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861.
Bossew P Ditto M Falkner T Henrich E Kienzl K Rappelsberger U 《Journal of environmental radioactivity》2001,55(2):187-194
Austria ranks among the countries that have been most strongly affected by the Chernobyl fallout. The mean contamination with 137Cs is 21.0 kBq/m2, of which 18.7 kBq/m2 is due to the Chernobyl accident, whereas global fallout contributes 2.3 kBq/m2. Maximum values of total 137Cs contamination are nearly 200 kBq/m2. Total deposition of Chernobyl 137Cs on Austrian territory is 1.6 PBq or a fraction of around 2% of the 137Cs released from the reactor. 2115 measurements were used to draw the Austrian "caesium map". The geographical pattern of fallout distribution shows regional differences of contamination as high as 1:100. 相似文献
862.
Integrated measures for preservation, restoration and improvement of the environmental conditions of the Lagoon Olho d'Agua basin 总被引:1,自引:0,他引:1
The Lagoon Olho d'Agua in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants. 相似文献
863.
Investigation on organic pollutants from a domestic heating system using various solid biofuels 总被引:1,自引:0,他引:1
Various herbaceous biofuels (straw, whole plant cereals and set aside hay) and spruce wood were tested for their potential to form PCDD/F, PCPh, PCBz and PAH during combustion. The trials were conducted in an automatically charged multi-fuel furnace for domestic applications (50 kWth). Both, flue gas and the different ash fractions were analysed. CO-emission results show, that combustion conditions were relatively uniform (mean CO-level: 200 mg/m3 at 13% O2 in flue gas). Likewise, the TOC- and PAH-emissions in the fuel gas remained constantly on a relatively low level. However, for the PCDD/F, PCPh and PCBz increased emissions were detected when herbacious fuels were applied. This may be attributed to their higher chlorine concentration and the high ash content, which is responsible for increased dust emissions during combustion. Similar observations were also found for the PCDD/F-concentrations in the ashes. Combustion chamber ashes usually showed a drastically reduced contamination with highly toxical compounds, compared to the ash fraction from the heat exchanger ash or to chimney soot. 相似文献
864.
The levels of toxaphene congeners, in addition to PCB congeners and organochlorine pesticides, were determined in various fish samples from different Danish waters. While PCB-153 and p,p'-DDE show different levels depending on the fishing area, with highest levels in fish from the Western Baltic Sea, toxaphene was detected in all the samples investigated at a more constant level. The distribution of the three toxaphene congeners Parlar #26, #50 and #62 depends on the fishing area, with the Western Baltic Sea being different from the other waters by having almost equal levels of toxaphene congeners #26 and #50. 相似文献
865.
Aldrich TE 《Chemosphere》2000,41(1-2):59-67
Environmental epidemiology is the specialized aspect of public health science that studies human health risk from environmental hazards. It is rises largely upon a foundation of public health surveillance, and relies heavily upon analyses of data for small areas and sparse population groups. To a degree, environmental epidemiology is assigned the role of discerning very subtle human health impacts, or discerning early evidence of a tragic sequence. In that context, environmental epidemiology has a substantial public education and risk communication role. Environmental epidemiology will be greatly advanced as effective biological markers of exposure and precursor health effects are developed. At this point in time, statistical methods are in place to monitor population-level disease rates in high-risk populations for early risk identification and sentinel event recognition. Advances in geographic methods have provided a boon to the discipline by advantaging spatial studies. These advances in the discipline still need further refinement and pilot experiences. The inclusion of environmental epidemiological considerations with instances of proposed industrial expansion, hazardous waste management, and contamination remediation is heartily recommended. 相似文献
866.
Holt MS Fox K Griessbach E Johnsen S Kinnunen J Lecloux A Murray-Smith R Peterson DR Schröder R Silvani M ten Berge WF Toy RJ Feijtel TC 《Chemosphere》2000,41(11):1799-1808
Monitoring and laboratory data play integral roles alongside fate and exposure models in comprehensive risk assessments. The principle in the European Union Technical Guidance Documents for risk assessment is that measured data may take precedence over model results but only after they are judged to be of adequate reliability and to be representative of the particular environmental compartments to which they are applied. In practice, laboratory and field data are used to provide parameters for the models, while monitoring data are used to validate the models' predictions. Thus, comprehensive risk assessments require the integration of laboratory and monitoring data with the model predictions. However, this interplay is often overlooked. Discrepancies between the results of models and monitoring should be investigated in terms of the representativeness of both. Certainly, in the context of the EU risk assessment of existing chemicals, the specific requirements for monitoring data have not been adequately addressed. The resources required for environmental monitoring, both in terms of manpower and equipment, can be very significant. The design of monitoring programmes to optimise the use of resources and the use of models as a cost-effective alternative are increasing in importance. Generic considerations and criteria for the design of new monitoring programmes to generate representative quality data for the aquatic compartment are outlined and the criteria for the use of existing data are discussed. In particular, there is a need to improve the accessibility to data sets, to standardise the data sets, to promote communication and harmonisation of programmes and to incorporate the flexibility to change monitoring protocols to amend the chemicals under investigation in line with changing needs and priorities. 相似文献
867.
Andréa MM Peres TB Luchini LC Pettinelli A 《Journal of environmental science and health. Part. B》2000,35(3):297-307
The soil oxidative and anaerobic processes, as well as, the microbial biomass were followed during three years in a cotton farm (Tatuí) where the recommended pesticides have been used for several years, and in an experimental field (S?o Paulo) treated first time with the same pesticides. The oxidative process was monitored by the dehydrogenase (DHA)-activity using triphenyltetrazolium chloride (TTC) as substrate. The anaerobic process was followed by the iron-oxide reduction, and the microbial biomass was estimated by the substrate (glucose)-indiced respiration. Increases in DHA-activity and in the microbial biomass occurred only in the farm soil, with concomitant decreases in iron-reduction. In the experimental field soil, the increases in DHA-activity were followed only by decreases in iron-reduction. Soil characteristics were the determining factor for different biological parameters after pesticide inputs. All the pesticides produced at least one clear but transient effect. 相似文献
868.
Reisel JR Kellner TA Neusen KF 《Journal of the Air & Waste Management Association (1995)》2000,50(4):522-528
Partially speciated hydrocarbon (HC) emissions data from several small utility engines, as measured by a Fourier Transform Infrared analyzer, are presented. The engines considered have nominal horsepower ratings between 3.7 and 9.3 kW. Both side-valve and overhead-valve engines are studied, and four different fuels are used in the engines. The results indicate that the small HCs present in the exhaust tend to be in the form of either methane or unsaturated HCs. Other small alkanes, such as ethane and propane, are present in only relatively small concentrations. In terms of ozone formation potential, the HCs in the form of methane will lead to little ozone, but the distribution of the C2 and C3 species is not ideal from an ozone reduction stand-point. It is also found that the presence of oxygen in the fuels appears to lead to somewhat more complete combustion, although the effects are not large. Finally, the overhead-valve engines appear to have lower HC emissions than side-valve engines, which is primarily due to higher operating A/F ratios and the engine geometry. 相似文献
869.
Wilson WE Mage DT Grant LD 《Journal of the Air & Waste Management Association (1995)》2000,50(7):1167-1183
This paper discusses the legal and scientific reasons for separating personal exposure to PM into ambient and nonambient components. It then demonstrates by several examples how well-established models and data typically obtained in exposure field studies can be used to estimate both individual and community average exposure to ambient-generated PM (ambient PM outdoors plus ambient PM that has infiltrated indoors), indoor-generated PM, and personal activity PM. Ambient concentrations are not highly correlated with personal exposure to nonambient PM or total PM but are highly correlated with personal exposure to ambient-generated PM. Therefore, ambient concentrations may be used in epidemiology as an appropriate surrogate for personal exposure to ambient-generated PM. Suggestions are offered as to how exposure to ambient-generated PM may be obtained and used in epidemiology and risk assessment. 相似文献
870.
In studies on the formation of disinfection byproducts (DBPs), it is necessary to scavenge residual active (oxidizing) chlorine in order to fix the chlorination byproducts (such as haloethanoates) at a point in time. Such research projects often have distinct needs from requirements for regulatory compliance monitoring. Thus, methods designed for compliance monitoring are not always directly applicable, but must be adapted. This research describes an adaptation of EPA Method 552 in which ascorbic acid treatment is shown to be a satisfactory means for reducing residual oxidizing chlorine, i.e., HOCl, ClO-, and Cl2, prior to determining concentrations of halocarboxylates. Ascorbic acid rapidly reduces oxidizing chlorine compounds, and it has the advantage of producing inorganic halides and dehydroascorbic acid as opposed to halogenated organic molecules as byproducts. In deionized water and a sample of chlorinated tap water, systematic biases relative to strict adherence to Method 552 were precise and could be corrected for using similarly treated standards and analyte-fortified (spiked) samples. This was demonstrated for the quantitation of chloroethanoate, bromoethanoate, 2,2-dichloropropanoate (dalapon), trichloroethanoate, bromochloroethanoate, and bromodichlorocthanoate when extracted, as the acids, into tert-butyl methyl ether (MTBE) and esterified with diazomethane prior to gas chromatography with electron capture detection (GC-ECD). Recoveries for chloroethanoate, bromoethanoate, dalapon, dichloroethanoate, trichloroethanoate, bromochloroethanoate, bromodichloroethanoate, dibromoethanoate, and 2-bromopropanoate at concentrations near the lower limit of detection were acceptable. Ascorbic acid reduction appears to be the best option presently available when there is a need to quench residual oxidants fast in a DBP formation study without generating other halospecies but must be implemented cautiously to ensure no untoward interactions in the matrix. 相似文献