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411.
Andreas Ahrens Frank Claus Kerstin Heitmann Dirk Jepsen Lothar Kistenbrügger 《Environmental Sciences Europe》2006,18(2):123-128
In October 2003, the EU Commission presented the proposal for a new Chemicals Regulation. In late autumn 2005, Parliament and Council were working on finding their position on the Commission’s proposal. From November 2004 to April 2005, a simulation was carried out at EU level aiming to test the workability of registration under REACh. Based on a strategic partnership, the European Chemical Industry Council together with other industry associations, the EU Commission and a number of Member States had launched this project. 53 manufacturers or users of chemicals and competent authorities of 13 EU Member States took part in the simulation: eight registration cases were dealt with in parallel. The participants had to conduct the registration of a substance (including preparatory work) and the dossier evaluation by the authorities. The simulation was performed in a ’free-flow mode’, which means, that the participants worked without any guidance on how to practically implement the duties and tasks as laid down in the draft regulation. In the final phase of the project, the three strategic parners worked towards a common understanding on potential workability problems and suitable options for solutions. This process resulted in a report including a set of agreed recommendations on 12 identified workability issues The recommendations are mostly related to the co-operation between registrants, the sharing of responsibilities and communication between manufactures and down-stream users as well as technical and scientific aspects of dossier compilation., In addition, the recommendations address the need to develop a common understanding across Europe regarding the role of authorities in evaluating the registration dossiers and developing suitable tools for the evaluation. In addition to the set of practical recommendations, SPORT has demonstrated that useful insights in the workability of a new piece of legislation can be gained from simulating the key processes in practise already during the legislative process. Such pilot trials could be seen as a contribution toBetter Regulation, one of the strategic goals of the EU Commission. 相似文献
412.
413.
A novel method, based on iterative numerical integration, is presented for deriving bioconcentration factors and rate constants of chemicals in aquatic organisms from experimental data of bioconcentration tests in which the chemical concentration in the water is variable over time and the test duration is too short to reach steady-state. The method is applied to reported data from fish and plant bioconcentration tests. The results demonstrate that this method can derive bioconcentration factors and rate constants with considerably less experimental error than other methods currently used, thus reducing uncertainty and variability in bioconcentration measurements. 相似文献
414.
Adam Faschan Marty Tittlebaum Frank Cartledge Harvill Eaton 《Environmental monitoring and assessment》1991,18(2):145-161
API separator sludge was solidified with various combinations of binders and absorbent soil additives. The binders utilized were Type I Portland Cement, Type C Flyash, and a 1:1 combination of the two. The soil additives used were bentonite, diatomite, Fuller's earth, and two brands of chemically altered bentonites, or organoclays. The effectiveness of the solidification materials was based on their effect on the physical and leaching characteristics of the sludge.It was determined the Portland cement and combination binders provided the sludge with adequate physical and strength characteristics. It was also determined the affinity of each additive for water had an important influence on the physical characteristics of the solidified sludge. The results of the leaching procedure indicated the binders alone reduced the leachability of organic constituents from the sludge by 1/5 to 1/10. It appeared the use of the additives with the binders may have further reduced the leachability of constituents from sludge, with the incorporation of the organoclay additives further reducing leachability by up to 1/2. Also, it appeared the absorbing capacity of the additives was directly related to their ability to reduce the leachability of organic constituents from the sludge. 相似文献
415.
Migual A. Mora Linda L. Laack M. Clare Lee Jose Sericano Robert Presley Piero R. Gardinali Lawrence R. Gamble Stephen Robertson Donell Frank 《Environmental monitoring and assessment》2000,64(2):477-492
The ocelot (Felis pardalis) isan endangered neotropical cat distributed within asmall range in the Lower Rio Grande Valley (LRGV), inTexas, U.S.A. Studies of the impacts of environmentalcontaminants in wild cats are few. Approximately onefourth of the estimated population (about 100) ofocelots in the LRGV was sampled to evaluate theimpacts of chlorinated pesticides, polychlorinatedbiphenyls, and trace elements on the population. Hairwas collected from 32 ocelots trapped between 1986–1992,and blood was collected from 20 ocelots trappedbetween 1993–1997. A few blood samples were obtainedfrom individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were alsoanalyzed. DDE, PCBs, and Hg were some of the mostcommon contaminants detected in hair and blood. MeanHg levels in hair ranged from 0.5 to 1.25 g g-1 dw,Se from 1.5 to 3.48 g g-1 dw, and Pb from 0.56 to26.8 g g-1 dw. Mean DDE concentrations in plasma ranged from 0.005 g g-1 ww to 0.153 g g-1 ww, and PCBs ranged from 0.006 g g-1 ww to 0.092 g g-1 ww. Mean Hg levels in red blood cells rangedfrom 0.056 g g-1 dw to 0.25 g g-1 dw. Concentrations of DDE, PCBs, or Hg, did not increasesignificantly with age, although the highestconcentrations of DDE and Hg were found in olderanimals. Overall, concentrations of DDE, PCBs, and Hgwere low and at levels that currently do not pose anythreat to health or survival of the ocelot. This isfurther supported by good reproduction of the ocelotin the LRGV, where adult females averaged about 1.5kittens/litter. Thus, it seems that the current majorthreat to recovery of the ocelot in the LRGV may behabitat loss, although potential impacts of newgeneration pesticides, such as organophosphorus andcarbamate insecticides need further study. 相似文献
416.
Frank Golley Sanne Bakker Toshihide Hamazaki 《Environmental monitoring and assessment》1992,22(2):117-122
CO2 flux of a deciduous forest and an old-field surface, and the ecotone between these two typical southern U.S. ecological communities, was studied in July, 1989. Rates of CO2 flux were greatest in the old field and least in the forest plots. The ecotone showed the greatest variation in CO2 flux. These differences appear to be due to differences in soil surface temperature, the old field being more exposed to direct solar radiation. The ecotonal community represents a landscape property which should be considered in studies of the transfer of carbon across the soil-atmosphere boundary. 相似文献
417.
Frank M. D'Itri 《Environmental monitoring and assessment》1991,19(1-3):165-182
Atmospheric cycling of mercury and other pollutants has become a major concern as industrialized countries have eliminated point discharges, sometimes by relocating the industries to underdeveloped and developing countries where point sources have become problems. Such circumventions may be to no avail in the long run as pollution continues to elevate levels of methylmercury in fish in waterways that are remote from direct contamination as well as where the source can be readily identified. Much has been learned about the cycling of mercury in the environment since human disabilities and deaths at Minamata, Japan, initially drew attention to the problem of methylmercury poisoning from the consumption of contaminated seafood in the 1950s. In that instance, methylmercury produced industrially concentrated to toxic levels in fish. As this manufacturing process was not used outside Japan, concern did not become immediate in other developed nations until the 1960s when it was established that mercury was not only biomethylated by microorganisms but also biomagnified through the food chain. Point sources to the waterways may have been eliminated too late to return the levels in fish to background because of the geochemical cycling of mercury through the environment. Despite decreases in domestic, industrial and agricultural point source releases over the last two decades, large quantities from non-point sources such as fossil fuel combustion, smelters, and incinerators are still being released. Much of this mercury is transported from the atmosphere to aquatic ecosystems and stored in sediments until it is again released to the water and atmosphere. 相似文献
418.
G. B. Wiersma C. W. Frank M. J. Case A. B. Crockett 《Environmental monitoring and assessment》1984,4(3):233-255
This paper describes the application of simple linear models to help design environmental monitoring systems. This process involves five steps: (1) The derivation of a schematic of the identified pollutant's transport and fate. (2) The derivation of the equation in the schematic. (3) Estimation of input data and numerical solution. (4) Comparison with initial field data. (5) Design of a monitoring system.Two examples of how this system was applied under field conditions are given. Advantages of this approach are: (1) It forces a consideration of the system as a whole rather than a series of distinct environmental components. (2) It forces a consideration of the physical-chemical and biological factors effecting pollutant transport in the system. (3) It sets up an analytical procedure for data analysis at the time the monitoring system is designed. (4) It helps show the functional relationship between pollutant levels in different environmental media. (5) It identifies points where sampling design could be changed to provide for a more efficient monitoring system. (6) It identifies gaps in our knowledge base. 相似文献
419.
A pilot study on the determination of perfluorooctanesulfonate and other perfluorinated compounds in blood of Canadians 总被引:7,自引:0,他引:7
A pilot study was conducted to provide preliminary data on the concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonamide (PFOSA) in the blood of Canadians. A set of 56 human serum samples was collected from non-occupationally exposed Canadians and analyzed by microbore HPLC-negative ion electrospray tandem mass spectrometry. PFOS was the main component of perfluorinated organic compounds (PFCs) and was detected in all 56 blood specimens at an average concentration of 28.8 ng mL(-1) and a range from 3.7 to 65.1 ng mL(-1). The concentration of PFOA was an order of magnitude lower than that of PFOS and was found only in 16 samples (29%) at concentrations above the limit of quantification (LOQ). PFOSA was not detected at levels above the method detection limit (MDL) in any of the samples. The levels of PFCs observed in the sample group of non-occupationally exposed humans in Canada were similar to the levels reported in a previous US study with a similar sample pool size. Two distinct PFOS isomers in human serum were identified by accurate mass determination. 相似文献
420.
Informal hierarchies are a common and important feature of many groups, yet we know little about the antecedent conditions that determine the strength of such hierarchies. Building on theory that has depicted hierarchy as a mechanism for reducing uncertainty and creating structure, we posit that informal hierarchies emerge most strongly in situations that are ambiguous, ill‐defined, and unstructured. Three independent studies confirm this notion, demonstrating that groups develop particularly strong informal hierarchies in situations characterized by both a lack of strong formal leadership and high task complexity. These findings support the theoretical notion that formal and informal hierarchies are closely related, but only under conditions of high task complexity in which the structuring functions of hierarchies are most crucial. 相似文献