The distribution of perfluoroalkyl compounds (PFCs) in the environment is well documented with higher concentrations observed in wildlife located in industrial and urban areas. This study examined the distribution of PFCs in relation to land use using blood samples collected from bottlenose dolphins during capture-release health assessment surveys conducted in Charleston, SC. The study area was partitioned into three subareas (ACW, CHS, and SRE) based upon habitat and land use characteristics. The ACW and CHS subareas are characterized by high degrees of industrial and urban land uses, while the SRE subarea is more residential and characterized by a lower degree of developed land use. Long-term monitoring data from photo-identification surveys were used to group bottlenose dolphins based on their proportions of sightings in the different subareas. Dolphins affiliated with both the ACW and CHS subareas were observed to have significantly higher mean plasma concentrations of perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) than those affiliated with the SRE subarea. Dolphins affiliated with the ACW subarea were found to have a significantly higher mean plasma concentration of PFUnA than those affiliated with the CHS subarea. Further examination of the distribution of the PFCs revealed positive correlations with developed land uses and negative correlations with wetland/marsh land cover. A positive correlation was also observed between PFUnA and agricultural land use. The variability and scale of the observed contaminant burdens have important implications for the conservation and management of living marine resources and illustrates the importance of long-term monitoring of free-ranging wildlife species. 相似文献
Plasma PFCs were measured in 157 bottlenose dolphins (Tursiops truncatus) sampled from two US southeast Atlantic sites (Charleston (CHS), SC and Indian River Lagoon (IRL), FL) during 2003-2005. ∑PFCs, perfluoroalkyl carboxylates (∑PFCAs), perfluoroalkyl sulfonates (∑PFSAs) and individual compounds were significantly higher in CHS dolphins for all age/sex categories compared to IRL dolphins. Highest ∑PFCs concentrations occurred in CHS juvenile dolphins (2340 ng/g w.w.); significantly higher than found in adults (1570 ng/g w.w. males; 1330 ng/g w.w. females). ∑PFCAs were much greater in CHS dolphins (≈ 21%) compared to IRL dolphins (≈ 7%); ∑PFSAs were 79% in CHS dolphins versus 93% in IRL dolphins. PFOS, the dominant compound, averaged 72% and 84%, respectively, in CHS and IRL dolphins. Decreasing PFC levels occurred with age on the bioaccumulation of PFCs in both sites. These observations suggest PFC accumulation in these two dolphin populations are influenced by site-specific exposures with significantly higher levels in CHS dolphins. 相似文献
High hydrogen pressure pyrolysis (hydropyrolysis) was performed on samples of solvent extracted Kimmeridge Clay Formation
source rock with a maturity equivalent to ca. 0.35% vitrinite reflectance. We describe the types and distributions of organic nitrogen compounds in the pyrolysis products
(hydropyrolysates) using GC-MS. Compounds identified included alkyl-substituted indoles, carbazoles, benzocarbazoles, quinolines
and benzoquinolines. The distributions of the isomers of methylcarbazoles, C2-alkylcarbazoles and benzocarbazoles in the hydropyrolysates were compared to a typical North Sea oil. The hydropyrolysates
compared to the North Sea oil, showed increased contributions from alkylcarbazole isomers where the nitrogen group is "exposed"
(no alkyl substituents adjacent to the nitrogen functionality) and appreciable levels of benzo[b]carbazole relative to benzo[a]- and benzo[c]carbazoles. Hydropyrolysis is found to be an ideal technique for liberating appreciable quantities of heterocyclic organic
nitrogen compounds from geomacromolecules. The products released from the immature Kimmeridge Clay are thought to represent
a potential source of nitrogen compounds in the bound phase (kerogen) able to contribute to the free bitumen phase during
catagenesis. 相似文献
In many countries, argillaceous formations are being considered as potential host rocks for repositories of radioactive waste. Therefore, in 1995 several organisations decided to start an international research project in the reconnaissance gallery of the Mont Terri motorway tunnel, in north-western Switzerland, in a Mesozoic shale formation, the Opalinus Clay (Aalenian).
This project is under the patronage of the Swiss National Hydrological and Geological Survey. The following organisations are also partners in the project: ANDRA and IPSN (France), BGR (Germany), ENRESA (Spain), Nagra (Switzerland), JNC and Obayashi (Japan), SCKCEN (Belgium).
The aims of the project are to analyse the hydrogeological, geochemical and rock mechanical properties of an argillaceous formation, the changes of these properties induced by the excavation of galleries and to evaluate and improve appropriate investigation techniques. In January, 1996, eight niches were excavated for the project and 15 experiments were started in boreholes of no more than 30 m in length. In the winter of 1997–1998 a new research gallery was excavated to host further experiments. Different excavation, drilling and investigation techniques have been tested and improved. Significant results of the different experiments are already available. Some of those dealing with hydrochemistry, porewater pressure measurements and the evolution of the excavation disturbed zone (EDZ) are reported in this paper. 相似文献