RESUMO
The global burden of water-based lead (Pb) exposure on children is largely unknown; however, the importance of water sources as a path of Pb exposure is receiving increased attention due to recent prominent exposure events related to corroded plumbing infrastructure in the US. This study investigated the contribution of Pb in household drinking and cooking water to Pb levels in blood (PbB) and urine (PbU) within 353 early school-aged children from Montevideo, Uruguay. Additionally, the analysis considered the child's iron status and the water content of iron (WFe) and zinc (WZn) in relation to water Pb and blood/urine Pb concentrations. Lead concentrations for both PbB and PbU were fairly low (M⯱â¯SD: 4.2⯱â¯2.1⯵g/dL; Median [5%, 95%]: 1.9 [0.6, 5.1⯵g/L, respectively]); however 21% of the sample had a PbB >5⯵g/dL butâ¯≤â¯10⯵g/dL. Overall, there was little evidence of an association between water metal concentrations and children's PbB/PbU. However, when the sample was stratified by children's iron status, WPb was positively related to PbU, but negatively related to PbB in iron-replete children, even after adjusting for WFe and WZn. In iron-deficient children, there was no elevation in PbU with increasing WPb. In this sample of children with low Pb levels, there were no overwhelming relationships between WPb and either PbB or PbU, however, there was some evidence that iron-replete status promotes excretion of WPb.
Assuntos
Água Potável/química , Exposição Ambiental/análise , Ferro/química , Chumbo/sangue , Chumbo/química , Chumbo/urina , Zinco/química , Criança , Água Potável/análise , Feminino , Humanos , Ferro/análise , Chumbo/análise , Masculino , Uruguai , Zinco/análiseRESUMO
Vulnerability assessments are commonly based on complex indices that may be inappropriate for characterizing risks in small groups of people exposed to environmental hazards. The aim was to present a multivariate and geostatistical approach to explore human health risks at the individual, household and community level. First, biological and socioeconomic characteristics from 179 children were used in a cluster analysis to find groups and identify vulnerability profiles. Then, both the exposure of children to arsenic and lead in soils and their accessibility to community resources were assessed using a geospatial analysis. The results identified three vulnerability profiles among children that were not in agreement with the environmental exposure and deficit of community resources. The proposed approach helps optimize strategies to manage both environmental and social risks based on the vulnerability of the exposed population.
Assuntos
Exposição Ambiental/análise , Medição de Risco/métodos , Fatores Socioeconômicos , Populações Vulneráveis/estatística & dados numéricos , Adolescente , Arsênio/análise , Arsênio/urina , Criança , Chile , Análise por Conglomerados , Humanos , Chumbo/análise , Chumbo/urina , Poluentes do Solo/análise , Poluentes do Solo/urina , Análise EspacialRESUMO
Lead exposure remains an important public health problem. Contaminated foods may act as a source of lead exposure, while certain nutrients may reduce lead absorption. We examined the cross-sectional associations of dietary patterns and the intake of several nutrients and foods with blood (Pb-B) and urinary (Pb-U) lead concentrations in children (5-8y) from Montevideo, Uruguay. From two 24-hour recalls completed by caregivers, we derived the mean daily intake of select nutrients and food groups (dairy, milk, fruit, root vegetables, foods rich in heme and non-heme iron), as well as "nutrient dense" and "processed" food patterns. Pb-B (n=315) was measured using atomic absorption spectrometry; Pb-U (n=321) using ICP-MS. Pb-U was adjusted for specific gravity and log-transformed to approximate a normal distribution. Iron deficiency (ID) and dietary variables were tested as predictors of Pb-B and log-Pb-U in covariate-adjusted regressions. Median [5%, 95%] Pb-B and Pb-U were 3.8 [0.8-7.8] µg/dL and 1.9 [0.6-5.1] µg/L, respectively; ~25% of Pb-B above current U.S. CDC reference concentration of 5µg/dL. ID was associated with 0.75µg/dL higher Pb-B, compared to non-ID (p<0.05). Consumption of root vegetables was not associated with Pb-B or log-Pb-U. Higher scores on the nutrient-dense pattern were related with higher Pb-Bs, possibly due to consumption of green leafy vegetables. Dietary intake of iron or iron-rich foods was not associated with biomarkers of lead. Conversely, children consuming more calcium, dairy, milk and yogurt had lower Pb-B and log-Pb-U. Our findings appear consistent with existing recommendations on including calcium-rich, but not iron- or vitamin-C-rich foods in the diets of lead-exposed children, especially where the consumption of these foods is low.
Assuntos
Dieta , Poluentes Ambientais/sangue , Poluentes Ambientais/urina , Chumbo/sangue , Chumbo/urina , Estado Nutricional , Criança , Cidades , Laticínios , Monitoramento Ambiental , Feminino , Frutas , Humanos , Deficiências de Ferro , Masculino , Uruguai , VerdurasRESUMO
Environmental hazards from natural or anthropological sources are widespread, especially in the north-central region of Mexico. Children represent a susceptible population due to their unique routes of exposure and special vulnerabilities. In this study we evaluated the association of exposure to environmental kidney toxicants with kidney injury biomarkers in children living in San Luis Potosi (SLP), Mexico. A cross-sectional study was conducted with 83 children (5-12 years of age) residents of Villa de Reyes, SLP. Exposure to arsenic, cadmium, chromium, fluoride and lead was assessed in urine, blood and drinking water samples. Almost all tap and well water samples had levels of arsenic (81.5%) and fluoride (100%) above the permissible levels recommended by the World Health Organization. Mean urine arsenic (45.6ppb) and chromium (61.7ppb) were higher than the biological exposure index, a reference value in occupational settings. Using multivariate adjusted models, we found a dose-dependent association between kidney injury molecule-1 (KIM-1) across chromium exposure tertiles [(T1: reference, T2: 467pg/mL; T3: 615pg/mL) (p-trend=0.001)]. Chromium upper tertile was also associated with higher urinary miR-200c (500 copies/µl) and miR-423 (189 copies/µL). Arsenic upper tertile was also associated with higher urinary KIM-1 (372pg/mL). Other kidney injury/functional biomarkers such as serum creatinine, glomerular filtration rate, albuminuria, neutrophil gelatinase-associated lipocalin and miR-21 did not show any association with arsenic, chromium or any of the other toxicants evaluated. We conclude that KIM-1 might serve as a sensitive biomarker to screen children for kidney damage induced by environmental toxic agents.
Assuntos
Arsênio/urina , Cromo/urina , Poluentes Ambientais/urina , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Arsênio/análise , Arsênio/sangue , Biomarcadores/urina , Criança , Pré-Escolar , Cromo/análise , Cromo/sangue , Creatinina/sangue , Água Potável/análise , Exposição Ambiental , Poluentes Ambientais/análise , Poluentes Ambientais/sangue , Feminino , Fluoretos/análise , Fluoretos/sangue , Fluoretos/urina , Taxa de Filtração Glomerular , Água Subterrânea/análise , Humanos , Nefropatias/sangue , Nefropatias/urina , Chumbo/análise , Chumbo/sangue , Chumbo/urina , Lipocalina-2/urina , Masculino , México , MicroRNAs/urina , Albumina Sérica/análiseRESUMO
BACKGROUND: Attention deficit hyperactivity disorder is the most common neuropsychiatric disorder in children; symptoms can persist into adult life by 60 %. Our objective was to quantify the levels of lead in blood and urine in pediatric patients with attention deficit hyperactivity disorder. METHODS: We did an observational study which included a captive population of children diagnosed with attention deficit hyperactivity disorder in the mental health service of Hospital General, from Centro Médico Nacional La Raza. Lead levels were determined in blood and urine by atomic absorption technique. RESULTS: We included 39 patients, 932 % male, with a mean age of 9.2 ± 2.16 years. The deficit and hyperactivity disorder combined type was the most frequent (69.2 %); 49 % of patients were found with toxic lead levels in blood (above 10 mg/dL); 17.9 % with stage III and 5.12 % with stage IV, according to the Mexican Official Standard (NOM-199-SSA-2000). Significant association was found between blood lead levels and the clinical expression of attention deficit hyperactivity disorder. CONCLUSIONS: Levels of lead exposure during early childhood have been shown to be inversely proportional to neurological development in the first seven years of life. Data results are insufficient to relate them with causality.
INTRODUCCIÓN: los síntomas del trastorno por déficit de atención e hiperactividad pueden persistir hasta la vida adulta en 60 % de quienes la padecieron en la niñez. Nuestro objetivo fue cuantificar los niveles de plomo en la sangre y la orina en niños con diagnóstico de trastorno por déficit de atención e hiperactividad para identificar si existe alguna relación. MÉTODOS: estudio observacional que incluyó a una muestra cautiva del Servicio de Higiene Mental del Hospital General del Centro Médico Nacional La Raza, con diagnóstico de trastorno por déficit de atención e hiperactividad. Se cuantificaron los niveles séricos y urinarios del plomo mediante la técnica de absorción atómica. RESULTADOS: se incluyeron 39 pacientes, 92.3 % del sexo masculino, con una edad promedio de 9.2 ± 2.16 años. El trastorno por déficit de atención e hiperactividad combinado fue el más frecuente (69.2 %). En 49 % de los pacientes se encontraron niveles de plomo en sangre superiores a 10 ?g/dL. Conforme los parámetros establecidos en la NOM-199-SSA1-2000, 17.9 % clasificaba en estadio III y 5.12 % en estadio IV. Se encontró relación significativa entre los niveles de plomo y la expresión clínica del trastorno por déficit de atención e hiperactividad. CONCLUSIONES: los niveles de exposición al plomo durante la infancia temprana han demostrado ser inversamente proporcionales al desarrollo neurológico en los primeros siete años de vida. Los datos son insuficientes para inferir la causalidad.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/etiologia , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/efeitos adversos , Chumbo/efeitos adversos , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Transtorno do Deficit de Atenção com Hiperatividade/urina , Biomarcadores/sangue , Biomarcadores/urina , Criança , Pré-Escolar , Exposição Ambiental/análise , Poluentes Ambientais/sangue , Poluentes Ambientais/urina , Feminino , Humanos , Chumbo/sangue , Chumbo/urina , Masculino , México , Fatores de RiscoRESUMO
A novel ion imprinted polyvinylimidazole-silica hybrid copolymer (IIHC) was synthesized and used as a selective solid sorbent for Pb(2+) ions preconcentration using an on-line solid phase extraction (SPE) system coupled to TS-FF-AAS. The ionic hybrid sorbent was prepared using 1-vinylimidazole and 3-(trimethoxysilyl)propylmethacrylate as monomers, Pb(2+) ions as template, tetraethoxysilane as reticulating agent and 2,2'-azobis-isobutyronitrile as initiator. The best on-line SPE conditions concerning sorption behavior, including sample pH (6.46), buffer concentration (9.0 mmol L(-1)), eluent (HNO(3)) concentration (0.5 mol L(-1)) and preconcentration flow rate (4.0 mL min(-1)), were optimized by means of full factorial design and Doehlert matrix. The analytical curve ranged from 2.5 to 65.0 µg L(-1) (r=0.999) with limit of detection of 0.75 µg L(-1); the precision (repeatability) calculated as relative standard deviation (n=10) was 5.0 and 3.6% for Pb(2+) concentration of 10.0 and 60.0 µg L(-1), respectively. From on-line breakthrough curve, column capacity was 3.5 mg g(-1). Preconcentration factor (PF), consumptive index (CI) and concentration efficiency (CE) were 128.0, 0.16 mL and 25.6 min(-1), respectively. The selective performance of the sorbent, based on relative selectivity coefficient, was compared to NIC (non imprinted copolymer) for the binary mixture Pb(2+)/Cd(2+), Pb(2+)/Cu(2+) and Pb(2+)/Zn(2+). The results showed that ion imprinted polyvinylimidazole-silica hybrid polymer had higher selectivity for Pb(2+) than NIC at 64.9, 16.0 and 8.8 folds. The developed method was successfully applied for highly sensitive and selective Pb(2+) determination in different kinds of water samples, parenteral solutions and urine. Accuracy was also assessed by analyzing certified reference fish protein (DORM-3) and marine sediment (MESS-3 and PACS-2) with satisfactory results.
Assuntos
Poluentes Ambientais/análise , Imidazóis/química , Chumbo/análise , Impressão Molecular/métodos , Polímeros/síntese química , Polivinil/química , Dióxido de Silício/química , Espectrofotometria Atômica , Poluentes Ambientais/isolamento & purificação , Poluentes Ambientais/urina , Análise de Injeção de Fluxo , Concentração de Íons de Hidrogênio , Íons/química , Chumbo/isolamento & purificação , Chumbo/urina , Polímeros/química , Extração em Fase SólidaRESUMO
Paints are composed of an extensive variety of hazardous substances, such as organic solvents and heavy metals. Biomonitoring is an essential tool for assessing the risk to occupational health. Thus, this study analyzed the levels of biomarkers of exposure for toluene, xylene, styrene, ethylbenzene, and lead, as well as the oxidative stress biomarker alterations in painters of an industry. Lipid peroxidation biomarker (MDA), delta-aminolevulinate dehydratase (ALA-D), nonprotein thyol groups, superoxide dismutase and catalase (CAT) were analyzed in exposed and nonexposed subjects. We estimated which of the paint constituents have the greatest influence on the changes in the biomarkers of oxidative stress in this case of co-exposure. The results demonstrated that despite the fact that all the biomarkers of exposure were below the biological exposure limits, the MDA levels and antioxidant enzyme activities were increased, while nonprotein thyol groups and ALA-D levels were decreased in painters when compared with nonexposed subjects. After statistic test, toluene could be suggested as the principal factor responsible for increased lipid peroxidation and inhibition of ALA-D enzyme; however, further studies on the inhibition of ALA-D enzyme by toluene are necessary.
Assuntos
Exposição Ocupacional/análise , Estresse Oxidativo/efeitos dos fármacos , Pintura/toxicidade , Xenobióticos/toxicidade , Adulto , Poluentes Ocupacionais do Ar/toxicidade , Poluentes Ocupacionais do Ar/urina , Derivados de Benzeno/toxicidade , Derivados de Benzeno/urina , Biomarcadores/sangue , Biomarcadores/urina , Catalase/sangue , Creatina/urina , Humanos , Chumbo/toxicidade , Chumbo/urina , Peroxidação de Lipídeos/efeitos dos fármacos , Saúde Ocupacional , Sintase do Porfobilinogênio/sangue , Medição de Risco , Estireno/toxicidade , Estireno/urina , Superóxido Dismutase/sangue , Tolueno/toxicidade , Tolueno/urina , Xenobióticos/urina , Xilenos/toxicidade , Xilenos/urinaRESUMO
The analysis of human biological samples, such as blood, urine, nails, and hair, is generally used for the verification of human exposure to toxic metals. In this review, various spectrometric methods for the determination of cadmium and lead in biological samples are discussed and compared. Several spectrometric techniques are presented and discussed with respect to various characteristics such as sensitivity, selectivity, and cost. Special attention is drawn to the procedures for digestion prior to the determination of cadmium and lead in hair, nails, blood, and urine.
Assuntos
Cádmio , Cabelo/química , Chumbo , Unhas/química , Espectrofotometria Atômica/métodos , Cádmio/sangue , Cádmio/química , Cádmio/urina , Humanos , Chumbo/sangue , Chumbo/química , Chumbo/urinaRESUMO
O objetivo deste estudo foi a avaliação da exposição ocupacional ao chumbo e manganês dos trabalhadores de uma oficina de recuperação de armamento de uma organização militar. O ar do ambiente de trabalho foi avaliado no monitoramento ambiental e os indicadores biológicos de dose interna, para chumbo e manganês, em sangue e na urina, foram utilizados no monitoramento biológico. A concentração de manganês e chumbo nos filtros e fluidos biológicos foi determinada por espectrometria de absorção atômica eletrotérmica. Os resultados do monitoramento ambiental indicaram níveis de Pb e Mn acima do TLV-TWA durante o processo de pintura (313,33 μg m-3) e solda (951 μg m-3). Os indicadores biológicos revelaram que cinco dos nove trabalhadores apresentam níveis de Pb-S que sugerem exposição ambiental ao chumbo (valores entre 5 e 10 μg dL-1). Pode-se concluir que existe uma pequena exposição ocupacional ao chumbo e ao manganês na oficina de tratamento superficial. Tal exposição é influenciada pelas condições meteorológicas e pela demanda variável de trabalho.
The aim of this study was the occupational exposure assessment to lead and manganese of workers in an armament repair shop of a military organization. The air of the working environment was assessed in the environmental monitoring while the internal dose biological indicators for lead and manganese, in blood and urine, were used in biological monitoring. Metals concentration in filters and biological fluids were determined by electrothermal atomic absorption spectrometry. The results of the environmental monitoring showed lead and manganese levels above the TLV-TWA during the process of painting (313.33 g m-3) and solder (951 μg m-3). The biological indicators revealed that five of the nine employees presented Pb-S levels that suggested an environmental exposure to lead (values between 5 and 10 μg dL-1). It can be concluded that there is a small occupational exposure to lead and manganese in the superficial treatment repair shop. This exposure is influenced by weather conditions and the variable demand of work.
Assuntos
Feminino , Humanos , Masculino , Chumbo/sangue , Chumbo/urina , Manganês/sangue , Manganês/urina , Exposição Ocupacional/análise , ArmasRESUMO
Lead exposure is an important issue in the research of several toxic effects resulting from the biochemical interaction between this metal and the organism. Calcium is a fundamental mineral for the maintenance of the organism homeostasis where there is interaction between lead and calcium in metabolic pathways. Environmental lead exposure by verifying the usefulness and applicability of urinary calcium/creatinine ratio (UCa/Cr) in this context was evaluated. This was an extensive socio-demographic study of the nutritional profile, lead exposure biomarkers in blood and the urine and UCa/Cr ratio. The children studied were from a low socio-economic group characterized by unsatisfactory nutritional diet. Lead environmental exposure was shown by biomarkers, with UCa/Cr ratio having positive and significant correlations with both lead and delta-aminolevulinic acid in urine (ALA-U), without colinearity diagnosis. There was a strong association between calcium excretion and lead exposure as a result of linear regression construction models. In children, lead increases calcium excretion which is an additional risk to infantile health. Urinary calcium/creatinine ratio may be a useful tool in the biological monitoring of lead exposure and health promotion programs.
Assuntos
Cálcio/urina , Exposição Ambiental/análise , Poluentes Ambientais/análise , Chumbo/análise , Adolescente , Brasil , Cálcio/metabolismo , Criança , Pré-Escolar , Creatinina/urina , Poluentes Ambientais/sangue , Poluentes Ambientais/urina , Feminino , Humanos , Lactente , Chumbo/sangue , Chumbo/urina , Masculino , Estado Nutricional , Classe SocialRESUMO
The aim of this study was the occupational exposure assessment to lead and manganese of workers in an armament repair shop of a military organization. The air of the working environment was assessed in the environmental monitoring while the internal dose biological indicators for lead and manganese, in blood and urine, were used in biological monitoring. Metals concentration in filters and biological fluids were determined by electrothermal atomic absorption spectrometry. The results of the environmental monitoring showed lead and manganese levels above the TLV-TWA during the process of painting (313.33 g m-3) and solder (951 microg m-3). The biological indicators revealed that five of the nine employees presented Pb-S levels that suggested an environmental exposure to lead (values between 5 and 10 microg dL-1). It can be concluded that there is a small occupational exposure to lead and manganese in the superficial treatment repair shop. This exposure is influenced by weather conditions and the variable demand of work.
Assuntos
Chumbo/sangue , Chumbo/urina , Manganês/sangue , Manganês/urina , Exposição Ocupacional/análise , Armas , Feminino , Humanos , MasculinoRESUMO
The aim of this work was to verify whether there are statistically significant correlation between the concentrations of lead in blood (Pb-B) and urine (Pb-U). Electrothermal atomic absorption spectrometry was used in the determination of lead concentration in biological material. Venous blood and spot urine were collected from workers occupationally exposed (95), adults (130) and children up to 15 years old (22) environmentally exposed. After a test showing significant differences between Pb-U and the three categories previously determined, cutting points for Pb-U were established to predict Pb-B values by the ROC curve. Thus, it is expected that Pb-B is lower than 10 microg.dL-(1) with Pb-U up to 0.55 microg.dL-(1), whereas lead levels in blood below 27.6 microg.dL-(1) are expected when the amount of the metal in urine is lower than 2.05 microg.dL-(1). So, urine can be used to replace blood for the assessment of the occupational exposure to lead. However, caution is advised in the case of environmental exposure, since urinary lead should be used just as an estimation of the metal content in blood.
Assuntos
Intoxicação por Chumbo/diagnóstico , Chumbo/sangue , Chumbo/urina , Doenças Profissionais/diagnóstico , Exposição Ocupacional/análise , Adulto , Biomarcadores/análise , Indicadores Básicos de Saúde , Humanos , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/urina , Doenças Profissionais/sangue , Doenças Profissionais/urina , Curva ROC , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Adulto JovemRESUMO
O objetivo deste trabalho foi verificar se há correlação estatisticamente significativa entre as concentrações de chumbo no sangue (Pb-S) e urina (Pb-U). A espectrometria de absorção atômica eletrotérmica foi utilizada na determinação da concentração de chumbo no material biológico. As amostras de sangue e de urina foram coletadas entre trabalhadores expostos ocupacionalmente (95) e entre adultos (130) e crianças até 15 anos (22) expostos ambientalmente. Após um teste que mostrou diferenças significativas entre Pb-U e as três categorias previamente determinadas, pontos de corte em Pb-U puderam ser fixados para a predição dos valores de Pb-S pela curva ROC. Assim, para Pb-U até 0,55 µg.dL-1, pode-se esperar que Pb-S seja menor do que 10 µg.dL-1, ao passo que níveis de chumbo no sangue até 27,6 µg.dL-1 são esperados quando o teor do metal na urina é menor do que 2,05 µg.dL-1. Logo, a urina pode ser utilizada em substituição ao sangue para avaliação da exposição ocupacional ao chumbo. Contudo, recomenda-se cautela no caso da exposição ambiental, devendo-se utilizar o chumbo urinário como uma estimativa do conteúdo do metal no sangue.
The aim of this work was to verify whether there are statistically significant correlation between the concentrations of lead in blood (Pb-B) and urine (Pb-U). Electrothermal atomic absorption spectrometry was used in the determination of lead concentration in biological material. Venous blood and spot urine were collected from workers occupationally exposed (95), adults (130) and children up to 15 years old (22) environmentally exposed. After a test showing significant differences between Pb-U and the three categories previously determined, cutting points for Pb-U were established to predict Pb-B values by the ROC curve. Thus, it is expected that Pb-B is lower than 10 µg.dL-¹ with Pb-U up to 0.55 µg. dL-¹, whereas lead levels in blood below 27.6 µg. dL-¹ are expected when the amount of the metal in urine is lower than 2.05 µg.dL-¹. So, urine can be used to replace blood for the assessment of the occupational exposure to lead. However, caution is advised in the case of environmental exposure, since urinary lead should be used just as an estimation of the metal content in blood.
Assuntos
Adulto , Humanos , Adulto Jovem , Intoxicação por Chumbo/diagnóstico , Chumbo/sangue , Chumbo/urina , Doenças Profissionais/diagnóstico , Exposição Ocupacional/análise , Biomarcadores/análise , Indicadores Básicos de Saúde , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/urina , Doenças Profissionais/sangue , Doenças Profissionais/urina , Curva ROC , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Adulto JovemRESUMO
Lead concentration in whole blood (BPb) is the primary biomarker used to monitor exposure to this metallic element. The U.S. Centers for Disease Control and Prevention and the World Health Organization define a BPb of 10 microg/dL (0.48 micromol/L) as the threshold of concern in young children. However, recent studies have reported the possibility of adverse health effects, including intellectual impairment in young children, at BPb levels < 10 microg/dL, suggesting that there is no safe level of exposure. It appears impossible to differentiate between low-level chronic Pb exposure and a high-level short Pb exposure based on a single BPb measurement; therefore, serial BPb measurements offer a better estimation of possible health outcomes. The difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments (i.e., cycling of Pb between bone, blood, and soft tissues). If we are to differentiate more effectively between Pb stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose have yet been accepted by the scientific community as a reliable substitute for a BPb measurement. This review focuses on the limitations of biomarkers of Pb exposure and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use, and we attempt to assess the influence of confounding variables on BPb levels. Finally, we discuss the interpretation of BPb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of Pb determinations in human specimens including hair, nails, saliva, bone, blood (plasma, whole blood), urine, feces, and exfoliated teeth.
Assuntos
Biomarcadores , Exposição Ambiental , Monitoramento Ambiental/métodos , Chumbo/análise , Chumbo/sangue , Osso e Ossos/química , Fezes/química , Cabelo/química , Humanos , Chumbo/urina , Unhas/química , Saliva/química , Dente/químicaRESUMO
OBJECTIVES: To assess the historical exposure and to study the relationships between lead concentrations in whole blood (B-Pb), plasma (P-Pb), urine (U-Pb), finger bone (Bone-Pb) and duration of employment in workers at a secondary lead smelter and to compare the relationships between B-Pb and P-Pb with results from previous studies of populations with a wide range of lead exposure. METHODS: In 39 lead workers (29 active, ten retired), recruited from those with the highest exposure at a German secondary lead smelter, levels of B-Pb, P-Pb and U-Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS). Bone-Pb was determined by in vivo X-ray fluorescence (XRF). Results were compared with data from a previous study on 90 workers (71 active, 19 retired) with lower exposure, from a Swedish secondary lead smelter, as well as with previously collected data from 42 active Russian lead workers and 34 Ecuadorian lead-exposed subjects. RESULTS: The median values in the active/retired German lead workers were: age 44/59 years, duration of employment 20/38 years, Bone-Pb 71/150 microg/g, B-Pb 500/330 microg/l, P-Pb 2.7/1.1 microg/l, and U-Pb 25/13 micromol/mol creatinine. Bone-Pb increased with duration of employment by 4.2 microg/g per year and 1.6 microg/g per year in German and Swedish workers, respectively. The median Bone-Pb was three times higher in both active and retired German workers than in Swedish smelter workers with essentially the same age distribution and duration of employment. The linear regression equation between B-Pb and log P-Pb in the combined group of Ecuadorian, German, Russian and Swedish lead-exposed subjects (n=176) was B-Pb=545 x log[P-Pb] + 258 (r(s)=0.94; P<0.001). CONCLUSIONS: The high Bone-Pb values recorded for the German smelters implied a historical lead exposure of considerable magnitude. The long-term high lead exposure also showed up in the B-Pb levels for both active and retired workers, leading to the implementation of necessary industrial safety measures in order to respond to biological threshold limits. The suggested equation describing the relationship between B-Pb and P-Pb in the combined group of subjects with a wide range of lead exposure can be useful in future cross-sectional and longitudinal studies of lead-exposed populations, relating, e.g., lead exposure to adverse health outcomes.
Assuntos
Osso e Ossos/química , Dedos , Chumbo/análise , Exposição Ocupacional , Adulto , Equador , Alemanha , Humanos , Chumbo/sangue , Chumbo/urina , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Federação Russa , Espectrometria por Raios X , SuéciaRESUMO
A method for the multielement determination of cadmium and lead in urine is proposed by simultaneous electrothermal atomic absorption spectrometry (SIMAAS) with an end-capped transversely heated graphite atomizer (EC-THGA). The best conditions for cadmium and lead determination were obtained in the presence of NH4H2PO4 as a chemical modifier, using 500 degrees C and 1800 degrees C as the pyrolysis and atomization temperatures, respectively. Urine samples were diluted 1 + 4 directly in autosampler cups with a mixture of 0.125% (w/v) Triton X-100 + 2.5% (v/v) HNO3 + 0.31% (w/v) NH4H2PO4. The optimized heating program was carried out in 57 s, and the instrument calibration was done with aqueous reference solutions. The use of EC-THGA increased the sensitivity of cadmium and lead by 14% and 25%, respectively. The detection limits (n = 20, 3delta) were 0.03 microg L(-1) (0.36 pg) for cadmium and 0.57 microg L(-1) (6.8 pg) for lead. The performance of EC-THGA was acceptable up to 500 heating cycles. The reliability of the entire procedure was checked with the analysis of a lyophilized urine certified reference material. The found concentrations were in agreement with the recommended values (95% confidence level).
Assuntos
Cádmio/urina , Chumbo/urina , Cádmio/normas , Temperatura Alta , Humanos , Chumbo/normas , Magnésio/química , Fosfatos/química , Reprodutibilidade dos Testes , Espectrofotometria Atômica/instrumentação , Espectrofotometria Atômica/métodosRESUMO
Avaliação da exposição ocupacional ao chumbo, passando pelos meios de prevenção, manifestações clínicas, normas técnicas vigentes em lei até o seu tratamento e correlação das profissões de maior risco com avaliações dos níveis de concentração no organismo.
Assuntos
Humanos , Chumbo , Chumbo/sangue , Chumbo/toxicidade , Chumbo/urina , Intoxicação do Sistema Nervoso por Chumbo em Adultos , Exposição Ocupacional , Saúde Ocupacional , Medicina do Trabalho , Riscos Ocupacionais , Níveis Máximos PermitidosRESUMO
Industrial growth has created the potential for environmental problems in Mexico, since attention to environmental controls and urban planning has lagged behind the pace of industrialization. The aim of this cross-sectional study was to assess lead exposure in children aged 6-9 yr attending 3 primary schools and living in the vicinity of the largest smelter complex in Mexico. One of the schools is located 650 m distant from a smelter complex that includes a lead smelter (close school); the second is located 1750 m away from the complex and at the side of a heavy traffic road (intermediate school) in Torreon, Coahuila. The third school is located in Comez Palacio, Durango, 8100 m away from the smelter complex and distant from heavy vehicular traffic or industrial areas (remote school). Lead was measured in air, soil, dust, and well water. Lead in blood (PbB) was determined in 394 children attending the above mentioned schools. Determinations were performed by atomic absorption spectrometry. Diet, socioeconomic status, hygienic habits, and other variables were assessed by questionnaire. Median (range) PbB values were 7.8 microg/dl (3.54-29.61) in the remote school, 21.8 microg/dl (8.37-52.08) in the intermediate school and 27.6 microg/dl (7.37-58.53) in children attending the close school. The percentage of children with PbB > 15 microg/dl was 6.80%, 84.9%, and 92.1% respectively. In this order, the geometric means (range) of Pb concentrations in air were 2.5 microg/m3 (1.1-7.5), 5.8 microg/m3 (4.3-8.5), and 6.1 microg/m3 (1.6-14.9). The Pb concentrations in dust from playgrounds areas in the intermediate and close school settings ranged from 1,457 to 4,162.5 mg/kg. Pb concentrations in drinking water were less than 5 microg/L. Soil and dust ingestion and inhalation appear to be the main routes of exposure. Our results indicate that environmental contamination has resulted in an increased body burden of Pb, suggesting that children living in the vicinity of the smelter complex are at high risk for adverse effects of lead.
Assuntos
Exposição Ambiental/análise , Chumbo/análise , Metalurgia , Poluentes Ocupacionais do Ar/análise , Carga Corporal (Radioterapia) , Criança , Poeira/análise , Humanos , Chumbo/sangue , Chumbo/urina , México , Poluentes do Solo/análise , Poluentes Químicos da Água/análiseRESUMO
The sodium salt of 2,3-dimercaptopropane-1-sulfonic acid (Dimaval; DMPS) challenge test has been given previously to humans exposed to elemental mercury (vapor) or mercuric salts, but not mercurous salts. The test (300 mg p.o., after an 11-hr fast) was given to 11 factory workers who make a skin lotion that contains mercurous chloride, eight users of the skin lotion and nine controls. Urines were analyzed for total mercury by using cold vapor atomic absorption spectrophotometry. The mercury excreted for 6 hr before and 6 hr after DMPS treatment was 113 micrograms +/- 26 and 5037 micrograms +/- 682 S.E.M. for the skin lotion makers; 16.2 micrograms +/- 3.4 and 1410 micrograms +/- 346 S.E.M. for the skin lotions users; and 0.49 micrograms +/- 0.11 and 18.4 micrograms +/- 7.1 S.E.M. for the controls, respectively. The increases in urinary mercury resulting from the DMPS challenge test were 45-, 87- and 38-fold, respectively. The results demonstrate that, in humans exposed to mercurous chloride, DMPS increases the urinary excretion of mercury and that the DMPS/mercury challenge test is of value for a more realistic estimation of mobilizable mercury. An attempt to associate genotoxicity, as indicated by micronuclei content in buccal cells, with mercury exposure was inconclusive, perhaps because of the small number of subjects.
Assuntos
Quelantes , Cloreto de Mercúrio/farmacocinética , Compostos de Mercúrio , Mercúrio/urina , Exposição Ocupacional , Unitiol , Adulto , Idoso , Carga Corporal (Radioterapia) , Feminino , Humanos , Chumbo/urina , Masculino , Mercúrio/efeitos adversos , Mercúrio/farmacocinética , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Pessoa de Meia-IdadeRESUMO
The effects of low lead exposure were investigated in 96 children (7-12 years old) living and studying within a 1 km radius of a lead smelter (exposed population) located in Torreón, Coahuila, México, and compared with 30 children living and studying 4.5 km from the same smelter (control population). Both populations had similar socio-economic conditions. The exposed population showed higher blood lead (PbB) and free erythrocyte protoporphyrin (FEP) concentrations (17.3 +/- 5.6 micrograms dl-1 and 53.9 +/- 46.1 micrograms dl-1, respectively) than controls (PbB, 5.4 +/- 3.1 micrograms dl-1 and FEP, 13.9 +/- 7.3 micrograms dl-1). PbB concentrations were inversely correlated to distance from the smelter (r2 = 0.494). However, in the exposed population, wind direction also had a significant effect on the PbB and urinary lead (PbU) concentrations. The exposed population was divided according to PbB into a high level lead group (PbB > 15 micrograms dl-1), which also showed high FEP concentrations and a low lead group (PbB < 15 micrograms dl-1). Clinically, the high lead group showed a greater incidence of general symptoms (colic, headache, paresthesia, myalgia and dizziness), impairment of some neuromuscular functions (neuromuscular conduction velocity and motor coordination) and a decrease of intelligence quotient (IQ), which was not related with sex or socio-economic status. These results are an evidence of morbidity in children with high PbB concentrations.