Effects of Homeopathic Preparations of Mercurius corrosivus on the Growth Rate of Moderately Mercury-Stressed Duckweed Lemna gibba L.

BACKGROUND: A bioassay with severely mercury-stressed duckweed (Lemna gibba L.) had revealed growth-inhibiting effects of homeopathically potentised mercury(II) chloride (Mercurius corrosivus, Merc-c.). We hypothesised that effects of potentised preparations are dependent on the stress level of the organisms used in the bioassay. The aim of the present investigation was to examine the response of duckweed to potentised Merc-c. at a lower stress level. METHODS: Duckweed was moderately stressed with 2.5 mg/L mercury(II) chloride for 48 hours. Afterwards plants grew in either Merc-c. (seven different potency levels, 24x-30x) or water controls (unsuccussed or succussed water) for 7 days. Growth rates of the frond (leaf) area were determined using a computerised image-analysis system for day 0-3 and 3-7. Three independent experiments with potentised Merc-c. and three systematic negative control experiments were performed. All experiments were randomised and blinded. RESULTS: Unsuccussed and succussed water did not significantly differ in their effects on duckweed growth rate. The systematic negative control experiments did not yield any significant effects, thus providing evidence for the stability of the experimental system. Data from the two control groups and the seven treatment groups (Merc-c. 24x-30x) were each pooled to increase statistical power. Duckweed growth rates for day 3-7 were enhanced (p < 0.05) after application of Merc-c. compared with the controls. Growth rates for day 0-3 were not influenced by the homeopathic preparations. CONCLUSIONS: Moderately mercury-stressed Lemna gibba L. yielded evidence of growth-enhancing specific effects of Merc-c. 24x-30x in the second observation period (day 3-7). This observation is complementary to previous experiments with severely mercury-stressed duckweed, in which a decrease in growth was observed in the first observation period (day 0-3). We hypothesise that the differing results are associated with the level of stress intensity (moderate vs. severe).

Low levels of lead and glutathione markers of redox status in human blood.

Exposure to lead (Pb) is implicated in a plethora of health threats in both adults and children. Increased exposure levels are associated with oxidative stress in the blood of workers exposed at occupational levels. However, it is not known whether lower Pb exposure levels are related to a shift toward a more oxidized state. To assess the association between blood lead level (BLL) and glutathione (GSH) redox biomarkers in a population of healthy adults, BLL and four GSH markers (GSH, GSSG, GSH/GSSG ratio and redox potential E h ) were measured in the blood of a cross-sectional cohort of 282 avid seafood-eating healthy adults living on Long Island (NY). Additionally, blood levels of two other metals known to affect GSH redox status, selenium (Se) and mercury (Hg), and omega-3 index were tested for effect modification. Regression models were further adjusted for demographic and smoking status. Increasing exposure to Pb, measured in blood, was not associated with GSSG, but was associated with lower levels of GSH/GSSG ratio and more positive GSH redox potential E h , driven by its association with GSH. No effect modification was observed in analyses stratified by Hg, Se, omega-3 index, sex, age, or smoking. Blood Pb is associated with lower levels of GSH and the GSH/GSSG ratio in this cross-sectional study of healthy adults.

Mercury poisoning through intravenous administration: Two case reports with literature review.

RATIONALE: Metallic mercury poisoning through intravenous injection is rare, especially for a homicide attempt. Diagnosis and treatment of the disease are challenging. PATIENT CONCERNS: A 34-year-old male presented with pyrexia, chill, fatigue, body aches, and pain of the dorsal aspect of right foot. Another case is that of a 29-year-old male who committed suicide by injecting himself metallic mercury 15 g intravenously and presented with dizzy, dyspnea, fatigue, sweatiness, and waist soreness. DIAGNOSIS: The patient's condition in case 1 was deteriorated after initial treatment. Imaging studies revealed multiple high-density spots throughout the body especially in the lungs. On further questioning, the patient's girlfriend acknowledged that she injected him about 40 g mercury intravenously 11 days ago. The diagnosis was then confirmed with a urinary mercury concentration of 4828 mg/L. INTERVENTIONS: Surgical excision, continuous blood purification, plasma exchange, alveolar lavage, and chelation were performed successively in case 1. Blood irrigation and chelation therapy were performed in case 2. OUTCOMES: The laboratory test results and organ function of the patient in case 1 gradually returned to normal. However, in case 2, the patient's dyspnea was getting worse and he finally died due to toxic encephalopathy and respiratory failure. LESSONS: Early diagnosis and appropriate treatment are critical for intravenous mercury poisoning. It should be concerned about the combined use of chelation agents and other treatments, such as surgical excision, hemodialysis and plasma exchange in clinical settings.

Zuotai and HgS differ from HgCl2 and methyl mercury in Hg accumulation and toxicity in weanling and aged rats.

Mercury sulfides are used in Ayurvedic medicines, Tibetan medicines, and Chinese medicines for thousands of years and are still used today. Cinnabar (α-HgS) and metacinnabar (ß-HgS) are different from mercury chloride (HgCl2) and methylmercury (MeHg) in their disposition and toxicity. Whether such scenario applies to weanling and aged animals is not known. To address this question, weanling (21d) and aged (450d) rats were orally given Zuotai (54% ß-HgS, 30mg/kg), HgS (α-HgS, 30mg/kg), HgCl2 (34.6mg/kg), or MeHg (MeHgCl, 3.2mg/kg) for 7days. Accumulation of Hg in kidney and liver, and the toxicity-sensitive gene expressions were examined. Animal body weight gain was decreased by HgCl2 and to a lesser extent by MeHg, but unaltered after Zuotai and HgS. HgCl2 and MeHg produced dramatic tissue Hg accumulation, increased kidney (kim-1 and Ngal) and liver (Ho-1) injury-sensitive gene expressions, but such changes are absent or mild after Zuotai and HgS. Aged rats were more susceptible than weanling rats to Hg toxicity. To examine roles of transporters in Hg accumulation, transporter gene expressions were examined. The expression of renal uptake transporters Oat1, Oct2, and Oatp4c1 and hepatic Oatp2 was decreased, while the expression of renal efflux transporter Mrp2, Mrp4 and Mdr1b was increased following HgCl2 and MeHg, but unaffected by Zuotai and HgS. Thus, Zuotai and HgS differ from HgCl2 and MeHg in producing tissue Hg accumulation and toxicity, and aged rats are more susceptible than weanling rats. Transporter expression could be adaptive means to reduce tissue Hg burden.

Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.

The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.

Selenium as an antidote in the treatment of mercury intoxication.

Selenium (Se) is an essential trace element for humans. It is found in the enzyme glutathione peroxidase. This enzyme protects the organism against certain types of damage. Some data suggest that Se plays a role in the body's metabolism of mercury (Hg). Selenium has in some studies been found to reduce the toxicity of Hg salts. Selenium and Hg bind in the body to each other. It is not totally clear what impact the amount of Se has in the human body on the metabolism and toxicity of prolonged Hg exposure.

Metallothionein, essential elements and lipid peroxidation in mercury-exposed suckling rats pretreated with selenium.

Detoxification of mercury (Hg) with selenium (Se) in the early postnatal period with regard to the expression of metallothionein protein (MT), essential element status, and lipid peroxidation level in tissues has not been studied. Seven-day-old Wistar pups were orally pretreated with Se [6 µmol Na2SeO3/kg body weight (b.w.)] for 3 days and then cotreated with Hg (6 µmol HgCl2/kg b.w.) for the following 4 days. This group (Se + Hg) was compared to the groups treated with Hg, Se, or vehicle (control). Compared to the Hg-group, Se + Hg-group exhibited lower renal MT expression, reduced accumulation of Hg, Cu and Zn, and reduced excretion of Se, Hg and Zn in urine. In the liver, MT was stimulated by Se treatment in both, Se and Se + Hg-group. Hepatic and brain levels of the endogenous essential elements Cu, Fe, Mg, and Zn remained unchanged in all of the studied groups. Brain Hg levels and oxidation of lipids measured as thiobarbituric acid reactive substances were diminished in Se + Hg-group of pups compared to the Hg-group. This study suggests that Se pretreatment can help reduce Hg in the tissues of suckling rats, simultaneously preventing impairment of essential element levels in the kidneys and their excessive excretion via urine. Also, Se was shown to prevent oxidative damage of lipids in the brain, which is particularly susceptible to Hg during the early postnatal period.

Arsenic and Mercury Containing Traditional Chinese Medicine (Realgar and Cinnabar) Strongly Inhibit Organic Anion Transporters, Oat1 and Oat3, In Vivo in Mice.

Toxic heavy metals, including mercury (Hg) and arsenic (As), accumulate preferentially in kidneys and always cause acute renal failure. The aim of this study was to investigate whether these samples affect organic anion transporters, Oat1 and Oat3, in vivo in mice kidney. Mice (n = 10) were orally treated with investigational samples. After last administration, all mice were i.v. p-aminohippuric acid (PAH), and the blood and kidneys samples were collected. The concentrations of PAH were quantified by spectrophotometry. mRNA expressions of Oat1 and Oat3 were assayed by real-time PCR. In comparison with corresponding control, major pharmacokinetic parameters of PAH in sera were significantly changed by investigational samples (p < 0.05), PAH accumulations in the kidney tissues were significantly higher (p < 0.05), PAH uptake by renal slices was greatly reduced, Oat1 and Oat3 mRNA expression were significantly inhibited in investigational sample groups. Arsenic and mercury containing traditional Chinese medicine (Realgar and Cinnabar) probably induce kidney damage through inhibiting several members of the organic anion transporters (such as OAT1 and OAT3).

Clinical manifestation and management of intravenous mercury injection: a case report.

Intentional self-injection of metallic mercury case report is presented. A 22 year old man with a past medical history of ethylene glycol suicidal poisoning was admitted to a Acad. N. Kipshidze Central University Clinic in Tbilisi, four months after deliberate intravenous injection of an unknown quantity of metallic mercury from several thermometers into his antecubital vein. After 2 months of asymptomatic period, the patient began to complain of pain and tremor in limbs, fatigue and skin rash. CT scan of the thorax and the abdomen confirmed multiple small opacities of metallic density in both lungs, liver and right kidney. After the procedure the patient was transferred to the toxicology center in Baku, Azerbaijan for chelation therapy. On arrival no biochemical abnormalities in hepatic or renal function or clinical pulmonary malfunction were detected, despite presence of slight symptoms of erethism, tremor mercuralis, knee joints arthralgia and lower extremities weakness. Chelation therapy with intramuscular injection of Unithiol (DMPS) was started in dose of 20mg/kg/day. After one month of chelation therapy, mercury blood concentration slowly decreased from initially 134 microgram/L to 105 microgram/L. This case report demonstrates mild acute toxicity following intravenous administration of unknown amounts of elemental mercury. Because of chelation therapy can remove approximately 1 mg of mercury per day the patient was recommended further long-term DMPS treatments under the control blood mercury levels. It is concluded that clinical manifestations of intravenous elemental mercury intoxication may be delayed despite significant increase in blood mercury level.

Treatment of mercury vapor toxicity by combining deferasirox and deferiprone in rats.

The hypothesis that combination of deferasirox and deferiprone chelators might be more efficient as combined therapy than single therapy in removing mercury from the body was considered. Male Wistar rats were exposed to mercury vapor for 2 weeks. After mercury administration some abnormal clinical signs such as red staining around the eyes, greenish mottling on the liver, weakness, loss of hair and weight, were observed in animals. Chelators were given orally after mercury vapor application for 2 weeks. Mercury toxicity symptoms in rats decreased after drug administration. After chelation therapy, these rats were anesthetized with ether vapor and immobilized by cervical dislocation and then their heart, liver, kidneys, intestine, spleen and testicles were sampled for determination of mercury and iron concentration. The combined chelation therapy results showed that these chelators are able to remove mercury from the body and toxicity symptoms decreased.

Dietary advice on Inuit traditional food use needs to balance benefits and risks of mercury, selenium, and n3 fatty acids.

Elevated concentrations of mercury (Hg) are commonly found in the traditional foods, including fish and marine mammals, of Inuit living in Canada's Arctic. As a result, Inuit often have higher dietary Hg intake and elevated Hg blood concentrations. However, these same traditional foods are excellent sources of essential nutrients. The goals of this study were 1) to identify the traditional food sources of Hg exposure for Inuit, 2) to estimate the percentage of Inuit who meet specific nutrient Dietary Reference Intakes and/or exceed the Toxicological Reference Values (TRVs), and 3) to evaluate options that maximize nutrient intake while minimizing contaminant exposure. A participatory cross-sectional survey was designed in consultation with Inuit in 3 Canadian Arctic jurisdictions (Nunatsiavut, Nunavut, and the Inuvialuit Settlement Region). Estimated intakes for EPA (20:5n3) and DHA (22:6n3) met suggested dietary targets, and estimated selenium (Se) intake fell within the Acceptable Range of Oral Intake. Estimated intakes of Hg (rs = 0.41, P < 0.001), Se (rs = 0.44, P < 0.001), EPA (rs = 0.32, P < 0.001), and DHA (rs = 0.28, P < 0.001) were correlated with their respective blood concentrations. Mean estimated Hg intake (7.9 µg · kg(-1) · wk(-1)) exceeded the TRV of 5.0 µg · kg(-1) · wk(-1), with 35% of the population above this guideline. Because the estimated intakes of each of the nutrients were strongly correlated (Se: rs = 0.92, P < 0.001; EPA: rs = 0.82, P < 0.001; DHA: rs = 0.81, P < 0.001) with estimated Hg intake, efforts to decrease Hg exposure must emphasize the overall healthfulness of traditional foods and be designed to prevent concomitant harm to the nutrient intakes of Inuit.

Inorganic mercury poisoning associated with skin-lightening cosmetic products.

INTRODUCTION: Mercury and mercury salts, including mercurous chloride and mercurous oxide, are prohibited for use in cosmetic products as skin-lightening agents because of their high toxicity. Yet, the public continue to have access to these products. METHODS: Reports of skin-lightening cosmetic products containing mercury and cases of mercury poisoning following the use of such products were identified using Medline (1950 - 28 March 2011) with mercury, mercury compounds, mercury poisoning, cosmetics and skin absorption as the subject headings. These searches identified 118 citations of which 31 were relevant. TOXICOKINETICS: The rate of dermal absorption increases with the concentration of mercury and prior hydration of the skin. The degree of dermal absorption varies with the skin integrity and lipid solubility of the vehicle in the cosmetic products. Ingestion may occur after topical application around the mouth and hand-to-mouth contact. After absorption, inorganic mercury is distributed widely and elimination occurs primarily through the urine and feces. With long-term exposure, urinary excretion is the major route of elimination. The half-life is approximately 1-2 months. FEATURES: The kidneys are the major site of inorganic mercury deposition; renal damage includes reversible proteinuria, acute tubular necrosis and nephrotic syndrome. Gastrointestinal symptoms include a metallic taste, gingivostomatitis, nausea and hypersalivation. Although penetration of the blood-brain barrier by inorganic mercury is poor, prolonged exposure can result in central nervous system (CNS) accumulation and neurotoxicity. Inorganic mercury poisoning following the use of skin-lightening creams has been reported from Africa, Europe, USA, Mexico, Australia and Hong Kong. Nephrotic syndrome (mainly due to minimal change or membranous nephropathy) and neurotoxicity were the most common presenting features. As mercury-containing cosmetic products can contaminate the home, some close household contacts were also reported to have elevated urine mercury concentrations. ASSESSMENT: Prevention from further exposure is the first step. Cream users and their close contacts should be evaluated for evidence of mercury exposure, the presence of target organ damage and the need for chelation treatment. Laboratory evaluation of affected subjects should include a complete blood count, serum electrolytes, liver and renal function tests, urinalysis, urine and blood mercury concentrations. Since blood mercury concentrations tend to return to normal within days of exposure, blood samples are useful primarily in short-term, higher-level exposures. Estimation of the urine mercury concentration is the best marker of exposure to inorganic mercury and indicator of body burden. A 24-hour urine for measurement of mercury excretion is preferred; a spot urine mercury concentration should be corrected for creatinine output. MANAGEMENT: Chelation therapy is indicated in patients with features of mercury poisoning and elevated blood and/or urine mercury concentrations. Unithiol (2,3-dimercapto-1-propanesulfonic acid, DMPS) is the preferred antidote though succimer (dimercaptosuccinic acid, DMSA) has also been employed. CONCLUSIONS: The use of mercury in cosmetic products should be strictly prohibited. The public should be warned not to use such products as their use can result in systemic absorption and accumulation of mercury causing renal, gastrointestinal and CNS toxicity.

Toxicological studies of "Chondrokola Rosh", an Ayurvedic preparation on liver function tests of rats.

Chondrokola Rosh (CKR) is a traditional metallic Ayurvedic preparation widely used by the rural and ethnic people of Bangladesh in dysuria. It is a preparation of various roasted metals (Hg and Cu), non-metal (sulphur and Mica) and medicinal herbs. Considering the controversy over the risk of toxic heavy metals in Ayurvedic herbo-mineral preparations, toxicological parameters on liver functions were investigated. A single dose of 100mg/kg body weight of the preparation was administered orally to the rats of both sexes for ninety days. In this evaluation a statistically significant (p<0.001) increase of serum albumin levels in male (17%) and female (15%) rat groups were observed. On the other hand, the plasma bilirubin level was decreased 50% and 28% respectively in both rats groups. But no remarkable differences were observed in plasma protein, sGPT, sGOT and ALP activities from their corresponding control values. This study showed that CKR had no remarkable toxic effect on liver of the animals despite the presence of traces of transformed heavy metals.

Exploration of biomarkers for total fish intake in pregnant Norwegian women.

OBJECTIVE: Few biomarkers for dietary intake of various food groups have been established. The aim of the present study was to explore whether selenium (Se), iodine, mercury (Hg) or arsenic may serve as a biomarker for total fish and seafood intake in addition to the traditionally used n-3 fatty acids EPA and DHA. DESIGN: Intake of fish and seafood estimated by an FFQ was compared with intake assessed by a 4 d weighed food diary and with biomarkers in blood and urine. SETTING: Validation study in the Norwegian Mother and Child Cohort Study (MoBa). SUBJECTS: One hundred and nineteen women. RESULTS: Total fish/seafood intake (median 39 g/d) calculated with the MoBa FFQ was comparable to intake calculated by the food diary (median 30 g/d, rS = 0.37, P < 0.001). Erythrocyte DHA and blood Hg, Se and arsenic concentrations were positively correlated with intake of fish and seafood, but the association for DHA was weakened by the widespread use of supplements. The main finding was the consistent positive association between the intake of fish/seafood and blood arsenic concentration. In multivariate analyses, blood arsenic was associated with blood Hg and fish and seafood intake. In these models, arsenic turned out to be the best indicator of intake of fish and seafood, both totally and in subgroups of fish/seafood intake. CONCLUSIONS: While DHA reflected the intake of fatty fish and n-3 PUFA supplements, blood arsenic concentration also reflected the intake of lean fish and seafood. Blood arsenic appears to be a useful biomarker for total fish and seafood intake.

Influence of selenium dose on mercury distribution and retention in suckling rats.

It is well known that metal-metal interactions in the body are age-dependent. We studied the influence of increasing selenium (Se) doses on mercury (Hg) distribution and retention in the postnatal period in Hg-exposed suckling rats. Seven-day-old Wistar pups were pretreated with three different oral doses of Se as sodium selenite (6.45, 12.9 and 19.4 micromol Se kg(-1) b.w.) over 3 days. This was followed by simultaneous Se (as sodium selenite) and Hg (as mercury chloride) oral administration over 4 days. The molar ratio between Se and Hg given to pups was 1:1, 2:1 and 3:1, respectively. Mercury and Se were measured in brain, kidneys, liver, plasma, erythrocytes and urine of pups on the day after the last administration by atomic absorption spectrometry. Results showed that in all samples Se concentrations rose almost proportionally to the dose of Se given to pups. Mercury concentration in organs, plasma and urine decreased with higher oral doses of Se. However, Hg concentration in erythrocytes increased with increasing Se dose. There was evidently a redistribution of Hg from plasma to erythrocytes at higher ratio of Se:Hg. Approximately equimolar doses of Se and Hg are necessary to produce maximum uptake of Hg by plasma and liver and minimum retention of Hg in the kidney and erythrocytes.

L-arginine reduces mercury accumulation in thymus of mercury-exposed mice: role of nitric oxide synthase activity and metallothioneins.

Mercury, an occupational and environmental contaminant, is a well-recognized health hazard. The thymus is a target for inorganic mercury (Hg2+); thymic function is impaired in Hg2+ intoxication and is partially restored by simultaneous L-arginine supplementation. The nitric oxide (NO)-nitric oxide synthase (NOS) pathway and metallothioneins (MTs) were studied to investigate the role of L-arginine in thymic function restoration after mercury exposure. Mice received a higher and a lower dose of inorganic mercury, with and without L-arginine supplementation. Saline-treated mice were used as controls. Thymus weight and thymulin were measured as indices of thymic function. Mice treated with Hg2+ alone displayed an accumulation of metal in the thymus, reduced NOS activity, a lower plasma nitrite plus nitrate concentration and an increased MTs expression compared with control mice. L-arginine supplementation was associated with lower Hg2+ concentrations in the organ and partial preservation of other measures. Reduced accumulation of Hg2+ in mice dosed with L-arginine was probably related to greater NO production and NO-MTs interactions.

Toxicokinetics and toxicodynamics of elemental mercury following self-administration.

INTRODUCTION: Intravenous injection of mercury has seldom been reported, especially in cases of attempted suicide, and is associated with variable clinical outcomes. CASE REPORT: A young woman came to our attention after self-injecting and ingesting mercury drawn from 37 thermometers. The patient suffered lung embolization complicated by adult respiratory distress syndrome (ARDS), toxic dermatitis, anemia, mild hepato-renal impairment, and died after 30 days. Mercury was monitored in biological fluids (blood, plasma, urine, and bronchoalveolar fluid) to study its toxicokinetics and to evaluate dose-effect relationships. Its urinary clearance significantly increased after a chelation challenge test with meso-2,3-dimercaptosuccinic acid (DMSA) (median values of 2.48 and 8.85 before and after the test, respectively, p < 0.05). CONCLUSIONS: Mercury poisoning by intravenous injection is a clinical emergency, potentially leading to death. When injected, the element has a very slow clearance, mainly renal. Our data do not allow any conclusion about the effectiveness of chelation therapy.

High fish consumption in French Polynesia and prenatal exposure to metals and nutrients.

French Polynesians consume high quantities of fish and are therefore exposed to seafood-related contaminants such as mercury (Hg) or lead (Pb) and nutrients such as iodine, selenium and long chain polyunsaturated fatty acids (LC-PUFAs). As the developing foetus is sensitive to contaminants and nutrients, a cross-sectional study was conducted in French Polynesia in 2005-2006 to assess prenatal exposure to contaminants and nutrients through fish consumption. Two hundred and forty one (241) delivering women originating from all islands of French Polynesia were recruited and agreed to answer questions on fish consumption and gave permission to collect umbilical cord blood for metals and nutrients analyses. All parameters were found in high concentrations in cord blood samples except for lead. Mercury concentrations averaged 64.6 nmol/L (or 13 microg/L) with values ranging from 0.25 to 240 nmol/L. Of the sample, 82.5% had Hg concentrations above the US-EPA blood guide-line of 5.8 microg/L. Tuna was the fish species which contributed the most to Hg exposure. High selenium and LC-PUFAs may counterbalance the potential risk of prenatal exposure to Hg in French Polynesia. Due to the high fish consumption of mothers, Polynesian newborns are prenatally exposed to high doses of mercury. Although selenium and omega-3 fatty acids may counteract mercury toxicity, informing pregnant women on both the mercury and nutrient content of local fish species is important.

Intravenous injection of metallic mercury: case report and course of mercury during chelation therapy with DMPS.

INTRODUCTION: Although several cases of i.v. injection of metallic mercury have been reported, it still remains an uncommon event. CASE REPORT: A 34-year-old male came to hospital because complaining of pleuritic chest pain. X-ray showed radio dense punctate lesions in both lung fields, as well as around both elbows. Mercury concentration in blood (140 microg/L) and urine (320 microg/L) from the patient were significantly elevated, compared with the reference concentrations of < or = 2.0 mug/L mercury in blood and urine. The course of renal elimination of mercury and the mercury concentration in whole blood during 5 months of chelation therapy with sodium 2,3-dimercapto-1-propanesulfonate (Dimaval) were monitored. Furthermore, the time-course of mercury in scalp hair from the patient was determined. CONCLUSION: We report a case of probable consecutive i.v. administration of metallic mercury.

Bioaccumulation potential of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss) as a function of fish growth.

The distribution and potential bioaccumulation of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss Walbaum, 1792), a major aquaculture species, was studied in relation to fish growth over a period of >3 years. Fish were reared under normal farming conditions, that is, fed a standard fish food and exposed to negligible levels of waterborne trace elements. The age-related variations in the content of each trace element in gills, kidney, liver, muscle, and skin were studied through nonparametric regression analysis. A buildup of all elements in all tissues and organs was observed, but due to dilution with growth, the concentrations did not increase, except in a few cases such as cadmium and mercury in liver and kidney. In muscle tissue, the concentrations of mercury, lead, and selenium did not alter significantly with growth, whereas cadmium increased but remained at exceedingly low levels. The concentration of arsenic in muscle tissue peaked at 14 months and then decreased in adult specimens. Arsenic speciation by high-performance liquid chromatography--inductively coupled plasma mass spectrometry revealed that arsenic in muscle was almost exclusively present in the form of nontoxic arsenobetaine. Application of a mercury mass balance model gave predicted concentrations in agreement with measured ones and showed that in farmed rainbow trout the ratio of mercury concentrations in feed and in fish is about 1:1. Therefore, rainbow trout does not approach the limits established for human consumption even when reared with feed at the maximum permitted levels. These findings highlight the low bioaccumulation potential of toxic trace elements such as cadmium, lead, and mercury in rainbow trout following dietary exposure. On the other hand, selenium concentrations in muscle (about 0.2 microg g (-1) of fresh weight) show that rainbow trout may be a good source of this essential element.