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.

Valores de referencia pediátricos de cromo y mercurio en orina del área de la Ciudad de Buenos Aires y alrededores / Pediatric reference values for chromium and mercury in urine in the City of Buenos Aires and Greater Buenos Aires

Introducción. Debido a la fuerte industrialización de la Ciudad de Buenos Aires y alrededores, la población podría estar expuesta a metales. Para poder evaluar el nivel de exposición de los niños al cromo y al mercurio, es fundamental tener valores de referencia (VR) propios. El objetivo fue determinar los VR pediátricos para cromo y mercurio en la muestra aislada de orina. Población y métodos: Se incluyeron niños y niñas no expuestos a los contaminantes evaluados que concurrieron al Servicio de Bajo Riesgo y al Consultorio del Jardín Maternal del Hospital de Pediatría S.A.M.I.C. "Prof. Dr. Juan P. Garrahan". Se cuantificó cromo (UCr), mercurio (UHg) y creatinina urinarios. Se calcularon los p95 con su intervalo de confianza del 95 % [IC 95 %] según el concepto para VR de la German Human Biomonitoring Commission. Resultados: Se incluyeron 160 pacientes en el estudio. Se obtuvieron 144 muestras de niños y niñas de entre 1 y 17 años (mediana: 7 años). Se cuantificó UCr a 137 muestras y UHg a 129. La mediana y rango de cromo fue 0,54 (indetectable -3,06) µg/g de creatinina y la de mercurio fue 0,49 (indetectable -7,57) µg/g de creatinina.Conclusiones: Los VR fueron, para UCr, hasta 1,5 µg/l [1,2-2,8] y hasta 2,2 µg/g de creatinina [1,8-3,0] y para UHg, hasta 2,5 µg/l [1,8-4,8] y 3,2 µg/g de creatinina [2,5-4,7

Introduction. Due to the heavy industrialization of the Autonomous City of Buenos Aires and Greater Buenos Aires, the population may have become exposed to metals.To assess the level of exposure to chromium and mercury in children, it is critical to have local reference values (RVs). Our objective was to determine pediatric RVs for chromium and mercury in a single urine sample.Population and methods: Children who were not exposed to the studied contaminants and who attended the Department of Low Risk Conditions and the Daycare Center Office of Hospital de Pediatría S.A.M.I.C. "Prof. Dr. Juan P. Garrahan" were included. Urinary chromium (UCr), urinary mercury (UHg), and urinary creatinine were measured. The p95 and its corresponding 95 % confidence interval (CI) were estimated based on the RV concept proposed by the German Human Biomonitoring Commission.Results: The study included 160 patients. A total of 144 samples from children aged 1-17 years (median: 7 years) were collected. UCr was measured in 137 samples and UHg, in 129 samples. The median value of chromium was 0.54 µg/g of creatinine (range, undetectable to 3.06), while that of mercury was 0.49 µg/g of creatinine (range, undetectable to 7.57). Conclusions: The RVs for UCr were up to 1.5 µg/L [1.2-2.8] and up to 2.2 µg/g of creatinine [1.8-3.0], and for UHg, up to 2.5 µg/L [1.8-4.8] and 3.2 µg/g of creatinine [2.5-4.7]

Avaliação dos níveis de chumbo e mercúrio em população exposta ambientalmente na Região Centro-oeste do Brasil / Evaluación de los niveles de plomo y mercurio en población expuesta ambientalmente en la región centro-oeste de Brasil / Lead and mercury levels in an environmentally exposed population in the Central Brazil

O objetivo foi avaliar o nível de exposição ao chumbo e mercúrio em população do Pantanal Mato-grossense, Brasil. Chumbo no sangue (Pb-S) (n = 119) e mercúrio na urina (Hg-U) (n = 109) de moradores da região foram determinados por espectrometria de absorção atômica. A comparação de médias e correlação entre as variáveis utilizaram o teste ANOVA e a regressão linear, respectivamente, com 95% de confiança. Pb-S médio foi 2,82 ± 1,53µg dL-1. A comparação de Pb-S estratificado por local de coleta (p ≤ 0,01), atividade laboral (p ≤ 0,01) e consumo de leite produzido na região (p ≤ 0,05) mostrou diferenças estatisticamente significativas. Também houve associações positivas entre Pb-S e local de coleta (p ≤ 0,01), profissão dos participantes (p ≤ 0,05), consumo de leite da região (p ≤ 0,01) e origem da água de consumo (p ≤ 0,01). A média de Hg-U foi 1,41 ± 0,98µg L-1. Os teores mostraram diferenças significativas apenas quanto à profissão dos participantes (p ≤ 0,01), e associações positivas surgiram entre Hg-U e atividade profissional (p ≤ 0,01) assim como índice de massa corporal dos sujeitos de estudo (p ≤ 0,01). As amostras apresentaram baixos níveis de chumbo e mercúrio, semelhantes àqueles encontrados em populações também expostas ambientalmente. Apesar dessas baixas concentrações, o conhecimento atual sobre toxicidade desses metais mostra que efeitos à saúde já podem ser sentidos em níveis antes considerados seguros, o que caracteriza o perigo.

El objetivo fue evaluar el nivel de exposición al plomo y mercurio en una población del Pantanal Mato-grossense, Brasil. El plomo en sangre (Pb-S) (n = 119) y mercurio en la orina (Hg-U) (n = 109) de los habitantes de esa región se determinó por espectrometría de absorción atómica. La comparación de medias y la correlación entre las variables utilizaron el test ANOVA y la regresión lineal, respectivamente, con un 95% de confianza. Pb-S medio fue 2,82 ± 1,53µg dL-1. La comparación de Pb-S estratificado por lugar de recogida (p ≤ 0,01), actividad laboral (p ≤ 0,01) y consumo de leche que se produjo en la región (p ≤ 0,05) mostró diferencias estadísticamente significativas. También hubo asociaciones positivas entre Pb-S y el lugar de recogida (p ≤ 0,01), profesión de los participantes (p ≤ 0,05), consumo de leche de la región (p ≤ 0,01) y origen del agua de consumo (p ≤ 0,01). La media de Hg-U fue 1,41 ± 0,98µg L-1. Los porcentajes mostraron diferencias significativas sólo respecto a la profesión de los participantes (p ≤ 0,01), y las asociaciones positivas surgieron entre Hg-U y la actividad profesional (p ≤ 0,01), así como índice de masa corporal de los sujetos de estudio (p ≤ 0,01). Las muestras presentaron bajos niveles de plomo y mercurio, semejantes a aquellos encontrados en poblaciones también expuestas ambientalmente. A pesar de esas bajas concentraciones, el conocimiento actual sobre toxicidad de estos metales muestra que los efectos sobre la salud, ya pueden ser apreciados en niveles antes considerados seguros, lo que caracteriza el peligro.

The objective was to assess the level of exposure to lead and mercury in a population in the Pantanal region in Mato Grosso State, Brazil. Blood lead (PbB) (n = 119) and urinary mercury (HgU) (n = 109) in local residents were measured by atomic absorption spectrometry. Comparison of means and correlations between variables used analysis of variance (ANOVA) and linear regression, respectively, with 95% confidence intervals. Mean PbB was 2.82 ± 1.53µg dL-1. The comparison of PbB stratified by collection site (p ≤ 0.01), work activity (p ≤ 0.01), and consumption of locally produced cow's milk (p ≤ 0.05) showed statistically significant differences. There were also positive associations between PbB and collection site (p ≤ 0.01), participants' profession (p ≤ 0.05), local milk (p ≤ 0.01), and source of drinking water (p ≤ 0.01). Mean HgU was 1.41 ± 0.98µg L-1. The levels only showed significant differences for participants' profession (p ≤ 0.01), and positive associations emerged between HgU and work activity (p ≤ 0.01) and body mass index (p ≤ 0.01). The samples showed low lead and mercury levels, similar to those found in other environmentally exposed populations. Despite these low concentrations, current knowledge on the toxicity of these metals shows that health effects can already be felt at levels that were previously considered safe, thus characterizing a health hazard.

Occupational exposure to mercury: air exposure assessment and biological monitoring based on dispersive ionic liquid-liquid microextraction

Exposure to mercury [Hg] as a heavy metal can cause health effects. The objective of this study was to assess occupational exposure to Hg in a chlor-alkali petrochemical industry in Iran by determining of Hg concentrations in air, blood and urine samples. The study was performed on 50 exposed subjects and 50 unexposed controls. Air samples were collected in the breathing zone of exposed subjects, using hopcalite sorbents. Analysis was performed using a cold vapor atomic absorption spectrophotometer [CV-AAS] according to NIOSH analytical method 6009. For all participants, blood and urine samples were collected and then transferred into sterile glass tubes. After micro-extraction with ionic liquid and back extraction with nitric acid, Hg concentrations in blood and urine samples were determined by CV-AAS. The mean concentration of air Hg was 0.042 +/- 0.003 mg/m[3]. The mean concentrations of Hg in blood and urine samples of exposed subjects were significantly higher than unexposed controls [22.41 +/- 12.58 versus 1.19 +/- 0.95 micro g/l and 30.61 +/- 10.86 versus 1.99 +/- 1.34 micro g/g creatinine, respectively]. Correlation of air Hg with blood Hg, urine Hg and blood Hg-urine Hg ratio were significant statistically [P< 0.05]. The values of Hg in blood and urine samples of chlor-alkali workers were considerably high. Correlation coefficients showed that blood Hg and blood Hg-urine Hg ratio are better indicators than urine Hg for assessing occupationally exposed workers in terms of current exposure assessment

Avaliação dos níveis de mercúrio sistêmico em profissionais da Odontologia. Parte III: avaliação transversal / Evaluation of systemic mercury levels in dental professionals. Part III: cross-sectional evaluation

Este estudo mensurou o nível de mercúrio em profissionais em função do período de exposição ao amálgama de prata comparado a pessoas não expostas. Coletou-se 60 amostras de urina distribuídas em seis grupos, divididos em pessoas com e sem restaurações de amálgama, estudantes após o primeiro contato ocupacional, dentistas até um ano de profissão, dentistas entre 5 a 10 anos de profissão e dentistas entre 15 a 20 anos de profissão. Determinou-se o mercúrio através de espectrofotometria de absorção atômica a vapor frio (CV-AAS) em amostras de urina. A análise dos resultados apresentou que houve diferença estatisticamente significante entre os grupos (p = 0,01012). A análise dos resultados constatou que existe um risco potencial de se aumentar os níveis sistêmicos de mercúrio em função do período de manipulação do amálgama dental, apesar de que os sujeitos da pesquisa apresentarem resultados dentro do limite de tolerância biológica proposto pela OMS.

Avaliação dos níveis de mercúrio sistêmico após remoção de restaurações de amálgama / Evaluation of systemic mercury levels after replacement of amalgam restoration

O objetivo deste trabalho foi avaliar o impacto da remoção de restaurações amálgama, nos níveis de mercúrio sistêmico, na urina de pacientes. Distribuíram-se 20 pacientes em dois grupos amostrais dependentes: GR1 (n = 10) – antes da remoção da restauração sem dique de borracha; GR2 (n = 10) – os mesmos pacientes do grupo GR1, após a remoção da restauração; GA1 (n = 10) – antes da remoção com diquede borracha; GA2 (n = 10) – os mesmos pacientes do grupo GA1, após a remoção da restauração. Entre os grupos dependentes houve diferença estatisticamente significativa (p = 0,005012 e p = 0,009747). Os pacientes apresentaram aumento nos níveis de mercúrio sistêmico, independentemente do uso de dique de borracha.

Determination of Hg in biological samples by inductively coupled plasma mass spectrometry / 法医学杂志

OBJECTIVE@#To establish an inductively coupled plasma mass spectrometry (ICP-MS) method for determination of Hg in biological samples.@*METHODS@#The samples were digested with microwave digestion instrument. ICP-MS was applied to detect Hg in blood, urine and hair specimens by using 115In as an internal marker. The ability of gold to eliminate the memory effect of mercury was investigated with the gold amalgamate produced by gold and mercury.@*RESULTS@#The limits of detection were in the 0.01 microg/L, and the accuracy of the method ranged from 97.0% to 107.1%. The concentration of gold was 10 microg/L and the memory effect of mercury was resolved.@*CONCLUSION@#The method is accurate, rapid, sensitive and suitable for the cases of mercury poisoning and the clinical diagnosis and monitoring for patients with mercury poisoning.

Exposição ocupacional ao mercúrio em trabalhadores do ambulatório odontológico de um Posto de Atendimento Médico / Occupational exposure to mercury in dental workers in an outpatient medical stations

O mercúrio, metal tóxico para os seres vivos e o meio ambiente, representa cerca de 50% do amálgama dentário, material restaurador amplamente utilizado na odontologia. A armazenagem e o descarte inadequados das sobras de amálgama são apontados pela literatura científica e pela OMS como fonte de contaminação ambiental por mercúrio, pois, mais de sete mil toneladas do metal são despejadas anualmente no meio ambiente na forma desse composto. O objetivo deste trabalho foi avaliar a exposição ocupacional ao mercúrio na odontologia. Comparou-se um grupo de cirurgiões-dentistas expostos ao mercúrio pelo manuseio do amálgama em um Posto de Atendimento Médico (PAM) da cidade do Rio de Janeiro e outro grupo que, em consultórios particulares, exerce exclusivamente especialidades que não requerem o uso do metal. Os trabalhadores auxiliares do PAM também foram avaliados. Coletaram-se amostras de ar do ambiente (forma ativa com impingers e passiva com dosímetros) e de urina dos participantes, nas quais a concentração de mercúrio foi determinada por espectrometria de absorção atômica com vapor frio. (...) Considerou-se como escassa a existência de cirurgiões-dentistas totalmente livres da exposição ao mercúrio. Concluiu-se que a manipulação do amálgama, mesmo em pequena quantidade, resultou em contaminação ambiental e biológica pelo mercúrio, a qual pode ter sido potencializada pela ventilação inadequada do local, descarte inadequado dos resíduos de amálgama e das cápsulas de amálgama vazias, bem como pelo uso incompleto de EPIs. Apesar das deficiências estruturais e falhas no gerenciamento de seus resíduos, a organização do trabalho no PAM oferecia boas condições aos trabalhadores. Recomendou-se a não utilização do amálgama e a implantação de medidas minimizadoras da exposição ocupacional e da contaminação ambiental proveniente do mercúrio presente no amálgama.

Mercury is a toxic metal for the living beings and the environment and it corresponds to about 50% of dental amalgam, which is a restoring material widely used in dentistry. The inadequate storage and disposal of amalgam wastes are pointed out by scientific literature and by the World Health Organization (WHO) as a source of environmental contamination by mercury on account of the annual disposal of over seven thousand tons of the metal in that compound form. The aim of this work was to evaluate the occupational exposure to mercury in dentistry. A group of dentists that were often exposed to mercury due to the handling of amalgam in a Community Health Center in Rio de Janeiro, Brazil, was compared to another group of dentists that work exclusively in private offices and whose specialties do not involve the use of dental amalgam. The assistants at the Community Health Center were also evaluated. Air samples were collected (actively with impingers and passively with dosimeters), as well as urine samples from the participants, in which the mercury concentration was determined by cold vapor atomic absorption spectrometry. The average mercury concentration in the urine of the exposed dentists was, in ìg L-1, at 1.79 ± 0.68, at 0.92 ± 0.33 for control group and at 1.7 ± 0.77 in the assistants. The average concentration of mercury in the air collected with impinger, in ìg m-3, was at 0.35 ± 0.04 in the “exposed” offices and at 0.19 ± 0.05 in the work environment of the group that was occupationally unexposed to mercury. Among the samples that were collected by means of a dosimeter, one of them presented mercury concentration at 2,30 ± 0,13 ìg m-3, whilst the remaining samples concentrations were equal or under the detection limit of the methodology...

Niveles basales de mercurio en orina en escolares del Municipio San Diego: Estado Carabobo

Se determinaron los niveles basales en orina de mercurio en 108 niños sin exposición conocida al metal, (54 femeninos y 54 masculinos), con edades comprendidas entre 6-12 años, quienes vivían y estudiaban en el Municipio San Diego del Estado Carabobo. Los análisis de orina de mercurio fueron realizados por el método de absorción atómica de vapor frío, los cuales se corrigieron posteriormente en función a la concentración de creatinina en orina (Ct), por el método de Jaffé modificado. La media geométrica de la muestra para orina de mercurio fue 1,18 μg/L y de 1,22 ug/g Ct para la corrección. No hubo asociación estadística entre los valores de orina de mercurio y el sexo. La media de orina de mercurio en el grupo de edades de 10-12 años (1,45 μg/L) fue significativamente superior (P < 0,05) a la del resto de los rangos de edades. Con relación a los valores corregidos la media más alta (1,30 μg/g Ct) se obtuvo en el rango de edades de 8-9 años, sin mostrar diferencias significativas con los otros rangos. Con los resultados de esta investigación se dispone de los valores medios de orina de mercurio, en una población de escolares, a fin de aportar algunos datos relativos a valores basales del mismo, sirviendo como base para que en estudios futuros se pudieran establecer los valores permisibles de mercurio en niños

Basal levels of mercury in urine were determined in 108 children (54 female, 54 male) without known exposure to the metal. Age range was 6-12 years old. They lived and studied in San Diego County, Carabobo State. Mercury in urine analyses were made by atomic absorption with cold vapor. Samples were corrected by creatinina concentration (Ct) by the modified Jaffe method. Geometric mean for mercury in urine was 1.18 μg/L and 1.22 μg/g Ct (Ct corrected). There was no statistical association between mercury in urine and sex. Mean value of mercury in urine in children aged 10-12 years old (1.45 μg/L) was statistically higher (P< 0.05) than the other ages. The higher Ct corrected mercury in urine (1.30 μg/g Ct), was obtained in the range of 8-9 years old, with no statistical difference with the others age ranges. The results obtained allow to have mean basal values of mercury in urine in a scholar population, in order to provide a tool for further studies which could need reference values of mercury in urine in children

Assessment of memory status among workers exposed to mercury

Mercury [Hg] has well established toxic effects on the central nervous system. To study the memory status of workers exposed to mercury. A comparative cross-sectional epidemiological study was carried out among 100 workers exposed to mercury vapour in a fluorescent lamp factory in Alexandria, Egypt. The comparative group comprised 100 workers not exposed to Hg or any other occupational hazard or systemic disease that may affect the memory status. All workers included in this study were interviewed to collect data on personal characteristics, medical and occupational histories, recent and remote memory status. Urine samples were collected to asses the level of mercury in urine in micro g/liter. The results of this study indicated that the mean age of workers was 40 +/- 8.46 years, their mean duration of exposure was 17.21 +/- 8.4 years and their mean urine mercury level was 32 micro g/L. Hg exposed workers showed a significant deficit in the ability to remember remote events and events that happened 10 years ago. Moreover the mean percentage of story events recalled was significantly lowered in mercury exposed workers. On the other hand there was no significant difference between Hg exposed workers and their controls in forward and backward repetition of numbers and in the mean percentage of pictures recalled. After allowing for the effects of age, and smoking, mercury exposed workers were at a higher risk of developing recent and remote memory disorders than unexposed workers. This study highlights the potential for deterioration of memory status among workers exposed to mercury in the fluorescent lamp industry, where deficits in both recent and remote memory were significantly associated with the level of mercury in urine

Avaliação dos teores de mercúrio na urina dos graduandos de odontologia / Evaluation mercury meaning in urine of dentistry undergraduate students

Objetivo: Avaliar os teores de mercúrio na urina dos graduandos de Odontologia do Centro de Ensino Superior do Estado do Pará (CESUPA) em 2002. Método: Avaliados os teores de mercúrio na urina de 20 alunos, através da espectofotometria de absorção atômica. Resultados: Análise estatística constatou que não houve indícios de exposição ocupacional; 80% dos alunos estavam com teores de mercúrio dentro dos limites de normalidade (10µg/L) e apenas 4 encontravam-se acima do limite de normalidade, porém, dentro do limite máximo tolerado (50µg/L). Conclusão: Os teores de mercúrio na urina de 80% dos graduandos de Odontologia encontram-se dentro do limite de normalidade (10µg/L) e, 20% dentro do limite biológico máximo tolerado (50µg/L) preconizado pela OMS, de acordo com a NR7.

Objective: To avaliate mercury meaning in urine of dentistry undergraduate students of "Centro de Ensino Superior do Estado do Pará" (CESUPA) in 2002. Method: There were analyzed the mercury meaning in the urine of 20 students using absorption atomic spectophotometry. Results: The statistic analysis results showed that there were no occupational exposition and, 80% of students had the values lower than the limits considered as normal (10µg/L) and, only 4 students had these values higher than the normal parameters, but in the maximum limit tolerable (50µg/L). Conclusion: The mercury meaning in the urine of 80% dentistry undergraduate students of CESUPA were in normal levels and, 20% were in the maximum limit tolerable as praised by World Health Organization (WHO),according to RN7.

Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55 percent) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81 percent). Three gold miners and 1 riverine (4/19 subjects, 21 percent) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50 percent), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.

Neuropsychological dysfunction related to earlier occupational exposure to mercury vapor

We assessed the neuropsychological test performances of 26 patients (mean age = 41.5 ± 6.1 years; mean years of education = 9.8 ± 1.8; 20 males) diagnosed with chronic occupational mercurialism who were former workers at a fluorescent lamp factory. They had been exposed to elemental mercury for an average of 10.2 ± 3.8 years and had been away from this work for 6 ± 4.7 years. Mean urinary mercury concentrations 1 year after cessation of work were 1.8 ± 0.9 æg/g creatinine. Twenty control subjects matched for age, gender, and education (18 males) were used for comparison. Neuropsychological assessment included attention, inhibitory control, verbal and visual memory, verbal fluency, manual dexterity, visual-spatial function, executive function, and semantic knowledge tests. The Beck Depression Inventory and the State and Trait Inventory were used to assess depression and anxiety symptoms, respectively. The raw score for the group exposed to mercury indicated slower information processing speed, inferior performance in psychomotor speed, verbal spontaneous recall memory, and manual dexterity of the dominant hand and non-dominant hand (P < 0.05). In addition, the patients showed increased depression and anxiety symptoms (P < 0.001). A statistically significant correlation (Pearson) was demonstrable between mean urinary mercury and anxiety trait (r = 0.75, P = 0.03). The neuropsychological performances of the former workers suggest that occupational exposure to elemental mercury has long-term effects on information processing and psychomotor function, with increased depression and anxiety also possibly reflecting the psychosocial context.

Diagnóstico de la contaminación por mercurio en el personal de una unidad odontológica de Caracas, Venezuela / Diagnosis of the mercury contamination among a dental unit staff from Caracas, Venezuela

El mercurio genera afecciones nerviosas, comportamentales, renales, inmunes y sexuales, entre otras. El personal que labora en la práctica odontológica, expuesto crónicamente a vapores de mercurio, constituye una población de riesgo toxicológico. El objetivo de este trabajo fue determinar el contenido de mercurio presente en el personal odontológico de un hospital venezolano, con el fin de evaluar el riesgo ocupacional. Para ello se colectaron muestras de sangre y orina del personal que labora en la Unidad Odontológica, los días lunes y viernes de cada semana durante cuatro semanas. El contenido de mercurio fue determinado mediante Espectroscopía de Absorción y Fluorescencia atómica con vapor frío. Mediante análisis de varianza se probaron estadísticamente las hipótesis relacionadas con la similitud en los valores de mercurio para los diferentes grupos humanos analizados y para los diferentes períodos de muestreo. Los niveles de mercurio en las muestras de orina del personal analizado resultaron por debajo del nivel umbral reseñado por la Organización Mundial de la Salud en 50 ug/L (ppb) de Hg. En muestras de sangre, el 21por ciento de la población evaluada presentó niveles superiores al valor umbral de 15 ug/L (ppb) de Hg. Se encontraron diferencias significativas en el contenido de mercurio de sangre y orina entre los grupos laborales. El contenido de mercurio presente en la muestras de sangre del 21 por ciento de la población evaluada revela que este grupo está en riesgo toxicológico al metal, recomendándose análisis más exhaustivos en estas personas.

Mercury generates nervous, behavior, immune and sexual affections, among others. The personnel working in dentistry, exposed chronically mercury steam, constitutes population in toxicological risk. The objective of this work was to determine mercury present in dentistry personnel of Venezuelan hospital, for evaluating the occupational risk. Blood and urine samples were collected of the personnel working in this Unit Dentistry, the days Monday and Friday of every week during four weeks. The mercury content was determined by means of spectroscopy of absorption and atomic fluorescence with cold steam. By means of variance analysis the hypotheses related to the similarity in the values of mercury for different analyzed human groups and different periods from sampling were proven statistically. Mercury levels in urine samples of analyzed personnel are underneath the level threshold reviewed by the Health World Organization in 50 ?g/L (ppb) Hg. 21% of evaluated population present levels superior to value threshold of 15 ppb of Hg in blood samples. Blood and urine mercury content between the labor groups were significantly differences. Mercury content present in blood samples of 21% of evaluated population reveals this group is in toxicological risk to metal, recommending more exhaustive analyses in these people.

Distribution of mercury in biological fluids

Mercury is widely distributed in nature in both the inorganic forms. The mercury is distributed through out the soft tissues with high concentration is the kidneys the study are distribution of mercury in body fluids. In this study [50] samples of [blood, plasma, serum wine, saliva] were collected from subject of age ranged between 25-45 years attending medical city from April to July 2002. All the samples were analyzed for their mercury concentration by spectrophotometer technique to study the distribution of mercury in all body fluids. The study revealed that the method used can be considered as a suitable method in the study of the distribution of mercury in body fluids and it was found that distribution of mercury level increases as follows:- [blood, Plasma, Serum, Urine, Saliva] the main portion of absorbed mercury is excreted from the body through the urine. The rest is concentrated in plasma, serum, blood and saliva

Mercury exposure and malaria prevalence among gold miners in Pará, Brazil

Economic development, including resource extraction, can cause toxic exposures that interact with endemic infectious diseases. Mercury is an immunotoxic metal used in the amalgamation of gold, resulting in both occupational exposures and environmental pollution. A cross-sectional medical survey was conducted in 1997 on 135 garimpeiros in Para, Brazil, because of their risks of both mercury exposure and malaria transmission. Mean levels of blood and urine mercury were well above non-exposed background levels. Twenty-six subjects had malaria parasitemia: Health symptoms consistent with mercury exposure were reported, but neither symptoms nor signs correlated with mercury levels in blood or urine. We did not find a dose response relationship between mercury exposure and likelihood of prevalent malaria infection, but there was a possible reduction in acquisition of immunity that may be associated with conditions in gold mining, including mercury exposure

Effects of occupational exposure to mercury vapor on the thyroid hormones and glutathione peroxidase enzyme

Evaluation of the effect of elemental mercury [Hg[0]] vapor exposure on the plasma glutathione peroxidase enzyme [PGLPX] and its impact on the thyroid function as evidenced by changes in the level of free thyroxin [T[4]], free triiodothyronine [T[3]], free T[4] /free T[3] ratio as well as the thyroid stimulating hormone [TSH] level. The level of glutathione peroxidase enzyme was estimated using the PGLPX-enzyme immunoassay [EIA]. Serum concentrations of TSH, free T[4] and free T[3] were determined by radioimmunoassay. Assessment of the urinary mercury level was carried out using the atomic absorption spectrometry. The creatinine-corrected urinary mercury [U-Hg] was considered an index of current exposure. This study was carried out on a group of 20 workers exposed to mercury vapor for an average of 29.15 years during the process of mercury electrolysis in an explosive industry and on 12 matched control workers. The mean U-Hg in the exposed population was high [136.86 +/- 45.68 micro g. gm[-1] creatinine] versus 35.44 +/- 14.87 [micro g. gm[-1] creatinine in the control group. There was a remarkable statistically significant increase in the free T4 level among exposed subjects as compared to controls [mean 1.565 ngm dL-1 versus 0.950 ngm dL[-1]]. The free T[4] /free T[3] ratio was also higher in the exposed subjects, but no significant difference was obtained for the level of T[3] and TSH. As for the PGLPX, a highly significant decrease was obtained in the exposed population compared to the control. A significant association was found between increased U-Hg and decreased TSH as well as PGLPX fall. The drop in the level of TSH was shown to be affected by the duration of exposure as evidenced by the statistically significant negative correlation. Regarding PGLPX, there was a significant negative correlation with the level of urea, bilirubin, as well as the free T4 and the free T[4] /free T[3] ratio. The study could indicate a slight effect of occupational exposure to mercury vapor on the function of the enzyme type I iodothyronine deiodinase, as evidenced by increased free T[4] /free T[3] ratio, and on the PGLPX level, as evidenced by the marked drop in its plasma level. Selenium deficiency might be considered an intermediate step in the pathogenesis of these changes

Exposicion ocupacional y efectos a la salud del mercurio metalico entre odontologos y asistentes dentales: un estudio preliminar: Valencia, Venezuela; 1998 / Occupational exposure and health effects of metallic mercury among dentists and dental assistants: a preliminary study, Valencia, Venezuela; 1998

Esta investigación pretendió establecer los efectos del Hg sobre la salud de odontólogos y asistentes dentales, su relación con condiciones de exposición, y el posible daño renal debido al Hg. La población fue de 66 personas, la muestra, 37 (56 por ciento), 22 odontólogos (59,5 por ciento, 19 hombres, 3 mujeres) y 15 asistentes dentales mujeres (40,5 por ciento). Se realizaron: encuesta opcional, Hg en orina (Hg-O) y actividad de N-Acetil-beta-D-glucosaminidasa en orina (BAG-O), como biomarcador precoz de daño renal. Los valores de HgO para los odontólogos fueron 22.4 más o menos 6,4 micra g/g creatinina, para los asistentes, 22,2 más o menos 6,1 mu g/g creatinina (p>0.05), y los de BAG-O, de 2,9 más o menos 3 U/L y de 5,2 más o menos 8,1 U/L, respectivamente, no existiento diferencias estadísticamente significativas (p0,05). No se detectó correlación entre el námero de amalgamas preparadas y de horas trabajadas con Hg-O y NAG-O. Los síntomas más frecuentes referidos por los odontólogos fueron irritabilidad, 54,5 por ciento, cefalea, 45,4 por ciento y artralgias, 40,9 por ciento. Por los asistentes, artralgia, 53,5 por ciento, irritabilidad, 46,7 por ciento, y cefalea, 46,7 por ciento, no existiendo riesgo significativo de sufrirlo para ningún grupo. Se requieren nuevas investigaciones que incluyan monitoreo ambiental del Hg, evaluación médica y pruebas neuroconductuales para detectar efectos precoces, asá como la aplicación de medidas de control en pro de la salud del personal.

Toxicidad de la amalgama dental: revisión bibliográfica / Dental amalgam toxicity: a review of the literature

El propósito del presente trabajo es realizar una revisión de diversos estudios sobre la liberación del mercurio de la amalgama dental y su posible toxicidad. Ya se ha medido el mercurio liberado y en teoría no excede los 50 ug diarios. Aunque se le atribuye ser causante de diversas enfermedades, el paciente es la persona menos expuesta a intoxicación, porque el dentista y su higienista o auxiliar es el más expuesto a sufrir las consecuencias de la toxicidad del mercurio