Exposición a plomo y mercurio en poblaciones de la ribera del río Bogotá: estudio multi-método / Lead and mercury exposure in populations on the banks of the Bogotá River: a multi-method study

RESUMEN Objetivos Este estudio buscó comprender la problemática sanitaria asociada con la presencia de plomo y mercurio en el agua del río Bogotá. Materiales y Métodos Se realizó un estudio mixto con entrevistas, encuesta y mediciones de zinc protoporfirina (ZPP) y mercurio en sangre a 172 individuos. Se identificaron variables asociadas con las mayores concentraciones, y mediante análisis comparativo cualitativo los atributos de los casos con mayor exposición. Resultados Las entrevistas reportaron que la contaminación del río se asocia con enfermedades, pese a que la exposición directa al agua no es frecuente. El agua del río es usada ampliamente para riego de cultivos que se venden en otros municipios. Las comunidades con mayor exposición al agua del río son de Tocaima y Girardot. Los mayores niveles de ZPP se observaron entre quienes vivían en estos municipios, con ocupación hogar y que realizaban actividades extralaborales con metales. Los niveles elevados de ZPP se asociaron con depresión, sangrado nasal y pérdida del apetito. Las mayores concentraciones de mercurio se presentaron entre habitantes de Girardot. Estas se asociaron con sudoración, desorientación, náuseas y diarrea. Conclusión Se presentaron bajos niveles de plomo y mercurio en la población estudiada, aunque hay casos específicos con alta vulnerabilidad social que requieren atención especial.(AU)

ABSTRACT Objectives This study sought to understand the health problems associated with the presence of lead and mercury in the water of the Bogotá River. Materials and Methods A mixed methods study was conducted using interviews, surveys and measurements of zinc protoporphyrin (ZPP) and mercury in blood from 172 individuals. Variables associated with the highest concentrations were identified, as well as the attributes of the cases with increased exposure by means of a qualitative comparative analysis. Results Interviews reported that river pollution is associated with diseases, although direct exposure to water is rare. River water is widely used for irrigation of crops that are sold in other municipalities. Communities with greater exposure to river water are Tocaima and Girardot. The highest levels of ZPP were observed among those living in these municipalities, did activities at home and performed non-work activities using metals. Increased ZPP levels were associated with depression, nasal bleeding and loss of appetite. The highest concentrations of mercury were found in the inhabitants of Girardot, and were associated with sweating, disorientation, nausea and diarrhea. Conclusion Low levels of lead and mercury were observed in the study population, although there are specific cases with high social vulnerability that require special attention.(AU)

Plomo y nefropatía: biomarcadores urinarios en la detección de daño renal precoz / Blood lead levels and markers of renal dysfunction among mechanical workshop workers

The role of lead (Pb) as an environmental cause of nephropathy is difficult to ascertain due to the difficulty to determine clinically its exposure. Aim: To assess lead levels and renal function in a group of males working in mechanical workshops. Material and Methods: Blood and urine samples were obtained from 100 mechanical workshop workers aged 38 ± 16 years and 95 non-exposed office clerks aged 37 ± 17 years. Blood lead and creatinine levels were determined. In exposed workers, urinary excretion of intestinal alkaline phosphatases (IAP) and N-acetyl-glucosaminidase (NAG) were measured as early markers of renal failure. Results: Blood lead levels were 66.4 ± 43 and 33.6 ± 18 µg/L among mechanical workshop workers and non-exposed controls, respectively, p < 0.01. The figures for serum creatinine were 0.9 ± 0.1 and 0.9 ± 0.1 respectively, p = NS. Among exposed workers urinary excretion of IAP was 0.47 ± 0.6 U/L and of NAG, 0.92 ± 1.1 U/L. There was a positive correlation between blood lead levels and NAG excretion (r = 0.284) and IAP excretion (r = 0.346). Conclusions: Exposed workers had higher blood lead levels and there was a weak positive association between these levels and the urinary excretion of NAG and IAP.

Análise proteômica em cérebro de ratos submetidos a tratamento subcrônico com chumbo: influência da suplementação com ferro / Proteomic analysis of brain in rats submitted to subchronic treatment with lead: influence of iron supplementation

O chumbo (Pb) é um metal pesado que pode ocasionar alterações em todos os sistemas. Porém os maiores danos à saúde ocorrem quando este acomete o sistema nervoso central (SNC). Muitos estudos demonstram as alterações clinicas/comportamentais causadas pela ação do Pb no SNC. Entretanto, ainda são necessários estudos que demonstrem as alterações bioquímicas causadas pelo Pb neste sistema. Por outro lado, tem sido relatado que o ferro (Fe) parece ter um efeito protetor na toxicidade cerebral causada pelo Pb. Assim, o objetivo deste estudo foi analisar a concentração de Pb no tecido cerebral, bem como realizar análise proteômica em cérebro de ratos intoxicados por Pb, submetidos à suplementação com Fe ou não. O experimento foi realizado com 30 ratos recém-desmamados (Rattus norvegicus, variedade Wistar) divididos em 6 grupos (n=5/grupo), de acordo com o tratamento recebido por 6 semanas, a saber: Controle (não exposto ao Pb ou Fe), Controle Fe (exposto à administração de 20 mg/Kg p.c. de FeSO4 a cada 2 dias, por gavagem gástrica), Pb 100 (exposto à água contendo 100 mg/L de Pb), Pb 400 (exposto à água contendo 400 mg/L de Pb) Pb100 + Fe (exposto à água contendo 100 mg/L de Pb e à gavagem com FeSO4) e Pb400 + Fe (exposto à água contendo 400 mg/L de Pb e à gavagem com FeSO4). Decorrido o período experimental, os animais foram eutanasiados e o cérebro dos animais foi removido, sendo descartados o cerebelo e o tronco encefálico. O restante foi submetido à concentração de Pb e à análise proteômica. Foi observada uma dose-resposta em relação à concentração de Pb no cérebro. A administração de FeSO4 reduziu os níveis de Pb no cérebro, embora sem significância estatística. A análise dos géis com os spots proteicos demonstrou uma redução na quantidade destes de acordo com o tratamento recebido pelos grupos. O grupo controle mostrou a maior quantidade de spots, ao passo que os grupos que receberam a maior concentração de Pb (400 mg/L) apresentaram as menores quantidade de...

Lead (Pb) is a heavy metal that may yield changes in all body systems, yet the greatest health damages occur when it affects the central nervous system (CNS). Many studies demonstrate the clinical/behavioral changes caused by the action of Pb on the CNS. However, studies are necessary to demonstrate the biochemical changes caused by Pb in this system. Conversely, it has been reported that iron (Fe) seems to play a protective role on the brain toxicity caused by Pb. Therefore, this study analyzed the concentration of Pb in the brain tissue, and conducted proteomic analysis in the brain of rats intoxicated by Pb, submitted or not to Fe supplementation. The study was conducted on 30 weaning rats (Rattus norvegicus, Wistar type) divided in 6 groups (n=5/group), according to the treatment established for 6 weeks, as follows: Control (not exposed to Pb or Fe), Control Fe (exposed to administration of 20 mg/Kg p.c. of FeSO4 at every 2 days, by gastric gavage), Pb 100 exposed to water containing 100 mg/L of Pb), Pb 400 (exposed to water containing 400 mg/L of Pb) Pb100 + Fe (exposed to water containing 100 mg/L of Pb and gavage with FeSO4) and Pb400 + Fe (exposed to water containing 400 mg/L of Pb and gavage with FeSO4). After the experimental period, the animals were killed and the brains of animals were removed, discarding the cerebellum and brainstem. The remaining structure was submitted to analysis of Pb concentration and proteomic analysis. A dose-response relationship was observed in Pb concentration in the brain. The administration of FeSO4 reduced the levels of Pb in the brain, though without statistical significance. The analysis of gels with proteic spots demonstrated reduction in their quantity according to the treatment performed in the groups. The control group exhibited greater concentration of spots, while groups receiving higher Pb concentration (400 mg/L) presented the lowest quantity of spots...

Análise proteômica em cérebro de ratos submetidos a tratamento subcrônico com chumbo: influência da suplementação com ferro / Proteomic analysis of brain in rats submitted to subchronic treatment with lead: influence of iron supplementation

O chumbo (Pb) é um metal pesado que pode ocasionar alterações em todos os sistemas. Porém os maiores danos à saúde ocorrem quando este acomete o sistema nervoso central (SNC). Muitos estudos demonstram as alterações clinicas/comportamentais causadas pela ação do Pb no SNC. Entretanto, ainda são necessários estudos que demonstrem as alterações bioquímicas causadas pelo Pb neste sistema. Por outro lado, tem sido relatado que o ferro (Fe) parece ter um efeito protetor na toxicidade cerebral causada pelo Pb. Assim, o objetivo deste estudo foi analisar a concentração de Pb no tecido cerebral, bem como realizar análise proteômica em cérebro de ratos intoxicados por Pb, submetidos à suplementação com Fe ou não. O experimento foi realizado com 30 ratos recém-desmamados (Rattus norvegicus, variedade Wistar) divididos em 6 grupos (n=5/grupo), de acordo com o tratamento recebido por 6 semanas, a saber: Controle (não exposto ao Pb ou Fe), Controle Fe (exposto à administração de 20 mg/Kg p.c. de FeSO4 a cada 2 dias, por gavagem gástrica), Pb 100 (exposto à água contendo 100 mg/L de Pb), Pb 400 (exposto à água contendo 400 mg/L de Pb) Pb100 + Fe (exposto à água contendo 100 mg/L de Pb e à gavagem com FeSO4) e Pb400 + Fe (exposto à água contendo 400 mg/L de Pb e à gavagem com FeSO4). Decorrido o período experimental, os animais foram eutanasiados e o cérebro dos animais foi removido, sendo descartados o cerebelo e o tronco encefálico. O restante foi submetido à concentração de Pb e à análise proteômica. Foi observada uma dose-resposta em relação à concentração de Pb no cérebro. A administração de FeSO4 reduziu os níveis de Pb no cérebro, embora sem significância estatística. A análise dos géis com os spots proteicos demonstrou uma redução na quantidade destes de acordo com o tratamento recebido pelos grupos. O grupo controle mostrou a maior quantidade de spots, ao passo que os grupos que receberam a maior concentração de Pb (400 mg/L) apresentaram as menores quantidade de...

Lead (Pb) is a heavy metal that may yield changes in all body systems, yet the greatest health damages occur when it affects the central nervous system (CNS). Many studies demonstrate the clinical/behavioral changes caused by the action of Pb on the CNS. However, studies are necessary to demonstrate the biochemical changes caused by Pb in this system. Conversely, it has been reported that iron (Fe) seems to play a protective role on the brain toxicity caused by Pb. Therefore, this study analyzed the concentration of Pb in the brain tissue, and conducted proteomic analysis in the brain of rats intoxicated by Pb, submitted or not to Fe supplementation. The study was conducted on 30 weaning rats (Rattus norvegicus, Wistar type) divided in 6 groups (n=5/group), according to the treatment established for 6 weeks, as follows: Control (not exposed to Pb or Fe), Control Fe (exposed to administration of 20 mg/Kg p.c. of FeSO4 at every 2 days, by gastric gavage), Pb 100 exposed to water containing 100 mg/L of Pb), Pb 400 (exposed to water containing 400 mg/L of Pb) Pb100 + Fe (exposed to water containing 100 mg/L of Pb and gavage with FeSO4) and Pb400 + Fe (exposed to water containing 400 mg/L of Pb and gavage with FeSO4). After the experimental period, the animals were killed and the brains of animals were removed, discarding the cerebellum and brainstem. The remaining structure was submitted to analysis of Pb concentration and proteomic analysis. A dose-response relationship was observed in Pb concentration in the brain. The administration of FeSO4 reduced the levels of Pb in the brain, though without statistical significance. The analysis of gels with proteic spots demonstrated reduction in their quantity according to the treatment performed in the groups. The control group exhibited greater concentration of spots, while groups receiving higher Pb concentration (400 mg/L) presented the lowest quantity of spots...

Assessing Lead Levels in Occupational Health : a Mini-Review

Lead is a well-established toxin that continues to pose a health risk. Blood lead levels (BLLs) and urinary chelatable lead are the tests of choice for assessing acute and chronic toxicity. We highlight some of the other tests available. As occupational exposure to lead is often accompanied by other toxic heavy metal exposure; measuring whole blood heavy metal levels should be considered for workers with chronically elevated BLLs

Intoxicação crônica por chumbo e implicações no desempenho escolar / Chronic poisoning by lead and implications for school performance / Intoxicación crónica por plomo e implicaciones en el desempeño escolar

Compreender as implicações da contaminação por chumbo contribui para o planejamento de políticas públicas mais efetivas para eliminação da exposição ao metal ou orientação de intervenções que minimizem os seus efeitos. Neste artigo o desempenho acadêmico de crianças contaminadas por chumbo foi avaliado em dois estudos. Para os participantes dos dois estudos as variáveis: contaminação crônica, escola, moradia e condições socioeconômicas foram semelhantes. No Estudo 1, transversal, objetivou-se avaliar a influência da pumblemia em 28 participantes, de ambos os sexos, de sete e quinze anos, separados em dois grupos de acordo com o nível de contaminação. No Estudo 2, longitudinal objetivou-se avaliar os efeitos da pumblemia no desempenho escolar de 10 crianças em um intervalo de quatro anos. Para do desempenho acadêmico foi utilizado o Teste de Desempenho Escolar (TDE). Os resultados do Estudo 1 apontaram para desempenho inferior significante para crianças com maior nível de contaminação. No Estudo 2, verificou-se que o nível de desempenho escolar continua significantemente inferior ao esperado para a série em que se encontram. Os dados parecem indicar para os efeitos deletérios da contaminação por chumbo no desempenho escolar...

To understand the implications of lead contamination contributes to more effective public politics to eliminate exposure to the metal and orientation of interventions that minimize their effects. In this paper we intended to evaluate the effects of lead contamination in children, with the Teste de Desempenho Escolar (TDE). In Study 1, transversal, aimed to evaluate the influence of blood lead levels in 28 participants of both sexes, of seven to fifteen years, divided into two groups according to the level of contamination. In Study 2, longitudinal study aimed to evaluate the effects of contamination on the school, performance of 10 children at an interval of four years. Results showed significant under performance for children with higher levels of contamination and that the level of academic performance remains significantly lower than expected for the series in which they find themselves. The data seem to indicate the deleterious effects of lead contamination in school performance...

Comprender las implicaciones de la contaminación por plomo contribuye para políticas públicas más efectivas para la eliminación de la exposición al metal y para la orientación de intervenciones que minimicen sus efectos. En este artículo se pretendió evaluar los efectos da contaminación por plomo en niños evaluados con el Test de Desempeño Escolar (TDE). En el Estudio 1, transversal, se pretendió evaluar la influencia de la plumbemia en 28 participantes, de ambos sexos, de siete y quince años, separados en dos grupos de acuerdo con el nivel de contaminación. En el Estudio 2, longitudinal, se pretendió evaluar los efectos de la plumbemia en el desempeño escolar de 10 niños en unintervalo de cuatro años. Los resultados señalaron un desempeño inferior significante para niños con mayor nivel de contaminación y que el nivel de desempeño escolar continua significantemente inferior al esperado para el curso en que se encuentran. Los datos parecen indicar los efectos deletéreos de la contaminación por plomo en el desempeño escolar...

Lipid profiles with increase blood lead level: Risk of cardiovascular disease in battery workers of Lucknow City.

In order to investigate the effects of lead exposure on risk of cardiovascular disease during Occupational battery workers i.e. lead exposure, plasma cholesterol and its fractions as high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride (T.G.) were determined in various battery workers in Lucknow city U.P., India. Increased risk of cardiovascular disease was observed in the various battery workers. Total cholesterol in the battery workers and control group was 142.14±31.92 (mg/dl) and 95.72±11.57 (mg/dl) respectively, which is higher in the battery workers than that of present in control group, While LDL cholesterol in the battery workers and control group was 158.30±22.70 (mg/dl) and 103.77± 4.62 (mg/dl) respectively. HDL cholesterol in the battery workers and control group was 38.80±10.13 (mg/dl) and 65.53±6.52 (mg/dl) respectively. The triglyceride levels were 162.06±90.85 (mg/dl) and 138.62±5.65 (mg/dl) in the battery workers and control group respectively, which is not affected [p > 0.05]. The LDL/HDL and Total cholesterol/HDL cholesterol ratio, Blood pressure, and blood lead level, was also higher in the battery workers, Results suggest that lead exposure increases cholesterol synthesis and transport to peripheral tissues whereas reverse cholesterol transport to the liver is not affected.

Experiências brasileiras e o debate sobre comunicação e governança do risco em áreas contaminadas por chumbo / Brazilian cases and the debate about risk communication and governance in areas contaminated by lead

No artigo são apresentados dois estudos de caso sobre contaminação por chumbo no Brasil. As situações estudadas referem-se a Santo Amaro da Purificação, nordeste, e Adrianópolis, sul, onde comunidades convivem com a contaminação ambiental e a exposição humana ao chumbo em decorrência das atividades industriais e de mineração desenvolvidas durantes décadas, por uma mesma empresa, de forma inconsistente com os padrões ambientais e de mineração, com pouco controle dos impactos ambientais e à saúde humana advindos. Os principais objetivos da investigação realizada foram analisar as estratégias de comunicação de risco adotadas junto às comunidades locais e avaliar o engajamento delas no processo de gerenciamento do risco. A metodologia aplicada incluiu análise de notícias jornalísticas e entrevistas realizadas com diferentes atores sociais, como moradores, jornalistas, pesquisadores e autoridades. Os resultados indicaram a necessidade de promover o envolvimento público no debate e no processo decisório. Os resultados validaram também a hipótese de que os modelos associativos (representados por associações de moradores, por exemplo) são importantes na promoção e no estímulo da participação pública no gerenciamento do risco.

This investigation focused on lead contamination case studies in Brazil. The situations studied involve communities living in Santo Amaro da Purificação and Adrianópolis, in the north-east and south of Brazil, respectively. These communities have all had to live with environmental contamination and human exposure to lead as a consequence of industrial, mining and processing activities that were conducted by the same company for decades in a manner inconsistent with modern mining and industrial standards, with little control of environmental and human health impacts. The investigation sought to analyze the strategies of risk communication to local people, and to evaluate their engagement in risk management. The methodological approach included the analysis of newspaper articles, and interviews conducted with different stakeholders, such as residents, journalists, researchers and authorities. The results indicated the need to promote public involvement in the debate and in the decision-making process. The results also confirmed the hypothesis that associative models (represented by local neighborhood associations, for instance) are important for promoting and eliciting public participation in risk management.

Chumbo, ambiente e saúde: o desafio do controle da exposição humana / Lead, environment and health: the challenge of controlling human exposure

Esta publicação reúne estudos abrangentes sobre as fontes e distribuição do chumbo no ambiente, desafios ao controle da exposição humana, e resultados das investigações realizadas nas principais áreas contaminadas por chumbo no Brasil. Reúne textos de pesquisadores do Brasil, Uruguai e Portugal, abordando também aspectos sobre efeitos do chumbo no organismo humano, como danos ao sistema nervoso central e outros agravos à saúde

El estres oxidativo como mecanismo de accion del plomo. Implicancias terapeuticas / Oxidative stress as a mechanism of action of lead. Therapeutic implications

El plomo (Pb) es un metal no esencial altamente toxico que afecta a diversos organos y tejidos. Si bien aun no ha sido descripto un mecanismo unico mediante el cual este metal ejerce sus efectos toxicos, un gran numero de estudios han puesto en evidencia el rol fundamental del estres oxidativo en la intoxicacion por Pb. A este respecto, ha sido informado que en la intoxicaci¨®n por Pb el estres oxidativo puede ocurrir a diferentes niveles: por generacion de acido ¦Ã-aminolevulinico (¦Ã-ALA), por la capacidad per se que posee el Pb para inducir peroxidacion lipidica en presencia de ion ferroso (Fe2+), o por deplecion de glutati¨®n (GSH) y enzimas antioxidantes. Sobre la base de estos antecedentes, el objetivo de esta revision es presentar evidencias recientes sobre la implicancia del estres oxidativo en los efectos adversos ocasionados por Pb, destacar la posibilidad de utilizacion de biomarcadores de estres oxidativo como un metodo complementario al diagnostico temprano de exposicion y revelar la importancia de los compuestos antioxidantes como nuevas herramientas en la prevencion y tratamiento de la intoxicacion por este metal.

Lead (Pb) is a highly toxic non-essential metal that affects different organs and tissues. Although at the present a unique mechanism by which this metal exerts its toxic effects has not been described, a large number of studies have highlighted the fundamental role of oxidative stress in the pathophysiology of Pb poisoning. In this regard, it has been reported that Pb-induced oxidative stress can occur at different levels: by the generation of ¦Ã-aminolevulinic acid (¦Ã-ALA), through its ability to induce lipid peroxidation in the presence of ferrous ion (Fe2+), or via glutathione (GSH) or antioxidant enzyme depletion. On the basis of these antecedents, the aim of this review is to present recent evidence regarding the implication of oxidative stress in the adverse effects caused by Pb, to emphasize the possibility to use oxidative stress biomarkers as a complementary method for early detection of Pb exposure, and to reveal the importance of antioxidant compounds as novel tools in the prevention and treatment of Pb exposure.

How does lead induce male infertility?

An important part of male infertility of unknown etiology may be attributed to various environmental and occupational exposures to toxic substances, such as lead. The reproductive effects of lead are complex and appear to involve multiple pathways, not all of which are fully understood. It is still unclear, for example, if male reproductive issues in lead-exposed persons are mostly related to the disruption of reproductive hormones, whether the problems are due to the lead's direct effects on the gonads, or both? This question has been difficult to answer, because lead, especially at high levels, may adversely affect many human organs. Although lead can potentially reduce male fertility by decreasing sperm count and motility, inducing abnormal morphology and affecting functional parameters; not all studies have been able to clearly demonstrate such findings. In addition, research has shown that the blood-testis barrier can protect testicular cells from direct exposure to high levels of blood lead. For these reasons and considering the wide spectrum of lead toxicity on reproductive hormones, the present review suggests that lead's main influence on male reproduction probably occurs by altering the reproductive hormonal axis and the hormonal control on spermatogenesis, rather than by a direct toxic effect on the seminiferous tubules of the testes. As blood lead concentrations below the currently accepted worker protection standard may still adversely affect male fertility, future studies should aim to establish more concrete linksbetween lead exposure [especially at low levels] and subsequent male infertility. Research should also pay more attention to lead's effects on reducing male fertility rates based on not only hormonal axis alteration, but also on the changes in sperm characteristic among exposed subjects

A exposição ao chumbo de militares alvejados por arma de fogo / Exposure to lead the military targeted by gunfire

O chumbo é um elemento de ocorrência natural, amplamente utilizado há milhares de anos. Atualmente, é um dos contaminantes mais comuns do ambiente, devido às inúmeras atividades industriais que favorecem a sua grande distribuição e à capacidade de penetrar no organismo através da inalação (ar atmosférico), ingestão (água, alimentose solo contaminados) e por via dérmica. Comumente, as munições de arma de fogo são compostas de 95 a 97 por cento de chumbo. O presente trabalho teve por objetivo identificar aexposição ao chumbo nos policiais militares alvejados por arma de fogo e que permanecem com algum projétil ou fragmentos alojados em seus corpos, mais especificamente, determinar as concentrações de chumbo no sangue de militares baleados e que possuíam projétil ou fragmentos alojados em seus corpos, comparandoas ao grupo controle, e identificar possíveis efeitos advindos da contaminação pelochumbo entre os militares estudados, relacionando-os às concentrações de chumbo encontradas...

Lead is a naturally occurring element widely used for thousands of years. Currently, it is one of the most common contaminants of the environment, due to several industrial activities that promote its widespread distribution and due to its capability to enter the human body through inhalation (air), ingestion (food, water and contaminated soil) anddermal. Usually, the ammunition of firearms is made from 95 to 97% of lead. This study aimed to identify the lead exposure in the military police shot by a firearm and with some remaining fragments or bullet lodged in their bodies, more specifically, to determine lead concentrations in the blood of soldiers who got shot and remained withbullet and /or ammunition fragments lodged in their bodies, comparing thoseconcentrations to the control group, and identify possible effects resulting from lead contamination in the military studied, relating them to the concentrations of lead found...

Ultrastructure alterations of retinal photoreceptors of the black rat, Rattus rattus exposed to certain heavy metals

This study was designed to investigate the impact of lead and cadmium on the retinal photoreceptors of rats. Adult black rats, Rattus rattus, were selected and divided into control and exposed groups. The exposed group was housed in industrial car batteries room containing fumes of lead and cadmium. The retina prepared for scanning and transmission electron microscopy. The scanning electron microscopy revealed different lead-cadmium changes represented by gradual increasing in spaces between segments of the photoreceptors, associated with swelling of their inner segments and accompanied with rupture, degeneration and decreased numbers of some rods and cones in the outer segments. Disorganization, shortening, a decrease in number of the photoreceptors and a great deformity were the characteristic changes after prolonged exposure to the heavy metals. The aforementioned damages of the photoreceptors were confirmed at the ultrastructural level using transmission electron microscope in the form of progressive disorganization, shortening, swelling, widening of the intradiscal spaces, vacuolization and degeneration of the lamellae of the outer segments [OS], followed by the damage of mitochondria of the inner segments[IS]. Excessive penetration of the processes of the pigmented epithelium [PE] filled with pigments of different shapes and sizes between the damaged segments were noted. These pathological changes were considered the first symptoms in the retinal toxicity. The present results are alarming and call for further investigations to elucidate the impact of exposure to these heavy metals for longer periods on the rat vision and eye structure

Protective effect of zinc over lead toxicity on testes

To determine the effects of lead and zinc on testes. Randomized control trial. Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from August 2003 to December 2005. Sixty adult [90 days old] albino rats were obtained from animal house JPMC for the study and divided into 3 groups. Group A received injection normal saline 1 cc intraperitoneally daily for 8 weeks. Group B received lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily. Group C received zinc chloride in a dose of 1 mg/kg body weight before half an hour of injection of lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily so that to provide pre-treatment. On the day of completion of treatment the animals were sacrificed testes removed and fixed in Bouins fluid. Testes were dehydrated in the ascending strength of alcohol, 5 micro m thick sections were cut and stained with PAS Iron Hematoxylin. Student's t-test was used for statistical analysis with significance at p<0.05. The mean diameter of seminiferous tubule was 291.91 +/- 1.18, 198.53 +/- 1.67 and 288.77 +/- 1.11 micro m in groups A, B and C respectively. Diameter of seminiferous tubules decreased by 31.99% in group B [p<0.001; CI 89.023 to 97.736] as compared group A and while group B comparing with group C, the diameter of seminiferous tubules was decreased by 31.25% [p-value=0.076; CI-94.264 to-86.203]. Mean thickness of germinal epithelium was 96.19 +/- 1.01, 50.69 +/- 1.20 and 94.94 +/- 0.54 micro m in groups A, B and C respectively. Thickness of germinal epithelium decreased by 47.30 in group B [P<0.001; CI 42.503 to 48.496] as compared to group A and while comparing group B with group C, the thickness of germinal epithelium was decreased by 46.61% [p=-44.25; CI-46.704 to-41.787]. Zinc prevented toxic effects of lead on germinal epithelium in the albino rats

Biosorption of lead(II) and chromium(VI) on groundnut hull: equilibrium, kinetics and thermodynamics study / Biosorción de plomo (II) y cromo (VI) en cáscaras de maní: estudio de equilibrio, cinética y termodinámica

The biosorption of lead(II) and chromium(VI) on groundnut hull was investigated. Batch biosorption experiments were conducted to find the equilibrium time and biosorption capacity. Effect of parameters like pH, temperature and initial metal concentration was studied. The maximum biosorption capacity of lead(II) and chromium(VI) was found to be 31.54 +/- 0.63 and 30.21 +/- 0.74 mg g-1, respectively. The optimum pH for lead(II) and chromium(VI) removal was 5 ± 0.1 and 2 +/- 0.1, respectively. The temperature change, in the range of 20 - 45ºC affected the biosorption capacity. The maximum removal of lead(II) was achieved at 20 +/- 2ºC, where as maximum uptake of chromium(VI) was observed at 40 +/- 2ºC. The biosorption data was fitted to the Langmuir and the Freundlich isotherm models. The Langmuir model showed better representation of data, with correlation coefficient greater than 0.98. The kinetics of biosorption followed the pseudo second order kinetics model. The thermodynamics parameters were evaluated from the experimental data.

Coleta de amostras e métodos analíticos para determinaçãode chumbo / Collection of samples and analytical methods for lead determination

Chumbo é, frequentemente, usado como um indicador de poluição. Uma vez liberado no meio ambiente, este poluente pode seguir diferentes rotas, podendo ser convertido em espécies mais solúveis, tornado-se biodisponível. Neste artigo é apresentado de forma sucinta chumbo como poluente urbano, procedimentos de amostragem (coleta de amostras), transporte, armazenamento e preservação de amostras de interesse ambiental (solos e águas) e amostras clínicas (sangue e urina). A importância e classificação das Salas Limpas, assim como as principais técnicas analíticas para a determinação de chumbo - AAS, ICP OES e ICP-MS - também são abordadas.

The metal lead has frequently used as a sensitive pollution indicator. Once released in the environment, this pollutant can follow different ways, being converted in highly soluble species, became bioavailable. In this paper is presented in a succinct form, lead as urban pollutant, sampling procedures (collection of samples), transport, storage and preservation of environmental (soils and waters) and clinical (bloodand urine) samples. The importance and classification of clean rooms, as well as the main analytical techniques for lead determination - AAS, ICP-OES and ICP-MS - are broached too.

Fontes de exposição humana ao chumbo no Brasil / Lead sources of human exposure in Brazil

Como resultado do crescimento da contaminação ambiental, houve um aumento do interesse relacionado ao acúmulo de metais pesados no corpo humano e seus efeitos danosos. Alguns desses metais, tal como o como chumbo, são elementos não essenciais e exercem efeitos tóxicos no sistema biológico. Apesar das medidas de controle estabelecidas por lei, intoxicações agudas e crônicas por chumbo ainda acontecem no Brasil. Algumas fontes de exposição a este metal são bem conhecidas, como por exemplo, atividades industriais como mineração, além de fábricas de reciclagem de baterias. No entanto, outras fontes, apesar de comuns, são completamente desconhecidas da população. Este artigo visa apresentar uma revisão da literatura passada e atual sobre as diversas fontes de exposição humana ao chumbo no Brasil.

As result of increased environmental contamination, the interest on the accumulation of heavy metals in the human body and its harmful effects has increased. Some metals, such as lead, are non-essential elements and exert toxic effects on biological system. Despite the control measures established by law, acute and chronic intoxication by lead still happen in Brazil. Some sources of lead exposure are wellknown, such as industrial activities like mining and factories for batteries recycling. However, other sources, although common, are completely unknown by population. This article aims to present a review of past and current literature on the various lead sources of human exposure in Brazil.

Efeitos cognitivos, neuropsicológicos e comportamentais da exposição a baixas concentrações de chumbo na infância / Cognitive, neuropsychological, and behavioral effects oflow-level lead exposure in childhood

O presente trabalho consiste em uma revisão bibliográfica a respeito da exposição ao chumbo em baixas concentrações e seus efeitos em crianças. Apesar do limite tolerado de chumbo no sangue, fixado pela OMS em 10mg/dl, diversos estudos transversais e longitudinais têm apontado que doses abaixo desse limite também geram consequências negativas no desenvolvimento infantil. Na primeira infância, observa-se correlação entre exposição pré-natal ao chumbo e déficits cognitivos; e correlação inversa entre níveis correntes de chumbo no sangue e desempenho cognitivo. A exposição a baixos níveis de chumbo na primeira infância também foi associada a prejuízo no desempenho cognitivo e escolar anos depois. Exposição ao chumbo na fase escolar tem sido associada a problemas no desempenho acadêmico, na atenção e em funções neuropsicológicas diversas. Estudos recentes detectaram ligação entre baixa exposição ao chumbo e problemas de comportamento na criança. A evidência acumulada indica risco de prejuízo neuropsicológico e adaptativo em crianças expostas abaixos níveis de chumbo. Os danos são maiores em concentrações muito baixas, inferiores ao nível tolerado pela OMS, indicando a necessidade de trabalhos de prevenção.

This is a literature review about low-level lead exposure and its effects on children. Although the current World Health Organization blood level of concern stands at 10 mg/dL, numerous prospective and cross sectional studies have extended the association of blood lead and developmental impairment to lower levels of lead exposure. During early childhood, there is a positive association between prenatal low-level-lead exposure and cognitive deficits. There is also a negative correlation between current blood lead level and cognitive performance. Low-level lead exposure in early childhood predicts cognitive and academic under achievement years later. During the school years, low-level lead exposure is concurrently associated to impairments in academic achievement, attention, and several neuropsychological functions. Recent investigations have detected a relationship between lead exposure and behavior problems in children. The evidence points to the neuropsychological and adaptive risks of low-level lead exposure during early and middle childhood and suggests that there is no safety margin at existing exposures. Harm is greater in very small concentrations, below the current WHO level of concern, thus indicating the need for prevention efforts.

Efectos del plomo sobre el aprendizaje en educandos del municipio Centro Habana, 2004-2006 / Lead effects on student learning from Centro Habana municipality, 2004-2006

Se realiza un estudio transversal en el que se estudiaron 65 niños con edades comprendidas entre 7 y 10 años, en el municipio Centro Habana, seleccionados de forma opinática. A todos se les realizó la determinación de plomo en sangre, examen físico completo donde se relacionaron las pruebas de desarrollo psicomotor y problemas de aprendizaje, con la finalidad de explorar estos en las actividades educativas. Se obtuvo información por parte de los maestros del rendimiento escolar y se obtuvo que el 46,2 por ciento de los niños tenían niveles de plomo en sangre por encima de lo permisible (10,0 µg/dL), de los cuales tuvieron problemas de aprendizaje el 67,7 por ciento y de ellos, se encontró 1 que tuvo valores de plomo en sangre por debajo de 6 µg/dL. Se observó asociación estadística de los educandos con el aprendizaje, atención y comportamiento asociados posiblemente con los niveles de plomo en sangre. Los resultados son estadísticamente significativos.

A cross-sectional study was conducted including 65 children aged between 7 and 10 in Centro Habana Municipality, selected by opinion. In all of them a determination of blood lead was performed, complete physical examination where psychomotor development and learning problems were related to explore these features in educational activities. The information on school performance was from professors where the 46,2 percent of children had blood lead levels above the permissible (10.0 µg/dL), the 67,7 percent had learning problems and one child with blood leas values under 6 µg/dL. There was a statistical association of students with learning, attention and behavior probably related to blood lead levels. Results are statistically significant.