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.

Mercury intoxication resembling pediatric rheumatic diseases: case series and literature review.

Mercury is the only metal that remains in liquid form at the room temperature. It is a very toxic metal and even short-term exposure can lead to poisoning. Mercury intoxication can affect many systems such as skin, cardiovascular, genitourinary, central and peripheral nervous, respiratory, and musculoskeletal system. Consequently, the diagnosis of mercury intoxication can be challenging due to its non-specific and multisystemic presentation. Herein, we report five pediatric cases with mercury intoxication from two families that were initially misdiagnosed as rheumatic disorders. We also performed a literature review about pediatric cases with mercury intoxication to investigate the clinical findings in children, the source of intoxication, and the current treatment preferences. As in our cases, reported patients were previously misdiagnosed as various infectious and/or rheumatic diseases before the diagnosis of mercury intoxication was established. A delay in diagnosis and treatment can cause serious morbidities and even mortality. We report this case series to emphasize the multisystemic presentation of mercury intoxication, and to remind and provide clues for physicians to recognize this rare toxicologic syndrome.

CYP3A Polymorphism and Chronic Mercury Intoxication.

We analyzed the relationship between polymorphic loci of CYP3A genes (CYP3A4 (rs2740574), CYP3A5 (rs776746) and CYP3A7 (rs2257401)) with the development of chronic mercury intoxication. Of 170 men examined, 120 were workers chronically exposed to mercury vapors and 50 were carriers of GG-HSPA1B (+1267A/G) genotype associated with chronic mercury intoxication. Urinary content of 4-hydroxyantipyrine (4-HAP) generated in the reaction predominantly catalyzed by CYP3A4/CYP3A5 was studied in workers without chronic mercury intoxication (group 1, N=46) and patients in the delayed period of chronic mercury intoxication (group 2, N=74) depending on the genotypes of CYP3A4 and CYP3A5. For polymorphic loci CYP3A5 and CYP3A7, a tendency to an increase in the frequency of genotypes with rare alleles was found (p=0.071 and p=0.078) in the combined group (group 2 together with GGHSPA1B genotype carriers) relative to group 1. The high level of linkage disequilibrium was noted, especially for the pair rs776746 and rs2257401 (LD (r)=0.89). In group 2, a trend to 4-HAP decrease compared to group 1 (p=0.056 and p=0.065) was revealed for carriers of AA-CYP3A4 and GG-CYP3A5 genotypes. The involvement of CYP3A in the development of mercury neurotoxic effect remains unclear.

The Association Between Mercury Exposure and Atopic Dermatitis in Early Childhood: A Mothers and Children's Environmental Health Study.

BACKGROUND: Atopic dermatitis is a chronic and relapsing inflammatory skin disease. Although mercury has been suggested as a risk factor, the underlying mechanism and the relationship between mercury and atopic dermatitis remains unclear. The objective of the present study was to investigate the relationship between mercury exposure and the presence of atopic dermatitis in early childhood. METHODS: This study is part of the prospective Mothers and Children's Environmental Health cohort study. A total of 1,751 pregnant women were enrolled in Mothers and Children's Environmental Health. After delivery, children were followed up. Blood samples were collected and mothers were asked about the presence of atopic dermatitis in their children via a questionnaire at 6, 12, 24, 36, and 60 months of age. RESULTS: After excluding participants who did not meet the inclusion criteria, a total of 1,061 mother-children pairs were included in the analysis. The geometric mean of mercury concentrations in cord blood was 5.1 µg/L. In adjusted models, cord blood mercury exposure (odds ratio [OR] = 1.1; 95% confidence interval [CI] = 1.0, 1.2 at 12-24 months) and postnatal mercury exposure (OR = 1.2; 95% CI = 1.0, 1.5 at 24-36 months, OR = 1.4; 95% CI = 1.1, 1.8 at 48-60 months) were associated with the presence of atopic dermatitis in children. CONCLUSIONS: Postnatal mercury exposure at 24 months of age increases the risk of atopic dermatitis in children.

Unusual complication of an Alaskan cruise: thinking outside the box.

A 69-year-old man with a medical history of hypertension and diabetes presented with altered mental status once he returned from a 14-day Alaskan cruise. An extensive workup for stroke was negative. His physical examination was normal without any focal motor deficits, but he had developed memory loss and paresthesia. He admitted to eating a lot of fish when he was in Alaska. The whole-blood mercury level was found to be elevated. He was managed conservatively and his symptoms resolved completely in a few days. This led to a diagnosis of organic mercury toxicity.

Human exposure to mercury and its hematological effects: a systematic review.

Mercury is a metal found in the environment from natural and anthropogenic sources. It is highly toxic to ecosystems and living beings. Most human exposures come from ingestion of contaminated seafood, outgassing from dental amalgam or occupational exposure (e.g. gold mining), among other cases. Large populations are exposed to mercury, making it a very important issue from the public health perspective. Adverse health effects are commonly seen in the nervous system, but every organ is a potential target, such as the bone marrow. The main goal of this study was to assess the available evidence on human exposure to mercury and its hematological effects. A search strategy was constructed, including key terms (MeSH, text word and equivalents) for querying 2 repositories of master dissertation and PhD thesis (Fiocruz/ARCA and University of São Paulo) and 4 different electronic databases: BVS/LILACS, MEDLINE/PubMed, Scopus and TOXLINE/NIH, for articles published from 1950 to February 2018. There was no language restriction and a tool (EPHPP) was used to assess the quality of included studies. According to pre-established criteria, 80 studies were retrieved, all of them observational (48 case reports, 24 cross-sectional, 6 case series and 2 cohorts), comprising 9,284 people. Despite the fact that most exposed ones (6,012) had normal blood cell count and mercury hematological effects did not seem very usual (1,914 cases: 14 severe and 29 deaths), three studies reported association (ß) for anemia, lymphopenia, neutrophilia and basophilia. We concluded that the gathered information pointed to mercury hematotoxic effects, some of them may be serious and even fatal.

Application of TDA AAS to Direct Mercury Determination in Postmortem Material in Forensic Toxicology Examinations.

Mercury is a heavy metal with high toxicity, the level of which depends on the form of the metal. One of the newer techniques for determining trace amounts of total mercury in various materials, including biological samples, is thermal decomposition, amalgamation and atomic absorption spectrometry (TDA AAS). The TDA AAS method was optimized and validated using a mercury analyzer (DMA-80). The limits of detection for mercury were 0.10 and 0.20 µg/L (nickel and quartz boats, respectively). The working range of the calibration curve was at least from 0.6 to 200 ng Hg/mL; the intra-day precision in samples (RSD)-in the range of: 1.66-6.86% (blood), 0.82-1.47% (urine) and 2.01-3.44% (hair); the inter-day precision (over 8 days): 2.51%, and 2.5% (blood spiked with 2.5 and 10 ng Hg, respectively), 5.10% and 3.16% (urine spiked with 2.0 and 6.0 ng Hg, respectively). The accuracy (as relative error, mean value) determined on the basis of the study of reference materials of blood (Seronorm Trace Elements Whole Blood L-1, L-2, L-3), urine (Seronorm Trace Elements Urine, Urine L-2), and hair (Human Hair NIES CRM No. 13) was: 2.00% (blood), 0.50% (urine) and 0.86% (hair); recovery of 2.5 ng Hg (blood): 93-97%. The method was used for the determination of mercury in 76 samples of various biological matrices, including samples of whole blood, urine, hair, bile and vitreous humor. Mercury concentrations in postmortem blood (n = 24) were in the range: 0.61-12.4 µg/L (median 3.02 µg/L); urine (n = 12): 0.16-2.19 µg/L (median 0.81 µg/L); hair (n = 14): 0.08-0.53 µg/g (median 0.22 µg/g); bile (n = 12): 1.15-7.11 µg/L (median 2.41 µg/L and vitreous humor (n = 13): 0.22-1.01 µg/L (median 0.47 µg/L). The method is suitable for the purposes of forensic toxicology analysis.

Protective Effect of Leaf Ethanolic Extract Etlingera hemisphaerica Blume Against Mercuric Chloride Toxicity in Blood of Mice.

This research was intended to investigate the protective effect of leaf ethanolic extract Etlingera hemisphaerica Blume (LE3H) against mercuric chloride (HgCl2) toxicity in blood of mice (Mus musculus). The experimental animals, 95 male M. musculus, received drink and food ad libitum. Three materials were tested: LE3H (0.13, 0.26, 0.39 mg/g body weight [bw]) was administered by gavage; HgCl2 (5 mg/kg bw) was administrated by gavage or intraperitoneal injection; and Imunos (the nutritional supplement to stimulate the immune system; 0.2 mg/g bw), as a positive control for LE3H treatment, was given by gavage. Blood samples were taken from the tails for determining number of blood cells. The animals were killed by cervical dislocation (CD), and then blood samples were collected from the hearts for protein electrophoresis. Results revealed the same number of leukocytes with LE3H (0.39 mg/g bw) treatment as with the Imunos treatment. HgCl2 administration increased leukocytes and decreased erythrocytes; HgCl2 administration followed by LE3H (0.39 mg/g bw) treatment protected the amount of blood cells as well as the control. HgCl2 administration showed a new 125 kDa protein and caused overexpression of 48 kDa protein; this protein profile could be protected by LE3H (0.39 mg/g bw) treatment as in the control condition. We conclude that LE3H provides a protective effect against HgCl2 toxicity in blood of M. musculus.

Human exposure to mercury and its hematological effects: a systematic review / Exposição humana ao mercúrio e seus efeitos hematológicos: uma revisão sistemática / Exposición humana al mercurio y sus efectos hematológicos: una revisión sistemática

Mercury is a metal found in the environment from natural and anthropogenic sources. It is highly toxic to ecosystems and living beings. Most human exposures come from ingestion of contaminated seafood, outgassing from dental amalgam or occupational exposure (e.g. gold mining), among other cases. Large populations are exposed to mercury, making it a very important issue from the public health perspective. Adverse health effects are commonly seen in the nervous system, but every organ is a potential target, such as the bone marrow. The main goal of this study was to assess the available evidence on human exposure to mercury and its hematological effects. A search strategy was constructed, including key terms (MeSH, text word and equivalents) for querying 2 repositories of master dissertation and PhD thesis (Fiocruz/ARCA and University of São Paulo) and 4 different electronic databases: BVS/LILACS, MEDLINE/PubMed, Scopus and TOXLINE/NIH, for articles published from 1950 to February 2018. There was no language restriction and a tool (EPHPP) was used to assess the quality of included studies. According to pre-established criteria, 80 studies were retrieved, all of them observational (48 case reports, 24 cross-sectional, 6 case series and 2 cohorts), comprising 9,284 people. Despite the fact that most exposed ones (6,012) had normal blood cell count and mercury hematological effects did not seem very usual (1,914 cases: 14 severe and 29 deaths), three studies reported association (β) for anemia, lymphopenia, neutrophilia and basophilia. We concluded that the gathered information pointed to mercury hematotoxic effects, some of them may be serious and even fatal.

O mercúrio é um metal que pode ser encontrado naturalmente no meio ambiente e através de fontes antropogênicas. É altamente tóxico para ecossistemas e seres vivos. A maior parte da exposição humana provém da ingestão de pescados contaminados, da liberação de gases da amálgama dentária ou da exposição ocupacional (p.ex.: extração de ouro). Vastas populações são expostas ao mercúrio, tornando-se uma questão de saúde pública muito importante. Efeitos adversos à saúde são comumente observados no sistema nervoso, mas todos os órgãos são alvos em potencial, como a medula óssea. O principal objetivo do estudo foi avaliar as evidências disponíveis sobre a exposição humana ao mercúrio e seus efeitos hematológicos. Uma estratégia de busca foi realizada, incluindo termos chave (palavras-chave, palavras do texto e equivalentes), para pesquisar dois repositórios de dissertações de mestrado e teses de doutorado (Fiocruz/ARCA e Universidade de São Paulo) e quatro bases de dados eletrônicas: BVS/LILACS, MEDLINE/PubMed, Scopus e TOXLINE/NIH (artigos publicados de 1950 até fevereiro de 2018). Não houve restrições de linguagem e uma ferramenta (EPHPP) foi utilizada para avaliar a qualidade dos estudos incluídos. De acordo com os critérios pré-estabelecidos, foram encontrados 80 estudos, todos observacionais (48 relatos de caso, 24 estudos transversais, 6 séries de casos e 2 coortes), que compreendiam 9.284 pessoas. Apesar do fato de que as pessoas mais expostas (6.012) tinham contagens de células sanguíneas normais, e os efeitos hematológicos do mercúrio não pareciam muito comuns (1.914 casos, 14 graves e 29 mortes), três estudos relataram a associação de (β) anemia, linfopenia, neutrofilia e basofilia. Concluímos que as informações coletadas indicam efeitos hematotóxicos do mercúrio, alguns dos quais podem ser muito graves e até fatais.

El mercurio es un metal que se puede encontrar de forma natural en el ambiente y mediante fuentes antropogénicas. Es altamente tóxico para los ecosistemas y seres vivos. Entre otras, la mayor parte de la exposición humana, proviene de la ingestión de pescado contaminado, liberación de gases de amalgamas dentales o exposición ocupacional (p.ej. extracción de oro). Vastas poblaciones están expuestas al mercurio, convirtiéndolo en un asunto muy importante desde la perspectiva de la salud pública. Los efectos adversos para la salud se observan comúnmente en el sistema nervioso, pero cada órgano es un objetivo potencial, como la médula ósea. El objetivo principal del estudio fue evaluar las evidencias disponibles sobre la exposición humana al mercurio y sus efectos hematológicos. Se realizó una estrategia de búsqueda, incluyendo términos clave (palabras-clave, palabras del texto y equivalentes), se consultaron 2 registros de trabajos finales de máster y tesis de doctorado (Fiocruz/ARCA y Universidad de São Paulo) y 4 bases de datos electrónicas diferentes: BVS/LILACS, MEDLINE/PubMed, Scopus y TOXLINE/NIH, para artículos publicados desde el año 1950, hasta febrero de 2018. No hubo restricciones de lengua y se usó la herramienta (EPHPP) para evaluar la calidad de los estudios incluidos. De acuerdo con los criterios preestablecidos, se recopilaron 80 estudios, todos observacionales (48 informes de casos, 24 estudios transversales, 6 series de casos, y 2 cohortes), que comprendieron a 9.284 personas. A pesar de que la mayoría de los expuestos (6.012) tenían un recuento normal de células sanguíneas y los efectos hematológicos del mercurio no parecían muy comunes (1.914 casos: 14 severos y 29 muertes), tres estudios informaron de la asociación (β) para anemia, linfopenia, neutrofilia y basofilia. Concluimos que la información recabada indicaba los efectos hematotóxicos del mercurio, algunos de los cuales pueden ser muy serios e incluso fatales.

Effects of diphenyl diselenide diet on a model of mercury poisoning.

This work investigated the preventive effect of diphenyl diselenide [(PhSe)2] against the toxic effects of mercury in silver catfish (Rhamdia quelen). The animals were treated during 30 consecutive days with a (PhSe)2 supplemented feed (3.0 mg kg-1) or commercial feed. During the last 5 days the animals received a daily intraperitoneal dose of HgCl2 (1.7 mg kg-1) or Saline (0.9%). Twenty-four hours after the last HgCl2 injection, the animals were euthanized by spinal cord section to biological material obtainment. Hepatic (AST and ALT) and renal (ammonia and creatinine) toxicity biomarkers, δ-ALA-D activity, TBARS, total and non-protein thiols levels and hepatic, renal and blood mercury (Hg) and zinc (Zn) content were evaluated. Considering renal parameters, HgCl2 exposition increased serum creatinine levels and decreased δ-ALA-D activity, total and non-protein thiols and TBARS levels. HgCl2 exposure also decreased blood δ-ALA-D activity. With exception of blood δ-ALA-D activity and total thiols levels, (PhSe)2 supplementation partially prevented mercury induced alterations. Animals exposed to HgCl2 presented an increase in liver and kidney Hg content and a decrease in liver and blood Zn content. The alteration in blood Zn content was partially prevented with (PhSe)2 supplementation. With the exception of mercury and zinc content, no effects of HgCl2 exposure on hepatic tissue were observed. These results show that (PhSe)2 supplementation can represent a promising alternative to prevent the toxic effects presented by Hg exposure.

Assessing mercury intoxication in isolated/remote populations: Increased S100B mRNA in blood in exposed riverine inhabitants of the Amazon.

Mercury is a heavy metal responsible for human intoxication worldwide and especially in the Amazon, where both natural and anthropogenic sources are responsible for exposure in riverine populations. Methylmercury is the most toxic specie of mercury with recognized neurotoxicity due to its affinity for the central nervous system. S100B protein is a well-established biomarker of brain damage and it was recently associated with mercury-related neurotoxicity. Accurate measurement is especially challenging in isolated/remote populations due to the difficulty of adequate sample conservation, therefore here we use S100B mRNA levels in blood as a way to assay mercury neurotoxicity. We hypothesized that individuals from chronically exposed populations showing mercury levels above the limit of 10 µg/g in hair would present increased levels of S100B mRNA, likely due to early brain damage. A total of 224 riverine individuals were evaluated for anthropometric data (age, body mass index), self-reported symptoms of mercury intoxication, c-reactive protein in blood, and mercury speciation in hair. Approximately 20% of participants showed mercury levels above the limit, and prevalence for most symptoms was not different between individuals exposed to high or low mercury levels. Rigorous exclusion criteria were applied to avoid confounding factors and S100B mRNA in blood was tested by RT-qPCR. Participants with ≥10 µg/g of mercury had S100B mRNA levels over two times higher than that of individuals with lower exposure. A significant correlation was also detected between mercury content in hair and S100B mRNA levels in blood, supporting the use of the latter as a possible candidate to predict mercury-induced neurotoxicity. This is the first report of an association between S100B mRNA and mercury exposure in humans. The combination of both exposure and intoxication biomarkers could provide additional support for the screening and early identification of high-risk individuals in isolated populations and subsequent referral to specialized centers.

Mercury poisoning in a fisherman working on a pelagic fishing vessel due to excessive tuna consumption.

OBJECTIVE: To report the case of a fisherman who developed chronic mercury poisoning due to excessive consumption of tuna while working on a pelagic fishing vessel. CASE REPORT: A 48-year-old male deep-sea fisherman developed paresthesia and pain in both legs while working at sea. He continued working for over 4 months on a pelagic fishing vessel but was eventually unable to function normally as his condition deteriorated. Upon arrival on land, he received specialist treatment, including imaging studies, for 2 months; however, the cause of the symptoms was not identified. An examination of his occupational history revealed that he had worked as a crew member on a pelagic fishing vessel catching tuna for the last 2 years and consumed tuna for two or more meals per day, every day. Two months after discontinuation of tuna consumption, he was tested for mercury. The result showed an elevated blood mercury level (BML) of 21.79 µg/l. Based on the half-life of mercury, the BML was evaluated as 38.70-53.20 µg/l when he was on board. Four months after discontinuing tuna consumption, his BML decreased to 14.18 µg/l, and the symptoms were almost ameliorated. The person responsible for preparing meals on a pelagic fishing ship should be aware that fish may contain high levels of heavy metals and should prepare meals for crew members according to the recommended levels. Crew members should also be aware that fish and shellfish may contain mercury, and hence, they should consume only an appropriate amount.

Endoscopic management of massive mercury ingestion: A case report.

RATIONALE: Ingestion of a massive amount of metallic mercury was thought to be harmless until the last century. After that, in a number of cases, mercury ingestion has been associated with appendicitis, impaired liver function, memory deficits, aspiration leading to pneumonitis and acute renal failure. Treatment includes gastric lavage, giving laxatives and chelating agents, but rapid removal of metallic mercury with gastroscopy has not been used. PATIENT CONCERNS: An 18-year-old man was admitted to our emergency department after drinking 1000 g of metallic mercury as a suicide attempt. DIAGNOSIS: Except from mild umbilical tenderness, he had no other symptoms. Radiography showed a metallic density in the area of the stomach. INTERVENTION: Gastroscopy was performed to remove the mercury. One large pool and several small droplets of mercury were removed from the stomach. OUTCOMES: Blood and urine mercury levels of the patient remained low during hospitalization. No symptoms of mercury intoxication developed during the follow-up period. LESSONS: Massive mercury ingestion may cause several symptoms, which can be prevented with prompt treatment. We used endoscopy to remove the mercury, which shortened the exposure time and minimized the risk of aspiration. This is the first case where endoscopy was used for the management of mercury ingestion.

Intentional intravenous mercury injection.

Mercury toxicity is commonly associated with vapour inhalation or oral ingestion, for which there exist definite treatment options.Intravenous mercury injection is rarely seen, with few documented cases. Treatment strategies are not clearly defined for such cases,although a few options do show benefit. This case report describes a 29-year-old man suffering from bipolar disorder, who presentedfollowing self-inflicted intravenous injection of mercury. Clinical and radiographic features, possible adverse clinical sequelae in preexistingmental illness and further complications are discussed, as well as possible treatment strategies in light of relevant literature.

Genetic Aspects of Susceptibility to Mercury Toxicity: An Overview.

Human exposure to mercury is still a major public health concern. In this context, children have a higher susceptibility to adverse neurological mercury effects, compared to adults with similar exposures. Moreover, there exists a marked variability of personal response to detrimental mercury action, in particular among population groups with significant mercury exposure. New scientific evidence on genetic backgrounds has raised the issue of whether candidate susceptibility genes can make certain individuals more or less vulnerable to mercury toxicity. In this review, the aim is to evaluate a new genetic dimension and its involvement in mercury risk assessment, focusing on the important role played by relevant polymorphisms, located in attractive gene targets for mercury toxicity. Existing original articles on epidemiologic research which report a direct link between the genetic basis of personal vulnerability and different mercury repercussions on human health will be reviewed. Based on this evidence, a careful evaluation of the significant markers of susceptibility will be suggested, in order to obtain a powerful positive "feedback" to improve the quality of life. Large consortia of studies with clear phenotypic assessments will help clarify the "window of susceptibility" in the human health risks due to mercury exposure.

Mercury induced haemocyte alterations in the terrestrial snail Cantareus apertus as novel biomarker.

The aim of the present work was to study the response of a suite of cellular and biochemical markers in the terrestrial snail Cantareus apertus exposed to mercury in view of future use as sensitive tool suitable for mercury polluted soil monitoring and assessment. Besides standardized biomarkers (metallothionein, acetylcholinesterase, and lysosomal membrane stability) novel cellular biomarkers on haemolymph cells were analyzed, including changes in the spread cells/round cells ratio and haemocyte morphometric alterations. The animals were exposed for 14 days to Lactuca sativa soaked for 1h in HgCl2 solutions (0.5 e 1 µM). The temporal dynamics of the responses were assessed by measurements at 3, 7 and 14 days. Following exposure to HgCl2 a significant alteration in the relative frequencies of round cells and spread cells was evident, with a time and dose-dependent increase of the frequencies of round cells with respect to spread cells. These changes were accompanied by cellular morphometric alterations. Concomitantly, a high correspondence between these cellular responses and metallothionein tissutal concentration, lysosomal membrane stability and inhibition of AChE was evident. The study highlights the usefulness of the terrestrial snail C. apertus as bioindicator organism for mercury pollution biomonitoring and, in particular, the use of haemocyte alterations as a suitable biomarker of pollutant effect to be included in a multibiomarker strategy.

[Differential diagnostic method of initial implications and degree I of the chronic mercury intoxication].

Currently available methods for diagnosis of chronic mercury intoxication (CMI) are applied at the any stage of the disease. Changes in these indices sometimes have no the specificity for any CMI stage, and a conclusion on them has the descriptive character. In addition, the above mentioned methods possess not sufficiently high accuracy in the diagnosis of intoxication at early stages of the development of the disease. The purpose of the research is the development of the method permitting to make the differential diagnosis between the initial symptoms of mercury poisoning and its first degree. 118 men who work/worked in the contact with mercury vapor were examined. There were evaluated electroencephalogram, long-latency auditory and cognitive evoked potentials, cerebral hemodynamics, noradrenaline (NA)content in the blood plasma. Statistical processing was performed with the use of «Statistica 6.0¼ software. The levels of NA in the development of CMI were shown to increase, by the time of the shaping of this disease the noted change was decompensated in the nature. The study of reactivity of cerebral vessels revealed the presence of abnormal responses during hypercapnic load in 14 - 24% of examined cases. In the analysis of auditory evoked potentials there was established the change in indices of latency and amplitude of the V- wave, which pronounced in the prolong response time, significant elongation in the P1 peak latency and the gain in the latency of N1 peak. There was established the presence of the wave-like change in the index of the latency of P300. In workers without an occupational disease, there was noted the marked elongation of the latent period of cognitive potential, while in patients with the newly made diagnosis the latency of P300 corresponded to standard values, and in the long term there was observed a sharp deterioration in this index. With the aid of the discriminant analysis with the calculation of canonical value there were revealed the most informative neurobiochemical indices, reoencephalogric ones and evoked potentials. The developed method of diagnosis allows to distinguish between the initial symptoms of mercury intoxication and the first stage of the disease.

Prenatal Maternal Occupational Exposure and Postnatal Child Exposure to Elemental Mercury.

OBJECTIVES: Young children are highly vulnerable to elemental mercury toxicity, and elementary mercury exposure in young children in China unfortunately occurs regularly because of the wide use of fluorescent lamps, glass thermometers, and other mercury-contained items. This study aimed to summarize such recent cases in a referral clinic and to make recommendations for postexposure treatment and prevention of future exposure. METHODS: Patients were evaluated between January 2007 and December 2009 in environmental health facilities throughout China and were referred to our clinic. A total of 6 children younger than 4 years with significant elemental mercury exposure were included in this case series analysis. The total mercury content in blood and hair (fetal hair if necessary) and average 24-hour urine mercury concentrations were analyzed. Meso-2,3-dimercaptosuccinic acid or surgery was prescribed for the patient if necessary. RESULTS: Young children were found to be exposed in 3 ways as follows: prenatal exposure through maternal occupational contact in compact fluorescent-lamp factories (2 cases), broken thermometers (3 cases), and other causes of accidental inhalation of mercury vapor during the embryonic and lactation periods (1 case). For 3 cases caused by broken thermometers, x-ray images helped to identify the position of mercury residues. Local excision was used to remove mercury from the floor of the mouth in 1 case. One child was prescribed oral meso-2,3-dimercaptosuccinic acid, and a good response was received. CONCLUSIONS: Substitution of mercury-in-glass thermometers and vigilance to prevent women of childbearing age from occupational mercury exposure were suggested. Treatment selection should vary according to patient situations.