Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 496: 165-178, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25079235

RESUMO

Concentrations of PAHs, PCBs and OCPs in sediments and mussels (caged and/or native) were determined at 16 stations in six major sites of coastal Turkey. The biological effects of pollution were evaluated using sediment toxicity tests and enzyme activity assays. EROD, PROD, GST, AChE, CaE, and GR activities were evaluated using the digestive glands of mussels. The total PAH concentrations in the sediments varied between nd and 79,674 ng g(-1) dw, while the total OCP concentrations were in the range of nd to 53.7 ng g(-1) dw. The total PAH concentrations in mussels varied between 22.3 and 37.4 ng g(-1) ww. The average concentrations of total PCBs in mussels were 2795 pg g(-1) ww in the shipyard, 797 pg g(-1) ww in Marina 2 and 53 pg g(-1) ww in Marina 1 stations. The results of whole-sediment toxicity tests showed a strong correlation between toxicity test results and pollutant concentrations. Selected cytosolic enzyme activities in digestive glands differed significantly depending on localities. These differences in enzyme activities were mainly related to the different pollutant levels of the sampling sites. The micro-organic contaminant profile patterns, toxicity tests and biomarker studies showed that shipyards and shipbreaking yards are the major potential sources of organic pollution in coastal areas.


Assuntos
Bivalves/fisiologia , Navios , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores , Monitoramento Ambiental , Sedimentos Geológicos/química , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Testes de Toxicidade , Turquia , Poluentes Químicos da Água/análise
2.
Environ Int ; 73: 85-93, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25108068

RESUMO

Triolein-containing semipermeable membrane devices (SPMDs) and butyl rubber (BR) based sorbents were employed as passive samplers in 14 coastal stations of Turkey including shipyards and marinas to characterize time-integrated levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) and their relationship to potential pollution sources. Passive samplers of SPMDs and BR sorbents were deployed for 30days in the spring of 2012. The maximum concentrations of total PAH and PCB compounds sequestered by SPMDs were 3338 ng g(-1) SPMD and 4247 pg g(-1) SPMD. (END)-I and DDT-related compounds were dominant OCP compounds for most of the sites in passive samplers. Total PAH concentrations in SPMDs were found 1.2 to 8 times higher than the concentrations in BRs. However, BR sorbents were able to sample some PAHs which could not be sampled by SPMDs. The concentrations of PCBs and OCPs in BRs were similar or higher than SPMDs. SPMD-data were used to estimate the average ambient water concentrations of the contaminants. Two existing theoretical approaches have been used to derive the concentrations of hydrophobic pollutants in the ambient waters. The results were found very similar and range from 7318 to 183864 pg L(-1) for PAHs, from 2 to 186 pg L(-1) for PCBs, and from 98 to 848 pg L(-1) for OCPs. Furthermore, a simple numerical model was designed to estimate the boat-related water concentrations in marinas by using the seawater data supplied by SPMDs. The model was mainly built on the water concentration and the capacities of a particular marina and then applied to two sites in the second marina. A good correlation was found between the model outputs and SPMD-water data.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Poluição Ambiental , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Água do Mar/química , Navios
3.
Toxicol In Vitro ; 28(5): 1036-45, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24794256

RESUMO

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) are persistent, toxic, and bioaccumulate in the environment. Due to their high analytical costs, these compounds are hardly regulated and mostly not monitored in the Third World. To overcome this, bioassays have been proposed as low-cost alternative methods. Two of the most established bioanalytical tools, the dioxin antibody-based enzyme-linked immunosorbent assay ELISA and the micro-EROD bioassay are evaluated and compared to high resolution gas chromatography and high resolution mass spectrometry (HRGC/HRMS) analytical methodology. The methods were tested using thirteen soils and sediment samples selected from diverse sites in Montevideo, Uruguay. The WHO2005 total toxic equivalent (WHO2005-TEQ) of soils ranged from 2.4 to 2212 (ng WHO2005-TEQ/kg dry sample) and from 0.14 to 9.4 (ng WHO2005-TEQ/kg dry sample) in sediments. This study shows significant contamination related to dioxin-like compounds, particularly in sites where uncontrolled burnings were carried out. ELISA and micro-EROD bioassay correlated well with HRGC/HRMS, R Spearman 0.773 and 0.913, respectively and were highly correlated to each other, R Spearman 0.879. Preliminary threshold values of bioassay toxic equivalents of 330 (ng/kg dry sample) for the micro-EROD bioassay and 220 (ng/kg dry sample) for ELISA are proposed.


Assuntos
Benzofuranos/toxicidade , Bioensaio , Citocromo P-450 CYP1A1/metabolismo , Bifenilos Policlorados/toxicidade , Dibenzodioxinas Policloradas/análogos & derivados , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Benzofuranos/análise , Dibenzofuranos Policlorados , Ensaio de Imunoadsorção Enzimática , Cromatografia Gasosa-Espectrometria de Massas , Sedimentos Geológicos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Dibenzodioxinas Policloradas/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Uruguai , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Mar Pollut Bull ; 70(1-2): 258-65, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23523120

RESUMO

Water concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were estimated from semipermeable membrane devices (SPMDs) and from sediment pollutant concentrations. SPMDs were deployed in the Istanbul Strait and Marmara Sea and retrieved after 7 and 21 days. Performance reference compounds (PRCs) were used to determine the site-specific sampling rates of the compounds. Water concentrations (C(w)) of the analyzed compounds estimated by using two different calculation methods for SPMDs were found similar. C(w) of total PAHs estimated from SPMDs (C(w-spmd)) were found between 13 and 79 ng L⁻¹ and between 7.0 and 68 ng L⁻¹ for 7 and 21 days of deployments respectively. Water concentrations of PCBs using sediment data was found as between 0.001 and 11.0 ng L⁻¹. The highest value of C(w-spmd) for two deployments were 2.8 ng L⁻¹ for OCPs. C(w) estimated from sediment concentrations were generally higher than those estimated from SPMDs.


Assuntos
Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/química , Praguicidas/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Hidrocarbonetos Clorados/análise , Membranas Artificiais
5.
Environ Sci Pollut Res Int ; 19(4): 1341-4, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22012199

RESUMO

Water of good quality is one of the basic needs of human life. Worldwide, great efforts are being undertaken for an assured water supply. In this respect, one of the largest water technology projects worldwide is the Yangtze Three Gorges Dam in China. There is a need for extensive scientific and technical understanding of the challenges arising from this large hydrological engineering project. German and Chinese groups from various scientific fields are collaborating to provide knowledge for the sustainable management of the reservoir. In this project description, the Yangtze Three Gorges Dam Project, its goals and challenges, are described in brief, and the contributions of the German research projects are presented.


Assuntos
Conservação dos Recursos Naturais , Cooperação Internacional , Abastecimento de Água , China , Meio Ambiente , Monitoramento Ambiental , Alemanha , Projetos de Pesquisa
6.
Artigo em Inglês | MEDLINE | ID: mdl-21707265

RESUMO

The aim of this study is to obtain data on the exposure of non-breast-fed infants to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), polychlorinated biphenyls (PCB), organochlorine pesticides (OCP), and bisphenol A (BPA) and its chlorinated derivatives through consumption of commercial infant foods with largest shares of the market in 22 European Union countries. The E-Screen bioassay was employed to assess the oestrogenicity of the baby foods and the ethoxyresorufin-O-deethylase (EROD) induction was measured to determine the levels of PCDD/F and PCB. Consequently, the highest total effective xenoestrogen burden (TEXB) of 73.60 pM Eeq g(-1) was found in the soy-based formula and the EROD bioassay was always below the limit of quantification (LOQ) (3.5 pg g(-1)). Overall, the estimated dietary exposure to BPA via commercial baby foods was lower than the tolerable daily intake (TDI) of 50 µg kg(-1) body weight (bw). Furthermore, the findings indicated that the dietary exposure of 0-9-month-old infants through the products investigated here does not exceed the maximum TDI of 4 pg WHO-TEQ (toxic equivalents) kg(-1) bw. However, exposure to more than 2 pg WHO-TEQ kg(-1) bw day(-1) might occur for 0-4-month-old infants consuming 'starting' hypoallergenic formula. Moreover, analysis of OCP indicated that the dietary exposure of non-breast-fed infants was not harmful. Considering the importance of early development and the vulnerability of infants and children, it is essential to determine their dietary exposure to contaminants in order to decide which efforts of risk reduction should receive highest priority.


Assuntos
Benzofuranos/toxicidade , Exposição Ambiental , Alimentos Infantis , Praguicidas/toxicidade , Fenóis/toxicidade , Dibenzodioxinas Policloradas/análogos & derivados , Compostos Benzidrílicos , Aleitamento Materno , Dibenzofuranos Policlorados , Europa (Continente) , Humanos , Lactente , Dibenzodioxinas Policloradas/toxicidade
7.
Mar Pollut Bull ; 63(5-12): 471-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21429532

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants due to their persistence and bioaccumulation potential both in organisms and in sediments. In this study, bioaccumulation and depuration experiments were performed employing local Mediterranean mussel species, Mytilus galloprovincialis, with two biomarkers: filtration rate and lysosomal stability (neutral red retention) assay. Benzo(a)anthracene (BaA) was chosen as the model PAH compound due to its common presence in several matrices in the marine environment. Bioconcentration Factors (BCFs) for the mussels exposed to different BaA concentrations were calculated from both kinetic rate constants and from the experimental data and found between 27-3184 and 16-2745, respectively. Experimental QSAR values were found comparable to the previous QSAR models created for BaA. The effect of BaA exposure on the mussels showed a more clear dose-response relationship according to the results of lysosomal stability compared to the filtration rate.


Assuntos
Benzo(a)Antracenos/metabolismo , Mytilus/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Cinética , Água do Mar/química
8.
Environ Monit Assess ; 176(1-4): 51-65, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20563639

RESUMO

This study was conducted to determine the status and trends of organochlorine pesticide (OCP) compounds in the sediment and mussel samples collected along the Istanbul Strait and from the coasts of an island in the Marmara Sea. The total concentrations of OCPs were found in the range of 40-13,852 pg g(-1) dry weight for sediments and 5,195-12,322 pg g(-1) wet weight for mussels. The levels of OCPs in both sediments and mussels were dominated by DDTs and HCHs; ß-HCH, 4,4(')-DDD and 4,4(')-DDE were the major pollutants. The degree of sediment pesticide contamination was more severe in the inner part of the strait. OCP concentrations in sediments and mussels were compared with the sediment guideline values and legal limits for human health, respectively. The results showed that OC pesticide contamination in the strait might not pose a serious threat to the health of the marine inhabitants at most of the stations.


Assuntos
Bivalves/metabolismo , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Diclorodifenil Dicloroetileno/análise , Diclorodifenildicloroetano/análise , Hexaclorocicloexano/análise , Oceanos e Mares
9.
Chemosphere ; 81(8): 1018-21, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20932547

RESUMO

In infant period, human milk and infant formulae are the major sources of exposure to dioxins (polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCB). Since in many parts of Europe the mothers are increasingly reluctant to breastfeed their babies, the main objective of the present study is to assess the level of exposure of non-breast-fed infants during their early development. Consequently, the concentration levels of PCDD/F and dioxin-like PCB were determined in industrial infant formulae including "starting" (aged 0-4months) and "follow-on" (after 4months) products of milk formula, soy formula and hypoallergenic infant formula, available on the EU market. Furthermore, dietary exposure to dioxin of exclusively formula-fed infants was assessed at each month from 0 to 9months. The results suggest that dietary exposure to dioxins via formulae is higher when consuming "starting" than "follow-on" infant formulae on a body-weight basis. Estimated dietary exposure after 4months of age was always below the lowest range of the Tolerable Daily Intake (TDI) of 1pg WHO-TEQkg(-1)bwd(-1) and Provisional Tolerable Monthly Intake (PTMI) of 70pg WHO-TEQkg(-1)bwmonth(-1). The highest estimated cumulative dietary exposure to PCDD/F and dioxin-like PCB was obtained considering infants of 0-1months fed with the "starting" hypoallergenic infant formula (2.8pg WHO-TEQkg(-1)bwd(-1) and 84pg WHO-TQkg(-1)bwmonth(-1)). However, these elevated levels are much lower than those observed in some studies in breast-fed infants. The study can be used for further risk assessments in regard to infant exposure.


Assuntos
Benzofuranos/análise , Poluentes Ambientais/análise , Fórmulas Infantis/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzofuranos Policlorados , Dioxinas/análise , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , União Europeia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Dibenzodioxinas Policloradas/análise
10.
Environ Pollut ; 157(12): 3238-47, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19596160

RESUMO

In forest soils along vertical profiles located in different parts of the Alps, concentrations of persistent organic pollutants (POPs), namely organochlorine pesticides (OCPs) like dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), heptachlor, aldrin, dieldrin and mirex, were measured. Though local characteristics of the sites are influenced by numerous factors like orographic and meteorological parameters, forest stand characteristics and humus parameters, we ascertained a marked vertical increase of concentrations of some organochlorine compounds in the soil. On the basis of climatological values of each site, we found that the contamination increase with altitude can be ascribed to a certain 'cold condensation effect'. In addition, the perennial atmospheric deposition of POPs is controlled by precipitation. Other key parameters explaining the accumulation of POPs are the soil organic carbon stocks, the turnover times, the re-volatilisation and degradation processes, which vary with altitude.


Assuntos
Poluentes Atmosféricos/química , Atmosfera/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes do Solo/análise , Altitude , Monitoramento Ambiental , Humanos
11.
Environ Pollut ; 157(12): 3272-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19552989

RESUMO

Atmospheric sampling of organochlorine pesticides (OCPs) was conducted using Semi Permeable Membrane Devices (SPMDs) deployed in the Alps at different altitudinal transects for two consecutive exposure periods of half a year and a third simultaneous year-long period. Along all the altitude profiles, the sequestered amounts of OCPs increased in general with altitude. SPMDs were still working as kinetic samplers after half a year for the majority of the OCPs. However, compounds with the lowest octanol-air partition coefficient (K(oa)), reached equilibrium within six months. This change in the SPMD uptake was determined for the temperature gradient along the altitude profile influencing K(oa), OCPs availability in the gaseous phase, and SPMD performance. In sum, it seems two effects are working in parallel along the altitude profiles: the change in SPMD performance and the different availability of OCPs along the altitudinal transects determined by their compound properties and concentrations in air.


Assuntos
Métodos Analíticos de Preparação de Amostras/instrumentação , Monitoramento Ambiental/instrumentação , Hidrocarbonetos Clorados/química , Praguicidas/química , Adsorção , Altitude , Europa (Continente) , Cinética , Membranas Artificiais , Estações do Ano
12.
Chemosphere ; 76(2): 159-66, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19394673

RESUMO

Sediment and mussel samples collected along the coasts of the Istanbul strait and an island in Marmara Sea (Turkey) were analyzed for six indicator polychlorinated biphenyl (PCB), 12 dioxin-like PCB (dl-PCB) and 17 polychlorinated dibenzo-p-dioxin/furan (PCDD/F) congeners. Samples contained different concentrations of PCBs and among these, congeners 153, 75, 105 and 118 in sediments and congeners 153, 138 and 118 in mussels were most abundant. The concentration levels of total PCBs and PCDD/Fs in sediments ranged from 17.9 to 539746 pg g(-1)dm and 2.04 to 60.5 pg g(-1)dm, respectively. The total WHO-TEQ values ranged between 0.01 and 17.8 pg g(-1)dm in sediments, and 0.98 and 1.01 pg g(-1)ww in mussels. None of the sediment and mussel samples analyzed exceeded the limits suggested in the sediment quality guideline and safe values set by the European Community for seafood intended for human consumption, respectively.


Assuntos
Benzofuranos/análise , Bivalves/química , Poluentes Ambientais/análise , Sedimentos Geológicos/química , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Animais , Benzofuranos/toxicidade , Dibenzofuranos Policlorados , Monitoramento Ambiental , Poluentes Ambientais/toxicidade , Bifenilos Policlorados/toxicidade , Dibenzodioxinas Policloradas/análise , Dibenzodioxinas Policloradas/toxicidade , Turquia
13.
Environ Int ; 35(3): 599-606, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19128832

RESUMO

Surficial sediments and mussels (Mytilus galloprovincialis) from the Istanbul Strait and Marmara Sea were analysed for sixteen parent polycyclic aromatic hydrocarbon (PAH) contents by gas chromatography-mass spectrometry (GC-MS) employing isotope dilution technique. Microalgae toxicity testing was applied to sediment elutriates and biological responses in terms of filtration rate and lysosomal stability were measured in mussels. Total PAH concentrations ranged from 2.1 to 3152 ng g(-1) dry wt in sediments and from 43-601 ng g(-1) wet weight in mussels. Molecular indices of phenanthrene/ anthracene, fluoranthene/pyrene and benzo(a)anthracene/chrysene were used to differentiate between pyrolytic and petroleum origin. Results showed that most of the contamination originates from high temperature pyrolytic inputs with some slight contribution of petrogenic PAH. PAH in sediments were frequently lower than the National Oceanic and Atmospheric Administration (NOAA)-ERM (Effects Range Medium) index. Results of sediment elutriate toxicity testing and biomarkers indicate that the cause of negative effects in sediments may result from different classes of pollutants and does not only relate with PAH contamination. Mussels from most of the stations showed both reduced lysosomal membrane stability and filtration rate indicating disturbed health although the two biomarker results did not always complement each other. The effect studies showed that the pollutants in the strait ecosystem have more pronounced effects in the middle parts than those at the Black Sea entrance.


Assuntos
Eucariotos/efeitos dos fármacos , Sedimentos Geológicos/química , Mytilus/química , Mytilus/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Água do Mar/química , Animais , Sobrevivência Celular , Cromatografia Gasosa-Espectrometria de Massas , Membranas Intracelulares/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Oceanos e Mares
14.
Chemosphere ; 71(2): 369-78, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17931686

RESUMO

Concentrations of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB) in Baltic Sea fish like herring (Clupea harengus membras), sprat (Sprattus sprattus balticus), perch (Perca fluviatilis), pikeperch (Sander lucioperca) and flounder (Platichthys flesus trachurus) collected from four areas of the Estonian coastal waters are reported. All samples are studied for their relationship between the length (cm) and wet weight (g); length (cm) and age (years); lipid content and dry matter. The level of PCDD/F and PCB concentrations in younger 1-5 years old Baltic herring and sprat collected in 2002-2005 from the eastern and central parts of the Gulf of Finland, Gulf of Riga and Open Baltic Sea (Central Baltic) is related to the fish age and compared with those found in the 1990s. In addition, PCDD/F and PCB concentrations of different age groups herring, sprat, perch, pikeperch and flounder collected in 2003-2004 from the Lake Peipsi, Gulf of Finland, Gulf of Riga and Open Baltic Sea are related also to their age. Consequently, it was manifested that in older Baltic fish the concentrations of PCDD/F and PCB were higher than in the younger age groups. By the help of principle component analysis (PCA) the effect of gender on the concentrations of PCDD/F for the juvenile Baltic herring and sprat collected in 2004-2005 is investigated for the first time. It was summarized that the biological factor age plays a large role for the contamination of the fish with important toxic organohalogenated compounds such as PCDD/F.


Assuntos
Benzofuranos/farmacocinética , Peixes/metabolismo , Bifenilos Policlorados/farmacocinética , Dibenzodioxinas Policloradas/análogos & derivados , Poluentes Químicos da Água/farmacocinética , Fatores Etários , Animais , Países Bálticos , Benzofuranos/análise , Tamanho Corporal , Peso Corporal , Dibenzofuranos Policlorados , Finlândia , Identidade de Gênero , Oceanos e Mares , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Dibenzodioxinas Policloradas/farmacocinética , Poluentes Químicos da Água/análise
15.
Environ Res ; 105(3): 300-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17706191

RESUMO

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) are sampled and investigated in a forested area in Middle-Europe. The campaigns, consisting in active and passive samplings, were conducted in the Bavarian and Bohemian Forest at four sites chosen for their similar soil and forest stand characteristics. Passive sampling was conducted using both semi-permeable membrane devices (SPMDs) and needles of well-exposed dominant spruce trees. Active air sampling was also performed at one site with a low volume air sampler. Correlations were performed to identify relationships and trends of PCDD/F. Lower chlorinated PCDD/F are accumulated in SPMDs, needles collected all compounds among homologues and their PCDD/F pattern is close to that of active sampling. Results of the analysed compounds obtained with the different sampling methods served as a basis for the establishment of advantages and disadvantages of the sampling tools applied and their possible optimisation.


Assuntos
Benzofuranos/análise , Membranas Artificiais , Picea/química , Dibenzodioxinas Policloradas/análogos & derivados , Poluentes do Solo/análise , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Benzofuranos/química , Dibenzofuranos Policlorados , Monitoramento Ambiental , Alemanha , Permeabilidade , Folhas de Planta/química , Dibenzodioxinas Policloradas/análise , Dibenzodioxinas Policloradas/química
17.
Sci Total Environ ; 322(1-3): 231-41, 2004 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-15081751

RESUMO

Photodegradation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce (Picea abies (L.) Karst.) needles was investigated. The role of sunlight and, in particular, the role of short wavelength UV-B radiation were studied in a sun simulator under controlled environmental conditions. The photodegradation of PCDD/Fs and PAHs follows first-order kinetics. Simulated sunlight containing UV-B induced two phases of photodegradation kinetics for PCDD/Fs, whereas no distinct phases of the kinetics were observed for PAHs. UV-B radiation plays a much more important role on the photodegradation for PCDD/Fs than that for PAHs. Direct photolysis dominates the photodegradation of PCDD/Fs and PAHs.


Assuntos
Benzofuranos/química , Picea/química , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/química , Hidrocarbonetos Policíclicos Aromáticos/química , Raios Ultravioleta , Adsorção , Benzofuranos/análise , Dibenzofuranos Policlorados , Cinética , Fotólise , Folhas de Planta/química , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise
18.
Aquat Toxicol ; 62(4): 305-19, 2003 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-12595170

RESUMO

The branched isomers of p-nonylphenol (NP) are perceived to be more resistant to biodegradation in aquatic environments as well as to have more estrogen-like toxicity than the straight chain isomers. By use of GC-MS, some of them have been identified and found to exist in higher concentrations in the isomeric compound mixture than the straight chain isomers. The investigations of the distribution and metabolism of these branched isomers in aquatic organisms are therefore considered to be important in understanding the mechanisms of toxicity of NP. A single tertiary isomer of NP, 4(3'-,6'-dimethyl-3'-heptyl)-phenol, was synthesized in the laboratory and used in in vivo studies of its organ distribution and metabolism in Lymnaea stagnalis L., following a constant exposure of the organisms to 14C-NP isomer in water over a period of 8 days at an average exposure concentration of 105 ppb (range: 93-116 ppb). The results obtained clearly showed the distribution and bioconcentration of the isomer residues in various internal organs of Lymnaea after uptake in water and food. Analysis of the extracts of the organ tissues and faeces by HPLC and GC-MS after digestion with Pankreatin/beta-glucuronidase and nitric acid, respectively, showed that the isomer was metabolized by conjugation to glucuronic acid and hydroxylation to a catechol. The findings from these studies and their implications in the biotransformation and estrogenicity of NP in Lymnaea stagnalis L. are further discussed in detail in this paper.


Assuntos
Lymnaea , Fenóis/metabolismo , Fenóis/farmacocinética , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão , Fezes/química , Cromatografia Gasosa-Espectrometria de Massas , Ácido Glucurônico , Hidroxilação , Isomerismo , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/fisiologia , Distribuição Tecidual
19.
Chemosphere ; 50(9): 1217-25, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12547335

RESUMO

Spruce (Picea abies (L.) Karst.) needles were exposed to exhaust gas containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) generated by combustion of polyvinyl chloride, wood, high-density polyethylene, and styrene. Photodegradation of PCDD/Fs adsorbed on spruce needles under sunlight irradiation was studied. The photodegradation of PCDD/Fs follows pseudo-first-order reaction kinetics, with photolysis half-lives ranging between 40 and 100 h. The photolysis rates of PCDF congeners are higher than PCDD congeners with the same chlorinated substitutions. Higher chlorinated PCDD/Fs tend to photolyze slowly. The wax components in spruce needles may act as proton donors and accelerate the photolysis rate. C-Cl cleavage through the addition of protons to PCDD/F molecules may be an important route for PCDD/Fs photodegradation.


Assuntos
Benzofuranos/efeitos da radiação , Poluentes Ambientais/efeitos da radiação , Fotólise , Picea/química , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/efeitos da radiação , Adsorção , Benzofuranos/análise , Dibenzofuranos Policlorados , Poluentes Ambientais/análise , Folhas de Planta/química , Dibenzodioxinas Policloradas/análise , Luz Solar , Fatores de Tempo
20.
Environ Pollut ; 122(2): 195-203, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12531307

RESUMO

A single tertiary isomer which is believed to be one of the major branched isomers of the isomeric nonylphenol was synthesized for use in investigations on its metabolism and estrogenicity in aquatic organisms. The physico-chemical properties of the isomer were determined to enable the prediction of its behaviour in aquatic environments. From laboratory investigations on its dissipation and distribution in lake water, which are reported in this paper, it was found that it had a half-life of dissipation of 38.1 days and 20.1 days in an open lake water and in an open lake water/ sediment system, respectively, and to be rapidly partitioned in to sediment giving a high concentration factor of 1.76 after 28 days with an initial dose concentration of 2.52 ppm. The main dissipation route was found to occur through volatilization and co-distillation. The isomer was, however, found to be resistant to biodegradation in both the lake water and sediment, showing only a slight 9% loss (after 56 days) and 4.2% loss (after 28 days), of the 14C-residues in lake water and lake water/sediment systems, respectively, by microbial activity. Transformation to other more polar metabolites possibly by hydroxylation was also found to be minimal in both lake water and sediment samples after 14 days by HPLC analysis. After 7 days, only 2.25 and 7.4% transformation to a more polar metabolite was detected in lake water and sediment samples, respectively.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Água Doce/química , Sedimentos Geológicos/química , Fenóis/análise , Biodegradação Ambiental , Meia-Vida , Isomerismo , Movimentos da Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...