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21.
In recent years, some perfluorinated compounds (PFCs) have been identified as potentially hazardous substances which are harmful to the environment and human health. According to limited data, PFC levels in humans could be influenced by several determinants. However, the findings are inconsistent. In the present study, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were measured in paired maternal and cord serum samples (N?=?237) collected between 1978 and 2001 in Southern Sweden to study the relationship between these and to investigate several potential determinants of maternal and fetal exposure to PFCs. Time trends of PFCs in Swedish women were also evaluated. The study is a part of the Fetal Environment and Neurodevelopment Disorders in Epidemiological Research project. PFOS, PFOA, and PFNA levels (median) were higher in maternal serum (15, 2.1, and 0.24 ng/ml, respectively) than in cord serum (6.5, 1.7, and 0.20 ng/ml, respectively). PFC levels were among the highest in women originating from the Nordic countries and the lowest in women from the Middle East, North Africa, and sub-Saharan Africa. Multiparous women had lower serum PFOA levels (1.7 ng/ml) than primiparous women (2.4 ng/ml). Maternal age, body mass index, cotinine levels, and whether women carried male or female fetuses did not affect serum PFC concentrations. Umbilical cord serum PFC concentrations showed roughly similar patterns as the maternal except for the gestational age where PFC levels increased with advancing gestational age. PFOS levels increased during the study period in native Swedish women. In summary, PFOS levels tend to increase while PFOA and PFNA levels were unchanged between 1978 and 2001 in our study population. Our results demonstrate that maternal country of origin, parity, and gestational age might be associated with PFC exposure.  相似文献   
22.
Dissolved organic carbon (DOC) may affect the transport of pollutants from incineration residues when landfilled or used in geotechnical construction. The leaching of dissolved organic carbon (DOC) from municipal solid waste incineration (MSWI) bottom ash and air pollution control residue (APC) from the incineration of waste wood was investigated. Factors affecting the mobility of DOC were studied in a reduced 2(6-1) experimental design. Controlled factors were treatment with ultrasonic radiation, full carbonation (addition of CO2 until the pH was stable for 2.5h), liquid-to-solid (L/S) ratio, pH, leaching temperature and time. Full carbonation, pH and the L/S ratio were the main factors controlling the mobility of DOC in the bottom ash. Approximately 60 weight-% of the total organic carbon (TOC) in the bottom ash was available for leaching in aqueous solutions. The L/S ratio and pH mainly controlled the mobilization of DOC from the APC residue. About 93 weight-% of TOC in the APC residue was, however, not mobilized at all, which might be due to a high content of elemental carbon. Using the European standard EN 13 137 for determination of total organic carbon (TOC) in MSWI residues is inappropriate. The results might be biased due to elemental carbon. It is recommended to develop a TOC method distinguishing between organic and elemental carbon.  相似文献   
23.
Pseudomosaicism is of particular concern in prenatal diagnosis when it involves mosaicism for a cytogenetic abnormality associated with a clinical syndrome which is compatible with postnatal life, such as trisomies for chromosomes 13, 18, and 21. The lack of data regarding the outcome of pregnancies involving these specific kinds of pseudomosaicism makes genetic counselling difficult. Three cases of prenatal diagnosis of pseudomosaicism for trisomy 13, each of which had a normal outcome, will be presented (Tables 1 and 2). The three main areas for consideration are: (1) the genetic counselling issues, (2) the additional prenatal diagnostic options available to evaluate the status of the fetus in an attempt to identify some of the clinical features of trisomy 13, and (3) the outcome of the pregnancies.  相似文献   
24.
Sustainable development relies on the eco-efficient use of all flows in society; more value created out of each resource unit. Supercritical water oxidation (SCWO) can be used for treatment of wet organic waste. The technology has been under development for over 20 years but has not yet been fully commercialized. SCWO allows for complete oxidation of all organics in sewage sludge and almost complete recovery of the inherent energy, essentially without harmful emissions. In this paper, a life-cycle assessment (LCA) of sewage sludge SCWO (Aqua-Critox) is presented and the results are compared with LCA results for other sludge handling options: agricultural use, co-incineration with municipal solid waste, incineration with subsequent phosphorus extraction (Bio-Con) and sludge fractionation with phosphorus recovery (Cambi-KREPRO). For SCWO, beneficial utilization of the heat of reaction is of crucial importance for the outcome. The electricity consumed by pumping and the nitrous oxide produced are other important parameters. The best sludge handling option from an environmental point of view depends on what aspect is considered more important in the impact assessment. Regarding global warming, the energy recovery methods perform better than agricultural use.  相似文献   
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26.
Which populations are replenished primarily by immigrants (open) and which by local production (closed) remains an important question for management with implications for response to exploitation, protection, and disturbance. However, we lack methods for predicting population openness. Here, we develop a model for openness and show that considering habitat isolation explains the existence of surprisingly closed populations in high-dispersal species, including many marine organisms. Relatively closed populations are expected when patch spacing is more than twice the standard deviation of a species'. dispersal kernel. In addition, natural scales of habitat patchiness on coral reefs are sufficient to create both largely open and largely closed populations. Contrary to some previous interpretations, largely closed marine populations do not require mean dispersal distances that are unusually short, even for species with relatively long pelagic larval durations. We predict that habitat patchiness has strong control over population openness for many marine and terrestrial species with a highly dispersive life stage and relatively sedentary adults. This information can be used to make initial predictions about where populations will be more or less resilient to local exploitation and disturbance.  相似文献   
27.
Climate-induced water availability changes in Europe   总被引:1,自引:0,他引:1  
Water availability changes in Europe are discussed in this paper, as seen in a perspective of climatic change. Such changes will be assessed in terms of the shifts in the watering of terrestrial ecosystems, as well as the shifts in the availability in terrestrial freshwater systems. A changing climate will have a major impact on the availability of water. Both wetter and drier conditions will have major implications for societal activities and land use patterns (e.g., agriculture, urban activities, waste water disposal, etc.).Some future research and monitoring activities are proposed by the authors to assess linkages in hydrological shifts to changes in land use patterns.  相似文献   
28.
Fluxes of some Volatile Organic Compounds (VOC) from grass were measured at a golf course in western Sweden, using the Relaxed Eddy Accumulation (REA) technique. The sampling was done by collecting VOC onto adsorbent tubes and the analysis was performed by thermal desorption followed by GC/MS. High emissions were observed after cutting. Transient fluxes of (Z)-3-hexenyl acetate (0.51 microg m(-2) s(-1)), (Z)-3-hexen-1-ol (0.14 microg m(-2) s(-1)) and (Z)-3-hexenal (0.40 microg m(-2) s(-1)) were measured, even at low temperatures. The REA technique requires a relatively large fetch area that is sometimes not available. Therefore, a procedure for correcting measured fluxes from a limited fetch is suggested.  相似文献   
29.
Lake sediment cores were analyzedto study the history of mercury (Hg) pollution andparticularly to determine whether recent sedimentconcentrations have declined in response todeclining atmospheric deposition of Hg. Sedimentcores from 6 forest lakes distributed fromsouthern to northern Sweden and 3 northernmountain lakes were analyzed for Hg using CVAAS. A400 cm sediment profile from Måkevatten insouthwest Sweden indicates that the onset of Hgpollution occurred in the 18th century. Anindisputable increase in Hg concentrationsoccurred concurrent with the appearance ofspheroidal carbonaceous flyash particles (SCP)derived from fossil-fuel combustion, in themid-19th century. There is a strong correlationbetween Hg and SCP concentrations in the sedimentcores (r=0.67 to 0.91), which suggests a strongrelationship between historical Hg pollution andfossil fuel burning. In contrast to sediment corestaken in 1979, maximum Hg concentrations are nowobserved below the sediment surface and declinetowards the sediment surface. This study confirmsthat reductions in atmospheric deposition of Hgover Sweden have resulted in a decreased transferof total Hg to aquatic environments as reflectedby lake sediments, and that lake sediment profilesof Hg concentrations reflect relative trends inthe atmospheric deposition of Hg rather thanpost-depositional diagenetic processes.  相似文献   
30.
Private forest owners are the main forest ownership group within Europe, and important conservation values have been found on their land. Yet, small plot sizes, societal heterogeneity, and structural changes impede developing and implementing effective conservation programs in private forests. We present a systematic literature review focusing on small-scale private forest owners and their perspectives on nature conservation by synthesizing research approaches, social-ecological drivers, and policy recommendations. Conservation perspectives were positively related to female gender, higher levels of education, formalized forest management, an active relation to the forest, and ecological values of the property. In contrast, high age, rural orientation, economic forest management factors, large parcel size, and economic and sentimental property values negatively influenced conservation perspectives. Applying a natural resource conflict management framework, we synthesized recommendations covering three dimensions: substance, procedure, relationship. Considering perspectives of small-scale private forest owners in current forestry decision-making has great potential to strengthen sustainable forest management that integrates nature conservation and resource use.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01615-w.  相似文献   
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