RESUMO
The former use of chlordecone (CLD) in the French West Indies has resulted in long-term pollution of soils. CLD is known to be potentially transferred towards animal products of animals reared outdoors, mainly through accidental soil ingestion. Several studies indicate that soil bound CLD is bioavailable when administered to farm animals. Currently there is a need to quantify the level of CLD absorption and its toxicokinetic characteristics in the ruminant and particularly in the goat. These are considered as important farm species in the French West Indies. The objective of this study was to evaluate the absorption rate and the half-life of CLD in the non-lactating goat. The goats were administered either intravenously (i.v., n = 6) or orally (p.o., n = 6) one dose (1 mg kg-1 body weight) of CLD. Blood samples were collected at defined times up to 160 days post-dosing. CLD was analyzed in serum by high-resolution gas chromatography. A comparison of the area under the serum concentration-time curves (AUC) showed that the i.v. route is equivalent to the oral route. Thus, CLD is considered almost completely absorbed after p.o. administration, as shown by the mean absolute bioavailability. The comparison between the pharmacokinetic profiles of CLD following oral and intravenous dose showed a difference during the first 14 days and a similar kinetic after this period. The half-life of CLD in serum was close to 20 days. These results highlight a possible strategy of decontamination due to the short half-life of CLD, obtained in dry goats that did not excrete fat matter.
Assuntos
Clordecona/farmacocinética , Clordecona/toxicidade , Cabras , Inseticidas/farmacocinética , Inseticidas/toxicidade , Poluentes do Solo/farmacocinética , Poluentes do Solo/toxicidade , Animais , Clordecona/sangue , Feminino , Cabras/sangue , Cabras/metabolismo , Meia-Vida , Inseticidas/sangue , Medição de Risco , Poluentes do Solo/sangue , Toxicocinética , Índias OcidentaisRESUMO
Rio Grande, the southernmost Brazilian port and industrial center, is marked by mercury-polluted ground cover. This pollution varies spatially, with levels exceeding 1,000 µg kg(-1) in 30% of the urban territory. The risk of Hg impact as a result of deliberate and involuntary geophagy is increased by restrained urban conditions in combination with the large proportion of the population living at low-income levels. Laboratory tests have demonstrated that ingestion of Hg-polluted soil by rats results in significant alterations in animal health such as stagnation in body weight increase, and significant mercury accumulation in the liver and kidney. The consumption of Hg-contaminated urban soil also provoked changes in hematological profiles of experimental animals by increasing the number of platelets. The present study indicates the potential for the local population of Rio Grande living in mercury-polluted districts, specifically young children, to experience health disturbances.
Assuntos
Mercúrio/toxicidade , Atividade Motora/efeitos dos fármacos , Poluentes do Solo/toxicidade , Animais , Peso Corporal , Brasil , Criança , Ingestão de Alimentos , Monitoramento Ambiental , Humanos , Masculino , Mercúrio/análise , Mercúrio/sangue , Especificidade de Órgãos , Ratos , Ratos Wistar , Medição de Risco , Solo/análise , Poluentes do Solo/análise , Poluentes do Solo/sangue , Espectrofotometria Atômica/veterináriaRESUMO
BACKGROUND: To study the changes of children lead exposure in the city of Torreon during the last five years, after environmental and public health interventions, using the timeline of lead in blood concentration as the biomarker of exposure and its relation to lead in soil concentrations. METHODS: This follow-up study started in 2001 and consisted of 232 children living in nine neighborhoods in Torreon. Children were tested at 0, 6, 12 and 60 months. Lead in blood concentrations, Hemoglobin, Zinc-Protoporphyrin, anthropometric measures and socioeconomic status questionnaire was supplied to the parents. RESULTS: Median and range of lead in blood concentrations obtained at 0, 6, 12, 60 months were: 10.12 µg/dl (1.9 - 43.8), 8.75 µg/dl (1.85 - 41.45), 8.4 µg/dl (1.7 - 35.8) and 4.4 µg/dl (1.3 - 30.3), respectively. The decrease of lead in blood levels was significantly related to ages 0, 6, 12 and 60 months of the follow-up study. The timeline of B-Pb was associated with the timeline of lead in soil concentrations. CONCLUSIONS: B-Pb levels have significantly decreased in the group of children studied. This could be explained by a) environmental interventions by authorities and the smelter companies, b) normal changes in hygienic habits as children age and c) lead redistribution from blood to hard tissues.
Assuntos
Exposição Ambiental/análise , Chumbo/análise , Chumbo/sangue , Adolescente , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/sangue , Carga Corporal (Radioterapia) , Criança , Feminino , Seguimentos , Hemoglobinas/química , Humanos , Masculino , Metalurgia , México , Protoporfirinas/sangue , Poluentes do Solo/análise , Poluentes do Solo/sangueRESUMO
The aim of this work was to evaluate contamination by polychlorinated biphenyls and mercury in soil, and to assess exposure level to both contaminants in children living in San Felipe, Nuevo Mercurio, Zacatecas, Mexico. We found soil levels of total polychlorinated biphenyls ranging from non detectable (nd) to 190 µg/kg. Mercury soil levels ranged from 8.9 to 10215.0 mg/kg. Exposure levels of total polychlorinated biphenyls assessed in blood and urinary mercury in children living in the studied community were 1,600 ± 8,800 ng/g lipid and 4.2 ± 7.1 µg/g creatinine, respectively.
Assuntos
Mercúrio/análise , Bifenilos Policlorados/análise , Poluentes do Solo/análise , Solo/química , Adolescente , Criança , Monitoramento Ambiental , Feminino , Humanos , Masculino , Mercúrio/sangue , Mercúrio/urina , México , Bifenilos Policlorados/sangue , Bifenilos Policlorados/urina , Poluentes do Solo/sangue , Poluentes do Solo/urinaRESUMO
CONTEXT: Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes. MATERIAL AND METHODS: We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data. RESULTS: Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86 ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3 microg/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous. CONCLUSION: These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment.
Assuntos
Clordecona/sangue , Contaminação de Alimentos , Praguicidas/sangue , Gravidez/sangue , Poluentes do Solo/sangue , Adolescente , Adulto , Estudos de Coortes , Dieta , Exposição Ambiental , Feminino , Guadalupe , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Regressão , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
The goal of this work was to identify the solid-phase control on lead (Pb) bioaccessibility in soils impacted by smelter activities in the city of San Luis Potosi, in north-central Mexico. Total Pb concentrations in 30 ha of soil terrain from a residential area adjacent to the smelter showed levels above the 400-mg/kg intervention guideline dictated by Mexican Environmental regulations. These concentrations, although raising human health and environmental concerns, showed low water-soluble lead (<0.1 mg/L) and relatively low lead bioaccessibility (2.4-20.5%). X-ray diffraction and electron microscopy techniques showed, in addition to common Pb phases reported in similar contaminated environments [galena (PbS) and anglesite (PbSO(4))], the presence of a solid lead arsenate phase. The Pb solubility measured in soils agrees very well with the low solubility reported for the Pb minerals identified and explains the relatively low Pb bioaccessibility values measured, presumably from their low dissolution during passage through the gastrointestinal tract. The results reported are highly relevant for smelter-originated environmental contamination scenarios in general.
Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Chumbo/análise , Poluentes do Solo/análise , Solo/análise , Extração em Fase Sólida/métodos , Disponibilidade Biológica , Criança , Pré-Escolar , Humanos , Lactente , Chumbo/sangue , Chumbo/química , Metalurgia , México , Microscopia Eletrônica de Varredura , Poluentes do Solo/sangue , Poluentes do Solo/química , Solubilidade , Difração de Raios XRESUMO
The objective of this study was to assess the levels of soil contamination and child exposure in areas next to a primary smelter (arsenic-copper metallurgical) located in the community of Morales in San Luis Potosi, Mexico. In Morales, 90% of the soil samples studied in this work were above 400 mg/kg of lead, and above 100 mg/kg of arsenic, which are guidelines recommended by the United States Environmental Protection Agency (EPA). Bioaccessibility of these metals was studied in vitro in 10 soil samples; the median values of bioaccessibility obtained in these samples were 46.5% and 32.5% for arsenic and lead. Since the concentrations of arsenic and lead in soil were above normal values, and taking into account the bioaccessibility results, exposure to these metals was evaluated in children. Regarding lead, children aged 3-6 years had the highest mean blood lead levels; furthermore, 90% of them had concentrations above 10 microg/dl (CDC's action level). Total urinary arsenic was higher in children aged 8-9 yr; however, the percentage of children with concentrations above 50 microg/g creatinine (CDC's action level) or 100 microg/g creatinine (World Health Organization [WHO] action level) was similar among different age groups. Using the EPAs integrated exposure uptake biokinetic model for lead in children (IEUBK), we estimated that 87% of the total lead in blood is obtained from the soil/dust pathway. The exposure dose to arsenic, estimated for the children living in Morales using Monte Carlo analysis and the arsenic concentrations found in soil, was above the EPA's reference dose. With all these results, it is evident that studies are needed in order to identify adverse health effects in children living in Morales; nevertheless, it is more important to develop a risk reduction program as soon as possible.
Assuntos
Arsênio/urina , Cobre , Chumbo/sangue , Metalurgia , Poluentes do Solo/análise , Arsênio/análise , Criança , Pré-Escolar , Cidades , Monitoramento Ambiental , Suco Gástrico/química , Mucosa Gástrica/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Secreções Intestinais/química , Chumbo/análise , México , Poluentes do Solo/sangue , Poluentes do Solo/urinaRESUMO
Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 micro g/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P<0.05; R(2)=0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P<0.05; R(2)=0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be useful in differentiating among sources by site-specific association to mean blood lead and the prevalence of elevated blood lead at the regional level.
Assuntos
Monitoramento Ambiental/métodos , Intoxicação por Chumbo/prevenção & controle , Chumbo/análise , Poluentes do Solo/análise , Saúde da População Urbana , Criança , Pré-Escolar , Monitoramento Epidemiológico , Feminino , Humanos , Lactente , Chumbo/sangue , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/epidemiologia , Masculino , México/epidemiologia , Poluentes do Solo/sangueRESUMO
A survey was conducted to determine the distribution and determinants of environmental and blood lead levels near a conventional and several cottage lead smelters and to assess the relationship between environmental and blood lead levels in a tropical, developing-country setting. Fifty-eight households were studied in the Red Pond community, the site of the established smelter and several backyard smelters, and 21 households were studied in the adjacent, upwind Ebony Vale community in Saint Catherine Parish, Jamaica. Households were investigated, using questionnaires, soil and housedust lead measurements, and blood lead (PbB) measurements from 372 residents. Soil lead levels in Red Pond exceeded 500 parts per million (ppm) at 24% of households (maximum--18,600 ppm), compared to 0% in Ebony Vale (maximum 150 ppm). Geometric mean PbB in Red Pond, where 44% of children less than 6 years of age had PbB levels greater than or equal to 25 micrograms per deciliter (micrograms/dL), was more than twice that Ebony Vale in all age groups (p less than 0.0005). Within Red Pond, proximity to backyard smelters and to the conventional smelter were independent predictors of soil lead (p less than 0.05). Soil lead was the strongest predictor of PbB among Red Pond subjects under 12 years of age. The blood lead--soil lead relationship in children differed from that reported in developed countries; blood lead levels were higher than expected for the household-specific soil lead levels that were observed.(ABSTRACT TRUNCATED AT 250 WORDS)