Extended-Gate FET Biosensor Based on GaN Micropillar Array and Polycrystalline Layer: Application to Hg2+ Detection in Human Urine.

Owing to the separation of field-effect transistor (FET) devices from sensing environments, extended-gate FET (EGFET) biosensor features high stability and low cost. Herein, a highly sensitive EGFET biosensor based on a GaN micropillar array and polycrystalline layer (GMP) was fabricated, which was prepared by using simple one-step low-temperature MOCVD growth. In order to improve the sensitivity and detection limit of EGFET biosensor, the surface area and the electrical conductivity of extended-gate electrode can be increased by the micropillar array and the polycrystalline layer, respectively. The designed GMP-EGFET biosensor was modified with l-cysteine and applied for Hg2+ detection with a low limit of detection (LOD) of 1 ng/L, a high sensitivity of -16.3 mV/lg(µg/L) and a wide linear range (1 ng/L-24.5 µg/L). In addition, the detection of Hg2+ in human urine was realized with an LOD of 10 ng/L, which was more than 30 times lower than that of reported sensors. To our knowledge, it is the first time that GMP was used as extended-gate of EGFET biosensor.

Association of Combined Per- and Polyfluoroalkyl Substances and Metals with Chronic Kidney Disease.

Background: Exposure to environmental pollutants such as metals and Per- and Polyfluoroalkyl Substances (PFAS) has become common and increasingly associated with a decrease in the estimated Glomerular Filtration Rate (eGFR), which is a marker often used to measure chronic kidney disease (CKD). However, there are limited studies involving the use of both eGFR and the urine albumin creatinine ratio (uACR), which are more comprehensive markers to determine the presence of CKD and the complexity of pollutant exposures and response interactions, especially for combined metals and PFAS, which has not been comprehensively elucidated. Objective: This study aims to assess the individual and combined effects of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), Cadmium (Cd), Mercury (Hg), and Lead (Pb) exposure on CKD using data from the National Health and Nutritional Examination Survey (NHANES) 2017-2018. Methods: We employed the use of bivariate logistic regression and Bayesian Kernel Machine Regression (BKMR) in our analysis of the data. Results: Logistic regression results revealed a positive association between PFOA and CKD. Our BKMR analysis revealed a non-linear and bi-phasic relationship between the metal exposures and CKD. In our univariate exposure-response function plot, Cd and Hg exhibited a U and N-shaped interaction, which indicated a non-linear and non-additive relationship with both low and high exposures associated with CKD. In addition, the bivariate exposure-response function between two exposures in a mixture revealed that Cd had a U-shaped relationship with CKD at different quantiles of Pb, Hg, PFOA, and PFOS, indicating that both low and high levels of Cd is associated with CKD, implying a non-linear and complex biological interaction. Hg's interaction plot demonstrated a N-shaped association across all quantiles of Cd, with the 75th quantile of Pb and the 50th and 75th quantiles of PFOA and PFOS. Furthermore, the PIP results underscored Cd's consistent association with CKD (PIP = 1.000) followed by Hg's (PIP = 0.9984), then PFOA and PFOS with a closely related PIP of 0.7880 and 0.7604, respectively, and finally Pb (PIP = 0.6940), contributing the least among the five environmental pollutants on CKD, though significant. Conclusions: Our findings revealed that exposure to environmental pollutants, particularly Hg and Cd, are associated with CKD. These findings highlight the need for public health interventions and strategies to mitigate the cumulative effect of PFAS and metal exposure and elucidate the significance of utilizing advanced statistical methods and tools to understand the impact of environmental pollutants on human health. Further research is needed to understand the mechanistic pathways of PFAS and metal-induced kidney injury and CKD, and longitudinal studies are required to ascertain the long-term impact of these environmental exposures.

Impact of multi-heavy metal exposure on renal damage indicators in Korea: An analysis using Bayesian Kernel Machine Regression.

Exposure to cadmium (Cd), arsenic (As), and mercury (Hg) is associated with renal tubular damage. People living near refineries are often exposed to multiple heavy metals at high concentrations. This cross-sectional study investigated the association between combined urinary Cd, As, and Hg levels and renal damage markers in 871 residents living near the Janghang refinery plant and in a control area. Urinary Cd, As, Hg, N-acetyl-ß-D-glucosaminidase (NAG), and ß2-microglobulin (ß2-MG) levels were measured. The combined effects of Cd, As, and Hg on renal tubular damage markers were assessed using linear regression and a Bayesian Kernel Machine Regression (BKMR) model. The results of the BKMR model were compared using a stratified analysis of the exposure and control groups. While the linear regression showed that only Cd concentration was significantly associated with urinary NAG levels (ß = 0.447, P value < .05), the BKMR model showed that Cd and Hg levels were also significantly associated with urinary NAG levels. The combined effect of the 3 heavy metals on urinary NAG levels was significant and stronger in the exposure group than in the control group. However, no relationship was observed between the exposure concentrations of the 3 heavy metals and urinary ß2-MG levels. The results suggest that the BKMR model can be used to assess the health effects of heavy-metal exposure on vulnerable residents.

Comparison of the accumulation of toxic metal biomarkers in Asian subgroups and other races in the United States: NHANES 2015-2016.

Toxic metals such as lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) that lead to many visceral organ and nervous system diseases have attracted global attention due to their gradual accumulation in human bodies. The tolerance levels of exposure to toxic metals among race/ethnic groups are different due to the variance of sociodemographic, dietary, and behavioral characteristics. Few studies focused on investigating the biomarker levels of toxic metals in different race/ethnic groups and the potential mechanisms for controlling the accumulation in human bodies. Therefore, we selected eight biomarkers for four toxic metals from the National Health and Nutrition and Examination Survey (NHANES) in the 2-year data cycle of 2015-2016 to reveal the accumulation levels in different races. According to the NHANES rules, we applied probability sampling weights. The geometric mean levels of these biomarkers were calculated in all five race/ethnic groups (Mexican American, white, black, Asian, and other Hispanic) and two Asian subgroups (U.S.-born Asian, and other-born Asian), and compared with each other. The results showed that all the biomarkers in other-born Asians were 1.1-6.7 times in blood and 1.1-3.6 times in urine higher than other race/ethnic groups. Except Hg and As, the lowest biomarker levels were recorded in U.S.-born Asians, only 0.6-0.9 times of lead and 0.3-0.8 times of cadmium than other race/ethnic groups. Furthermore, the major factors of higher Hg and As biomarker levels in Asians were dietary intake of seafood and rice, indicating different accumulation mechanisms among Asians and other race/ethnic groups, especially for U.S.-born Asians. These findings provided new insight into a deeper understanding the accumulation of toxic metals and human health.

A method for reliable quantification of mercury in occupational and environmental medical urine samples by inductively coupled plasma mass spectrometry.

Over the last years, inductively coupled plasma mass spectrometry (ICP-MS) has been applied as a method for human-biomonitoring of metals in the concentration range of occupational and environmental medicine. In large scale routine monitoring, the determination of mercury (Hg) by ICP-MS remains challenging due to several reasons. Amongst others, stability of dissolved Hg and avoiding memory effects are the key facts for reliable quantification. To address these issues, we developed a robust approach for biomonitoring of mercury in human urine samples by ICP-MS. Using a solution containing HNO3, HCl and thiourea, prepared samples and calibrators were stabilized for up to 72 h. A rinse time of only 30 seconds efficiently prevented contamination of consecutive samples with Hg concentrations up to 30 µg L-1, hence significantly reducing acquisition times compared to published methods. Recovery experiments revealed iridium as an ideal internal standard to compensate matrix effects independently from creatinine concentration. Recoveries of 95.0-104.0% were obtained for Hg levels covering the range of biomonitoring guidance values established by the German Human-Biomonitoring Commission. Excellent intra-day precision and inter-day precision of ≤3.0% for two different Hg levels were achieved. The detection and quantification limit accounted for 21.7 ng L-1 and 65.6 ng L-1, respectively, enabling reliable quantification even in the range of environmental background exposures. Additionally, the method was externally validated by successful participation in the inter-laboratory comparison program G-EQUAS. With the developed method, we hence provide a sensitive and robust tool for mercury exposure assessments in future large scale human-biomonitoring studies.

Metal Exposure in Arica, Chile: Examining Toxic Elements.

BACKGROUND: Bioaccumulation of toxic metals in the population is associated with adverse health effects. Although some elements are essential for humans, high levels of exposure can be dangerous. OBJECTIVE: To describe the levels of Inorganic Arsenic (AsIn), Cadmium (Cd), Chromium (Cr), and Mercury (Hg) in urine, and Lead (Pb) in blood in the population of Arica, Chile. METHODOLOGY: Descriptive study. Beneficiaries of the Health Surveillance Program of Law 20.590 in sites of higher risk of exposure in the commune of Arica were considered eligible. The results of biological samples to measure their concentrations of AsIn, Cd, Cr, Hg in urine, and Pb in blood between August 2016 and May 2021 are described. RESULTS: 9520 samples from a population with a mean age of 40.5 years were studied. 4.21% of the adult population and 6.57% of the children had AsIn values above 35 µg/L, while at least 95 % of the total samples had levels below 33 µg/L. At least 90 % of the samples had Cd levels below 1.1 µg/L, and 8.44 % had Cd levels above 2 µg/L, higher in males (11.67%). There were no values above the reference in children. 99.77% and 99.33% had Cr and Pb values below the reference limit, respectively (using the lowest reference range established by Chile Ministry of Health (MINSAL) < 5 µg/L). Children did not present risk values for Cr, and 0.16% presented Pb concentrations between 5-10 µg/dL. All samples presented Hg concentrations below risk levels (< 10 µg/L). CONCLUSIONS: The results of this study suggest that a small percentage of the samples analyzed in the beneficiary population of Arica register metal concentration levels above national reference levels established by MINSAL, mainly AsIn, Cd, and Pb. It is essential to continue biomonitoring to reduce and prevent exposure to these metals, which can have harmful effects on human health.

A multiple and comprehensive approach to assess health risk in amalgam-exposed Chinese workers.

Fluorescent lamp manufacturing workers have been extensively exposed to mercury (Hg). Our aim was to assess their health risks using several approved occupational health risk assessment methods, and to find out which method was more suitable for identification of occupational health risks. Work locations, and air and urine samples were collected from 530 exposed workers in Zhejiang, China. Based on the calculated exposure doses, health risks and risk ratios (RRs) as health risk indices, were evaluated using: Environmental Protection Agency (EPA), Australian, Romanian, Singaporean, International Council on Mining and Metals (ICMM), and Control of Substances Hazardous to Health (COSHH) methods. Among the workers, 86.0% had higher Hg levels than the Chinese occupational exposure limits of 0.02 mg/m3, and 16.7% urine samples were higher than the biological exposure limits of 35.0 µg/g·creatinine. Among workers at the injection, etc. locations, their average RRs, evaluated by the EPA, COSHH and Singaporean methods were 0.97, 0.76, and 0.60, respectively, and were significantly higher than the ICMM (0.39), Australian (0.30) and Romanian (0.29) methods. The RRs from the Singaporean method showed significant correlations with the urinary Hg levels (P < 0.01). In conclusion, the Singaporean method was more appropriate than the others for health risk evaluation because the excessive risks were significantly associated with urinary Hg levels among the workers.

Low-Level Environmental Mercury Exposure and Thyroid Cancer Risk Among Residents Living Near National Industrial Complexes in South Korea: A Population-Based Cohort Study.

Background: Previous studies suggested that mercury may be linked to thyroid cancer due to its bioaccumulation in the thyroid gland, but no studies have evaluated the association between mercury exposure and thyroid cancer risk. We examined the relationship between mercury exposure and thyroid cancer risk, with the potential modification of hematological parameters. Methods: We performed a secondary analysis of a prospective cohort study among residents living near industrial complexes in South Korea (recruited from 2003 to 2011). Incident thyroid cancer cases (C73, ICD-10 code) were identified from the National Cancer Registry and Statistics Korea. Urinary mercury concentrations were measured using thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). Cox proportional hazards regression models (adjusted for age, sex, educational level, smoking status, and employment) were used to estimate the hazard ratio (HR) and confidence interval [CI] between mercury exposure and the incidence of thyroid cancer. Results: We documented 69 cases of thyroid cancer in a total of 5213 participants during follow-up (median 8.7 years). The geometric mean of urinary mercury concentration was 1.8 µg/L for thyroid cancer cases and 1.2 µg/L for noncases (p for difference = 0.001). After adjusting for potential confounders, those in the highest tertile of urinary mercury levels had a twofold higher risk of thyroid cancer (HR = 1.97 [CI 1.03 - 3.80] in the highest tertile vs. the lowest tertile, p for trend = 0.043). This association was stronger for those with lower mean corpuscular volume and mean corpuscular hemoglobin status. Conclusions: Urinary mercury concentration was positively associated with the risk of thyroid cancer among residents living near national industrial complexes, and this association was influenced by red blood cell indices status. These results provide some evidence suggesting the adverse effects of environmental metal pollution in the development of thyroid cancer.

Nephrotic syndrome of minimal change disease following exposure to mercury-containing skin lightening cream: A case report and literature review.

Long-term exposure to mercury-containing skin lightening cream can cause mercury-related nephropathy, among which, membranous nephropathy (MN) and minimal change disease (MCD) are the main pathological types. In contrast to these two conditions, MCD with IgA deposition is not a common disease. In the present study, we report a 65-year-old Asian woman who developed nephrotic syndrome following long-term use of mercury-containing skin lightening cream. The urine mercury level of the patient was significantly increased, and the results of the renal biopsy indicated diagnosis of MCD with IgA deposition. Following three courses of treatment with sodium dimercaptopropane sulfonate (DMPS) alone and discontinuation of the skin cream, the symptoms of the patient were relieved without use of glucocorticoids, with proteinuria turning negative and a significant reduction in urine mercury levels. During the 6-month follow-up period, routine urinalysis remained normal. By reviewing relevant published literature, we summarized the pathological characteristics, possible mechanism of action, and treatment strategies of mercury poisoning-related MCD. The possibility of mercury poisoning should be considered for patients with nephropathy and history of use of skin lightening cosmetics. In these patients, the urine mercury levels should be measured in time so that mercury removal therapy can be implemented early.

[Study on the difference of curative effect of conventional mercury displacement treatment on mercury in brain and kidney].

Objective: To explore the expulsion effect of sodium dimercaptopropanesulfonate (DMPS) on mercury in different organs of mercury poisoning and the therapeutic effect of glutathione (GSH) combined with antioxidant therapy on mercury poisoning. Methods: In February 2019, 50 SPF male SD rats were randomly divided into 5 groups, 10 rats in each group: A (saline negative control group) , B (HgCL2 positive control group) , treatment group (C: intramuscular injection of DMPS 15 mg/kg treatment, D: intramuscular injection of DMPS30 mg/kg treatment, E: intramuscular injection of DMPS 15 mg/kg and intraperitoneal injection of GSH200 mg/kg treatment) . Rats in group B, C, D and E were subcutaneously injected with mercury chloride solution (1 mg/kg) to establish a rat model of subacute mercury poisoning kidney injury. Rats in group A were subcutaneously injected with normal saline. After the establishment of the model, rats in the treatment group were injected with DMPS and GSH. Rats in group A and group B were injected with normal saline. At 21 d (treatment 7 d) and 28 d (treatment 14 d) after exposure, urine and blood samples of 5 rats in each group were collected. Blood biochemistry, urine mercury, urine microalbumin and mercury content in renal cortex, cerebral cortex and cerebellum were detected. Results: After exposure to mercury, the contents of mercury in renal cortex, cerebrum and cerebellum of rats in group B, C, D and E increased, and urine microalbumin increased. Pathology showed renal tubular injury and renal interstitial inflammation. Compared with group B, urinary mercury and renal cortex mercury in group C, D and E decreased rapidly after DMPS treatment, and there was no significant decrease in mercury levels in cerebellum and cerebral cortex of rats, accompanied by transient increase in urinary albumin after DMPS treatment (P<0.05) ; the renal interstitial inflammation in group E was improved after GSH treatment. There was a positive correlation between urinary mercury and the contents of mercury in renal cortex, cerebral cortex and cerebellum (r=0.61, 0.47, 0.48, P<0.05) . Conclusion: DMPS mercury expulsion treatment can significantly reduce the level of metal mercury in the kidney, and there is no significant change in the level of metal mercury in the cortex and cerebellum.

The impact of essential and toxic elements on cardiometabolic risk factors in adults and older people.

BACKGROUND AND AIM: Evidence suggests an association between essential and toxic elements and the worsening of cardiometabolic risk factors. This study aimed to investigate the concentrations of zinc, copper, selenium, arsenic, cadmium, and mercury and their relationship with cardiometabolic risk factors in adults and older people. METHODS: This cross-sectional study was carried out with 112 adults with a mean age of 59 (sd 14) years old and a BMI of 29.30 (sd 5.11) Kg/m2. The subject's weight and height were measured for body mass index (BMI) calculation, classified according to the cut-off points recommended by the World Health Organization (WHO). We evaluated sociodemographic, clinical, lifestyle, waist circumference - WC, visceral adiposity index - VAI, glycemic lipid profile, blood pressure, and high-sensitive C-reactive protein (hs-CRP). Cardiovascular risk was defined by The Global Risk Score (GRS) score. Plasma zinc, selenium, copper levels, urinary arsenic, cadmium, and mercury levels were measured using the inductively coupled plasma mass spectrometry technique (ICP-MS). RESULTS: There was a negative association between urinary arsenic and VAI (ß - 0.03, p < 0.01), triglycerides (ß - 1.10, p < 0.01), and VLDL cholesterol (ß - 0.14, p = 0.02). Plasma copper and copper/zinc ratio were positively associated with fasting glucose and hs-CRP (ß 0.38, p < 0.01; ß 36.02, p = 0.01, ß 0.004, p < 0.01, ß 0.68, p < 0.001, respectively). Urinary arsenic (ß - 0.14, p = 0.04) and cadmium (ß - 36.42, p = 0.04) were negatively associated with systolic blood pressure. Also, urinary cadmium was negatively associated with diastolic blood pressure (ß - 21.55, p = 0.03), and urinary mercury showed an opposite behavior (ß 1.45, p = 0.03). CONCLUSION: Essential and toxic elements in urine and plasma could be potential biomarkers for cardiovascular risk factors. A healthy lifestyle should be adopted; in addition, government policies should be developed to guarantee sustainable production and a safe environment.

Effects of heavy metals in acute ischemic stroke patients: A cross-sectional study.

ABSTRACT: Cerebrovascular disease is the second commonest cause of mortality globally and among the commonest causes of disability. However, research executed to probe the heavy metal exposure-stroke incidence relationship is scarce. Accordingly, we executed our study to probe the relationship of heavy metal concentrations (ie, concentrations of lead [Pb], mercury [Hg], cadmium [Cd], and arsenic) in the serum and urine of acute ischemic stroke (AIS) patients with several patient variables.For enrollment, we chose patients who had a first AIS within 7 days after the onset of a stroke. Thus, 33 newly diagnosed patients with AIS were recruited. We determined the aforementioned metals' concentrations by executing inductively coupled plasma mass spectrometry. We also gauged the association between such metal concentrations and patient variables by employing Spearman correlation coefficient. To examine the differences in metal concentrations between the different variables, we implemented an independent Mann-Whitney U test.In our cohort analysis, we noted serum Pb and Cd concentrations to be positively correlated with serum creatinine and hemoglobin. Serum and urine Cd concentrations had a negative correlation with impaired HbA1c in AIS patients. Urine Hg had a positive correlation with C-reactive protein in the participants. Participants who smoked or consumed alcohol had significantly higher Pb and Cd levels in serum than did those who neither smoked nor drank. Patients with AIS who smoked or consumed alcohol had high levels of serum Pb and serum Cd than did those who did not. Patients with AIS who consumed alcohol had significantly higher Pb and Hg urine concentrations than did those who did not.Our study indicated that serum Cd and Pb elevation increased the AIS risk in southern Taiwan patients.

Study on the difference of curative effect of conventional mercury displacement treatment on mercury in brain and kidney / 中华劳动卫生职业病杂志

Objective: To explore the expulsion effect of sodium dimercaptopropanesulfonate (DMPS) on mercury in different organs of mercury poisoning and the therapeutic effect of glutathione (GSH) combined with antioxidant therapy on mercury poisoning. Methods: In February 2019, 50 SPF male SD rats were randomly divided into 5 groups, 10 rats in each group: A (saline negative control group) , B (HgCL2 positive control group) , treatment group (C: intramuscular injection of DMPS 15 mg/kg treatment, D: intramuscular injection of DMPS30 mg/kg treatment, E: intramuscular injection of DMPS 15 mg/kg and intraperitoneal injection of GSH200 mg/kg treatment) . Rats in group B, C, D and E were subcutaneously injected with mercury chloride solution (1 mg/kg) to establish a rat model of subacute mercury poisoning kidney injury. Rats in group A were subcutaneously injected with normal saline. After the establishment of the model, rats in the treatment group were injected with DMPS and GSH. Rats in group A and group B were injected with normal saline. At 21 d (treatment 7 d) and 28 d (treatment 14 d) after exposure, urine and blood samples of 5 rats in each group were collected. Blood biochemistry, urine mercury, urine microalbumin and mercury content in renal cortex, cerebral cortex and cerebellum were detected. Results: After exposure to mercury, the contents of mercury in renal cortex, cerebrum and cerebellum of rats in group B, C, D and E increased, and urine microalbumin increased. Pathology showed renal tubular injury and renal interstitial inflammation. Compared with group B, urinary mercury and renal cortex mercury in group C, D and E decreased rapidly after DMPS treatment, and there was no significant decrease in mercury levels in cerebellum and cerebral cortex of rats, accompanied by transient increase in urinary albumin after DMPS treatment (P<0.05) ; the renal interstitial inflammation in group E was improved after GSH treatment. There was a positive correlation between urinary mercury and the contents of mercury in renal cortex, cerebral cortex and cerebellum (r=0.61, 0.47, 0.48, P<0.05) . Conclusion: DMPS mercury expulsion treatment can significantly reduce the level of metal mercury in the kidney, and there is no significant change in the level of metal mercury in the cortex and cerebellum.

Urinary Heavy Metals and Longitudinal Changes in Blood Pressure in Midlife Women: The Study of Women's Health Across the Nation.

[Figure: see text].

Epidemiology, clinical presentation, treatment, and follow-up of chronic mercury poisoning in China: a retrospective analysis.

BACKGROUND: There are no reports on the incidence of chronic mercury poisoning in a large population in China. This study investigated the epidemiology, clinical manifestations, treatment, and follow-up of Chinese patients with chronic mercury poisoning. METHODS: Data for 288 mercury poisoning patients were collected at our hospital from July 2014 to September 2019, including sex, age, admission time, blood mercury content, urine mercury content, creatinine, urinary mercury/creatinine ratio, 24-h urinary protein levels, electromyography (EMG) findings, renal biopsy, and follow-up. Patient characteristics were evaluated by statistical and correlation analyses. RESULTS: First, mercury poisoning in China mainly occurred through occupational exposure and the inappropriate use of mercury-containing cosmetics and Chinese folk remedies (CFRs). Second, the most common symptoms were nervous system (50.3 %), kidney (16.4 %) and breathing (8.0 %). Mercury poisoning-induced Nephrotic syndrome (NS) and peripheral neuropathy are common long-term complications. The complications of occupational and cosmetics-induced mercury poisoning are consistent with international belief. However, the NS caused by CFRs is mainly membranous nephropathy and the probability of peripheral neuropathy caused by CFRs is higher than other pathogens. Third, follow-up data shows that 13 patients with EMG-confirmed neurological injury, 10 showed full recovery after 38.50 ± 8.03 months. Furthermore, among 18 patients with NS, 15 had normal urine protein and serum albumin levels after 22.67 ± 10.26 months. CONCLUSIONS: Regulation of skin-lightening cosmetic products, safety surveillance of CFRs, and prevention and control of occupational exposure must be improved to decrease the incidence of mercury poisoning in China.

Blood and Urine Inorganic and Organic Mercury Levels in the United States from 1999 to 2016.

BACKGROUND: Mercury is an environmental hazard. Organic mercury is biologically more toxic than inorganic mercury. Therefore, we studied recent trends in the blood levels of organic and inorganic mercury in the United States. METHODS: A total of 56,445 participants that had blood mercury and urine mercury measurements in National Health and Nutrition Examination Survey (NHANES) 1999-2016 were included. The organic mercury level was obtained by subtracting the inorganic mercury level from the total mercury level. Results were analyzed using SPSS complex sample module version 25. Pregnant women, children ages <20 years, and different ethnicities were analyzed as subgroups. RESULTS: Blood organic mercury level increased from (geometric mean [95% confidence interval]) 0.08 [0.07-0.10] to 0.17 [0.16-0.18] µg/L during 1999-2016. It increased significantly (P <0.001) from 0.03 [0.02-0.03] to 0.07 [0.06-0.07] µg/L in children ages <20 and from 0.14 [0.09-0.21] to 0.36 [0.16-0.83] µg/L in pregnant women in this period (P <0.001). In 2013-2016, non-Hispanic Asians had the highest blood organic mercury level among different ethnicities, 0.93 [0.82-1.05] µg/L (P <0.001). Blood inorganic mercury level decreased from 0.31 [0.31-0.31] in 1999-2000 to 0.21 [0.21-0.22] µg/L in 2015-2016 (P <0.001). Urine mercury level decreased from 0.75 [0.71-0.80] in 1999-2000 to 0.16 [0.16-0.17] µg/L in 2015-2016 (P <0.001). CONCLUSION: Blood organic mercury increased over the period 1999-2016 in the US population, including children and pregnant women, whereas there was a steady decline in both blood inorganic mercury and urine mercury levels.

Effect of erythropoietin on mercury-induced nephrotoxicity: Role of membrane transporters.

Mercury is a widespread pollutant. Mercuric ions uptake into tubular cells is supported by the Organic anion transporter 1 (Oat1) and 3 (Oat3) and its elimination into urine is through the Multidrug resistance-associated protein 2 (Mrp2). We investigated the effect of recombinant human erythropoietin (Epo) on renal function and on renal expression of Oat1, Oat3, and Mrp2 in a model of mercuric chloride (HgCl2)-induced renal damage. Four experimental groups of adult male Wistar rats were used: Control, Epo, HgCl2, and Epo + HgCl2. Epo (3000 IU/kg, b.w., i.p.) was administered 24 h before HgCl2 (4 mg/kg, b.w., i.p.). Experiments were performed 18 h after the HgCl2 dose. Parameters of renal function and structure were evaluated. The protein expression of Oat1, Oat3 and Mrp2 in renal tissue was assessed by immunoblotting techniques. Mercury levels were determined by cold vapor atomic absorption spectrometry. Pretreatment with Epo ameliorated the HgCl2-induced tubular injury as assessed by histopathology and urinary biomarkers. Immunoblotting showed that pretreatment with Epo regulated the renal expression of mercury transporters in a way to decrease mercury content in the kidney. Epo pretreatment ameliorates HgCl2-induced renal tubular injury by modulation of mercury transporters expression in the kidneys.

Temporal trends of urinary mercury in Chinese people from 1970s to 2010s: A review.

Mercury (Hg) is one of the most toxic heavy metals. It can migrate around the globe and magnify through the food chain, ultimately harming human health. Urinary Hg reflects recent exposure of Hg, which reflects the status of environmental contamination by Hg. This review summarized the levels and presented temporal trends of urinary Hg in Chinese people (both the general public and the occupationally exposed people) reported from 1970s to 2010s. It was found that urinary Hg levels in 92.3% of the reported population were less than the reference value (10.0 µg/L) recommended by Chinese health authority, while 76.9% were less than the reference value (4.0 µg/L) recommended by World Health Organization (WHO) in the general public in China. For the temporal trend from 1970s to 2010s, the urinary Hg levels in the general public in China were found to decrease gradually. In the occupationally exposed people, the urinary Hg levels generally exceeded the reference value (10.0 µg/L) for the general public, and about half of them were higher than the occupational exposure limit (35.0 µg/g creatinine) set by Chinese Occupational Health Standard (WS/T 265 - 2006). From 1970s to 2010s, the urinary Hg levels in occupationally exposed population increased first and then decreased slowly. Hg miners in Guizhou were found to have the highest urinary Hg levels, while workers in Anhui, Chongqing, Qinghai and Shanxi also had high levels of urinary Hg. In all, the urinary Hg levels in both the general public and the occupationally exposed people decreased from 1970s to 2010s, especially in recent decades. Attention should be paid to occupationally exposed people since high levels of urinary Hg were found in them. The message provided in this review can help better understand the situation of Hg burden in Chinese people and lay a basis for the coming effectiveness evaluation on the implementation of Minamata Convention on Mercury. Capsule abstract: The urinary Hg levels in both the general public and the occupationally exposed people in China are decreasing.

Urinary Mercury Levels and Predictors of Exposure among a Group of Italian Children.

Urinary mercury (Hg) levels are suitable to assess long-term exposure to both elemental and inorganic Hg. In this study, the urinary Hg levels of 250 children (aged 6-11 years) from three areas with different anthropogenic impacts in the Rieti province, central Italy, were assessed. The Hg concentrations were in the range of 0.04-2.18 µg L-1 with a geometric mean equal to 0.18 µg L-1 [95% confidence interval (CI), 0.17-0.20 µg L-1] or 0.21 µg g-1 creatinine (95% CI, 0.19-0.23 µg g-1 creatinine), and a reference value calculated as 95th percentile of 0.53 µg L-1 (95% CI, 0.44-0.73 µg L-1) or 0.55 µg g-1 creatinine (95% CI, 0.50-0.83 µg g-1 creatinine). In all cases, urinary Hg data were below the HBM-I values (7 µg L-1 or 5 µg g-1 creatinine) established for urine, while the 95th percentile was above the German Human Biomonitoring Commission's RV95 (0.4 µg L-1) set for children without amalgam fillings. A significant correlation (p < 0.05) was found between creatinine-corrected results and residence area, with higher urinary Hg levels in children living in the industrial area. Multiple linear regression analysis showed that creatinine was the main predictor of urinary Hg.