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1.
Ambio ; 47(5): 574-584, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29243054

RESUMO

Brazil is currently one of the largest pesticide consumers worldwide. However, a lack of scientific information regarding airborne pollution is still an issue, with tragic consequences to human health and the environment. To reduce pollution of the lower air layers, where pesticide spraying occurs, green barriers that filter the air could be an effective mitigation procedure. Modifying pulverization habits, by pulverizing in the late afternoon instead of in the morning could also reduce pesticide volatilization, while other recommendations with the purpose of lowering the pesticide amounts currently applied are likewise pursued. Data obtained about volatilization have demonstrated that, in order to reduce air pollution risks, one of the most effective preventive strategies is to ban products with high vapor pressure. Global/local stakeholders need to assume the responsibility to find the best way to reduce airborne pesticide pollution, which has increasingly shown disastrous effects as major poisons to human health and the environment.


Assuntos
Praguicidas/química , Clima Tropical , Poluição do Ar , Brasil , Humanos , Volatilização
2.
J Environ Sci Health B ; 52(12): 843-849, 2017 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-28949807

RESUMO

Pesticide air pollution by spraying was evaluated under different temperature, humidity and wind climatic conditions in Brazil. Field experiments were performed with application towards the soil and in guava orchards, where spray dispersion was monitored by adding p-aminobenzoic acid (PABA), a fluorescent substance, as a tracer to the water contained in the spray tanks. Samples were collected with filter membranes (Whatman 180025), and the PABA was extracted from the filters by shaking with water in a Petri dish and measured in a spectrofluorometer. A spray aimed towards the soil with filters positioned on the ground and hung at different heights did not show different upward dispersion as observed when lateral pulverization was conducted. In this case, a tractor with a sprayer moved through a 3 m high and 6 m wide frame with filter membranes mounted at 60 cm intervals. Spray dispersion patterns were modified by guava leaf resistance. No influence of temperature and humidity was observed in this short-lived spraying process. Nevertheless, wind drift can occur during airborne dispersion and is an important pesticide pollution source which requires control. Droplets with PABA powered by assisted spraying upwards returned to the ground by gravity and, therefore, did not constitute a vertical source of atmospheric pollution.


Assuntos
Poluição do Ar/análise , Praguicidas/análise , Ácido 4-Aminobenzoico/análise , Agricultura/métodos , Poluentes Atmosféricos/análise , Brasil , Monitoramento Ambiental , Psidium , Clima Tropical , Vento
3.
Environ Technol ; 33(4-6): 695-701, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22629645

RESUMO

Organic micropollutants are often found in domestic and industrial effluents. Thus, it is important to learn their fate, the metabolites generated and their sorption during biological treatment processes. This work investigated the biodegradation of 14C-dicofol organochloride during wastewater aerobic treatment and sludge anaerobic biodigestion. The performance of these processes was evaluated by physical-chemical parameters. Radioactivity levels were monitored in both treatments, and residues of dicofol (DCF) and dichlorobenzophenone (DBP) were quantified by HPLC/UV. The efficiency of the aerobic and anaerobic processes was slightly reduced in the presence of DCF and DBP. After aerobic treatment, only 0.1% of DCF was mineralized, and 57% of radioactivity remained sorbed on biological sludge as DBP. After 18 days of anaerobiosis, only 3% of DCF and 5% of DBP were detected in the sludge. However, 70% of radioactivity remained in the sludge, probably as other metabolites. Dicofol was biodegraded in the investigated process, but not mineralized.


Assuntos
Bactérias Aeróbias/metabolismo , Bactérias Anaeróbias/metabolismo , Dicofol/metabolismo , Herbicidas/metabolismo , Resíduos Industriais/prevenção & controle , Esgotos/microbiologia , Purificação da Água/métodos , Biodegradação Ambiental , Radioisótopos de Carbono/isolamento & purificação , Radioisótopos de Carbono/metabolismo , Dicofol/isolamento & purificação , Herbicidas/isolamento & purificação , Marcação por Isótopo , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo
4.
J Environ Sci Health B ; 47(6): 505-11, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22494373

RESUMO

Pesticides applied on sugarcane reach the subsoil of riparian forests and probably contaminate the river water. This work was conducted to learn about the phytoremediation of atrazine and subsoil contamination using the common riparian forest species of Cecropia hololeuca Miq. and Trema micranta (L.) Blum. These plants were grown in soil microcosms where (14)C-atrazine at 1/10 of the field-recommended dose was applied at the bottom of the microcosm simulating the movement from contaminated ground water to the upper soil layers and into plants. Residues of (14)C-atrazine were detected in all parts of the microcosm including soil, rhizosphere and the roots in different layers of the microcosm, stem and leaves. Atrazine mineralization was higher (10.2%) in the microcosms with plants than the control microcosms without plants (1.2%). The upward movement of this pesticide from deeper to more superficial soil layers occurred in all the microcosms with plants, powered by evapotranspiration process. From the atrazine applied in this study about 45% was taken up by C. hololeuca and 35% by T. micrantha. The highest amount of radioactivity (%) was found in the fine roots and the specific radioactivity (% g(-1)) showed that thick, fine roots and leaves bioaccumulate atrazine. The enhanced mineralization of atrazine as well the phytostabilization effect of the tree biomass will reduce the bioavailability of these residues and consequently decrease the hazardous effects on the environment.


Assuntos
Atrazina/metabolismo , Cecropia (Planta)/metabolismo , Recuperação e Remediação Ambiental/métodos , Herbicidas/metabolismo , Poluentes do Solo/metabolismo , Árvores/metabolismo , Trema/metabolismo , Atrazina/análise , Biodegradação Ambiental , Herbicidas/análise , Raízes de Plantas/metabolismo , Poluentes do Solo/análise
5.
Braz. j. microbiol ; 39(2): 311-313, Apr.-June 2008. graf
Artigo em Inglês | LILACS | ID: lil-487710

RESUMO

The fate of organochlorine 14C-dicofol in activated sludge process was investigated. Results showed that the major part of radioactivity remained adsorbed on biological sludge. Consequently, its final disposal deserves special attention. The small amounts of dicofol, biotransformed or not, which remained in the treated effluent could contaminate receiving bodies.


A dinâmica do organoclorado 14C-dicofol no processo de lodos ativados foi investigada. Os resultados mostraram que a maior parte da radioatividade ficou adsorvida no lodo biológico. Consequentemente, o seu descarte final merece atenção especial. Pequenas quantidades de dicofol, biotransformadas ou não, permanecem no efluente tratado podendo contaminar os corpos receptores.


Assuntos
Lodos Ativados , Águas Residuárias , Esgotos Domésticos , Dicofol/análise , Dicofol/isolamento & purificação , Microbiologia Ambiental , Técnicas In Vitro , Inseticidas Organoclorados , Biotransformação , Métodos , Radioatividade
6.
J Environ Sci Health B ; 43(3): 214-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18368540

RESUMO

The fate of (14)C atrazine was investigated using microcosms and an undisturbed Red-Yellow Latossol (Oxisol) under simulated rainfall conditions of 200 mm water month(-1). Experiments were carried out using microcosm cores, the first with an uncovered surface soil; the second set with uncovered subsurface soil; the third with subsurface soil covered with 3 cm of cow manure and the last with subsurface soil covered with 5 cm of grass straw. Average values for the amount of atrazine leached after 60 days were as follows: surface soil 1.6%; subsurface 47.3%; subsurface plus manure 17.3% and subsurface plus straw 24.8%. In the surface soil, 53% of the (14)C atrazine remained within the upper 1 cm, while in the subsurface microcosms the atrazine was more evenly distributed. The authors report that surface soil was retained atrazine and its metabolites for 60 days. The addition of a straw or manure covering to exposed subsoil helped to retard atrazine leaching.


Assuntos
Atrazina/química , Herbicidas/química , Microbiologia do Solo , Poluentes do Solo/química , Adsorção , Atrazina/análise , Biodegradação Ambiental , Herbicidas/análise , Cinética , Esterco , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluição da Água
7.
Braz J Microbiol ; 39(2): 311-3, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24031222

RESUMO

The fate of organochlorine (14)C-dicofol in activated sludge process was investigated. Results showed that the major part of radioactivity remained adsorbed on biological sludge. Consequently, its final disposal deserves special attention. The small amounts of dicofol, biotransformed or not, which remained in the treated effluent could contaminate receiving bodies.

8.
J Environ Sci Health B ; 41(4): 415-25, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16753960

RESUMO

Microbial displacement in the soil is an important process for bioremediation and dispersal of wastewater pathogens. We evaluated cell movement in surface and subsurface red-yellow podzolic soil driven by advection and microbial motility and also survival of a microbial population at high pressure as is prevalent in deep soil layers. Pseudomonas fluorescens Br 12, resistant to rifampycin and kanamycin, was used as a model organism traceable in non-sterile soil. Our results showed that more than 40% of the P. fluorescens population survived under high pressure, and that microbial motility was not a major factor for its displacement in the soil. Cells were adsorbed in similar amounts to surface and subsurface soils, but more viable cells were present in the leachate of surface than in subsurface soils. The nature of this unexpected cell binding to the subsurface soil was studied by EPR, Mossbauer, NMR, and infrared techniques, suggesting iron had a weak interaction with microbes in soil. P. fluorescens movement in soil resulted mainly from convection forces rather than microbial motility. The transport of this bacterium along the transept toward groundwater encountered restricted viability, although it survived under high pressure conditions simulating those in deep soil layers.


Assuntos
Praguicidas/metabolismo , Pressão , Pseudomonas fluorescens/crescimento & desenvolvimento , Pseudomonas fluorescens/metabolismo , Microbiologia do Solo , Biodegradação Ambiental , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Dinâmica Populacional
9.
J Environ Sci Health B ; 41(5): 523-30, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16785164

RESUMO

Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl-14C] paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 microg paraquat g(-1) substrate. The action of the worms did not influence the loss of 14C from the substrates, as the 14C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.


Assuntos
Herbicidas/farmacocinética , Oligoquetos/metabolismo , Paraquat/farmacocinética , Poluentes do Solo/farmacocinética , Solo/análise , Animais , Biodegradação Ambiental , Bioensaio , Disponibilidade Biológica , Radioisótopos de Carbono , Relação Dose-Resposta a Droga , Monitoramento Ambiental/métodos , Herbicidas/metabolismo , Paraquat/metabolismo , Poluentes do Solo/metabolismo
10.
Environ Res ; 93(3): 316-27, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14615243

RESUMO

The closing down of a lindane factory near Rio de Janeiro, over 45 years ago, left an area heavily contaminated with hexachlorocyclohexane (HCH). Remediation by soil liming was applied by government authorities in 1995. This study aims to evaluate the HCH distribution and impact on soil microbiota due to contamination and liming. Microcosm experiments with uncontaminated soil mixed with HCH and lime indicated that lime-promoted dechlorination of HCH molecules led to leaching and volatilization of metabolites. The treatment applied transformed but did not solve the problem as most of the HCH remains in the soil. Reduced microbial respiratory activity was measured in contaminated field samples. Higher respiration rates in uncontaminated soil were reduced by HCH and lime addition; the sole addition of HCH caused a temporary increase in soil respiration, and stimulation occurred with oxygen and/or nutrient addition. A heterotrophic bacterial population around 10(9)CFU/g was found in polluted field soil, some well-known degraders having been isolated. Native soil microbiota showed resistance to high amounts of HCH and alkaline pH. The results allow considering bioremediation rather than chemical treatments to clean up the area.


Assuntos
Hexaclorocicloexano/análise , Hexaclorocicloexano/toxicidade , Inseticidas/análise , Inseticidas/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Bactérias , Biodegradação Ambiental , Compostos de Cálcio/química , Poluição Ambiental/prevenção & controle , Concentração de Íons de Hidrogênio , Óxidos/química , Dinâmica Populacional
12.
Ciênc. cult. (Säo Paulo) ; 43(3): 199-201, May-Jun. 1991. tab
Artigo em Inglês | LILACS | ID: lil-113833

RESUMO

O crescimento de 200 estirpes de Bacillus, isoladas de solos arenosos, argiloso e orgânico do Rio de Janeiro, foi inibido nas concentraçöes de 10 ppm de Kelthane e 100 ppm de Folidol, testadas com culturas puras. O gênero Bacillus representou uma parcela majoritária da populaçäo de bactérias heterotróficas nesses solos. O efeito dos pesticidas nas contagens microbianas em microcosmos e extrato de solo foi reduzido. Após as primeiras horas de exposiçäo as contagens foram reduzidas em concentraçöes de 100 e 500 ppm, voltando a valores estáveis durante 2 a 4 semanas de experimento. As populaçöes microbianas mistas no solo säo menos afetadas pelos pesticidas que os microorganismos em cultura pura


Assuntos
Bacillus/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Dicofol/farmacologia , Fungos/crescimento & desenvolvimento , Paration/farmacologia , Microbiologia do Solo , Brasil , Contagem de Colônia Microbiana , Fatores de Tempo
13.
Rev. latinoam. microbiol ; 30(2): 139-42, abr.-jun. 1988. ilus
Artigo em Inglês | LILACS | ID: lil-94119

RESUMO

Se efectos del Hg, Cd, zn y Pb en el crecimiento y actividad de nitrogenasa de Azospirillum spp, en un medio químicamente definido. A concentraciones de metal de 0.1 y l ppm se inhibió la actividad de nitrogenasa y el crecimiento, respectivamente. El Pb inhibe el 25% de lactividad de reducción de acetileno (ARA) con 1 ppmj, permaneciendo constante inclcusive con incrementos concentración. el crecimiento no se inhibió por el óxido ni el cloruro de plomo. El Zn inhibe el 50% de ARA con 1 ppm, permaneciendo constante con incrementos de concentración. Por otro lado el crecimiento se inhibió continuamente con incrementos de concentración. En contraste, con Hg y Cd, se inhibió el 50% de ARA a concentraciones menores (0.4 ppm) que las necesarias para inhibir el 50% de crecimiento (2.4 y 6 ppm, respectivamente). Se observó resistencia cuando se incubó 24hs. de crecimiento con Cd; la inhibición al 50% de ARA necesita una concentración de Cd de 18 ppm, valor que es mucho más alto comparado con 1 hora de incubación (0.4 ppm). Sin embargo, la enzima es más sensible al Cd que el crecimiento. Se discute la importancia de estos hallazgos en la contaminación ambiental


Assuntos
Poluição Ambiental , Metais , Fixação de Nitrogênio , Nitrogenase
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