Emotional and motor symptoms in riverside dwellers exposed to mercury in the Amazon. / Manifestações emocionais e motoras de ribeirinhos expostos ao mercúrio na Amazônia.

INTRODUCTION:: The investigation of clinical and neurological impactations associated with exposure to mercury levels in exposed populations is necessary in the Amazon. OBJECTIVE:: To analyze emotional and motor symptoms of riverside dwellers exposed by diet in the municipalities of Itaituba and Acará, in Pará, Brazil. METHODS:: Hair samples were collected to assess the total mercury (HgT). Demographic data as well as emotional (depression, anxiety and insomnia) and motor (paresthesia, muscle weakness, loss of balance when walking, tremors, limb pain and dysarthria) symptomatology data were obtained. RESULTS:: Mean levels of HgT in Itaituba were significantly higher (p < 0.0001) than in Acará. Emotional symptoms were identified in 26 (26.5%) participants from Itaituba and in 24 (52.2%) from Acará. Specific motor complaints in Itaituba occurred in 63 (64.3%) volunteers; the most frequently mentioned afflictions were limb pain (36.7%), paresthesia (32.6%) and muscle weakness (27.5%). In Acará, 33 (71.7%) participants had motor symptoms, the majority of which complained of paresthesia (54.3%), limb pain (52.2%) and tremors (34.8%). Average HgT levels in Itaituba in those with emotional and motor symptoms were above the tolerable levels (6 µg/g) determined by the World Health Organization. CONCLUSION:: Results showed that mercury levels in emotional and motor symptoms in Itaituba are higher than in riverside dwellers in Acará. Further studies, including the application of specific qualitative and/or quantitative standard tests, as well as the investigation of other clinical signs are necessary.

Manifestações emocionais e motoras de ribeirinhos expostos ao mercúrio na Amazônia / Emotional and motor symptoms in riverside dwellers exposed to mercury in the Amazon

RESUMO: Introdução: A investigação dos impactos clínico-neurológicos associados às concentrações de exposição ao mercúrio em populações expostas é necessária na Amazônia. Objetivo: Analisar as manifestações emocionais e motoras de ribeirinhos expostos pela dieta nos municípios de Itaituba e Acará, ambos no Pará. Método: Foram coletadas amostras de cabelo para a determinação de mercúrio total (HgT), obtidos dados demográficos e sintomatológicos emocionais (depressão, ansiedade e insônia) e motores (parestesia, fraqueza muscular, desequilíbrio ao andar, tremor, dor nos membros e disartria). Resultados: A concentração mediana de HgT em Itaituba foi significativamente superior (p < 0,0001) àquela em Acará. As manifestações emocionais foram identificadas em 26 (26,5%) participantes de Itaituba e em 24 (52,2%) em Acará. Com relação às queixas motoras especificas, em Itaituba ocorreram em 63 (64,3%) voluntários, sendo mais referidas a dor nos membros (36,7%), a parestesia (32,6%) e a fraqueza muscular (27,5%). No Acará, 33 (71,7%) participantes apresentaram manifestações motoras, com o maior número queixando de parestesia (54,3%), dor nos membros (52,2%) e tremor (34,8%). As concentrações médias de HgT em Itaituba naqueles com manifestações emocionais e com manifestações motoras estiveram acima do considerado tolerável (6 µg/g) pela Organização Mundial de Saúde. Conclusão: Os resultados revelaram que a concentração de mercúrio nas manifestações emocionais e motoras de Itaituba são maiores do que nos ribeirinhos do Acará. Novos estudos são necessários com a aplicação de testes convencionais qualitativos e/ou quantitativos específicos, assim como também a investigação de outros sinais clínicos.

ABSTRACT: Introduction: The investigation of clinical and neurological impactations associated with exposure to mercury levels in exposed populations is necessary in the Amazon. Objective: To analyze emotional and motor symptoms of riverside dwellers exposed by diet in the municipalities of Itaituba and Acará, in Pará, Brazil. Methods: Hair samples were collected to assess the total mercury (HgT). Demographic data as well as emotional (depression, anxiety and insomnia) and motor (paresthesia, muscle weakness, loss of balance when walking, tremors, limb pain and dysarthria) symptomatology data were obtained. Results: Mean levels of HgT in Itaituba were significantly higher (p < 0.0001) than in Acará. Emotional symptoms were identified in 26 (26.5%) participants from Itaituba and in 24 (52.2%) from Acará. Specific motor complaints in Itaituba occurred in 63 (64.3%) volunteers; the most frequently mentioned afflictions were limb pain (36.7%), paresthesia (32.6%) and muscle weakness (27.5%). In Acará, 33 (71.7%) participants had motor symptoms, the majority of which complained of paresthesia (54.3%), limb pain (52.2%) and tremors (34.8%). Average HgT levels in Itaituba in those with emotional and motor symptoms were above the tolerable levels (6 µg/g) determined by the World Health Organization. Conclusion: Results showed that mercury levels in emotional and motor symptoms in Itaituba are higher than in riverside dwellers in Acará. Further studies, including the application of specific qualitative and/or quantitative standard tests, as well as the investigation of other clinical signs are necessary.

[Life quality in individuals having occupational diseases caused by various occupational factors].

The article presents main results of studies concerning life quality in individuals having chronic occupational diseases of important social value. Life quality in patients with chronic mercurial intoxication and dust bronchitis appeared to result from personal, social and psychologic features.

[Metallic mercury poisoning and neuropsychological effects: a case report]. / Metalik civa zehirlenmesi ve nöropsikolojik etkileri: bir olgu sunumu.

Mercury is an extremely toxic heavy metal that can devastate central nervous system. We present the case of a 15 year old adolescent with mercury intoxication following 4 days of exposure to elemental mercury at home who was consulted by department of pediatrics with complaints of demonstrated emotional lability, memory impairment, disinhibition, and impulsivity. Olanzapin 2,5 mg/day was initiated. Her neuropsychological performance was evaluated by a neuropsychological test battery at initial examination. Deterioration in neuropsychological functions like interference effect and attention (Stroop Test TBAG form), verbal fluency and switching to other category (Verbal Fluency Test, /(VFT), verbal short term and long term memory and recognition (Auditory Verbal Learning Test, /(AVLT) was detected. In 9 months follow up period her complaints resolved. Initial neuropsychological deficits were also fully recovered at follow up. There was an increase in intelligence scores with increased ability to pay and sustain attention. She had better performance at Stroop Test TBAG form, VFT and AVLT which was similar to her normal peers. In this case report, the clinical aspects of central nervous system involvement in mercury intoxication and protection from potential toxic effects of laboratory materials like mercury at schools were discussed. School administrators should be aware of and parents and students should be given necessary protective information.

[Quantitative estimation of the health status dynamics of persons occupationally exposed to mercury vapor: a remote period of intoxication].

The article presents the results of the dynamic clinical observation for persons suffered from occupational chronic mercury intoxication in the remote post-exposure period of the disease. The estimation of the dynamics of syndrome manifestations of chronic mercury intoxication and co-morbidity are presented. The important role of mercury exposure load as a predictor of deterioration of actual health of the patients in the remote period of intoxication is demonstrated.

Care of patients who are worried about mercury poisoning from dental fillings.

INTRODUCTION: Public concern about adverse health effects from mercury exposure from dental amalgams remains a high-profile issue. Patients with nonspecific neuropsychiatric symptoms may incorrectly attribute their complaints to mercury poisoning, and some alternative medical providers diagnose mercury toxicity using nonvalidated tests or without testing at all. CASE REPORT: We report the case of a 37-year-old female who was referred to our outpatient medical toxicology clinic by her family medicine physician after a wellness doctor involved in her care ordered a dimercaptopropanesulfonic acid (DMPS) challenge urine study that revealed an "elevated" mercury level. DISCUSSION: The use of postchelator challenge urine testing to diagnose mercury poisoning has not been validated. Use of such tests may cause falsely elevated urine mercury levels resulting in misdiagnosis of mercury poisoning and unncessary, expensive, and potentially dangerous chelation therapy. CONCLUSION: Family medicine physicians may encounter patients who are concerned about mercury poisoning after undergoing postchelator challenge urine testing. In patients with a low suspicion for mercury toxicity, reassurance is adequate. In patients with moderate to high suspicion for mercury toxicity, a validated test for mercury, such as a 24-hour urine mercury level, or referral to a medical toxicologist is the most appropriate approach.

[Morphologic and neurochemical effects in long-term period of mercurial intoxication (experimental data)].

The article deals with influence of longstanding inhalation of mercurial vapors on behavior of white rats, on morphologic and functional disorders in nervous system, on peculiarities of neuromediators metabolism in brain homogenate over the post-contact period.

Dental amalgam and psychosocial status: the New England Children's Amalgam Trial.

High-dose exposures to elemental mercury vapor cause emotional dysfunction, but it is uncertain whether the levels of exposure that result from having dental amalgam restorations do so. As part of the New England Children's Amalgam Trial, a randomized trial involving 6- to 10-year-old children, we evaluated the hypothesis that restoration of caries using dental amalgam resulted in worse psychosocial outcomes than restoration using mercury-free composite resin. The primary outcome was the parent-completed Child Behavior Checklist. The secondary outcome was children's self-reports using the Behavior Assessment System for Children. Children's psychosocial status was evaluated in relation to three indices of mercury exposure: treatment assignment, surface-years of amalgam, and urinary mercury excretion. All significant associations favored the amalgam group. No evidence was found that exposure to mercury from dental amalgams was associated with adverse psychosocial outcomes over the five-year period following initial placement of amalgams.

Effects of trophic poisoning with methylmercury on the appetitive elements of the agonistic sequence in fighting-fish (betta splendens)

The aggressive display in Betta splendens is particularly prominent, and vital to its adaptation to the environment. Methylmercury is an organic variation of Hg that presents particularly pronounced neuro-behavioral effects. The present experiments aim to test the effect of acute and chronic poisoning with methylmercury on the display in Bettas. The animals were poisoned by trophic means in both experiments (16 ug/kg in acute poisoning; 16 ug/kg/day for chronic poisoning), and tested in agonistic pairs. The total frequency of the display was recorded, analyzing the topography of the agonistic response. The methylmercury seems to present a dose- and detoxification-dependent effect on these responses, with a more pronounced effect on motivity in acute poisoning and on emotionality in the chronic poisoning. It is possible that this effect could be mediated by alteration in the mono-amino-oxidase systems (AU)

El despliegue agresivo en la Betta splendens es especialmente prominente y es vital para su adaptación al medio ambiente. Metil-mercurio es una variación orgánica de Hg que presenta efectos neuro-conductuales especialmente pronunciados. Los experimentos actuales intentan poner aprueba el efecto de envenenamiento agudo y crónico con metil-mercurio sobre el despliegue en Bettas. Los animales fueron envenenados tróficamente en ambos experimentos (16 ug/kg eel envenenamiento agudo) y probados en parejas agonistas. Se registró la frecuencia total del despliegue, analizando la topografía de la respuesta agonista. El metil-mercurio parece presentar un efecto dependiente de la dosis y de la detoxificación sobre estas respuestas, con un efecto más pronunciado sobre la motilidad en el envenenamiento agudo y sobre la emotividad en el envenenamiento crónico. Posiblemente, este efecto podría mediarse por la alteración en los sistemas de mono-amino-oxidasa (AU)

[Behavioral activity of white rats under inhalation of metallic mercury].

Prolonged inhalation of metallic mercury vapors by white rats appeared to result in toxic encephalopathy manifesting in disorders of orientative and investigatory, emotional behavior - increased anxiety, aggressiveness, negative e motionalism, higher locomotion activity. Throughout the experiment the animals had increased aggressiveness and muscular tone.

Behavioral changes in metallothionein-null mice after the cessation of long-term, low-level exposure to mercury vapor.

The neurobehavioral changes in wild-type and metallothionein (MT)-null mice after the cessation of long-term, low-level exposure to Hg0 were investigated. MT-null and wild-type females were continuously (24 h/day) exposed to mercury vapor (Hg0) at 0.055 mg/m3 (range: 0.043-0.073 mg/m3), which was similar to the current threshold limit value (TLV), for 29 weeks. The effects on behavior, such as locomotor activity in the open field (OPF), learning ability in the passive avoidance response (PA) and spatial learning ability in the Morris water maze (MM) were examined immediately and 12 weeks after the cessation of exposure. Immediately after the exposure had ceased, total locomotor activity in OPF was decreased in the both strain of mice, although the MT-null mice appeared to show more distinct effect. In the PA test, the exposed animals of both strains showed learning impairment as compared to un-exposed mice. Twelve weeks after the cessation of exposure, the locomotor activity in OPF was elevated in the exposed mice of both strains, while the learning ability in the PA test appeared normal in both strains. Spatial learning ability was not affected at all. Immediately after the exposure had ceased, the brain mercury concentration of the exposed wild-type mice was 1.75 microg/g, twofold of that in the MT-null mice. In 12 weeks, brain mercury levels decreased to approximately 1/20 of those in immediately after the exposure in both of the strains. These results for the first time indicated that long-term, low-level exposure to Hg0 could exert neurobehavioral effects, which were not reversible even after a long exposure-free period. Whereas the effects on learning ability were presumably transient, the effects on spontaneous behavior as evaluated in OPF were persistent. Finally, the MT-null mice seemed more susceptible to Hg0-induced neurotoxicity than the wild-type mice, confirming our previous results.

Effects of prenatal exposure to mercury on cognitive and psychomotor function in one-year-old infants: epidemiologic cohort study in Poland.

PURPOSE: The aim of the study is to assess the cognitive and psychomotor status of 1-year-old infants whose mothers were exposed to low, but varying, amounts of mercury during pregnancy. METHODS: Mercury levels in cord and maternal blood at delivery were used to assess prenatal environmental exposure to mercury. Bayley Scales of Infant Development were used to assess neurobehavioral health outcomes. The cohort consisted of 233 infants who were born at 33 to 42 weeks of gestation between January 2001 and March 2003 to mothers attending ambulatory prenatal clinics in the first and second trimesters of pregnancy. Enrollment included only nonsmoking women with singleton pregnancies between the ages of 18 and 35 years who were free from chronic diseases. RESULTS: The geometric mean (GM) for maternal blood mercury level for the group of infants with normal neurocognitive performance was lower (GM = 0.52 mug/L; 95% confidence interval [CI], 0.46-0.58) than that observed in the group with delayed performance (GM = 0.75 mug/L; 95% CI, 0.59-0.94), and this difference was significant (p = 0.010). The GM of cord blood mercury level in the normal group also was lower (GM = 0.85 mug/L; 95% CI, 0.78-0.93) than that observed in the group with delayed performance (GM = 1.05 mug/L; 95% CI, 0.87-1.27), and this difference was of borderline significance (p = 0.070). The relative risk (RR) for delayed performance increased more than threefold (RR = 3.58; 95% CI, 1.40-9.14) if cord blood mercury level was greater than 0.80 mug/L. Risk for delayed performance in the group of infants with greater maternal mercury levels (>0.50 mug/L) also was significantly greater (RR = 2.82; 95% CI, 1.17-6.79) compared with children whose mothers had mercury levels less than 0.50 mug/L. CONCLUSIONS: The results may be of public health importance because delayed psychomotor or mental performance in infants is assumed to be an indicator of later neurocognitive development in children, which may persist into adult life.

A aplicação da neuropsicologia na pesquisa experimental: o exemplo da intoxicação por vapor de mercúrio / Neuropsychology in experimental research: mercury intoxication as an example of application

O desenvolvimento da neuropsicologia acompanhou a evolução do estudo do cérebro desde os registros mais antigos. A ciência neuropsicológica faz uso de medidas quantitativas de desempenho e tecnologias para produção de neuroimagem que, em conjunto, permitem a observação das relações cérebro-comportamento. No âmbito experimental, a neuropsicologia tem revelado novos conhecimentos na investigação de alterações cognitivas, psicomotoras ou comportamentais associadas a patologias congênitas ou adquiridas. No presente artigo são abordados aspectos históricos da neuropsicologia experimental e apresentados os principais resultados de um estudo referente às alterações neuropsicológicas de pacientes com histórico de intoxicação por vapor de mercúrio, presentes anos após o período de exposição ao metal (AU)

A aplicação da neuropsicologia na pesquisa experimental: o exemplo da intoxicação por vapor de mercúrio / Neuropsychology in experimental research: mercury intoxication as an example of application

O desenvolvimento da neuropsicologia acompanhou a evolução do estudo do cérebro desde os registros mais antigos. A ciência neuropsicológica faz uso de medidas quantitativas de desempenho e tecnologias para produção de neuroimagem que, em conjunto, permitem a observação das relações cérebro-comportamento. No âmbito experimental, a neuropsicologia tem revelado novos conhecimentos na investigação de alterações cognitivas, psicomotoras ou comportamentais associadas a patologias congênitas ou adquiridas. No presente artigo são abordados aspectos históricos da neuropsicologia experimental e apresentados os principais resultados de um estudo referente às alterações neuropsicológicas de pacientes com histórico de intoxicação por vapor de mercúrio, presentes anos após o período de exposição ao metal

[Ill due to amalgam? 10 rules for managing the symptomatic patient]. / Krank durch Amalgam? Zehn Regeln für den Umgang mit Betroffenen.

Over the past two decades, mercury released by amalgam fillings has been held responsible for a number of mental and somatic health complaints. However, a systematic relation between increased mercury levels and the severity of the reported symptoms has never been demonstrated in any of the present well-controlled multidisciplinary studies. These studies, however, have found a high prevalence of mental disorders, especially somatization syndromes, among patients with self-diagnosed "amalgam illness". Additionally, our own studies indicate that amalgam anxiety is often merely one aspect of a general environmental anxiety. Overall, the present findings suggest a psychological etiology for amalgam-related complaints. Our psychosomatic model of "amalgam illness" integrates external factors, individual predispositions and specific processes of perception, awareness, evaluation and attribution. Practical management strategies for primary care physicians can be derived from this model.