Methylmercury Neurotoxicity in Amazonian Children Downstream from Gold Mining

Grandjean, Philippe; White, Roberta F.; Nielsen, Anne L.; Cleary, David; Santos, Elisabeth Conceição de Oliveira

doi:10.2307/3434402

Cited by 58 publications

(77 citation statements)

References 4 publications

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“…Stanford-Binet Copying [31]: Because this test had been successfully used in the field as an outcome parameter in MeHg-exposed children [20] and the scoring system is simpler, it replaced the Bender Visual Motor Gestalt Test, which was used as a measure of visual constructional abilities in the 7-year examinations. Administration of all 16 designs allowed equal numbers of test trials for all participants.…”

Section: Neuropsychological Examinationmentioning

confidence: 99%

“…The outcome measures therefore included the total score for the full set items (16 designs) and the score for the last five items. As in our previous research involving other cohorts [20], an immediate memory condition was added as a measure of short-term memory for visuospatial material. This condition was administered immediately after the subject drew the 16 designs, with the instruction to draw all of the designs the subject could recall.…”

Section: Neuropsychological Examinationmentioning

confidence: 99%

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Impact of prenatal methylmercury exposure on neurobehavioral function at age 14 years

Debes¹,

Budtz‐Jørgensen²,

Weihe³

et al. 2006

Neurotoxicology and Teratology

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297

167

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A cohort of 1022 consecutive singleton births was generated during [1987][1988] in the Faroe Islands, where increased methylmercury exposure occurs from traditional seafood diets that include pilot whale meat. The prenatal exposure level was determined from mercury analyses of cord blood, cord tissue, and maternal hair. At age 14 years, 878 of 1010 living cohort members underwent detailed neurobehavioral examination. Eighteen participants with neurological disorders were excluded. Blood and hair samples obtained from the participants were analyzed for mercury. The neuropsychological test battery was designed based on the same criteria as applied at the examination at age 7 years. Multiple regression analysis was carried out and included adjustment for confounders. Indicators of prenatal methylmercury exposure were significantly associated with deficits in finger tapping speed, reaction time on a continued performance task, and cued naming. Postnatal methylmercury exposure had no discernible effect. These findings are similar to those obtained at age 7 years, and the relative contribution of mercury exposure to the predictive power of the multiple regression models was also similar. An analysis of the test score difference between results at 7 and 14 years suggested that mercury-associated deficits had not changed between the two examinations. In structural equation model analyses, the neuropsychological tests were separated into five groups; methylmercury exposure was significantly associated with deficits in motor, attention, and verbal tests. These findings are supported by independent assessment of neurophysiological outcomes. The effects on brain function associated with prenatal methylmercury exposure therefore appear to be multi-focal and permanent.

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Section: Neuropsychological Examinationmentioning

confidence: 99%

Section: Neuropsychological Examinationmentioning

confidence: 99%

Impact of prenatal methylmercury exposure on neurobehavioral function at age 14 years

Debes¹,

Budtz‐Jørgensen²,

Weihe³

et al. 2006

Neurotoxicology and Teratology

Self Cite

297

167

View full text Add to dashboard Cite

show abstract

“…Two 15-ml whole blood samples and a 20-ml urine specimen were collected from each subject for laboratory tests. Methods for blood collection are the same as used by Grandjean et al (1999) 12 . The urine samples were prepared for mercury analysis in Rio de Janeiro and Santarém, Brazil.…”

Section: Methodsmentioning

confidence: 99%

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

Silbergeld

Nash²,

Trevant

et al. 2002

Rev. Soc. Bras. Med. Trop.

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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. Twentysix 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. Key-words: Mercury. Garimpagem. Malaria. Toxicity.Resumo O desenvolvimento econômico, incluindo extração de recursos naturais, pode causar exposições tóxicas que interagem com doenças infecciosas endêmicas. O mercúrio é um metal imunotóxico usado na amalgamação do ouro, resultando em exposição ocupacional e poluição ambiental. Devido aos riscos da exposição ao mercúrio e transmissão de malária em 135 garimpeiros do Pará, Brasil, uma avaliação médica "crosssectional" foi coduzida em 1997. Níveis médios de mercúrio no sangue e na urina encontram-se bem acima dos níveis basais daqueles não expostos. Vinte e seis indivíduos apresentaram parasitemia de malária; sintomas relacionados com exposição ao mercúrio foram adquiridos, mas nenhum dos sintomas/sinais está correlacionado com níveis de mercúrio no sangue ou na urina. Não foi encontrada nenhuma relação de dose-resposta entre exposição ao mercúrio e provável infecção de malária prevalente. Entretanto, verificou-se uma possível redução na aquisição de imunidade que talvez esteja relacionada às condições de garimpagem, incluindo exposição ao mercúrio. Palavras-chaves: Mercúrio. Garimpagem. Malária. Toxicidade.

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“…In these populations, there is strong evidence of early nervous system dysfunction and, to a less extent, immunologic and cardiovascular effects among both adults and children (Lebel et al, 1996(Lebel et al, , 1998Grandjean et al, 1999;Amorim et al, 2000;Dolbec et al, 2000;Harada et al, 2001;Cordier et al, 2002;Mergler, 2002;Yokoo et al, 2003;Silbergeld et al, 2005;Fillion et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Daily mercury intake in fish-eating populations in the Brazilian Amazon

Passos

Silva

Lemire

et al. 2007

J Expo Sci Environ Epidemiol

113

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Although high levels of fish consumption and bioindicators of mercury exposure have been reported for traditional populations in the Amazon, little is known about their actual daily intake of Hg. Using an ecosystem approach, calculate daily mercury intake in adult fish-eaters, examine the relations between mercury intake and bioindicators of exposure and the factors that influence these relations. A cross-sectional dietary survey on fish and fruit consumption frequency was carried out with 256 persons from six villages of the Tapajo´s River. Fish portion per meal was determined. Mercury concentration was determined for 1123 local fish specimens. Daily mercury intake (mg/kg/day) was determined for men and women from each village using the average fish-mercury concentration for the fish caught in their fishing zone, the average quantity of fish per meal, fish-species frequency consumption and participants' body weight. Fish-mercury averaged 0.33 mg/g70.33. Daily mercury intake varied between 0 and 11.8 mg/kg/day (mean 0.92 mg/kg/day70.89) and varied by gender and village. Mean blood-and hair-mercury were 58.7736.1 mg/l and 17.9711.5 mg/g, respectively. There was a strong and positive relation between blood-mercury and daily mercury intake, with an inverse relation for fruit intake and schooling; significant variations were observed with immigrant status, and among villages. Hair-mercury was directly associated with daily mercury intake and inversely related to schooling and fruit consumption. Fruit consumption modified the relation between daily mercury intake and blood-mercury levels: for the same daily mercury intake, persons eating more fruit had lower blood-mercury concentrations (ANCOVA Interaction term: F ¼ 10.9, Po0.0001). The median difference of the ratio of blood-mercury to daily mercury intake between low and high fruit consumers was 26, representing a 26.3% reduction. These findings reveal high levels of daily mercury intake. Rigorous studies for developing risk-based reference doses in the Amazon should be undertaken to orient viable risk-management strategies to reduce exposure, while maintaining fish diet.

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Methylmercury Neurotoxicity in Amazonian Children Downstream from Gold Mining

Cited by 58 publications

References 4 publications

Impact of prenatal methylmercury exposure on neurobehavioral function at age 14 years

Impact of prenatal methylmercury exposure on neurobehavioral function at age 14 years

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

Daily mercury intake in fish-eating populations in the Brazilian Amazon

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