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101.
Pigs accidentally given feed contaminated by dioxin-like pollutants are a serious public health issue. We have examined whether pigs with limited exposure during early periods of fattening would be categorized as non-compliant with the EU limit at slaughtering when growth-dilution, excretion and metabolism effects are considered. Sixteen female and sixteen castrated male weaned pigs were divided into four groups (e.g. DG0, DG1, DG2 and DG3) in week 2 after birth. From weeks 3 to 13, groups DG1, DG2, and DG3 pigs were fed with a polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) and polychlorinated biphenyl (PCB) mixture at dosages of 1, 10 and 100 ng-toxic equivalent (TEQ) per kg dry mass feed in capsules, respectively. From weeks 13 to 23, the animals were nourished with clear feed. Control group DG0 was always fed with clear feed. Subcutaneous fat samples were collected at weeks 13, 18 and 23 by biopsies. The pollutant residues were analyzed by high resolution gas chromatography-high resolution mass spectrometry and quantified by a 13C-isotope dilution method. The results showed the following: (1) when slaughtered at week 23, the TEQ for DG1 pigs (0.66 ± 0.21 pg/g fat) was under the EU limit of 1 pg PCDD/F-TEQ/g fat; (2) PCDD/F congener-specific first-order elimination rates were linearly correlated with their toxicity equivalency factors (TEFs), and the rates were significantly dose-dependent for the more toxic congeners (TEF ≥ 0.1). Therefore, the pigs' exposure above the EU limit during the early fattening stage did not necessarily lead to their categorization as non-compliant pork; and the residual TEQ for pork can be predicted from early exposure concentrations based on the models established here.  相似文献   
102.
The Khorezm region is located in the northwest of Uzbekistan, approximately 350 km from the current shore of the Aral Sea. It comprises a large‐scale irrigation system that conveys water from the river Amu Darya to agricultural land cropped mainly with cotton, wheat, and rice. Khorezm's water resources are vulnerable as they depend on upstream developments and are indispensable to rural livelihoods and state budgets. Since water scarcity is expected to increase in the future, sustainable water management is a necessity. Hence, the objectives of the paper are to: (1) conceptualize the distinctive features of water management in Khorezm; (2) provide an integrated analysis of water management by establishing linkages between society, technical infrastructure, and the bio‐physical environment; and (3) make policy and technology recommendations for improved water management. To conceptualize water management in Khorezm, the paper distinguishes three types of practices: formal practices, strategic practices, and discursive practices. Based on these, it presents an analysis of water management on the state water management level, the water user association level, and the farmer and field level. For each level, recommendations are given. The paper concludes that elements of integrated water resources management (IWRM) such as transparency, accountability, participation, and technical efficiency are relevant to improve water management in Khorezm, as elsewhere. In addition, it underlines the need to create legal space for agency and innovation. Technical tools such as models are increasingly important for facilitating transparency and enabling agents to access and make use of information across the management hierarchy.  相似文献   
103.
Sorsogon City is a rapidly urbanising coastal area in the Philippines. Its location, combined with a rapidly changing and growing urban fabric, leaves it vulnerable to both incremental climate change and associated extreme weather events. In this paper, UN-HABITAT data are used to draw out the climate change vulnerabilities and policy responses in Sorsogon City. Vulnerability “hotspots” highlight the spatial intersection of socio-economic justice concerns, particularly in terms of vulnerability to increased cyclone activity. We discuss vulnerabilities of Sorsogon City and its citizens to climate change and measures undertaken through various social, environmental and technical systems and interventions to increase resilience. The paper also attempts to unpick the relationship between the neat, concise reported city and the complexities of urban life using the Sorsogon experiment to consider the limitations of such approaches to governing climate change. We group these under four headings: social simplification in the absence of data; over-governance (and under-representation); quick wins versus strategic investment; and stretching the ecological and vulnerability footprints of the city. The experience of Sorsogon City is then extended to reflect on issues of governance and planning in other Asian coastal cities.  相似文献   
104.
The contaminated air with burning plastic floor and electronic scrap was monitored with semipermeable membrane devices (SPMDs) and fresh unpolluted spruce needles at the same time for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). It was found that there were more polychlorinated dibenzofurans (PCDFs) than polychlorinated dibenzo-p-dioxins (PCDDs) collected from contaminated air. The total amounts of PCBs were much higher than that of PCDD/Fs, but the contribution of them to the WHO-TEQ was less than that of PCDD/Fs. Triolein-containing SPMDs can absorb much more PCDD/Fs and PCBs than spruce needles when they were exposed in contaminated air simultaneously. The logarithm of the concentrations of PCDD/Fs and PCBs in SPMDs and in spruce needles at the same sampling time exhibited a significant linear correlation, the correlation coefficients were larger than 0.86 for PCDD/Fs and 0.92 for PCBs. SPMDs and spruce needles are effective passive air sampler for PCDD/Fs and PCBs. SPMDs and spruce needles can complement each other in passive air sampling.  相似文献   
105.
The diving behaviour of southern rockhopper penguins (Eudyptes c. chrysocome) was studied at two breeding sites in the Southwest Atlantic: the Falkland Islands and Staten Island, Argentina. Incubating and brooding birds were equipped with time-depth recorders to monitor their foraging activities. Rockhopper penguins from Staten Island started their breeding season about 3 weeks earlier than their conspecifics from the Falkland Islands. The foraging area used by incubating males from the Falkland Islands comprised about 150,000 km² to the northeast of the breeding site and was characterised by shelf and slope waters, whereas the foraging area of incubating males from Staten Island comprised 350,000 km² of oceanic waters to the southeast of the breeding site. A number of dive parameters were measured and compared between the four study groups: Incubating males and brooding females from the Falkland Islands, and incubating males and females from Staten Island. In all study groups, dive depth correlated positively to light intensity, dive duration and vertical velocity. However, significant differences between various diving parameters of the study groups were noted, not only in terms of diving performance, but also as regards diving efficiency (DE). A principal component analysis (PCA) on 16 variables revealed that 75% of the variance could be explained by only two principal components: diving pattern (PC1) and diving effort (PC2). PC1 indicated that the birds from Staten Island, both males and females, dived deeper, covered a greater vertical distance per hour and had higher ascent rates, but spent less time underwater and at the bottom of a dive, and had a lower DE than conspecifics from the Falkland Islands. PC2, which included the percentage of foraging dives, the number of dives per hour, dive duration, bottom time and descent rate, differed significantly between incubating males from the Falkland Islands and the other three groups, which were all very similar. Overall, the diving behaviour was notably similar to that of conspecifics from the Indian and Pacific Oceans. The implications of the results in terms of intra-specific adaptations as well as potential threats from human activities are discussed.  相似文献   
106.
Phthalates are ubiquitous environmental chemicals with potential detrimental health effects. The purpose of our study was to quantify dietary intake of phthalates and of DEHA (Di-ethylhexyl adipate) using duplicate diet samples and to compare these data with the calculated data based on urinary levels of primary and secondary phthalate metabolites. 27 female and 23 male healthy subjects aged 14-60 years collected daily duplicate diet samples over 7 consecutive days. Overall, 11 phthalates were measured in the duplicates by GC/MS and LC/MS methods. Urinary levels of primary and secondary phthalate metabolites are also available. The median (95th percentile) daily intake via food was 2.4 (4.0) microg/kg b.w. (Di-2-ethylhexyl phthalate, DEHP), 0.3 (1.4) microg/kg b.w. (Di-n-butyl phthalate, DnBP), 0.6 (2.1) microg/kg b.w. (Di-isobutyl phthalate, DiBP) and 0.7 (2.2) microg/kg b.w. for DEHA. MEPH (Mono-2-ethylhexyl phthalate) was detectable only in minor concentrations in the samples, thus conversion of DEHP to MEHP and dietary intake of MEHP were negligible. When comparing back-calculated intake data of the DEHP metabolites with dietary DEHP intake from the day before significant correlations were observed for most of the metabolites. No correlation was found for DnBP and only a weak but significant correlation for DiBP. The median and 95th percentile daily dietary intake of all target analytes did not exceed the recommended tolerable daily intake. Our data indicated that food was the predominant intake source of DEHP, whilst other sources considerably contributed to the daily intake of DnBP and DiBP in an adult population.  相似文献   
107.
For decades there has been a controversial debate over how far religious faith communities are specifically engaged in ecological practices (EP). Therefore we studied four Austrian and two German Benedictine monasteries religious ethics and spirituality as a means of a driving force for initiating EP. We draw upon theories of organizational learning processes and capacity-building of sustainability to interpret our empirical findings. The majority of monasteries are highly engaged in EP, initiated either as an outcome of individual activities or through a specific mostly informally acting group, but rarely an organizationally or systematically integrated goal of the monasteries, or a focus of capacity building. Monasteries follow a technical and economic decision-making process in implementing EP. Spirituality plays a limited role in the initiation of EP. The environment of monasteries–acceptance or critique against ecological practices–influences the monasteries decisions. Institutionalization of ecological practices into the monasteries organizational structure is rare.  相似文献   
108.
Results of leaching experiments using active and inactively simulated HLW glass in concentrated NaCl solution are described. Measured solution concentrations of glass components, fission products and actinides are compared with computed data. The computed pH value corresponds with the findings from experiments with inactively simulated glass samples. Moreover, the concentrations of silica and strontium can be described adequately by reaction path modelling. The computed U concentration is explained by the precipitation of schoepite or Na2U2O7. The computed Am concentration significantly exceeds the measured data. This may be attributed to sorption processes on corrosion products of the glass, which are relevant also for lanthanide elements under the conditions of the experiments. This hypothesis is tested by solid solution approaches and by computing sorption of Am onto SiO2 precipitates.  相似文献   
109.
Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4–6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems.  相似文献   
110.
Persistent organic pollutants such as polychlorinated biphenyls (PCBs) are associated with detrimental health outcomes including cardiovascular diseases. Remediation of these compounds is a critical component of environmental policy. Although remediation efforts aim to completely remove toxicants, little is known about the effects of potential remediation byproducts. We previously published that Fe/Pd nanoparticles effectively dechlorinate PCB 77 to biphenyl, thus eliminating PCB-induced endothelial dysfunction using primary vascular endothelial cells. Herein, we analyzed the toxic effects of PCB congener mixtures (representative mixtures of commercial PCBs based on previous dechlorination data) produced at multiple time points during the dechlorination of PCB 77 to biphenyl. Compared with pure PCB 77, exposing endothelial cells to lower chlorinated PCB byproducts led to improved cellular viability, decreased superoxide production, and decreased nuclear factor kappa B activation based on duration of remediation. Presence of the parent compound, PCB 77, led to significant increases in mRNA and protein inflammatory marker expression. These data implicate that PCB dechlorination reduces biological toxicity to vascular endothelial cells.  相似文献   
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