Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Chemosphere ; 86(3): 264-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22018855

RESUMO

Decabromodiphenyl ethane (DPDPE) is a flame retardant that has been on the market for more than 20 years and is used as a replacement for decabromodiphenyl ether (BDE-209). Environmental data on DPDPE are scarce but for BDE-209, studies have shown that long-range transport in the atmosphere leads to contamination of remote regions. Given their similar physical-chemical properties, we hypothesized that this is also true for DPDPE. In this study we explored the European continent as a source for DBDPE by collecting air samples at a back-ground location in southern Sweden. Twelve samples with stable air mass back trajectories over the 24 h sampling period were analysed. BDE-209 and 5 polycyclic aromatic hydrocarbons (PAHs) were also included in the study. The concentration ranges of DBDPE and BDE-209 were similar, 0.077-7.9 and 0.093-1.8 pg m(-3) air, respectively. The highest concentrations were detected when the air originated from the European continent and the lowest during periods with rather stagnant air over southern Scandinavia. The concentrations of DBDPE and BDE-209 did not co-vary, indicating that there are different major sources of the two compounds. In air, the compounds measured in this study are predominantly associated with particles. PAHs in the atmosphere are known to originate primarily from combustion processes and their concentrations were highly correlated with several measures of atmospheric particle concentration, i.e. PM 10, PM 2.5, soot, and N 450 (number of particles in the size range approximately 420-450 nm). No clear correlations were found between the concentrations of DBDPE or BDE-209 and any of the measures of particle concentrations, indicating that the emissions of these are not related to the major sources of emissions of soot or small particles.


Assuntos
Poluentes Atmosféricos/análise , Bromobenzenos/análise , Éteres Difenil Halogenados/análise , Poluição do Ar/estatística & dados numéricos , Atmosfera/química , Monitoramento Ambiental , Material Particulado/análise , Suécia
2.
Environ Toxicol Chem ; 28(1): 9-17, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18717624

RESUMO

Previous analyses of 52 peregrine falcon (Falco peregrinus) eggs collected from two wild and one captive population in Sweden 1987 through 1999 were complemented by including additional polybrominated diphenyl ether (PBDE) congeners (BDE-35, -183, -184, -185, -196, -197, -203, and -207). In addition, 31 eggs not previously analyzed for hexabromocyclododecane (HBCD) and BDE-209 were analyzed for these. Geometric mean concentrations of BPBDEs, HBCD, and the hexabrominated biphenyl (BB-153) were 3,100, 140, and 81 ng/g of lipid weight for the southern population; 2,500, 110, and 84 ng/g of lipid weight for the northern population; and 47, not detected, and 8 ng/g of lipid weight for the captive population. The BDE congener pattern was dominated by BDE-153, -99, and -100. The results were used to investigate whether a difference in PBDE congener pattern could be distinguished between the two wild populations of peregrine falcons due to different diets, as the southern population preys mainly on birds belonging to the terrestrial food chain while the northern population preys more on aquatic birds. A multivariate t-test showed a subtle but significant (p < 0.001) difference in PBDE congener pattern between the two populations. However, our hypothesis that higher-brominated congeners of PBDEs would be present to a greater extent in the terrestrial food chain was not supported by principal component analysis. The average brood size for individual females from the southern population decreased with increasing concentrations of IPBDE in the eggs (log-linear regression p < 0.01).


Assuntos
Ovos/análise , Hidrocarbonetos Bromados/análise , Aves Predatórias/fisiologia , Animais , Suécia
3.
Environ Sci Technol ; 38(1): 127-32, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14740727

RESUMO

Polybrominated diphenyl ethers (PBDE) are commonly used flame retardants. During the past years, concerns have increased due to their occurrence in the environment and humans. In general, the concentrations of lower brominated (tetra-penta) diphenyl ethers in biota exceed those of the most heavily used product, decabromodiphenyl ether (DecaBDE). In this study, the photolytic debromination of DecaBDE has been investigated in order to study the formation of lower brominated diphenyl ethers. The time course of photolysis of DecaBDE was studied in toluene, on silica gel, sand, sediment and soil using artificial sunlight and on the natural matrices (sediment, soil, sand) also using natural sunlight. DecaBDE was photolytically labile and formed debromination products in all matrices studied. Nona- to tetraBDEs were formed as well as some PBDFs. The half-lives in toluene and on silica gel were less than 15 min, and half-lives on other matrices ranged between 40 and 200 h. No differences were seen in the debromination pattern of BDE congeners sequentially formed in the different matrices or under different light conditions. However, the debromination rates were strongly dependent on the matrix with longer half-lives on natural matrices than artificial ones.


Assuntos
Bromobenzenos/química , Retardadores de Chama/análise , Bromo/química , Bromobenzenos/análise , Sedimentos Geológicos/química , Meia-Vida , Éteres Difenil Halogenados , Éteres Fenílicos , Fotoquímica , Bifenil Polibromatos , Dióxido de Silício , Luz Solar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA