[Intelligence quotient loss in Mexican pottery artisan's children]. / Pérdida de coeficiente intelectual en hijos de alfareros mexicanos.

BACKGROUND: In Mexico, artisans frequently use lead oxide or greta in order to produce utensils, which are destined to preparation and storage of food and drinks. Additionally, the risk of lead poisoning of artisans and their families is greater than in general population, and within these families, children are the most susceptible to lead poisoning. The aim of this study was to estimate IQ loss in Mexican children from potter families exposed to lead. METHODS: Lead concentrations in soil were determined in 19 potter's homes that functioned as pottery workshops in seven Mexican states between 2009 and 2012. This information was used to estimate blood lead levels through the integrated exposure uptake biokinetic (IEUBK) model. The loss of IQ points was then estimated according to the Lanphear and Schwartz models. RESULTS: The mean lead concentration found in the workshops' soil was 1098.4 ppm. Blood lead levels estimated in children under 8 years old were 26.4 µg/dL and the loss of IQ points comprised from 7.13 to 8.84 points depending on the model. CONCLUSIONS: It is possible that 11 children from families of artisans in Mexico may be losing between 7.13 to 8.84 IQ points, due to lead exposure in their houses-workshops. This loss in IQ points could have important health, economic and social impacts.

Introducción: en México, los alfareros continúan usando frecuentemente el óxido de plomo o greta para producir utensilios, los cuales se destinan a la preparación y almacenamiento de alimentos y bebidas. Adicionalmente, el riesgo de intoxicación por plomo de los alfareros y sus familias es mayor que en la población general, y en tales familias, los niños son los más susceptibles a la intoxicación por plomo. El objetivo del estudio fue estimar la pérdida de puntos de coeficiente intelectual (CI) en hijos de alfareros mexicanos expuestos al plomo. Métodos: durante el periodo de 2009 a 2012 se determinaron las concentraciones de plomo en suelo de 19 casas-talleres de alfareros en siete estados mexicanos. Esta información se utilizó para estimar el nivel de plomo en sangre, por medio del modelo biocinético integrado de absorción por exposición (IEUBK, por sus siglas en inglés). Posteriormente, se calcularon los puntos perdidos de CI según los modelos de Schwartz y Lanphear. Resultados: la concentración promedio de plomo en suelo fue de 1098.4 ppm. Se estimó un nivel de plomo en sangre de 26.4 µg/dL para menores de 8 años. La pérdida de puntos de CI estimada fue 7.13 y 8.84, según el modelo utilizado. Conclusión: es posible que al menos 11 niños de familias alfareras mexicanas estén perdiendo entre 7.13 y 8.84 puntos de CI, debido a la exposición al plomo en sus casas-talleres, lo que supone importantes impactos económicos, sociales y de salud.

Environmental lead exposure and otoacoustic emissions in Andean children.

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.

Longitudinal associations between blood lead concentrations lower than 10 microg/dL and neurobehavioral development in environmentally exposed children in Mexico City.

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.

[Effects of lead exposure on the human body and health implications]. / Os efeitos do chumbo sobre o organismo humano e seu significado para a saúde (Informe especial).

OBJECTIVE: To review the literature concerning the risks associated with exposure to lead and lead compounds, especially in children and in populations that are occupationally exposed. DATA SOURCES: Using "chumbo" [lead] and "efeitos" [effects] as search terms, two large databases, namely PubMed (United States National Library of Medicine) and LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde [Latin American and Caribbean Literature in the Health Sciences]), were searched for studies on lead toxicity from 1988 to 2002. Other sources used to conduct the search include the web page of the United States Agency for Toxic Substances and Disease Registry, in Atlanta, Georgia, and the library of the Toxicology Laboratory of the Center for Workers' Health and Human Ecology at the National School of Public Health [Centro de Estudos da Saúde de Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública], Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. CONCLUSIONS: The toxic effects of lead and lead compounds have been extensively studied for over a century. In recent years, epidemiologic studies have focused primarily on the neurotoxic effects of lead on children, particularly in terms of impaired intellectual ability and behavioral problems. However, there is still insufficient information on the mechanisms of action that account for such toxicity. More in-depth studies are also needed on the effects of lead exposure on bone, the central nervous system, the cardiovascular system, the kidneys, the liver, the male and female reproductive systems, and the endocrine system. The potential teratogenicity and carcinogenicity of lead, as well as its effect on pregnancy outcomes and neonatal growth and development, also require further study.

Os efeitos do chumbo sobre o organismo humano e seu significado para a saúde / Effects of lead exposure on the human body and health implications

OBJETIVO: Fazer um levantamento bibliográfico acerca dos riscos associados à exposição ao chumbo e seus compostos, especialmente nas populações expostas ocupacionalmente e nas crianças. FONTE DOS DADOS: Pesquisa do período de 1988 a 2002 nas bases de dados PubMed e Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS); página da agência de controle de substâncias tóxicas e doenças do governo dos Estados Unidos (Agency for Toxic Substances and Disease Registry) na Internet; acervo bibliográfico do Laboratório de Toxicologia do Centro de Estudos da Saúde do Trabalhador e Ecologia Humana da Escola Nacional de Saúde Pública, Brasil. CONCLUSÕES: Os estudos científicos sobre a toxicologia do chumbo são desenvolvidos há mais de um século. Contudo, ainda são insuficientes as informações sobre os mecanismos de ação que originam os efeitos tóxicos desse metal. Os resultados da exposição ao chumbo sobre os ossos, os sistemas nervoso central e cardiovascular, os rins e o fígado devem ser estudados com maior profundidade, bem como os efeitos sobre a reprodução masculina e feminina, o sistema endócrino e a formação do feto. Também é essencial esclarecer se o chumbo tem efeitos teratogênicos e carcinogênicos em seres humanos.

Objective. To review the literature concerning the risks associated with exposure to lead and lead compounds, especially in children and in populations that are occupationally exposed. Data sources. Using "chumbo" [lead] and "efeitos" [effects] as search terms, two large databases, namely PubMed (United States National Library of Medicine) and LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde [Latin American and Caribbean Literature in the Health Sciences]), were searched for studies on lead toxicity from 1988 to 2002. Other sources used to conduct the search include the web page of the United States Agency for Toxic Substances and Disease Registry, in Atlanta, Georgia, and the library of the Toxicology Laboratory of the Center for Workers' Health and Human Ecology at the National School of Public Health [Centro de Estudos da Saúde de Trabalhador e Ecologia Humana, Escola Nacional de Saúde Pública], Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. Conclusions. The toxic effects of lead and lead compounds have been extensively studied for over a century. In recent years, epidemiologic studies have focused primarily on the neurotoxic effects of lead on children, particularly in terms of impaired intellectual ability and behavioral problems. However, there is still insufficient information on the mechanisms of action that account for such toxicity. More in-depth studies are also needed on the effects of lead exposure on bone, the central nervous system, the cardiovascular system, the kidneys, the liver, the male and female reproductive systems, and the endocrine system. The potential teratogenicity and carcinogenicity of lead, as well as its effect on pregnancy outcomes and neonatal growth and development, also require further study

Succimer (meso-2,3-dimercaptosuccinic acid (DMSA)) treatment of Andean children with environmental lead exposure.

The authors studied children in Andean villages contaminated by a lead-glazing cottage industry. Mean blood lead (PbB) level in 35 exposed children, aged 3-14 years, a year before treatment, at the time of initiation of a comprehensive lead education and prevention program, was 53.4 microg/dL. PbB levels immediately before and three weeks after a ten-day regimen of succimer treatment of the 35 children were 43.4 microg/dL and 34.3 microg/dL, respectively, showing a 21% reduction and a significant difference between means (t = 5.09, p = 0.0001). PbB levels of the same children a year before treatment and immediately pre-treatment were also significantly different (t = 10.59, p = 0.0001). Thus, a ten-day course of succimer chelation effectively reduced PbB in children with moderate to severe Pb intoxication, and the education and prevention program, initiated with parents, health care providers, and educators, also contributed significantly to reducing PbB.

Niveles de plomo en sangre y factores asociados, en niños del municipio de Centro Habana / Blood lead levels and associated factors in children from Centro Habana municipality

La exposición al plomo y la consecuente intoxicación afecta múltiples sistemas del organismo humano y constituye un problema de salud mundial. Los niños son más vulnerables y las manifestaciones precoces de afectación se presentan con niveles de hasta 10 µg/ml. La falta de estudios recientes del problema en Cuba motivó esta investigación para evaluar los niveles elevados de plomo en sangre de niños expuestos entre 3 y 8 años de edad, e identificar factores asociados con estos. Se determinó el nivel de plomo en sangre en 85 niños residentes en casas construidas antes de 1928, en el municipio de Centro Habana. Las madres respondieron un cuestionario acerca de hábitos y conductas que exponen a los niños a la intoxicación con plomo; 40 por ciento de ellos tenían el plomo en sangre superior a 10 µg/dl. Los factores asociados fueron, entre otros: no lavarse las manos antes de alimentarse, jugar con juguetes de plomo, llevarse juguetes a la boca y comer tierra(AU)

Niveles de plomo en sangre y factores asociados, en niños del municipio de Centro Habana / Blood lead levels and associated factors in children from Centro Habana municipality

La exposición al plomo y la consecuente intoxicación afecta múltiples sistemas del organismo humano y constituye un problema de salud mundial. Los niños son más vulnerables y las manifestaciones precoces de afectación se presentan con niveles de hasta 10 µg/ml. La falta de estudios recientes del problema en Cuba motivó esta investigación para evaluar los niveles elevados de plomo en sangre de niños expuestos entre 3 y 8 años de edad, e identificar factores asociados con estos. Se determinó el nivel de plomo en sangre en 85 niños residentes en casas construidas antes de 1928, en el municipio de Centro Habana. Las madres respondieron un cuestionario acerca de hábitos y conductas que exponen a los niños a la intoxicación con plomo; 40 por ciento de ellos tenían el plomo en sangre superior a 10 µg/dl. Los factores asociados fueron, entre otros: no lavarse las manos antes de alimentarse, jugar con juguetes de plomo, llevarse juguetes a la boca y comer tierra.