RESUMO
Children living near artisanal and small-scale gold mining (ASGM) are at risk of exposure to mercury, a neurotoxicant. It is not certain whether such exposures are harming development, as they occur in underresourced contexts entwined with other stressors, such as malnutrition and enteric infection. This study sought to investigate the association between hair-mercury levels and visual-motor, cognitive, and physical development among children living near ASGM in the Peruvian Amazon. Total hair-mercury levels were measured in 164 children ages 5-12 living in Madre de Dios, Peru. Primary outcomes included Visual-Motor Integration assessed via the Beery-VMI Developmental Test, General Cognitive Ability assessed via the Batería-III Woodcock-Munoz (Spanish-language Woodcock-Johnson Tests of Cognitive Abilities), and Physical Health assessed via anthropometry/hemoglobin counts. Mean (SD) hair-mercury level was 2.06 (2.43) µg/g. Fifty-four children (32.9%) had hair-mercury levels above the World Health Organization reference level of 2.0 µg/g. After controlling for sex, child age, maternal education, and family socioeconomic status, each one unit increase in log hair-mercury level was associated with a 1.01 unit decrease in Visual-Motor Integration (95%CI: -2.06, 0.05, p = 0.061), a 2.59 unit decrease in General Cognitive Ability (95%CI: -4.52, -0.66, p = 0.012), and a 2.43 unit decrease in Physical Health (95%CI: -5.34, 0.49, p = 0.096). After adjustment for covariates, children with hair-mercury levels exceeding the World Health Organization reference level scored 4.68 IQ points lower in Cognitive Ability than their peers. Mercury exposures related to ASGM may be harming child development in the Peruvian Amazon. Children in this region may benefit from intervention to reach their full developmental potential.
RESUMO
BACKGROUND: Studies with children exposed to methylmercury (MeHg) through fish consumption in the Brazilian Amazon region report that the high levels of hair Hg are associated with significant decreases in intelligence, memory, attention, and visuospatial processing. OBJECTIVE: To investigate the relationship between mercury exposure and neuropsychological functions in riverside communities of the Brazilian Amazon. METHOD: 263 participants aged 6 to 14 years old were assessed, from resettlement regions, near the Madeira river, Rondônia, Brazil. To assess the neuropsychological functions we used the following instruments: intelligence (WASI), working memory (Corsi Block-Tapping Task and Digit Span), verbal fluency (Word Generation - NEPSY II), inhibitory control (Inhibition Errors - NEPSY II), shifting (Trail Making Test) and manual motor dexterity (Grooved PegBoard Test). Socioeconomic status was obtained through household surveys. Total Hg levels were quantified hair samples (Total HgH) collected from the occipital region of the scalp and analyzed by Cold Vapor Atomic Absorption Spectrometry. RESULTS: The group in the upper quartile of Total HgH levels presented lower scores on the tasks that assessed estimated IQ, visuospatial working memory, semantic knowledge and phonological verbal fluency, when compared to the group in the lower quartile level. A regression analysis controlled for age, sex, and maternal education showed that for each increase of 10⯵g/g of Total HgH, there was a decrease around half standard deviation in Verbal IQ, estimated IQ scores, semantic knowledge, phonological verbal fluency and for verbal and visuospatial working memory. CONCLUSIONS: High concentrations of Total Hg in hair were associated with a lower performance in neuropsychological functions tests. The results show that environmental exposure to Hg is associated to children and adolescents' lower neuropsychological performance in the riverine and resettled areas of the Brazilian Amazon region.
Assuntos
Comportamento do Adolescente/efeitos dos fármacos , Desenvolvimento do Adolescente/efeitos dos fármacos , Comportamento Infantil/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Cabelo/química , Intoxicação do Sistema Nervoso por Mercúrio/etiologia , Mercúrio/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Adolescente , Fatores Etários , Brasil , Criança , Estudos Transversais , Exposição Ambiental/efeitos adversos , Feminino , Contaminação de Alimentos , Humanos , Masculino , Mercúrio/análise , Intoxicação do Sistema Nervoso por Mercúrio/diagnóstico , Intoxicação do Sistema Nervoso por Mercúrio/fisiopatologia , Testes Neuropsicológicos , Medição de Risco , Fatores de Risco , Alimentos Marinhos/efeitos adversos , Alimentos Marinhos/análise , Poluentes Químicos da Água/análiseRESUMO
Infrastructure for conducting neurological research in resource-limited settings (RLS) is limited. The lack of neurological and neuropsychological (NP) assessment and normative data needed for clinical interpretation impedes research and clinical care. Here, we report on ACTG 5271, which provided neurological training of clinical site personnel and collected neurocognitive normative comparison data in diverse settings. At ten sites in seven RLS countries, we provided training for NP assessments. We collected normative comparison data on HIV- participants from Brazil (n = 240), India (n = 480), Malawi (n = 481), Peru (n = 239), South Africa (480), Thailand (n = 240), and Zimbabwe (n = 240). Participants had a negative HIV test within 30 days before standardized NP exams were administered at baseline and 770 at 6 months. Participants were enrolled in eight strata, gender (female and male), education (<10 and ≥10 years), and age (<35 and ≥35 years). Of 2400 enrolled, 770 completed the 6-month follow-up. As expected, significant between-country differences were evident in all the neurocognitive test scores (p < 0.0001). There was variation between the age, gender, and education strata on the neurocognitive tests. Age and education were important variables for all tests; older participants had poorer performance, and those with higher education had better performance. Women had better performance on verbal learning/memory and speed of processing tests, while men performed better on motor tests. This study provides the necessary neurocognitive normative data needed to build infrastructure for future neurological and neurocognitive studies in diverse RLS. These normative data are a much-needed resource for both clinicians and researchers.
Assuntos
Ensaios Clínicos como Assunto , Cognição/fisiologia , Pessoal de Saúde/educação , Testes de Estado Mental e Demência , Adulto , África , Fatores Etários , Ásia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/psicologia , Países em Desenvolvimento/economia , Escolaridade , Feminino , Infecções por HIV/complicações , Infecções por HIV/psicologia , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais , América do Sul , Aprendizagem Verbal/fisiologiaRESUMO
A presente pesquisa teve como objetivo contribuir para a caracterização de um fenótipo cognitivo de adolescentes com Síndrome de Down (SD). Foi realizado um estudo multicasos de seis adolescentes diagnosticados com SD, sendo três do sexo masculino e três do sexo feminino, na faixa etária de 13 e 14 anos. Os participantes foram submetidos a uma avaliação neurocognitiva baseada na metodologia desenvolvida por Luria. De maneira geral, os resultados apontam para a presença de dificuldades em tarefas que envolvem o pensamento lógico (e abstrato) e a linguagem expressiva, e, por outro lado, um melhor desempenho em atividades que envolvem habilidades visuoespaciais de menor complexidade, ou seja, com menos interferência do funcionamento executivo, notadamente as funções de planejamento e iniciativa. Ressalta-se que estes resultados podem ser considerados enquanto subsídios para o desenvolvimento de intervenções futuras baseadas nos pontos fortes e fracos do fenótipo cognitivo destes adolescentes (AU
This research aimed to contribute to the characterization of a cognitive phenotype in adolescents with Down syndrome (DS). A multicases study of six adolescents (three males and three females, aged 13 and 14 years) diagnosed with DS, was conducted. The participants underwent a neurocognitive evaluation based on the methodology developed by Luria. Overall, the results indicate the presence of difficulties in tasks that involve logical thinking and expressive language, and, on the other hand, a bett er performance in activities involving visuospati al skills of lower complexity, ie with less interference of executive functioning, such as the functions of planning and initiative. We emphasize that these results can be considered as subsidies for the development of future interventions based on the strengths and weaknesses of the cognitive phenotype of these adolescents (AU)
Assuntos
Humanos , Masculino , Feminino , Adolescente , Síndrome de Down , Testes Neuropsicológicos , Testes de Aptidão , Testes PsicológicosRESUMO
A presente pesquisa teve como objetivo contribuir para a caracterização de um fenótipo cognitivo de adolescentes com Síndrome de Down (SD). Foi realizado um estudo multicasos de seis adolescentes diagnosticados com SD, sendo três do sexo masculino e três do sexo feminino, na faixa etária de 13 e 14 anos. Os participantes foram submetidos a uma avaliação neurocognitiva baseada na metodologia desenvolvida por Luria. De maneira geral, os resultados apontam para a presença de dificuldades em tarefas que envolvem o pensamento lógico (e abstrato) e a linguagem expressiva, e, por outro lado, um melhor desempenho em atividades que envolvem habilidades visuoespaciais de menor complexidade, ou seja, com menos interferência do funcionamento executivo, notadamente as funções de planejamento e iniciativa. Ressalta-se que estes resultados podem ser considerados enquanto subsídios para o desenvolvimento de intervenções futuras baseadas nos pontos fortes e fracos do fenótipo cognitivo destes adolescentes
This research aimed to contribute to the characterization of a cognitive phenotype in adolescents with Down syndrome (DS). A multicases study of six adolescents (three males and three females, aged 13 and 14 years) diagnosed with DS, was conducted. The participants underwent a neurocognitive evaluation based on the methodology developed by Luria. Overall, the results indicate the presence of difficulties in tasks that involve logical thinking and expressive language, and, on the other hand, a bett er performance in activities involving visuospati al skills of lower complexity, ie with less interference of executive functioning, such as the functions of planning and initiative. We emphasize that these results can be considered as subsidies for the development of future interventions based on the strengths and weaknesses of the cognitive phenotype of these adolescents