Whole Blood Hg Research Articles

Essential and non-essential trace elements among working populations in Ghana

BackgroundLead battery repair workers (LBRW) and electronic repair workers (ERW) may be exposed to inorganic components during work. This study aimed at determining essential and non-essential trace elements in male LBRW, ERW, referents and a group of female petty traders (FPT) in Kumasi (Ghana), taking into account iron status and inflammation. MethodsAltogether 64 LBRW, 64 ERW, 65 referents and 26 FPT were investigated in this cross-sectional study. Urine, whole blood and serum were collected for determination of trace elements. C-reactive protein and ferritin were determined in serum. ResultsThe LBRW had higher blood concentrations of manganese (B-Mn) and lead (B-Pb) and antimony in urine (U-Sb), and lower concentrations of cobalt in blood (B-Co). Being ERW was associated with higher concentrations of blood cadmium (B-Cd), urinary tin (U-Sn) and serum chromium (S-Cr). Concentrations of selenium (B-Se), Co and mercury (B-Hg) in whole blood and iodine in urine (U-I) were relatively high. Marginal iron status appeared to be a determinant for elevated concentrations of Co in particular, but also Mn and Cd in blood. Systemic inflammation was associated with the concentrations of copper and Se. The concentrations of Hg in whole blood were highly associated with Se and arsenic (As) in whole blood, indicating fish consumption as a common source of intake of these elements. However, Hg in whole blood was only slightly associated with Se in serum. ConclusionsThe ERW had elevated concentrations of B-Cd, S-Cr, and U-Sn, while B-Mn, B-Pb, and U-Sb concentrations were higher among the LBRW. Iron status and inflammation had substantial impact on some element concentration. This population had high concentrations of B-Se, B-Hg and B-Co and U-I.

Mercury, omega-3 fatty acids, and seafood intake are not associated with heart rate variability or QT interval

ABSTRACTMercury (Hg), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) concentrations differ across seafood types. Our aim was to investigate the association of Hg, EPA, and DHA, as well as avid consumption of diverse seafood types, with cardiovascular variables heart rate variability (HRV) and QT interval duration (QTc) in a contemporary population. We measured HRV and QTc by Holter monitor, EPA and DHA in plasma, total Hg in whole blood, and possible confounders in 94 avid seafood consumers from Long Island, NY. Participants had mean Hg of 8.4 mcg/L, mean EPA of 1.2%, and mean DHA of 3.7% of total fatty acids. Adjusted for possible confounders, EPA+DHA, Hg, and total seafood consumption were not associated with HRV or QTc. Associations with consumption of specific seafood types were suggested (eg, tuna steak with QTc and anchovies with HRV) but require verification.

Differences in the responses of three plasma selenium-containing proteins in relation to methylmercury-exposure through consumption of fish/whales

Putative protective effects of selenium (Se) against methylmercury (MeHg) toxicity have been examined but no conclusion has been reached. We recently reported the lack of serious neurological symptoms in a Japanese fish-eating population with high intakes of MeHg and suggested a potential protective role for Se. Here, relationships between levels of Hg and Se in the blood and plasma samples, with a quantitative evaluation of Se-containing proteins, obtained from this population were examined. While levels of the whole-blood Hg (WB-Hg) and plasma Se (P-Se) showed a positive correlation, stratified analysis revealed that they correlated only in samples with higher (greater than the median) levels of MeHg. A food frequency questionnaire showed that consumption of fish/whales correlated with WB-Hg, but not with P-Se, suggesting that the positive correlation between WB-Hg and P-Se might not be the result of co-intake of these elements from seafood. Speciation of plasma Se revealed the differences in the responses of two plasma selenoproteins, glutathione peroxidase (GPx) and selenoprotein P (SePP), in relation to Hg exposure. In the high-Hg group, SePP showed a positive correlation with WB-Hg, but GPx did not. In the low-Hg group, neither SePP nor GPx showed any correlation with WB-Hg. These observations suggest that the increase in P-Se in the high-Hg group might be associated with an increase in SePP, which may, in turn, suggest an increased demand for one or more selenoproteins in various organs, for which SePP supplies the element.

Low-level mercury in children: Associations with sleep duration and cytokines TNF-α and IL-6

There is a sizeable literature suggesting that mercury (Hg) exposure affects cytokine levels in humans. In addition to their signaling role in the immune system, some cytokines are also integrally associated with sleep behavior. In this cross-sectional study of 9–11 year old children (N=100), we measured total blood Hg in whole blood, serum levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), and objectively measured sleep and activity using actigraphy. Increasing blood Hg was associated with significantly shorter sleep duration and lower levels of TNF-α. IL-6 was not associated with sleep or blood Hg. This study is the first to document an association between total blood Hg and sleep (albeit a small effect), and the first to consider the associations of total blood Hg with cytokines TNF-α and IL-6 in a pediatric sample. Further research using alternative designs (e.g., time-series) is necessary to determine if there is a causal pathway linking low-level Hg exposure to sleep restriction and reduced cytokines.

Reference levels of blood mercury and association with metabolic syndrome in Korean adults

Mercury (Hg) is a nonessential and toxic metal that is widely distributed in the environment. This study was performed to estimate the representative blood Hg level, to determine the contributing factors to Hg exposure, and to analyze the association of blood Hg with metabolic syndrome in Korean adults. Mercury exposure is assessed by total Hg concentration in blood. A total of 2,114 healthy adults who have not been exposed to Hg occupationally were sampled by the multistaged, sex-, and age-stratified probability method. Information was collected regarding the subjects' demographic characteristics, lifestyles, and past medical history. The participants then underwent physical examination and blood sampling. The geometric mean concentration of Hg in whole blood was 3.90 μg/L, which was significantly influenced by sex, age, smoking, alcoholic consumption, residence area, and seafood intake after adjustment for confounders. Significant increases in body mass index, waist circumference, diastolic blood pressure, total cholesterol, and triglyceride were observed according to the blood Hg levels after adjustment for covariates. Also, Hg exposure was significantly associated with metabolic syndrome and their components such as obesity and increased fasting glucose. The blood Hg level in Korean adults is higher than that in USA and other Western countries, while it is similar to or lower than that in other Asian countries. The blood Hg level is influenced by sociodemographic factors and individual lifestyles including dietary habits. Furthermore, blood Hg is associated with metabolic syndrome, in which Hg exposure may play a role as a possible risk factor for cardiovascular diseases.

Mercury Concentration of Whole Blood and Red Blood Cell in Taiwan Residents

PP-31-151 Background/Aims: People are exposed to different forms of mercury (Hg), and about 80% of methylmercury (MeHg) in blood is associated with red blood cells (RBC), where it is largely bound to hemoglobin. We aimed at measuring the Hg concentration in whole blood (WB) and RBC and evaluating their correlation in Taiwan residents. Methods: We recruited 43 volunteers (18 male and 23 female) aged between 19 and 48 years who were not exposed to Hg. Samples of blood (5 mL) were collected and 3 mL RBC was obtained at the same time. The amount of total Hg in WB and RBC is determined by using cold vapor atomic absorption spectroscopy. The WB and RBC samples were treated by microwave-assisted digestion to reach complete solubilization before determination. Results: We found 95% of Hg kept in RBC, the concentration of Hg in WB and RBC was 5.91 ± 2.81 and 11.22 ± 5.68 ng/g, respectively. A high correlation of Hg concentration between WB and RBC was observed (r = 0.93, P < 0.001), this correlation was higher in males (r = 0.95) than that in females (r = 0.90). We divided volunteers into 2 groups by median of age; both WB and RBC Hg concentrations were found almost the same in these 2 metrics. The Hg concentration of WB observed in males was higher than in females (6.14 vs. 5.72 ng/g, P = 0.34), however, in RBC, the results showed adverse direction (10.47 vs. 11.80, P = 0.28). Conclusion: We found the WB and RBC Hg concentrations in Taiwan residents were 5.91 ± 2.81 and 11.22 ± 5.68 ng/g, respectively, this level was higher as compared with the residents of United States and European countries.

COMPARISON OF MERCURY BURDENS IN CHRONICALLY DEBILITATED AND HEALTHY LOGGERHEAD SEA TURTLES (CARETTA CARETTA)

An increase in the incidence of debilitated loggerhead sea turtle (Caretta caretta) strandings in the southeastern United States has been observed in recent years. These turtles are characterized by emaciation and heavy burdens of external and internal parasites, and bacterial infections, but the underlying cause of their condition is unknown. To investigate further the causes of these strandings, a health assessment was performed on stranded, debilitated loggerhead turtles, and contaminant concentrations in various tissues were compared to those from healthy turtles. This portion of the study investigated the potential role of mercury (Hg) toxicity in the debilitated condition described above. Hematocrit, total protein, albumin, globulin, glucose, calcium, lymphocyte counts, heterophil:lymphocyte ratios, aspartate aminotransferase, uric acid, sodium, and chloride were altered in debilitated loggerheads relative to healthy animals. However, none of the aforementioned health indicators correlated with Hg concentrations in either red blood cells (RBCs) or plasma. The Hg concentration in RBCs was 129+/-72 (mean+/-standard deviation) times higher than in plasma, causing a significant dilution of Hg in whole blood due to extreme anemia. Mercury concentrations in RBCs (73.7+/-21.2 ng/g) and scutes (455+/-57 ng/g) from debilitated turtles were similar to or lower than those reported for healthy animals, indicating no elevation in Hg exposure before and during the progression of this condition. These findings suggest that Hg toxicity does not play a role in the debilitated loggerhead condition observed in the southeastern United States.

Blood indices of selenium and mercury, and their correlations with fish intake, in young people living in Britain.

Relationships between Se and Hg in erythrocytes, and between these indices and intakes of fish and other foods, were studied as an adjunct to the British National Diet and Nutrition Survey (NDNS) of young people aged 4-18 years. Hg was measured in 965 packed erythrocyte samples by inductively coupled plasma mass spectrometry. Fe measurements permitted the calculation of whole-blood Hg. Erythrocyte and plasma Se, and 7 d weighed dietary intake estimates, were available. Erythrocyte Hg was positively skewed, normalised by log-transformation. It was 20 % higher in girls than boys (3.17 v. 2.65 nmol/l, P=0.004), and increased with age in boys but not girls. It was directly and strongly correlated with erythrocyte or plasma Se. Hg and Se concentrations were directly correlated with fish intake. Certain other food groups were also directly correlated with Se and Hg concentrations, but less strongly than for fish. The strength and consistency of the relationship between erythrocyte Hg and Se suggests an important chemical link. Previous studies suggest that Se protects against the toxicity of Hg, and that fish is an important source of both. No toxic levels of Hg were found, which is reassuring because of the known health benefits of fish consumption, especially oily fish. Hg intakes need to be monitored, especially in women of child-bearing age, to ensure that Food Standards Agency guidelines are met.

Determination of total mercury in whole blood by flow injection cold vapor atomic absorption spectrometry with room temperature digestion using tetramethylammonium hydroxide

An improved method is described for the determination of total Hg in whole blood based on flow injection cold vapor atomic absorption spectrometry (FI-CVAAS). Aliquots of whole blood (300 µl) are diluted 1 + 1 v/v with 10% v/v tetramethylammonium hydroxide (TMAH) solution, incubated for 1 h at room temperature and then further diluted 1 + 4 v/v with 2% v/v HCl. The TMAH approach is directly compared to a previously published method that utilizes an on-line microwave-assisted heating step as part of the FI arrangement. Thus, the key issue addressed here is the elimination of the on-line microwave digestion step from the FI manifold, because of problems observed with precipitation in the reaction coil and high back pressure in FI manifold. Matrix-matched calibration standards are used and the method detection limit (3σ) is 0.2 µg l−1. Method accuracy is traceable to Standard Reference Material (SRM) 966 Toxic Metals in Bovine Blood from the National Institute of Standards and Technology (NIST). Additional validation data are provided based on the analysis of whole blood materials from the New York State Department of Health's Proficiency Testing Program for Trace Elements and from the trace elements intercomparison program operated by the Institut National de Sante Publique du Quebec, Canada. Accuracy (−2.5%) and precision (<6.0% repeatability and <10% intermediate precision) of the TMAH method compare favorably with values obtained for the on-line microwave method (<10.0% repeatability and <15% reproducibility), and the TMAH method is essentially free of the disadvantages associated with the latter method.

Assessment of white blood cell phagocytosis as an immunological indicator of methylmercury exposure in birds.

White blood cell (WBC) phagocytosis was investigated as a potential immunological indicator of methylmercury (MeHg) exposure in birds. The assay was first assessed using chicken WBCs dosed with MeHg in vitro either in whole blood or as isolated cells and later using blood of wild common loons exposed in vivo to a range of dietary MeHg and having a range of blood-Hg concentrations. Whole blood and isolated WBCs from captive chickens were exposed to a range of MeHg concentrations for 3 h. After MeHg exposure, cells were incubated with fluorescent latex microbeads (diameter = 1.75 microm), fixed, and analyzed for size, complexity, and fluorescent intensity by flow cytometry. MeHg significantly depressed phagocytic activity when added to isolated WBCs at concentrations > 0.01 microg/ml, but not when added to whole blood up to 50 microg/ml. Similarly, no significant relationship between the concentration of Hg in whole blood and phagocytic capacity of WBCs in free-living loons was observed. Our results suggest that the phagocytosis assay, although rapid and convenient for use in field studies with wildlife species, is not a responsive immunological indicator of MeHg exposure at environmentally realistic concentrations of blood-Hg in wild loons. Assays that measure other immunologic endpoints (e.g., bacterial killing assay, PHA skin test, and mitogen-induced lymphocyte proliferation) should be assessed with respect to their ability to detect MeHg immunotoxicity in wild birds.

On-line microwave sample pretreatment for the determination of mercury in blood by flow injection cold vapor atomic absorption spectrometry

A method for on-line treatment of whole blood in a microwave oven and determination of mercury by flow injection cold vapor atomic absorption spectrometry was developed. After dilution of the whole blood and addition of oxidant, all further treatment and measurement were performed automatically, on-line. Recoveries of five mercury compounds were complete. Good agreement between measured and recommended values of mercury in whole blood reference materials was obtained. Measured mercury values also agreed with results from other accepted methods. Sample throughput was about 45 measurements/hr. Detection limit (3s) in diluted sample was 0.1 μg/l corresponding to 1μg/l Hg in whole blood. The RSD value at 0.5 μg/l Hg in the diluted sample was 6–7% (11 measurements and 0.5 ml sample volume). Mercury concentrations between 1 and 150 μg/l in whole blood can be measured using this method. For three replicate measurements, 0.5 ml of whole blood is required.

Decrease in mercury concentration in blood after long term exposure: a kinetic study of chloralkali workers.

The elimination of mercury (Hg) in blood was investigated in 14 chloralkali workers exposed to metallic Hg vapour for 1-24 (median 10) years. Blood and urine samples were collected on several (median eight) occasions during a period of 17-26 days. The initial Hg concentrations were about 80 nmol/l in whole blood (B-Hg) and 17 nmol/mmol creatinine in urine (U-Hg). The decrease in Hg in whole blood, plasma (P) and erythrocytes (Ery) was best characterised by a two compartment model. In a model with a common half life for all subjects, the best fit for B-Hg was obtained with half lives of 3.8 days for a fast phase and 45 days for a slow phase. The half life of the fast phase was shorter for P-Hg than for Ery-Hg, whereas the opposite was the case for the slow phase. The half lives of the slow phases in whole blood and plasma were longer, and the relative fractions of the slow phases were higher (about 50%) after long term exposure than those (about 20%) reported after brief exposure. Slower elimination indicates higher accumulation of Hg in organs with long half lives, and possibly the presence of at least one additional, even slower compartment. The U-Hg fluctuated substantially during the sampling period, and average concentrations decreased only slightly.

Biochemical and morphological studies of monkeys chronically exposed to methylmercury.

This study was designed to correlated autopsy findings with the effects on cage behavior, laboratory values, and mercury clearance of long-term, low-dose exposure of primates to methylmercury. Six rhesus monkeys were given daily methylmercury hydroxide (MeHg) orally in apple juice on a preplanned dosage schedule. Three were sacrificed while receiving MeHg (group I) and the other 3 were sacrificed 2-5 mo after cessation of MeHg administration (group II). Whole-blood Hg levels (organic and inorganic) were assayed weekly, and major organ levels were assayed at autopsy. Whole-blood Hg levels were maintained between 1 and 2 micrograms/ml when the monkeys were given a MeHg dose of 80-125 micrograms/kg . d for up to 1 yr. The Hg burden of the major organs appeared to be dose- and duration-related. After periods of clearance (2.5-5 mo), intestinal wall Hg burden decreased to less than 1 microgram/g, and the hepatic Hg burden was still between 1.12 and 2.37 micrograms/g. However, the kidneys had a higher concentration of Hg, ranging from 10.34 to 29.54 micrograms/g. Whenever there was a high concentration of Hg, significant ultrastructural changes were observed. In the kidneys there were intracytoplasmic vacuoles and electron-dense inclusion bodies. In the small intestine of the animals cleared of mercury (group II), there were normal Paneth cells, as well as some degenerative cells characterized by dilation of endoplasmic reticulum and the presence of intracellular inclusion bodies. These findings suggest the long turnover time of Hg in these cell populations. During the period of study, weekly routine laboratory data including hematology, blood chemistry, and liver and kidney function tests did not reveal any significant changes.