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RESUMO Fases líquidas não aquosas leves (LNAPL), como combustíveis líquidos, estão presentes em muitas áreas contaminadas. Para o gerenciamento dessas áreas, é importante conhecer a mobilidade desse produto, a fim de subsidiar decisões sobre sistemas de remediação e avaliação de risco. Uma alternativa para quantificar a mobilidade é o parâmetro transmissividade de LNAPL, ainda pouco aplicado no Brasil. Esse trabalho avaliou a aplicabilidade desse parâmetro em diferentes áreas contaminadas por LNAPL. Foram realizados testes em três áreas com litologias, tipos de contaminantes e históricos de contaminação distintos. Em alguns testes, não foi possível determinar a transmissividade de LNAPL devido à instabilidade do nível de fluidos, por consequência da operação de sistemas de bombeamento e precipitação, além de problemas operacionais durante a realização do teste. Apesar de ser um teste simples, em alguns casos, a determinação de transmissividade de LNAPL pode ser inviável, principalmente para LNAPL de baixa mobilidade por requerer testes mais prolongados. Os principais fatores determinantes no valor de transmissividade de LNAPL foram a litologia, a posição do poço na pluma e a posição do nível d'água em relação a série histórica. Assim, a transmissividade de LNAPL pode ser um parâmetro útil no gerenciamento de áreas contaminadas, cuja interpretação deve ser feita de forma cautelosa e integrada com outros dados de investigação da área.
ABSTRACT Light non-aqueous phase liquids (LNAPL), such as liquid fuels, are present in many contaminated sites. To adequately manage these sites, it is important to know the product mobility, to support decisions on remediation systems and risk assessment. One alternative to quantify mobility is to quantify the LNAPL transmissivity, which is rarely applied in Brazil. This work aimed to evaluate the applicability of this parameter in LNAPL contaminated sites with different conditions. Tests were performed in three sites, with different lithologies, types of contaminants and contamination histories. In some tests, it was not possible to obtain representative values of LNAPL transmissivity due to fluids levels instability, caused by pumping systems and precipitation events, and operational problems during the tests. Despite being a simple test, in some cases, the determination of LNAPL transmissivity may not be feasible, especially for low mobility LNAPLs, that require long period tests. The main factors controlling LNAPL transmissivity values were lithology, position of the well in the plume, and water level elevation in relation to the historical series. Thus, LNAPL transmissivity can be a useful parameter in the management of contaminated sites, but its interpretation must be made cautiously and integrated with other site data.
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Glyphosate has become the most commonly used herbicide worldwide and is reputedly environmentally benign, nontoxic, and safe for use near wildlife and humans. However, studies indicate its toxicity is underestimated and its persistence in the environment is greater than once thought. Its actions as a neurotoxin and endocrine disruptor indicate its potential to act in similar ways to persistent organic pollutants such as the organochlorines dichlorodiphenyltrichloroethane (DDT) and dioxin. Exposure to glyphosate and glyphosate-based herbicides for both wildlife and people is likely to be chronic and at sublethal levels, with multiple and ongoing exposure events occurring in urban and agricultural landscapes. Despite this, there has been little research on the impact of glyphosate on wildlife populations, and existing studies appear in the agricultural, toxicology, and water-chemistry literature that may have limited visibility among wildlife biologists. These studies clearly demonstrate a link between chronic exposure and neurotoxicity, endocrine disruption, cell damage, and immune suppression. There is a strong case for the recognition of glyphosate as an emerging organic contaminant and substantial potential exists for collaborative research among ecologists, toxicologists, and chemists to quantify the impact of glyphosate on wildlife and to evaluate the role of biosentinel species in a preemptive move to mitigate downstream impacts on people. There is scope to develop a decision framework to aid the choice of species to biomonitor and analysis methods based on the target contaminant, spatial and temporal extent of contamination, and perceived risk. Birds in particular offer considerable potential in this role because they span agricultural and urban environments, coastal, inland, and wetland ecosystems where glyphosate residues are known to be present.
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Aves , Contaminantes Ambientales/toxicidad , Glicina/análogos & derivados , Herbicidas/toxicidad , Especies Centinela , Animales , Animales Salvajes , Glicina/toxicidadRESUMEN
Biochemical processes involving insulin and its receptor are responsible for regulating carbohydrate and fat metabolism. Disruption of these signaling pathways could lead to obesity, insulin resistance and diabetes, among other health problems. Diabetes has a global impact and its high prevalence has been associated with genetic and environmental factors. Recently, there has been a strong interest in establishing the relationship between type II diabetes and exposure to environmental contaminants, particularly persistent organic pollutants (POPs). This association has is based on epidemiological evidence and results from in vitro and in vivo experiments. In this review, the authors present some of the epidemiological aspects of diabetes, the biochemical pathways involved in insulin action, and how these environmental toxicants have impacted on population, through diverse mechanisms, to produce this disease. While several authors consider that the etiology of diabetes has a very important component derived from exposure to environmental pollutants, it is clear that there is still a substantial amount of work to develop in order to identify cause-effect relationships and the mechanisms involved.
Los procesos bioquímicos que involucran la insulina y su receptor son los responsables de regular el metabolismo de carbohidratos y grasas. La alteración de estas vías de señalización puede conllevar a obesidad, resistencia a la insulina y diabetes, entre otros problemas de salud. La diabetes impacta a nivel global y su alta prevalencia ha sido asociada con factores genéticos y ambientales. Recientemente ha surgido un amplio interés por establecer la relación existente entre la diabetes tipo 2 y la exposición a contaminantes ambientales, en especial los compuestos orgánicos persistentes (COPs). Esta asociación está basada en evidencia epidemiológica y resultados de experimentos in vitro e in vivo. En esta revisión los autores presentan algunos de los aspectos epidemiológicos de la diabetes, las rutas bioquímicas que participan en la acción de la insulina, y como estos tóxicos ambientales han impactado sobre la población, a través de diversos mecanismos, para producir esta enfermedad. Si bien algunos autores consideran que la etiología de la diabetes tiene un componente importante derivado de la exposición a contaminantes ambientales, es claro que aún falta mucho por desarrollar para identificar verdaderas relaciones causa-efecto y los mecanismos involucrados.
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Humanos , Receptor de Insulina , Contaminantes Orgánicos , Diabetes Mellitus/epidemiología , InsulinaRESUMEN
La ciudad de León cuenta con 500 empresas de curtiduría y 9 dedicadas al procesamiento del sebo cuyos subproductos (descarne) son desechos que se vierten al medio ambiente en grandes cantidades, ya que no representan un interés para su procesamiento y comercialización, lo que ha causado diversos problemas de contaminación en las zonas habitacionales circundantes por el vertido de aguas residuales, residuos sólidos y emisiones atmosféricas. El impacto al medio se puede considerar como adverso, directo y temporal; reversible, pero con un alto costo económico, lo que implica la necesidad de establecer medidas preventivas de control y mitigación. En el presente estudio se describen las etapas delproceso, las buenas y malas prácticas, los procedimientos estándares de operación y los impactos al medio ambiente originados por el inadecuado manejo de los residuos de las industrias sebaderas. Los resultados muestran que el 80 por ciento de las empresas procesadoras carece de sistemas de almacenamiento adecuado y no poseen sistemas de control ambiental. De igual manera, la mayoría de los operarios no cuenta con equipos de protección personal y no existe un adecuado manejo de sustancias utilizadas en los procesos, lo que incrementa el riesgo de accidentes laborales.
The city of León has 500 tannery companies and nine work in fat processing, whose by-product waste (rawhide) is dumped to the environment in tons because there is no interest in processing and commercializing this substance. This situation has caused several contamination problems in surrounding residential areas because ofthe discharge of wastewater, solid waste, and atmospheric emissions. Impact on environment can be considered as adverse, direct and temporal, as well reversible, but excessively expensive, which involvesthe need of established preventive measures of control and mitigation.The present study describes the different stages of the process, goodand bad practices, standard operational procedures, and environmentalimpacts due to the inadequate handling of waste by these companies. Results show that 80 percent of the processing companies lack appropriate storage systems and do not have an environmental control system. Additionally, most of the operators do not have personal protective equipment and there is not a proper handling of the substances used in processes; this increases the risk of work-related accidents.
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Contaminación Ambiental , Riesgos Ambientales , Impactos de la Polución en la Salud , Curtiembre , Exposición Profesional , Contaminantes Orgánicos , Recolección de Datos , MéxicoRESUMEN
Los contaminantes orgánicos persistentes poseen propiedades tóxicas, son resistentes a la degradación, se bioacumulan y son transportados por el aire, el agua y las especies migratorias a través de las fronteras internacionales; en consecuencia se depositan lejos del lugar de su liberación, acumulándose en ecosistemas terrestres y acuáticos. Para atender a esta problemática a nivel mundial se firmó el 23 de mayo de 2001 el Convenio de Estocolmo. Aunque por ahora los COP estan prohibidos en la mayoria de los países, todavía existen en el mundo muchos sitios contaminados con estas sustancias. La remediación de sitios que presentan contaminantes orgánicos persistentes requiere consideraciones distintas a las contempladas en la recupe-ración por contaminación de hidrocarburos. El siguiente texto revisa la literatura sobre la biodegradación anaeróbica y aeróbica de los bifeniles policlorados (PCB) y las posibles estrategias para estimular dicha biodegradación. La degradación de los demás COP será descritas en textos adicionales.
Persistent organic pollutants are chemicals that are toxic to humans and wildlife, remain intact in the environment for long periods, accumulate in living organisms and can become widely distributed geographically by air, water or migrating species. As a result, these contaminants have been found all over the world including in places, such as the Polar Regions, which are very far from their application site. The Stockholm Convention was signed in 23/5/01 in order to cope with this international environmental problem. Although POPs were banned by most countries, there are still a lot of sites contaminated with these substances. The remediation of these sites is problematic and requires distinct considerations from those which are established for hydrocarbon remediation. This manuscript reviews the literature about anaerobic and aerobic biodegradation of polychlorinated biphenyls (PCB) and possible strategies to stimulate these processes. The degradation of the other POPs would be reviewed in additional texts.
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An international team of scientists from government agencies and universities in the United States, U.S. Virgin Islands (USVI), Trinidad & Tobago, the Republic of Cape Verde, and the Republic of Mali (West Africa) is working together to elucidate the role Saharan dust may play in the degradation of Caribbean ecosystems. The first step has been to identify and quantify the persistent organic pollutants (POPs), trace metals, and viable microorganisms in the atmosphere in dust source areas of West Africa, and in dust episodes at downwind sites in the eastern Atlantic (Cape Verde) and the Caribbean (USVI and Trinidad & Tobago). Preliminary findings show that air samples from Mali contain a greater number of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and in higher concentrations than the Caribbean sites. Overall, POP concentrations were similar in USVI and Trinidad samples. Trace metal concentrations were found to be similar to crustal composition with slight enrichment of lead in Mali. To date, hundreds of cultureable micro-organisms have been identified from Mali, Cape Verde, USVI, and Trinidad air samples. The sea fan pathogen, Aspergillus sydowii, has been identified in soil from Mali and in air samples from dust events in the Caribbean. We have shown that air samples from a dust-source region contain orders of magnitude more cultureable micro-organisms per volume than air samples from dust events in the Caribbean, which in turn contain 3-to 4-fold more cultureable microbes than during non-dust conditions. Rev. Biol. Trop. 54 (Suppl. 3): 9-21. Epub 2007 Jan. 15.
Un grupo internacional de agencias gubernamentales y universidades de los Estados Unidos, las Islas Vírgenes (EUA), Trinidad y Tobago, la República de Cabo Verde y la República de Mali (África Oeste), está trabajando en conjunto para elucidar el papel que el polvo del Sahara puede estar jugando en el deterioro de los ecosistemas caribeños. El primer paso ha sido identificar y cuantificar los Contaminantes Orgánicos Persistentes (POPs, por sus siglas en inglés), los metales traza y los microorganismos viables presentes en la atmósfera de las áreas fuente de polvo de África occidental y en áreas ubicadas en la dirección del viento, como el Atlántico este (Cabo Verde) y el Caribe (IVEUA y Trinidad y Tobago), durante los episodios de transporte de polvo. Resultados preliminares indican que las muestras de aire de Mali contienen mayor número y mayores concentraciones de pesticidas, bifenilos policlorinados (PCBs) e hidrocarburos policíclicos aromáticos (PAHs) que las de los sitios del Caribe. Las concentraciones de POPs fueron similares en las muestras de USVI y de Trinidad. Se encontró que las concentraciones de metales traza fueron similares a las de la composición de la corteza, con un ligero enriquecimiento de plomo en Mali. Hasta la fecha, cientos de microorganismos cultivables han sido identificados en las muestras de Mali, Cabo Verde, IVEUA y Trinidad. Hallamos el patógeno de los abanicos de mar, Aspergillus sydowi, en las muestras de aire de Mali y en las muestras del Caribe durante polvaredas. Hemos demostrado que las muestras de aire provenientes de una región fuente de polvo, contienen más microorganismos cultivables por volumen -en órdenes de magnitud- que las muestras de aire tomadas en polvaredas en el Caribe, las cuales a su vez contienen tres a cuatro veces más microorganismos cultivables que aquellas tomadas cuando no hay polvaredas.
