26 resultados para Heptachlor
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Mode of access: Internet.
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ATSDR/TP-92/11.
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A new procedure for determining eleven organochlorine pesticides in soils using microwave-assisted extraction (MAE) and headspace solid phase microextraction (HS-SPME) is described. The studied pesticides consisted of mirex, α- and γ-chlordane, p,p’-DDT, heptachlor, heptachlor epoxide isomer A, γ-hexachlorocyclohexane, dieldrin, endrin, aldrine and hexachlorobenzene. The HS-SPME was optimized for the most important parameters such as extraction time, sample volume and temperature. The present analytical procedure requires a reduced volume of organic solvents and avoids the need for extract clean-up steps. For optimized conditions the limits of detection for the method ranged from 0.02 to 3.6 ng/g, intermediate precision ranged from 14 to 36% (as CV%), and the recovery from 8 up to 51%. The proposed methodology can be used in the rapid screening of soil for the presence of the selected pesticides, and was applied to landfill soil samples.
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Estuaries are perhaps the most threatened environments in the coastal fringe; the coincidence of high natural value and attractiveness for human use has led to conflicts between conservation and development. These conflicts occur in the Sado Estuary since its location is near the industrialised zone of Peninsula of Setúbal and at the same time, a great part of the Estuary is classified as a Natural Reserve due to its high biodiversity. These facts led us to the need of implementing a model of environmental management and quality assessment, based on methodologies that enable the assessment of the Sado Estuary quality and evaluation of the human pressures in the estuary. These methodologies are based on indicators that can better depict the state of the environment and not necessarily all that could be measured or analysed. Sediments have always been considered as an important temporary source of some compounds or a sink for other type of materials or an interface where a great diversity of biogeochemical transformations occur. For all this they are of great importance in the formulation of coastal management system. Many authors have been using sediments to monitor aquatic contamination, showing great advantages when compared to the sampling of the traditional water column. The main objective of this thesis was to develop an estuary environmental management framework applied to Sado Estuary using the DPSIR Model (EMMSado), including data collection, data processing and data analysis. The support infrastructure of EMMSado were a set of spatially contiguous and homogeneous regions of sediment structure (management units). The environmental quality of the estuary was assessed through the sediment quality assessment and integrated in a preliminary stage with the human pressure for development. Besides the earlier explained advantages, studying the quality of the estuary mainly based on the indicators and indexes of the sediment compartment also turns this methodology easier, faster and human and financial resource saving. These are essential factors to an efficient environmental management of coastal areas. Data management, visualization, processing and analysis was obtained through the combined use of indicators and indices, sampling optimization techniques, Geographical Information Systems, remote sensing, statistics for spatial data, Global Positioning Systems and best expert judgments. As a global conclusion, from the nineteen management units delineated and analyzed three showed no ecological risk (18.5 % of the study area). The areas of more concern (5.6 % of the study area) are located in the North Channel and are under strong human pressure mainly due to industrial activities. These areas have also low hydrodynamics and are, thus associated with high levels of deposition. In particular the areas near Lisnave and Eurominas industries can also accumulate the contamination coming from Águas de Moura Channel, since particles coming from that channel can settle down in that area due to residual flow. In these areas the contaminants of concern, from those analyzed, are the heavy metals and metalloids (Cd, Cu, Zn and As exceeded the PEL guidelines) and the pesticides BHC isomers, heptachlor, isodrin, DDT and metabolits, endosulfan and endrin. In the remain management units (76 % of the study area) there is a moderate impact potential of occurrence of adverse ecological effects and in some of these areas no stress agents could be identified. This emphasizes the need for further research, since unmeasured chemicals may be causing or contributing to these adverse effects. Special attention must be taken to the units with moderate impact potential of occurrence of adverse ecological effects, located inside the natural reserve. Non-point source pollution coming from agriculture and aquaculture activities also seem to contribute with important pollution load into the estuary entering from Águas de Moura Channel. This pressure is expressed in a moderate impact potential for ecological risk existent in the areas near the entrance of this Channel. Pressures may also came from Alcácer Channel although they were not quantified in this study. The management framework presented here, including all the methodological tools may be applied and tested in other estuarine ecosystems, which will also allow a comparison between estuarine ecosystems in other parts of the globe.
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Sediments can be natural archives to reconstruct the history of pollutant inputs into coastal areas. This is important to improve management strategies and evaluate the success of pollution control measurements. In this work, the vertical distribution of organochlorine pesticides (DDTs, Lindane, HCB, Heptachlor, Aldrin and Mirex) was determined in a sediment core collected from the Gulf of Batabanó, Cuba, which was dated by using the (210)Pb dating method and validated with the (239,240)Pu fallout peak. Results showed significant changes in sediment accumulation during the last 40 years: recent mass accumulation rates (0.321 g cm(-2) yr(-1)) double those estimated before 1970 (0.15 g cm(-2) yr(-1)). This change matches closely land use change in the region (intense deforestation and regulation of the Colon River in the late 1970s). Among pesticides, only DDTs isomers, Lindane and HCB were detected, and ranged from 0.029 to 0.374 ng g(-1) dw for DDTs, from<0.006 to 0.05 ng g(-1) dw for Lindane and from<0.04 to 0.134 ng g(-1) dw for HCB. Heptachlor, Aldrin and Mirex were below the detection limits (∼0.003 ng g(-1)), indicating that these compounds had a limited application in the Coloma watershed. Pesticide contamination was evident since the 1970s. DDTs and HCB records showed that management strategies, namely the banning the use of organochlorine contaminants, led to a concentration decline. However, Lindane, which was restricted in 1990, can still be found in the watershed. According to NOAA guidelines, pesticides concentrations encountered in these sediments are low and probably not having an adverse effect on sediment dwelling organisms.
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Sediment contamination is evaluated by determining organic micropollutants (organochlorine compounds - OCs and polycyclic aromatic hydrocarbons - PAHs) in two important Brazilian water reservoirs. Trace levels of OCs were observed in the Santana reservoir (44.8 ng g-1 d.w. of p,p'-DDT), while in the Funil reservoir the levels were below detection level. Forty-eight percent of the found sigmaocs were polychlorinated biphenyls, 29% dichlorodiphenyltrichloroethane (DDT), 18% Drins, and 5% other pesticides (HCB, Heptachlor, Heptachlor-epoxide, gamma-HCH and a-Endosulfan). We observed lower levels of sigmaPAH in the Funil reservoir (1 to 275 ng g-1d.w.) than in the Santana reservoir (2.2 to 26.7 µg g-1 d.w.).
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The present article presents an assessment of PTS in Brazil including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, benzene hexachloride, aldrin, dieldrin, endrin, p,p,-DDT, p,p,DDE, p,p,-DDD, hexachlorocyclohexanes (alpha-HCH, beta-HCH, gamma-HCH and delta-HCH), endossulfan, heptachlor and pentachlorophenol. The data presented here are related to a survey of PTS levels in different environmental matrixes (soil, sediment, water, air, biota) and human tissues (milk, blood, human hair), according to the scope of the UNEP-GEF Regionally Based Assessment of PTSs. Potential sources were evaluated considering national products and imports, since most of the literature does not allow source identification. Finally, Brazilian legislation was updated.
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The main objective of this paper was to evaluate the level of occurrence of the organochlorine compounds in samples of sediments, bivalves and two fish species collected in the Piracicaba River basin (São Paulo, Brazil). The isomers alpha and gamma of HCH and Heptachlor were most frequently detected in samples of sediments and specimens of bivalve and fish. Therefore, although the levels of these compounds found were not critically high, they are still found in the environment. This fact suggests that they are still being used, despite the fact that the use of these compounds was outlawed more than twenty years ago.
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Objetivo: Evaluar la exposición a plaguicidas organoclorados empleados en salud publica en la población trabajadora del programa de control de vectores en tres regiones de Colombia en 2013. Métodos: Se realizó un estudio descriptivo de corte transversal en el grupo de trabajadores del programa de control de enfermedades transmitidas por vectores -ETV- (coordinadores, técnicos, entomólogos, técnicos y auxiliares) de los departamentos de Meta, Nariño y Risaralda. A todos los participantes se les realizó una entrevista en la cual se recogió, mediante cuestionario, información de las tres variables de muestreo: sociodemográficas, ocupacionales, clínicas y toxicológicas. Se determinaron los niveles de 13 organoclorados en suero mediante cromatografía de gases en el Instituto Nacional de Salud. Se llevó a cabo un análisis descriptivo y se llevo a cabo un análisis para determinar la distribución de medias entre variables de exposición ocupacional (Ji2 para cualitativas y U de Mann-Whitney para cuantitativas). Posteriormente, se llevó a cabo un análisis multivariado para estimar la asociación controlando por variables de antigüedad, exposición laboral a organoclorados. Resultados: El reporte de manipulación de insecticidas organoclorados fue del 39,1%. El 100% de los trabajadores que usaron organoclorados refirieron el uso DDT. El 7,5% (n=3) refirieron el uso de Aldrin. Los organoclorados fueron hexaclorbenceno, hexaclorocicloexano, heptacloro, heptaclorepoxi, α-Clordano, 4,4-DDT, 4,4-DDE, β -endosulfan, 2,4- DDT, endosulfan sulfato y mirex. Los organoclorados con niveles pico más altos fueron β-HCH, 4,4- DDT y α –HCH. Los síntomas de mayor presentación fueron: cefalea 28,7%, mareo 29,9%, disminución de fuerza en MMSS 17,2% y síntomas neurosiquiátricos.
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The present article presents an assessment of PTS in Brazil including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, benzene hexachloride, aldrin, dieldrin, endrin, p,p,-DDT, p,p,DDE, p,p,-DDD, hexachlorocyclohexanes (alpha-HCH, beta-HCH, gamma-HCH and delta-HCH), endossulfan, heptachlor and pentachlorophenol. The data presented here are related to a survey of PTS levels in different environmental matrixes (soil, sediment, water, air, biota) and human tissues (milk, blood, human hair), according to the scope of the UNEP-GEF Regionally Based Assessment of PTSs. Potential sources were evaluated considering national products and imports, since most of the literature does not allow source identification. Finally, Brazilian legislation was updated.
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Thirty-seven samples of human milk (colostrum) from donors living in the Ribeirao Preto region were analyzed to determine the levels of organochlorine pesticide residues. Donors were classified into two groups, i.e., occupationally exposed and non-exposed to pesticides. Other factors such as age, previous lactations, race, smoking habit, occupation, family income and educational level were also considered. Analysis was performed by preliminary lipid extraction followed by fractional partition on a column and finally by gas chromatography with an electron capture detector. Lindane was found in 32% of the samples in amounts of less than 0.001 mg/kg; heptachlor was found in 65% of the samples at mean levels of 0.001 mg/kg, i.e., a level five-fold lower than that established by FAO/WHO (1970) for cow's milk. Aldrin and endrin were not detected in any of the samples. Dieldrin was detected in only one sample at a level of 0.038 mg/kg, which is considered high. DDT and DDE amounts are reported as total DDT and at least one of these compounds was present in every sample. Amounts detected in donors occupationally exposed to pesticides ranged from 0.008 to 0.455 mg/kg (mean, 0.149 mg/kg), i.e., three times the limit established by FAO/WHO (1970), while values for donors who had not been exposed ranged from 0.002 to 0.072 mg/kg (mean, 0.025 mg/kg), i.e., half the limit. Considering the level of acceptable daily intake proposed by FAO/WHO (1973), lactents ingested 1% of the acceptable intake of lindane (all donors), 30% of the acceptable intake of heptachlor (all donors), 60% of the acceptable intake of DDT (non-exposed donors), and 3.7 times the acceptable intake of DDT (exposed donors). Comparing the present results with those obtained 10 years ago, the total DDT level in human milk is decreasing in this part of the country. The mean amount of organochlorine residues in non-exposed women's milk was one of the lowest levels among those recorded in the literature. DDT levels of occupationally exposed women's milk were comparable with those reported for developed countries and lower than those detected in Latin American countries. When the results of this survey are considered in relation to the advantages of breast-feeding, the risk-benefit balance is still favorable to breast-feeding. However, given the lack of long-term epidemiological studies, undesirable or harmful long-lasting effects cannot be excluded.
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A small-scale method was developed for the simultaneous determination of γ-HCH, heptachlor, aldrin, dicofol, mirex, endosulfan I, endosulfan II and endosulfan sulphate in soil. The extraction and clean-up steps were combined into one step by transferring soil samples to chromatographic columns prepacked with neutral alumina. The pesticides elution was processed with n-hexane : dichloromethane (7:3) and the concentrated eluate was analysed using gas-liquid chromatography with electron capture detection. Analyses of the in vitro fortified samples with the selected pesticides were performed at three different levels. Mean recoveries for aldrin, γ-HCH and heptachlor, at levels of 2, 10 and 20 ng/g, ranged from 71 to 87%; for dicofol, at levels of 8, 40 and 80 ng/g, ranged from 97 to 103%; for endosulfan I and II, at levels of 5, 25 and 50 ng/g, ranged from 88 to 96%; for mirex, at levels of 6, 30 and 60 ng/g, ranged from 86 to 110%; and for endosulfan sulphate, at levels of 15, 75 and 150 ng/g, ranged from 93 to 104%. The method can be used for rapid determination of these pesticides in soil. © Springer-Verlag 1996.
Otimização de um método cromatográfico de análise de pesticidas organoclorados em amostras de peixes
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Considering that persistent organic pollutants (POPs) including synthetic substances belonging to differents organic functions, including organochlorine pesticides (OCPs), which are the most persistent and bioaccumulative, with high toxicity to humans and animals. Accordingly environmental and biological monitoring is necessary, in order to have greater control regarding the irresponsible use of these products. Though there are several analytical methodology reported in the literature to make determinations of this pesticide, they present some difficulties, requiring several steps to make the clean up of the sample. The proposed project aims to optimize a new analytical method that allows to perform the extraction of organochlorine pesticides in fish tissues, employing acetone as solvent assisted by ultrasound bath, making the method more quickly and not requiringfurther steps to purify the sample. Were analyzed the recoveries of pesticides in study in samples of tilapia average values: Heptachlor=84,7±9,8%; Aldrin=87,3±3,5%; Endosulfan=101,4±18,6%; DDE= 90,5± 3,3%, Endrin=102,2±13,8%., DDD=92,1±19,9%; DDT=90,8±6,8%. The real samples showed values granted for our legislation and low values of error
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We report on two patients with a history of chronic exposure to organochlorine insecticides who developed clinical and electromyographic signs and symptoms of chronic motor neuron disease. Measurements of aldrin, lindane and heptachlor confirmed the intoxication. We emphasize the importance of searching for toxic and environmental factors in cases of motor neuron disease especially in Third World countries, where workers usually wear no adequate protective equipment.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)