RESUMO
OBJECTIVES: Lead (Pb) and manganese (Mn) are confirmed neurotoxins but it is unclear to what extent low-level exposure produces a unique behavioral signature. The objective of this study was to investigate latent cognitive profiles among children (6-8 years) from Montevideo, Uruguay co-exposed to these metals. METHOD: Among 345 children, blood Pb and hair Mn were measured using atomic absorption spectroscopy and ICP-MS, respectively. Sixteen measures, reflecting multiple domains of cognitive functioning were gathered: (1) three tests from Cambridge Neuropsychological Test Automated Battery (CANTAB): Intra-Extra Dimensional Shift (IED), Spatial Span (SSP) and Stockings of Cambridge (SOC), (2) ten tasks from Woodcock-Muñoz Achievement Battery, Revised (WM): Visual-Motor Integration, Verbal Comprehension (Vocabulary, Synonyms, Antonyms, Analogies), Visual-Auditory Comprehension, Concept Formation, Visual Spatial Thinking, Number Inversion and Spatial Relations, (3) Bender Gestalt task, and (4) Weschler block design task. Scores were modeled using latent profile analysis (LPA). Association between blood Pb and hair Mn on performance profiles was assessed using ordinal regression, controlling for confounders. An interaction between Pb and Mn was tested. RESULTS: Mean ± SD of blood Pb was 4.1 ± 2.1 µg/dL and 35% of children had blood Pb ≥ 5 µg/dL. Median [5%, 95%] hair Mn level was 0.8 [0.3, 4.1] ppb. Three latent cognitive performance profiles were identified: high (n = 46, 13%), average (n = 209, 61%) and low (n = 90, 26%). Each one-unit increase in blood Pb was associated with a 28% greater likelihood of belonging to a poorer-performing profile. The association was non-linear, with the effect of Pb on profile membership strongest at lower levels of exposure. There was no meaningful interaction between Pb and Mn. CONCLUSIONS: A behavioral signature for low-level Pb & Mn exposure was not identified, but the likelihood of membership in low-performing profile was higher at lowest levels of blood Pb. There was no effect measure modification between Pb and Mn. Future research should address how complex environments created by chemical exposures and the social context relate to cognitive performance in young children.
Assuntos
Comportamento Infantil/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Cognição/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/psicologia , Chumbo/efeitos adversos , Intoxicação por Manganês/psicologia , Manganês/efeitos adversos , Fatores Etários , Carga Corporal (Radioterapia) , Criança , Estudos Transversais , Poluentes Ambientais/análise , Poluentes Ambientais/sangue , Feminino , Cabelo/química , Humanos , Chumbo/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/diagnóstico , Intoxicação do Sistema Nervoso por Chumbo na Infância/etiologia , Masculino , Manganês/análise , Intoxicação por Manganês/sangue , Intoxicação por Manganês/diagnóstico , Intoxicação por Manganês/etiologia , Medição de Risco , Fatores de Risco , UruguaiRESUMO
A range of studies has been conducted on the detrimental effects of lead in mining and smelting communities. The neurocognitive and behavioural health effects of lead on children are well known. This research characterized the conjoint influence of lead exposure and home enriched environment on neurocognitive function and behaviour for first-grade children living in a Mexican lead smelter community. Structural equation models were used for this analysis with latent outcome variables, Cognition and Behaviour, constructed based on a battery of assessments administered to the first-grade children, their parents, and teachers. Structural equation modelling was used to describe complex relationships of exposure and health outcomes in a manner that permitted partition of both direct and indirect effects of the factors being measured. Home Environment (a latent variable constructed from information on mother's education and support of school work and extracurricular activities), and child blood lead concentration each had a main significant effect on cognition and behaviour. However, there were no statistically significant moderation relationships between lead and Home Environment on these latent outcomes. Home Environment had a significant indirect mediation effect between lead and both Cognition and Behaviour (p-value<0.001). The mediation model had a good fit with Root Mean Square Error of Approximation <0.0001 and a Weighted Root Mean Square Residual of 0.895. These results were highly significant and suggest that Home Environment has a moderate mediation effect with respect to lead effects on Behaviour (ß=0.305) and a lower mediation effect on Cognition (ß=0.184). The extent of home enrichment in this study was most highly related to the mother's support of schoolwork and slightly less by the mother's support of extracurricular activities or mother's education. Further research may be able to develop approaches to support families to make changes within their home and child rearing practices, or advocate for different approaches to support their child's behaviour to reduce the impact of lead exposure on children's cognitive and behavioural outcomes.
Assuntos
Comportamento Infantil/efeitos dos fármacos , Cognição/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/etiologia , Chumbo/efeitos adversos , Metalurgia , Mineração , Características de Residência , Carga Corporal (Radioterapia) , Distribuição de Qui-Quadrado , Criança , Desenvolvimento Infantil/efeitos dos fármacos , Educação Infantil , Pré-Escolar , Estudos Transversais , Escolaridade , Poluentes Ambientais/sangue , Humanos , Chumbo/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/psicologia , Modelos Logísticos , México , Relações Mãe-Filho , Análise Multivariada , Testes Neuropsicológicos , Apoio SocialRESUMO
INTRODUÇÃO: A contaminação por chumbo afeta todos os sistemas do corpo humano, principalmente o sistema nervoso. OBJETIVO: Investigar se há correlação entre o nível de plumbemia e o desempenho em testes do processamento auditivo. MÉTODO: Estudo retrospectivo. 73 crianças, com idade entre 7 a 15 anos, residentes em uma área onde houve emissão de partículas de chumbo acima do permitido, com nível de plumbemia maior ou igual a 10 microgramas/dL, exames audiológicos (audiometria e timpanometria) dentro dos padrões de normalidade. Para avaliar o processamento auditivo foram utilizados o Teste de Fusão Auditiva-Revisado (AFT-R), subteste 1, e o Teste Dicótico de Dígitos (etapa de integração binaural). Foi utilizado o teste de Spearman para verificar a correlação entre os dados. RESULTADOS: O nível de plumbemia variou de 10 a 30,2microgamas/dL, sendo a média correspondente a 15,8 microgramas/dL (desvio-padrão de 4,8). Dessas crianças, 60,3% apresentaram desempenho ruim no teste AFT-R, ou seja, resultados superiores a 60ms. Quanto ao Teste Dicótico de Dígitos, 46,2% das crianças apresentaram desempenho ruim para a orelha direita e 67,3% apresentaram desempenho ruim na orelha esquerda. Conforme o resultado do teste de correlação de Spearman, não houve significância estatística entre o nível de chumbo e os resultados dos testes do processamento auditivo. CONCLUSÃO: Não houve correlação entre o nível de plumbemia e o desempenho nas habilidades do processamento auditivo, entretanto crianças contaminadas pelo chumbo apresentaram desempenho inferior nas habilidades do processamento auditivo.
INTRODUCTION: The contamination by lead affects all the nervous systems from the human body, mostly the nervous system. OBJECTIVE: Investigate if there is correlation between the blood lead levels and the performance in tests of hearing process. METHOD: Retrospective study. 73 children, with ages between 7 to 15 years, residents in a area where happened emission of lead above the permitted, with level of blood lead level bigger or equal to 10 micrograms/dL, audiological exams (audiometry and tympanometry) inside the normality patterns. To evaluate the hearing process were used the Auditory Fusion Test-Revised (AFT-R), subtest 1, and the dichotic test of digits (binaural integration stage). Was used the Spearman test to verify the correlation between the data. RESULTS: The blood lead level varieties from 10 to 30,2 micrograms/dL, being the average corresponding to 15,8 micrograms/dL (standard deviation of 4,8). From those children, 60,3% presented a bad performance for the right ear and 67,3% presented a bad performance of the left ear. According to the results of the tests of correlation of Spearman, there were no significant statistical between the level of lead and the results of hearing processing tests. CONCLUSION: There were no correlation between the blood lead level and the performance in the abilities of the hearing process; however the contaminated children by the lead presented a lower performance in the abilities of the hearing processing.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Audição , Criança , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Indicadores de Contaminação , Fonoaudiologia , Testes de Impedância Acústica , Testes de AptidãoRESUMO
Biological and psychosocial factors affect child development and behavior. Whereas biological underpinnings behind the neurotoxic effects of lead are studied extensively, the effects of psychosocial factors contributing to poor behavioral outcomes in lead-exposed children are not well understood. Parental attributes and practices may moderate or mediate the effects of lead on children's behavioral outcomes. We investigated the hypothesis that maternal and child lead and hemoglobin levels are associated with maternal perceptions of their parenting. Specifically, we hypothesized that children with higher blood lead (BLL) and lower hemoglobin concentrations would be associated with poorer maternal self-assessments of their parenting skills or the mother-child relationship. Children aged 13-55 months and their mothers (n=109) were recruited from among the participants of a previous lead and anemia screening study and from preschools in Montevideo, Uruguay. The mother-child pair attended two study visits: one to collect biological samples and answer demographic and child questionnaires, including statements regarding parenting; and a second to evaluate maternal IQ, depression and stress, and child development. Of the children, 51.6% had blood lead concentrations (BLLs) ≥ 5 µg/dL, 18.0% had anemia, and 8% had both conditions. Among mothers, 48.4% had BLLs ≥ 5 µg/dL, 16.0% had anemia, and 11% had both. BLLs ≥ 5 µg/dL in mother or child were associated with lower maternal perceptions of being skilled at discipline (p<0.05). Maternal anemia was associated with lower likelihood that mothers would let their children explore and play (p<0.05), whereas child anemia was associated with maternal perception of lower emotional support (p<0.01). In addition to shared environmental exposures, parenting and family interactions need to be considered as potentially contributing factors to poorer outcomes in lead-exposed children.
Assuntos
Comportamento Infantil , Desenvolvimento Infantil , Poluentes Ambientais/sangue , Hemoglobinas/análise , Intoxicação do Sistema Nervoso por Chumbo em Adultos/psicologia , Intoxicação do Sistema Nervoso por Chumbo na Infância/psicologia , Chumbo/sangue , Comportamento Materno , Mães/psicologia , Poder Familiar , Percepção , Adulto , Anemia/sangue , Anemia/psicologia , Biomarcadores/sangue , Pré-Escolar , Depressão/sangue , Depressão/psicologia , Emoções , Poluentes Ambientais/efeitos adversos , Comportamento Exploratório , Análise Fatorial , Feminino , Humanos , Lactente , Chumbo/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo em Adultos/sangue , Intoxicação do Sistema Nervoso por Chumbo em Adultos/diagnóstico , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/diagnóstico , Masculino , Relações Mãe-Filho , Análise Multivariada , Testes Neuropsicológicos , Jogos e Brinquedos , Medição de Risco , Fatores de Risco , Estresse Psicológico/sangue , Estresse Psicológico/psicologia , Inquéritos e Questionários , Uruguai , Adulto JovemRESUMO
Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f(2) frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6-16 yr) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 µg/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was markedly higher than the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) 10-µg/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f(2) frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000 to 8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children.
Assuntos
Orelha Interna/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/epidemiologia , Intoxicação do Sistema Nervoso por Chumbo na Infância/fisiopatologia , Emissões Otoacústicas Espontâneas/efeitos dos fármacos , Adolescente , Limiar Auditivo/efeitos dos fármacos , Criança , Estudos Transversais , Equador/epidemiologia , Exposição Ambiental/prevenção & controle , Feminino , Células Ciliadas Auditivas Externas/efeitos dos fármacos , Audição/efeitos dos fármacos , Humanos , Chumbo/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Intoxicação do Sistema Nervoso por Chumbo na Infância/prevenção & controle , Masculino , Otoscopia , Prevalência , Saúde da População Rural , Espectrofotometria AtômicaRESUMO
This report presents case profiles of three siblings in a family of lead (Pb) glazing workers living in a Pb-contaminated Andean village who presented with extreme plumbism (blood Pb levels: 47 to 128 microg/dl) from childhood to adolescence. These cases are examples of persons who have chronic Pb poisoning as a result of prolonged occupational and environmental exposure in a Pb-glazing ceramic cottage industry in the study area. Using behavioral and physiological techniques for measuring the integrity of the peripheral and central auditory systems, including otoacoustic emissions, and replicated auditory brainstem electrophysiological potentials, the authors found normal auditory neurosensory function in each patient, thus ruling out hearing impairment as a basis for adverse neurocognitive outcomes. This finding is contrary to the prevailing view regarding the detrimental effects of Pb poisoning on the cochlear and auditory brainstem of children. Performance on tests of visual spatial intelligence and auditory memory/attention was below average in these patients, which may underlie their reported learning disabilities. In two of the cases, there was an improvement in cognitive performance following a lowering of PbB levels from chelation therapy and Pb prevention education, suggesting some level of reversibility of their neurocognitive deficits. Nevertheless, these case profiles suggest that if the patients persist in Pb-glazing activities, in spite of repeated chelation therapy and family counseling, they may continue to be re-intoxicated and remain at risk for learning disabilities and other neurological impairments.
Assuntos
Poluentes Ambientais/toxicidade , Intoxicação do Sistema Nervoso por Chumbo na Infância/patologia , Adolescente , Cerâmica , Terapia por Quelação , Criança , Doença Crônica , Equador/epidemiologia , Poluentes Ambientais/química , Feminino , Audição , Humanos , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Masculino , Succímero/uso terapêuticoRESUMO
OBJECTIVES: To investigate the relationship between blood lead (PbB), zinc protoporphyrin (ZPP) levels and performance on a test of auditory memory in Andean children and adolescents with chronic lead (Pb) exposure. DESIGN AND METHODS: PbB and ZPP levels were measured in blood samples from 166 participants (aged 6-16 yrs.) exposed to Pb in a local ceramic glazing cottage industry in Ecuadorian villages. PbB levels and ZPP/heme ratios were analyzed in relation to performance on the Digit Span subtest of the Wechsler IV intelligence scale, a test of auditory memory. RESULTS: Mean PbB level for the study group was 18.0 microg/dL (S.D.: 15.1; range: 3.0-86.0), and the mean ZPP/heme ratio was 105.7 mumol/mol (S.D.: 100.9; range: 36.0-592.0). There was no significant difference in PbB and ZPP levels between the 84 females and the 82 males. The mean Digit Span scale score (DS SS) for the study group was 6.81 (S.D.: 2.95; range: 1.0-17.0), which is below the average score of 10 for the test, with the females performing significantly better than males (t=2.435; p=0.01). Regression analyses revealed statistically significant inverse associations between DS SS and PbB level (r=0.251, p=0.001), and between DS SS and ZPP/heme ratio (r=0.246, p=0.001). CONCLUSION: Elevated PbB levels, representing acute exposure, and ZPP levels, reflecting chronic Pb exposure in this cohort of Andean inhabitants were associated with poor performance on a test of auditory memory, suggesting that the children and adolescents in the study area have neurocognitive deficits that may affect learning.
Assuntos
Transtornos Cognitivos/diagnóstico , Cognição/fisiologia , Exposição Ambiental , Intoxicação do Sistema Nervoso por Chumbo na Infância/fisiopatologia , Chumbo/sangue , Protoporfirinas/sangue , Adolescente , Estudos de Casos e Controles , Criança , Transtornos Cognitivos/sangue , Transtornos Cognitivos/fisiopatologia , Equador , Feminino , Heme/análise , Humanos , Chumbo/toxicidade , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Masculino , Fatores de TempoRESUMO
OBJECTIVE: Increasing evidence suggests that 10 microg/dL, the current Centers for Disease Control and Prevention screening guideline for children's blood lead level, should not be interpreted as a level at which adverse effects do not occur. Using data from a prospective study conducted in Mexico City, Mexico, we evaluated the dose-effect relationship between blood lead levels and neurodevelopment at 12 and 24 months of age. METHODS: The study population consisted of 294 children whose blood lead levels at both 12 and 24 months of age were < 10 microg/dL; blood lead levels were measured by graphite furnace atomic absorption spectroscopy; Bayley Scales of Infant Development II were administered at these ages. The outcomes of interest were the Mental Development Index and the Psychomotor Development Index. RESULTS: Adjusting for covariates, children's blood lead levels at 24 months were significantly associated, in an inverse direction, with both Mental Development Index and Psychomotor Development Index scores at 24 months. Blood lead level at 12 months of age was not associated with concurrent Mental Development Index or Psychomotor Development Index scores or with Mental Development Index at 24 months of age but was significantly associated with Psychomotor Development Index score at 24 months. The relationships were not altered by adjustment for cord blood lead level or, in the analyses of 24-month Mental Development Index and Psychomotor Development Index scores, for the 12-month Mental Development Index and Psychomotor Development Index scores. For both Mental Development Index and Psychomotor Development Index at 24 months of age, the coefficients that were associated with concurrent blood lead level were significantly larger among children with blood lead levels < 10 microg/dL than it was among children with levels > 10 microg/dL. CONCLUSIONS: These analyses indicate that children's neurodevelopment is inversely related to their blood lead levels even in the range of < 10 microg/dL. Our findings were consistent with a supralinear relationship between blood lead levels and neurobehavioral outcomes.
Assuntos
Transtornos do Comportamento Infantil/induzido quimicamente , Deficiências do Desenvolvimento/induzido quimicamente , Exposição Ambiental , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Chumbo/sangue , Transtornos Psicomotores/induzido quimicamente , Transtornos do Comportamento Infantil/epidemiologia , Pré-Escolar , Fatores de Confusão Epidemiológicos , Deficiências do Desenvolvimento/epidemiologia , Relação Dose-Resposta a Droga , Feminino , Sangue Fetal/química , Humanos , Lactente , Recém-Nascido , Chumbo/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/epidemiologia , Masculino , Concentração Máxima Permitida , México/epidemiologia , Testes Neuropsicológicos , Estudos Prospectivos , Transtornos Psicomotores/epidemiologia , Desempenho Psicomotor , Fatores Socioeconômicos , População UrbanaRESUMO
Objetivo. Identificar si existe una asociación negativa entre los niveles de plomo en sangre y la coordinación visomotora y el equilibrio de escolares. Material y métodos. Se realizó un estudio transversal en 255 niños de 8 a 10 años de edad, que asistían a escuelas del Sector 1 del Instituto de Educación Pública del Estado de Oaxaca, durante noviembre y diciembre de 1998. Se aplicaron pruebas de evaluación de percepción visual de Frostig y la subescala de equilibrio Frostig Movement Skills Test Battery y se les tomó una muestra de sangre para determinación de plomo por medio de espectrometría de absorción atómica. Asimismo, se aplicó un cuestionario sociodemográfico se evaluó la historia de salud del niño. Se relacionó el nivel de plomo sanguíneo con los resultados de las pruebas de percepción visual y del equilibrio mediante modelos de regresión múltiple. Se usó la técnica de simulaciones de Montecarlo para probar el efecto de plomo dentro del modelo. Resultados. La media geométrica de las concentraciones de plomo en sangre fue de 11.5 µg/dl (DE geométrica= +6.3, -5.2). El nivel de plomo se relacionó significativamente con el cociente de integración visomotora (p>0.042). Este disminuye 1.78 (IC 95 por ciento -3.51, -0.06) puntos por cada incremento de 10 µg/dl en los niveles de plomo en sangre del niño. De las pruebas que constituyeron este cociente, sólo se relacionó significativamente el plomo con la de coordinación ojo-mano (p=0.045) y de relaciones espaciales (p=0.039). El ingreso familiar también se relacionó significativamente con el cociente de integración visomotora, a mayor ingreso los resultados en las pruebas del niño fueron más altos. Sólo 3.1 por ciento de los niños obtuvieron puntuaciones consideradas clínicamente anormales. No se encontró una relación significativa entre el plomo y el cociente de la respuesta motriz reducida, el cociente de percepción visual general y las pruebas de equilibrio. Conclusiones. La relación negativa entre plomo y la habilidad visomotora concuerda con los resultados encontrados en niños en otros países. Al parecer las concentraciones de plomo en sangre, que son comunes en los niños de Oaxaca, son suficientes para ocasionar una limitación visomotora de naturaleza sutil. Los resultados de este estudio señalan la necesidad de reforzar la iniciativa de reducir la exposición de niños a fuentes de exposición conocidas, en especial barro vidriado y, por lo tanto, reducir niveles poblacionales de plomo en sangre.
Assuntos
Humanos , Masculino , Feminino , Equilíbrio Postural/efeitos dos fármacos , Chumbo/sangue , Desempenho Psicomotor , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangueRESUMO
A preliminary study explored the relative contribution of residential sources of lead exposure on mentally challenged children who attend "special education" institutions (GI) compared to a group of age and sex matched school children (G2). We captured descriptive information and analyzed demographic variables, personal and household information, medical effects, environmental exposure factors, and children habits. Home paint, dust, soil, and water sampling was conducted and blood lead (BPb) levels determined. Eighteen G1 and 20 G2 children were studied. The mean G1 BPb was 16.9 +/- 7.9 microg/dl and was significantly higher than that in G2. Fifty percent of G1 children had PbB >20 microg/dl and 72.2% were >10 microg/dl. Low muscular strength, decreased osteotendinose reflexes, fine and gross motricity, deficient equilibrium, and hipotonic muscular tone coincided with >18 microg/dl BPb levels. In 61.1% of G1 homes paint lead levels were higher than permissible levels and 33.3% had dust lead exceeding that level. The high BPb levels in G1 probably resulted from ingestion of household paint, dust, and soil via "hand-to-mouth" activity. Environmental exposure to lead can be an important source of lead intake by infants and children and could affect neurological development. This study provides new insights currently unavailable for these children in Venezuela.
Assuntos
Exposição Ambiental/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/etiologia , Chumbo/sangue , Doenças do Sistema Nervoso/etiologia , Antropometria , Criança , Pré-Escolar , Poeira/efeitos adversos , Feminino , Humanos , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Estilo de Vida , Masculino , Pintura/efeitos adversos , Pica/complicações , Projetos Piloto , Pobreza , Classe Social , Poluentes do Solo/efeitos adversos , Espectrofotometria Atômica , Estatísticas não Paramétricas , Inquéritos e Questionários , Venezuela , Poluentes Químicos da Água/efeitos adversosRESUMO
OBJECTIVE: We examined whether or not the effect of elevated blood lead levels on children's psychomotor development was modified by their nutritional status. DESIGN: Anthropometry, developmental quotients (DQs), blood lead levels and haemoglobin were measured in lead exposed and unexposed children with different levels of nutritional status. Social background and maternal height and verbal intelligence were also measured. Testers, anthropometrists and interviewers established reliabilities with a trainer before the study began. SETTING: Children were from two suburban areas in Kingston, Jamaica. All measurements on the children were carried out at a research unit. Social background and maternal measurements were carried out at the children's homes. SUBJECTS: The exposed group comprised 58 children (3-6 years) attending the same preschool which was situated in a lead contaminated environment. The unexposed group comprised 53 children attending a nearby preschool without lead contamination. RESULTS: The exposed children had significantly higher blood lead levels and lower DQs, and their homes had poorer facilities than the unexposed children. The deficit in DQ was greater (10.6 points) among children with weight for height less than -1 SD (National Center for Health Statistics references) than among better nourished children (2 points). CONCLUSIONS: Undernourished children exposed to lead may have more serious developmental deficits than better nourished children.