 95% confidence interval (1.038-1.256)), copper (OR = 1.384 (1.197-1.601)), zinc (OR = 1.520 (1.296-1.783)), cadmium (OR = 1.153 (0.990, 1.342)) and antimony (OR = 1.452 (1.237-1.704)), and negatively related with urinary barium (OR = 0.905 (0.831-0.985)). Also, we found significant dose-response relationships between urinary iron, zinc, antimony and mean platelet volume, as well as between mean platelet volume and 10-year ASCVD risk (all p for trends < 0.05). Furthermore, mediation analyses indicated that mean platelet volume mediated 17.55%, 6.15% and 7.38% of the associations between urinary iron, zinc, antimony and 10-year ASCVD risk, respectively (all p value < 0.05)., Conclusions: Elevated concentrations of urinary iron, copper, zinc, cadmium and antimony were associated with increased risk of 10-year ASCVD. Mean platelet volume partially mediated the associations of urinary iron, zinc and antimony with 10-year ASCVD risk.

Laboratory testing is an important tool to assist clinicians in evaluation of patients with potential environmentally-related illness, however, it can be challenging to select or interpret the appropriate toxicological tests. Recent advances in analytical techniques and expanded consumer access to environmental laboratories led to a rise in laboratory testing for various environmental toxicants, including metals. However, most environmental tests have scant clinical evidence and are not validated for clinical use. While the tests themselves may not present direct harm to the patients, the results of inappropriately selected tests may lead to significant patient stress and unnecessary follow-up or treatment. Given the lack of environmental health content in medical training, pediatricians may feel ill-equipped to address most environmental issues they encounter in practice, including the interpretation of environmental toxicant lab results. This article provides an overview of how to approach a child and family with environmental health concerns about "toxic metals", select appropriate metal tests if indicated, and enlist the assistance of the Pediatric Environmental Health Specialty Units (PEHSU) for further management guidance., Competing Interests: Declaration of Competing Interest Each author declares no conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Toxic heavy metals (THMs) are contaminants commonly found in the environment. Although a large number of studies have demonstrated their damage to the biological functions of the human being, their potential associations with the risk of developing schizophrenia remain controversial. In this study, we investigated the associations between four THMs (chromium (Cr), cadmium (Cd), lead (Pb) and arsenic (As)) in serum and the risk of schizophrenia. In total, 95 patients with schizophrenia (cases) and 95 normal subjects (controls) were recruited from Hebei Province, China. The serum concentrations of the 4 THMs were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). A higher concentration of Pb was found significantly associated with an elevated risk of schizophrenia (OR = 3.146; 95%CI: 1.238-7.994, p = 0.016), while significant association for the other three THMs were not observed. Besides, significant correlations were found between the metabolic biomarkers and the concentrations of Pb and As, respectively. In order to further characterize the association between these THMs and schizophrenia with greater statistical power, we conducted meta-analysis by including 538 cases and 1040 controls from the current study and 5 available datasets published from 2002 to 2018. Using a random-effect model, Cr was significantly associated with schizophrenia (SMD = 0.3246; 95%CI: 0.0166-0.6326, p < 0.01). Overall, this study suggested that higher levels of Pb and Cr may be one of the factors associated with an elevated risk of schizophrenia.

Platelet-rich fibrin (PRF) is widely used blood-derived biomaterial which is directly applied to the surgical wounds. Depending on its autologous origin, PRF is thought as a safe material. However, it is not known to what extent the blood-derived toxins can be found in the PRF by considering the systemic exposure rates of the individuals to the toxins. The aim of this pilot study was to test the hypothesis whether PRF contains any blood-origin heavy metals (HMs) and smoking increases their concentrations as an environmental HM source. PRF samples were obtained from systemically healthy 30 non-smoker and 30 smoker volunteers. All liquid and dry fibrin parts of the PRF samples were analyzed in terms of 15 toxic elements using inductively coupled plasma mass spectrometry. All analyzed HMs were detected in all investigated PRF samples within various concentrations in both groups. In addition, significantly high levels of cadmium, arsenic, lead, manganese, nickel, chromium, and vanadium were detected in dry fibrin matrices of PRF samples of smokers comparing with non-smokers (p < 0.05). Only cadmium was at significantly high levels in the liquid part of PRF samples of smokers (p < 0.05). This is the first study evaluating toxic ingredients of PRF. The results revealed that PRF contains various toxic HMs. Additionally, systemic exposure to environmental HM sources such as smoking may significantly increase HM concentrations in PRF. Further studies are required to investigate the transmission potentials of HMs to the applied tissues and biological importance of PRF-origin HMs.

Thallium is highly toxic and its effects are cumulative. The clinical symptoms of thallium poisoning are non-specific, thereby delaying admission and treatment. This study aimed to summarize the clinical features and treatment experience of patients with delayed admission who experience thallium poisoning.We conducted a retrospective descriptive analysis of patients in our hospital from 2008 to 2018 who had thallium poisoning and experienced a delay in hospital admission. The time from symptom onset to admission was assessed. The patients were divided into 3 groups and descriptive analyses of their clinical characteristics, including basic patient information, symptoms, laboratory test results, examination findings, treatment methods, outcomes, and follow-up information, were conducted.A total of 34 patients with thallium poisoning were included: 8 were admitted to the hospital early or with mild delay, 9 had a moderate delay, and 17 had a severely delayed admission. The time from illness onset to admission was 13 (interquartile range, 7.5-26) days. Some patients with delayed admission had significant symptoms associated with central nervous system damage, and changes in magnetic resonance images and electroencephalograms were also noted. After admission, all patients received Prussian blue treatment, and some patients with relatively high blood concentration received blood purification treatments. Following treatment, the blood and urine thallium concentrations of all patients decreased significantly, and their symptoms were alleviated.Our results show that delayed patient admission in cases of thallium poisoning is associated with greater risk of central nervous system damage. Use of Prussian blue combined with blood purification treatments might improve patients' conditions.

Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn 2+ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl 2 ) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl 2 (2-5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P < 0.05 was considered as statistically significant. The haematocrit (HCT) significantly increased and blood coagulation time significantly reduced in the nano-zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P < 0.05). It seems that in the oral administration of nano-zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.