Уточнить поиск
Результаты 1-10 из 31
Persistent organochlorine residues in harbour porpoise (Phocoena phocoena) from the Black Sea.
1997
Tanabe S. | Madhusree B. | Ozturk A.A. | Tatsukawa R. | Miyazaki N. | Ozdamar E. | Aral O. | Samsun O. | Ozturk B.
Do trans-Pacific air masses deliver PBDEs to coastal British Columbia, Canada
2009
Noël, Marie | Dangerfield, Neil | Hourston, Roy A.S. | Belzer, Wayne | Iversen, Pat Shaw | Yunker, Mark B. | Ross, Peter S.
In order to distinguish between ‘local’ and ‘background’ sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in coastal British Columbia (Canada) air, we collected samples from two sites: a remote site on western Vancouver Island, and a near-urban site in the Strait of Georgia. Seasonally-integrated samples of vapor, particulate, and rain were collected continuously during 365 days for analysis of 275 PCB and PBDE congeners. While deposition of the legacy PCBs was similar at both sampling sites, deposition of PBDEs at the remote site amounted to 42% (10.4 mg/ha/year) of that at the near-urban site. Additional research into atmospheric circulation in the NE Pacific Ocean will provide more insight into the transport and fate of priority pollutants in this region, but trans-Pacific delivery of PBDEs to the west coast of North America may underlie in part our observations. For example, approximately 40% of >12,000 ten-day back trajectories calculated for the remote site originated over Asia, compared to only 2% over North America. Legacy PCBs and current-use PBDEs are dispersed through atmospheric processes in coastal British Columbia, Canada.
Показать больше [+] Меньше [-]Particle-size distribution and gas/particle partitioning of atmospheric polybrominated diphenyl ethers in urban areas of Greece
2009
Mandalakis, Manolis | Besis, Athanasios | Stephanou, Euripides G.
Ambient concentrations, gas/particle partitioning and particle-size distribution of polybrominated diphenyl ethers (PBDEs) were investigated in two urban areas (Athens and Heraklion) of Greece. Atmospheric (gas + particle) concentrations of Sigma PBDE varied from 21 to 30 pg m-3 in the center of Athens and from 4 to 44 pg m-3 in the suburbs of Heraklion. A predominance of particulate PBDEs was observed in Athens (71-76% in particles), whereas the opposite was evident in Heraklion (69-92% in gas phase). In both urban areas, PBDE particle-size distribution featured a distinct enrichment in smaller particles. A similar trend was also observed in aerosols of a background marine site. For all sampling sites, more than 46% of Sigma PBDE was associated with particles of <0.57 μm in diameter. Our results imply that particulate PBDEs may have long atmospheric residence time and they may be capable of reaching the deeper parts of the human respiratory system. Analysis of size-segregated aerosol samples indicates a predominance of polybrominated diphenyl ethers in the small particle-size fraction.
Показать больше [+] Меньше [-]Pulsed gas injection: A minimum effort approach for enhanced natural attenuation of chlorobenzene in contaminated groundwater
2009
Balcke, Gerd Ulrich | Paschke, Heidrun | Vogt, Carsten | Schirmer, Mario
Chlorobenzene-contaminated groundwater was used to assess pulsed gas sparging as a minimum effort aeration strategy to enhance intrinsic natural attenuation. In contrast to existing biosparging operations, oxygen was supplied at minimum rate by reducing the gas injection frequency to 0.33 day⁻¹. Field tests in a model aquifer were conducted in a 12 m long reactor, filled with indigenous aquifer material and continuously recharged with polluted groundwater over 3 years. The closed arrangement allowed yield balances, cost accounting as well as the investigation of spatial distributions of parameters which are sensitive to the biodegradation process. Depending on the injection frequency and on the gas chosen for injection (pure oxygen or air) oxygen-deficient conditions prevailed in the aquifer. Despite the limiting availability of dissolved oxygen in the groundwater, chlorobenzene degradation under oxygen-deficient conditions proved to be more effective than under conditions with dissolved oxygen being available in high concentrations. Minimum rate gas sparging resulted in sustained biodegradation of chlorobenzene in a polluted groundwater aquifer.
Показать больше [+] Меньше [-]Persistent organic pollutants, heavy metals and parasites in the glaucous gull (Larus hyperboreus) on Spitsbergen
2009
Sagerup, Kjetil | Savinov, Vladimir | Savinova, Tatiana | Kuklin, Vadim | Muir, Derek C.G. | Gabrielsen, Geir W.
The prediction of a higher parasite infection as a consequence of an impaired immune system with increasing persistent organic pollution (POP) and heavy metal levels were investigated in adult glaucous gull (Larus hyperboreus) from Svalbard. The levels of chlorinated pesticides, polychlorinated biphenyls (PCBs), toxaphenes and polybrominated diphenyl ethers (PBDEs) were measured in liver. Cupper, cadmium, lead, mercury, selenium and zinc were measured in kidney samples. An elevated ratio of PCB-118 was found, suggesting that local contamination from the settlement was detectable in the glaucous gull. Eight cestodes, four nematodes, two acanthocephalan and three trematode helminth species were found in the intestine. A positive correlation was found between cestode intensities and selenium levels and between acanthocephalan intensities and mercury levels. No correlation was found between parasite intensities and POP concentrations. It is concluded that the contaminant levels found in glaucous gulls do not cause immune suppression severe enough to affect parasite intensity. Consistent relationships between contaminant level and parasite intensity, as an immunotoxic endpoint unit, were not found in the present study.
Показать больше [+] Меньше [-]Organohalogen compounds in human breast milk from mothers living in Payatas and Malate, the Philippines: Levels, accumulation kinetics and infant health risk
2009
Malarvannan, Govindan | Kunisue, Tatsuya | Isobe, Tomohiko | Sudaryanto, Agus | Takahashi, Shin | Prudente, Maricar | Subramanian, Annamalai | Tanabe, Shinsuke
Human breast milk samples (n = 33) from primipara and multipara mothers from Payatas a waste dump site, and Malate a reference site in the Phillipines were collected in 2004 and analyzed for eight organohalogen compounds, viz., PCBs, DDTs, CHLs, HCHs, HCB, TCPMe, PBDEs and HBCDs. DDTs and PCBs were predominant in all the samples. Overall mean concentrations of PBDEs found in our study were higher (7.5 ng/g lipid wt.) than those reported for Japan and many other Asian countries. Primipara mothers had significantly higher levels of DDTs, CHLs and HCHs than multipara mothers, but not PBDEs and HBCDs. A few individuals accumulated CHLs close to or even higher than the tolerable daily intake guidelines proposed by Health Canada. First comprehensive study on organohalogen contaminants in human breast milk from the Philippines.
Показать больше [+] Меньше [-]Temporal variations of VOC concentrations in Bursa atmosphere
2017
Yurdakul, Sema | Civan, Mihriban | Kuntasal, Öznur | Doğan, Güray | Pekey, Hakan | Tuncel, Gürdal
The levels and sources of VOCs in the atmosphere of Bursa have been investigated by measuring C2–C12 VOCs which include alkanes, alkenes, alkines, aromatics and halogenated hydrocarbons in two different campaigns. The first campaign was carried out between September 14 and November 6, 2005, and the second one between March 17 and May 10, 2006. The concentrations of 112 VOCs were detected in the collected samples. The median total concentrations of VOCs were 115 and 86 μg m−3 for the first and second campaigns, respectively. Alkanes (x− = 51.50 μg m−3) are the most abundant group in the Bursa airshed, which is followed by aromatics (x− = 49.38 μg m−3), alkenes (x− = 36.86 m-3) and halogenated compounds (x− = 13.07 μg m−3). In the present study, the VOCs showed well defined diurnal, weekday/weekend and seasonal variations. Diurnal variation of most of the measured organic compounds followed traffic rush-hours. On the other hand, some VOCs such as 1-octene, 1-nonene, 1-undecene, n-nonane, n-decane, 1,2,3-trimethylbenzene, undecane and dodecane have displayed unusual profiles that do not follow the traffic pattern during the first campaign due to asphalting operations. Moreover, the average T/B ratio obtained in the first campaign was found to be significantly higher than the second one. This relatively high difference between T/B ratios is an indication of the availability of different sources rather than the traffic. Therefore, it can be suggested that there were additional VOC sources than traffic in Bursa city center.
Показать больше [+] Меньше [-]Transfer of methyl chloroform, trichloroethylene and tetrachloroethylene to milk, tissues and expired air following intraruminal or oral administration in lactating goats and milk-fed kids
1995
Hamada, T. | Tanaka, H. (National Institute of Animal Industry, Tsukuba Norindanchi PO Box 5, Ibaraki 305 (Japan))
Temporal changes in some chlorinated hydrocarbon residue levels of Canadian breast milk and infant exposure
1994
Mes, J. (Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Protection Branch, Health and Welfare Canada, Tunney's Pasture, Ottawa K1A 0L2 (Canada))
Organochlorine pesticide residues in human milk in Punjab, India
1994
Kalra, R.L. | Balwinder Singh | Battu, R.S. (Department of Entomology, Punjab Agricultural University, Ludhiana, Punjab (India))