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201.
We exposed female European starlings to a pentabromodiphenyl ether (Penta-BDE) mixture through subcutaneous implants, and examined levels and profiles of polybrominated diphenyl ethers (PBDEs) together with reproductive effects. Sum PBDE levels increased significantly in the serum of the exposed females from 218 ± 43 to 23,400 ± 2035 pg/ml. Sum PBDE concentrations in the eggs of the exposed group ranged from 130 ± 12 to 220 ± 37 ng/g wet weight (ww). The profile in serum after egg laying was very similar to that in eggs. There were no detectable levels of HO-PBDEs in both serum and eggs. Fewer females of the exposed group initiated egg laying compared to the control group, although the difference was not significant. In addition, egg weight and volume were significantly higher in the exposed group. These results suggest that, at the investigated exposure levels (150 μg sum PBDEs/bird), PBDEs may have a negative effect on reproductive performance.  相似文献   
202.
Although eggs have frequently been used as a biomonitoring tool for contamination with organohalogenated pollutants (OHPs), few studies have investigated the processes of maternal transfer in birds. Here, maternal transfer of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) was investigated through comparison of the concentrations and profiles between whole homogenised female blue tits (Cyanistes caeruleus) and their eggs. In addition, we examined if there was an effect of laying order on the concentrations of PCBs, OCPs and PBDEs. PCBs were the most abundant contaminants in female blue tits and their eggs, followed by OCPs and PBDEs. Among the OCPs, p,p'-DDE was the most dominant compound and accounted for more than 80% of the sum OCPs. Egg concentrations decreased significantly in relation to the laying order from 1623+/-148 ng/g lipid weight (lw) to 1040+/-47 ng/g lw for the sum PCBs, from 342+/-24 ng/g lw to 235+/-17 ng/g lw for the sum OCPs and from 49+/-5 ng/g lw to 27+/-5 ng/g lw for the sum PBDEs. When reviewing all studies investigating laying order effects of OHPs in birds, no clear patterns emerged, which may be due to differences in study species and methodology among studies. Despite the fact that there were laying order effects in blue tit clutches, the variance in concentrations of PCBs and PBDEs was larger among clutches than within clutches. Variance in OCP concentrations among clutches was similar to the variance within clutches. These results suggest that one randomly collected blue tit egg from a clutch is useful as biomonitoring tool for PCBs and PBDEs, while for OCPs it is recommended to consistently use the same egg from the laying sequence as a biomonitoring tool. Lipid-normalized concentrations of sum PCBs, sum OCPs and sum PBDEs in female blue tits after clutch completion were comparable to the concentrations in the first-laid eggs. The egg/female lipid concentration ratios for sum PCBs, sum OCPs and sum PBDEs decreased significantly from 1.0+/-0.09 to 0.7+/-0.003, 1.1+/-0.1 to 0.7+/-0.02 and 1.2+/-0.14 to 0.8+/-0.05, respectively, during the course of egg laying. The profiles of the females and eggs differed significantly for the PCBs, OCPs and PBDEs. There was a higher contribution of lower chlorinated PCB congeners (CB 28, CB 52, CB 95, CB 101 and CB 110), BDE 183, p,p'-DDT and other less persistent OCPs in the females compared to their eggs. Maternal transfer in blue tits seemed to be selective for the more bioaccumulative and persistent congeners/compounds.  相似文献   
203.
Abstract: Total Maximum Daily Load (TMDL) implementation generates benefits and costs from water quality improvements, which are rarely quantified. This analysis examines a TMDL written to address bacteria and aquatic‐life‐use impairments on Abrams and Opequon Creeks in Virginia. Benefits were estimated using a contingent valuation survey of local residents. Costs were based on the number and type of best management practices (BMPs) necessary to achieve TMDL pollution reduction goals. BMPs were quantified using watershed‐scale water quality simulation models (Generalized Watershed Loading Function and Hydrological Simulation Program‐FORTRAN). Based on our projections, the costs to achieve TMDL induced pollution reduction goals outweigh the estimated benefits. Benefit‐cost ratios ranged between 0.1 and 0.3.  相似文献   
204.
Acid gas geological disposal is a promising process to reduce CO2 atmospheric emissions and an environment-friendly and economic alternative to the transformation of H2S into sulphur by the Claus process. Acid gas confinement in geological formations is to a large extent controlled by the capillary properties of the water/acid–gas/caprock system, because a significant fraction of the injected gas rises buoyantly and accumulates beneath the caprock. These properties include the water/acid gas interfacial tension (IFT), to which the so-called capillary entry pressure of the gas in the water-saturated caprock is proportional. In this paper we present the first ever systematic water/acid gas IFT measurements carried out by the pendant drop technique under geological storage conditions. We performed IFT measurements for water/H2S systems over a large range of pressure (up to P = 15 MPa) and temperature (up to T = 120 °C). Water/H2S IFT decreases with increasing P and levels off at around 9–10 mN/m at high T (≥70 °C) and P (>12 MPa). The latter values are around 30–40% of water/CO2 IFTs, and around 20% of water/CH4 IFTs at similar T and P conditions. The IFT between water and a CO2 + H2S mixture at T = 77 °C and P > 7.5 MPa is observed to be approximately equal to the molar average IFT of the water/CO2 and water/H2S binary mixtures. Thus, when the H2S content in the stored acid gas increases the capillary entry pressure decreases, together with the maximum height of acid gas column and potential storage capacity of a given geological formation. Hence, considerable attention should be exercised when refilling with a H2S-rich acid gas a depleted gas reservoir, or a depleted oil reservoir with a gas cap: in the case of hydrocarbon reservoirs that were initially (i.e., at the time of their discovery) close to capillary leakage, acid gas leakage through the caprock will inevitably occur if the refilling pressure approaches the initial reservoir pressure.  相似文献   
205.
Environmental Science and Pollution Research - A field experiment with thin-layer capping was conducted in the Grenland fjords, Norway, for remediation in situ of mercury and dioxin-contaminated...  相似文献   
206.
The body of information presented in this paper is directed to researchers in stack testing methodology and to those concerned with reduction of emissions through equipment upgrading programs. Extensive testing was done using the U.S. Environmental Protection Agency’s Method 5 stack sampling train to obtain emission factors for existing apartment house boilers and incinerators in the City of New York. In addition to calculating emission factors, stack emission data were examined to compare results of simultaneous emission tests and to compare the dry particulate catch of the sampling train with the total particulate catch which included the impinger catch. Conclusions reached as a result of the testing were that published emission factors for boilers burning moderately high-sulfur residual oil are applicable to New York City boilers burning low-sulfur residual oil. In addition, it was found that the back half of the sampling train—the impinger section—collects a relatively constant amount of material when sampling oil-fired boilers. This may be due to absorption of S02 and S03 in the impingers and the subsequent formation of sulfuric acid. Comparison of simultaneous boiler tests indicated that the sampling train may be sensitive to variations in operating personnel, sampling conditions, and boiler operation. From tests of on-site incinerators, it was determined that previously published emission factors may be too high for well maintained and properly operated incinerators. The back half particulate catch was found to be relatively large which may have resulted from condensation of unburned organics from the burning waste material.  相似文献   
207.
The applicability of microarrays to monitor harmful algae across a broad range of ecological niches and toxic species responsible for harmful algal events has been one of the key tasks in the EU Seventh Framework Programme (FP7)-funded Microarrays for the Detection of Toxic Algae project. The technique has a strong potential for improving speed and accuracy of the identification of harmful algae and their toxins to assist monitoring programmes. Water samples were collected from a number of coastal sites around Ireland, including several that are used in the Irish National Phytoplankton and Biotoxin Monitoring Programme. Ribosomal RNA was extracted from filtered field samples, labelled with a fluorescent dye, and hybridised to probes spotted in a microarray format on a glass slide. The fluorescent signal intensity of the hybridisation to >120 probes on the chip was analysed and compared with actual field counts. There was a general agreement between cell counts and microarray signal. Results are presented for field samples taken from a range of stations along the Irish coastline known for harmful algal events during the first field trial (July 2009–April 2010).  相似文献   
208.
In this study, the presence of bisphenol A (BPA) in human placental and fetal liver samples collected from 1998 to 2008 was investigated to provide a more detailed analysis of the transfer of BPA across the placenta and fetal exposure to BPA. The average concentrations in placental samples were 12.6 ng g−1 for free BPA, 17.2 ng g−1 for BPA-glu, and 30.2 ng g−1 for total BPA. The highest concentrations in placental samples were 165 ng g−1 for free BPA, 178 ng g−1 for BPA-glu, and 280 ng g−1 for total BPA. Samples with higher levels of BPA-glu had higher levels of free BPA in general. Fetal age was observed to have a significant effect on BPA-glu levels in placental samples, but not on free or total BPA. The percentages of free BPA relative to total BPA for the placental samples varied considerably from 4.2% to 100%, suggesting that the ability of maternal liver and/or the placenta to conjugate BPA is highly variable during early to mid-gestation. The average concentrations in fetal liver samples were 9.02 ng g−1 for free BPA, 19.1 ng g−1 for BPA-glu, and 25.8 ng g−1 for total BPA. The highest concentrations in fetal liver samples were 37.7 ng g−1 for free BPA, 93.9 ng g−1 for BPA-glu, and 123 ng g−1 for total BPA. The percentages of free BPA level relative to total BPA for all fetal liver samples varied from 12.4% to 99.1%, indicating extensive variability in the ability of the human feto-placental unit to glucuronidate BPA.  相似文献   
209.
A pilot study is presented evaluating selected chlorinated pesticides as chemical tracers for water masses in a sub-Arctic fjord system (Godth?bsfjord, western Greenland). Polyoxymethylene (POM) based passive water samplers were deployed during summer-autumn 2010. The levels of the analysed chlorinated pesticides in the fjord surface waters were found to be low compared to earlier studies. α-Hexachlorocyclohexane (α-HCH) and hexachlorobenzene (HCB) were the predominant contaminants. However, these two compounds have higher levels in oceanic water compared to freshwater influenced fjord waters. These chemicals can thus be considered as indicators for direct atmospheric long-range transport, while the organochlorine pesticides like trans-, cis-chlordane, trans-nonachlor and oxychlordane that are detected in the inner parts of the fjord are indicators for potential freshwater sources such as rivers and glacial meltwater runoff (secondary sources). The average values were 50 pg L(-1) for HCB and 11 pg L(-1) for α-HCH. These concentrations are comparable to levels in fjords in Svalbard (Norwegian Arctic), but lower than in open and/or ice covered oceans in the Canadian Arctic. Two air samplers were deployed for the identification of direct atmospheric contributions. Local contamination sources do not contribute significantly. The study demonstrated the value of passive water sampling devices for comprehensive hydrological characterization of Arctic coastal waters.  相似文献   
210.
The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5–3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.  相似文献   
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