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81.
Three beehive matrices, sampled in six different apiaries from West France, were analyzed for the presence of four polycyclic aromatic hydrocarbons (PAH4: benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene). Samples were collected during four different periods in both 2008 and 2009. Honey samples showed the lowest levels of PAH4 contamination (min = 0.03 μg kg−1; max = 5.80 μg kg−1; mean = 0.82 μg kg−1; Sd = 1.17). Bee samples exhibited higher levels of PAH4 contamination (min = 0.32 μg kg−1; max = 73.83 μg kg−1; mean = 7.03 μg kg−1; Sd = 17.83) with a great dispersion of the concentrations due to four main events of high concentrations. Pollen samples showed only one major episode with the highest PAH4 concentration found (min = 0.33 μg kg−1; max = 129.41 μg kg−1; mean = 7.10 μg kg−1; Sd = 22.28). The PAH4 concentrations found were significantly influenced by the landscape context for all beehive samples.  相似文献   
82.
In the context of massive summer mortality events of the Pacific oyster Crassostrea gigas, the aim of this study was to investigate the early effects on genes, enzymes and haemocyte parameters implicated in immune defence mechanisms in C. gigas oysters exposed to a potentially hostile environment, i.e. to an herbicide alone or within a mixture. Following 2 h of exposure to the herbicide diuron at 1 μg L−1, the repression of different genes implicated in immune defence mechanisms in the haemocytes and the inhibition of enzyme activities, such as laccase-type phenoloxidase (PO) in the plasma, were observed. The inhibition of superoxide dismutase (SOD) activity in the plasma was also observed after 6 and 24 h of exposure. In the mixture with the herbicides diuron and isoproturon, and the pharmaceutical ibuprofen, catecholase-type PO activity in the plasma and the percentage of phagocytosis in the haemocytes were reduced after 6 h of exposure. Our results showed that early effects on molecular, biochemical and cellular parameters can be detected in the presence of diuron alone or within a mixture, giving an insight of its potential effect in situations that can be found in natural environments, i.e. relatively high concentrations for short periods of time.  相似文献   
83.
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) bioaccumulate through the food chain and are therefore of public health concern. Exposure to these compounds was assessed in the second French Total Diet Study (TDS). Food samples (n=583) were collected to be representative of the whole diet of the population, prepared as consumed, and analyzed. Contamination data were combined with national individual food consumption data. Mean exposure (95th percentile) to PCDD/F+DL-PCBs was assessed to be 0.57 (1.29) pg TEQ(WHO-98) (kg bw)(-1) d(-1) in the adult population and 0.89 (2.02) pg TEQ(WHO-98) (kg bw)(-1) d(-1) in the child and teenager population. Less than 4% of the population exceeded the health-based guidance value for PCDD/F+DL-PCBs. Mean exposure (95th percentile) to the six indicator PCBs (PCB 28, 52, 101, 138, 153, 180) was estimated at 2.71 (7.90) ng (kg bw)(-1) d(-1) in the adult population and 3.77 (11.7) ng (kg bw)(-1) d(-1) in the child and teenager population. Only 2.6% of the adults [CI(95%): 1.9; 3.3] and 6.5% of the children and teenagers [5.2; 7.8] exceeded the health-based guidance value for total PCBs. These results show that the contamination levels in food and therefore the exposure of the general French population to PCDD/Fs and PCBs have declined (by a factor of 3.2 for PCDD/F+DL-PCBs and about three for total PCBs) since the last evaluation, which was conducted using another methodology in 2005 and 2007, and show the efficiency of the European risk management measures which came into force after these evaluations.  相似文献   
84.

Purpose  

A former wood exploitation revealing high Cu and As concentration of the soils served as a case study for assisted phytoextraction.  相似文献   
85.

Introduction  

High concentrations of hexabromocyclododecane (HBCD) sometimes recorded in free-range hens' eggs are thought to be due to soil ingestion. Of the three stereoisomers of HBCD (α-, β-, and γ-HBCD), γ-HBCD is the main component in the commercial mixture, as well as in environmental matrices, whereas the isomer profile is α-dominated in biota. In fish and in mammals, this shift is thought to be due to a rapid elimination of γ-HBCD and to its bioisomerization to the more persistent α-HBCD. The aim of the current controlled study was to better understand the fate of ingested HBCD in laying hens. The isomer profile in soil being γ-dominated, excretion kinetics of γ-HBCD into egg yolk, and accumulation in liver and in abdominal fat were investigated.  相似文献   
86.
基于获得高效纤维素降解细菌的目的,通过LB培养基的培养以及刚果红培养基的筛选,从牛粪堆肥中筛选获得2株高效纤维素降解细菌。经鉴定,分别为枯草芽胞杆菌(Bacillus subtilis)和地衣芽胞杆菌(Bacillus licheniformis)。所筛选得到的菌种具有很高的滤纸降解能力,可在6d内使滤纸剧烈崩溃,振摇成均匀糊状;其中,地衣芽胞杆菌的羧甲基纤维素钠酶活峰值在发酵第4天达到峰值(237U/g)。  相似文献   
87.
A method, based on spatial analysis of the different criteria to be taken into consideration for building scenarios of CO2 capture and storage (CCS), has been developed and applied to real case studies in the Hebei province. Totally 88 point sources (42 from power sector, 9 from iron and steel, 18 from cement, 16 from ammonia, and 3 from oil refinery) are estimated and their total emission amounts to 231.7 MtCO2/year with power, iron and steel, cement, ammonia and oil refinery sharing 59.13%, 25.03%, 11.44%, 3.5%, and 0.91%, respectively. Storage opportunities can be found in Hebei province, characterised by a strong tectonic subsidence during the Tertiary, with several kilometres of accumulated clastic sediments. Carbon storage potential for 25 hydrocarbon fields selected from the Huabei complex is estimated as 215 MtCO2 with optimistic assumption that all recovered hydrocarbon could be replaced by an equivalent volume of CO2 at reservoir conditions. Storage potential for aquifers in the Miocene Guantao formation is estimated as 747 MtCO2 if closed aquifer assumed or 371 MtCO2 if open aquifer and single highly permeable horizon assumed. Due to poor knowledge on deep hydrogeology and to pressure increase in aquifer, injecting very high rates requested by the major CO2 sources (>10 MtCO2/year) is the main challenge, therefore piezometry and discharge must be carefully controlled. A source sink matching model using ArcGIS software is designed to find the least-cost pathway and to estimate transport route and cost accounting for the additional costs of pipeline construction due to landform and land use. Source sink matching results show that only 15–25% of the emissions estimated for the 88 sources can be sequestrated into the hydrocarbon fields and the aquifers if assuming sinks should be able to accommodate at least 15 years of the emissions of a given source.  相似文献   
88.
This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function of value chains, their contribution to the livelihoods of farmers and fishers, the effectiveness of government policy and the potential for value chain governance mechanisms, such as contracts and certification, to steer towards sustainable production. The results indicate that actors in the high value Pangasius hypopthalmus export chain have a higher potential income, but face considerably higher economic vulnerability from global markets. Alternatively, Henichorhychus/Labiobarbus spp. fishers are severely constrained in their ability to negotiate higher prices for their fish but appear to be less vulnerable to economic and environmental change. The paper concludes that for value chain governance to improve the livelihoods of fishers and farmers in both high and low value chains, new arrangements are needed that better accommodate customary institutions and informal market relations.  相似文献   
89.
Residues of pesticides in fish farming productions from barrage ponds are seldom studied in spite of increasing health questionings and environmental concerns. The purpose of this study is to establish the pesticide contamination profiles of sediments and edible fish from five ponds in Northeastern France. Multi-residues method and liquid chromatography–tandem mass spectrometry analysis were used to quantify 13 pesticides (azoxystrobin, carbendazim, clomazone, diflufenican, dimethachlor, fluroxypyr, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop and thifensulfuron-methyl). Ten sediments and 143 muscles samples were analysed, corresponding to two successive fishing campaigns (first fishing date and second fishing date (P2), about 1 year later) on five sites (noted C-0, C-25, C-45, C-75 and C-85 to express the increasing gradient of crop area). Isoproturon was present in all sediments samples (1.8–56.4 μg/kg dry weight). During P2 period, carbendazim was quantified in the fish of site C-0 (0.09?±?0.02, 0.2?±?0.1 and 0.17?±?0.06 μg/kg wet weight (ww) for roach, carp and perch, respectively). Metazachlor was only quantified in perch of the site C-25 (0.13?±?0.02 μg/kg ww). Concentrations of isoproturon were similar for the sites C-45 and C-75 with 0.4?±?0.1 and 0.75?±?0.06 μg/kg ww for carp and perch, respectively. Contamination of fish reflected generally concentrations in surroundings. Isoproturon was the most concentrated and its main source was water for perch while carp was exposed through both water and sediments, highlighting their life strategies in pond.  相似文献   
90.
Interdisciplinary scientific knowledge is necessary but not sufficient when it comes to addressing sustainable transformations, as science increasingly has to deal with normative and value-related issues. A systems perspective on coupled human–environmental systems (HES) helps to address the inherent complexities. Additionally, a thorough interaction between science and society (i.e., transdisciplinarity = TD) is necessary, as sustainable transitions are sometimes contested and can cause conflicts. In order to navigate complexities regarding the delicate interaction of scientific research with societal decisions these processes must proceed in a structured and functional way. We thus propose HES-based TD processes to provide a basis for reorganizing science in coming decades.  相似文献   
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