AN EVALUATION OF ALTERNATIVE POLICIES FOR CONTROLLING AGRICULTURAL NONPOINT SOURCE POLLUTION1

An economic analysis of nonpoint source pollution management was conducted for the Nansemond River and Chuckatuck Creek watersheds in Southeast Virginia. The potential effects of alternative public policies on farm income, land use, and pollution loadings were investigated. Regulatory programs could have quite different impacts depending on which pollutant is targeted. Cost-share rates greater than 50 percent would have little additional effect on pollution from crop enterprises, but would reduce pollution from livestock     

EuroBionet: a pan-European biomonitoring network for urban air quality assessment

EuroBionet, the 'European Network for the Assessment of Air Quality by the Use of Bioindicator Plants', is an EU-funded cooperative project currently consisting of public authorities and scientific institutes from 12 cities in 8 countries. In 2000, the bioindicator plants tobacco (Nicotiana tabacum Bel W3), poplar (Populus nigra 'Brandaris'), spiderwort (Tradescantia sp. clone 4430), Italian rye grass (Lolium multiflorum italicum) and curly kale (Brassica oleracea acephala) were exposed to ambient air at 90 monitoring sites according to standardised methods. Visible injuries and growth parameters were assessed and the accumulation of toxic substances in leaves determined. The exposure of tobacco resulted in a gradient with low levels of ozone-induced foliar injury in N and NW Europe, and medium to high values in the southern and central regions. The results of heavy metal and sulphur analyses in rye grass samples generally showed low to very low sulphur and low to medium heavy metal concentrations in leaves. In some cities, however, local hot spots of heavy metal contamination were detected. Analyses of the PAH contents in curly kale leaves gave low to medium values, with locally elevated levels at traffic-exposed sites.     

Microsatellite analysis provides efficient confirmation of fetal trophoblast isolation from maternal circulation

Fetal trophoblasts can be found in maternal circulation from an early stage of pregnancy and thus provide a potential source of DNA for non-invasive prenatal diagnosis. We have developed a two-step method for trophoblast isolation between the 8th and 12th week of pregnancy. Blood was sampled from 14 women undergoing termination of pregnancy or spontaneous abortion. Immunomagnetic beads precoated with HLA class I and II, and with anti-cytokeratin-18 monoclonal antibodies, were used to remove CD8+ and other maternal cells, and to select for fetal trophoblasts, respectively. Microsatellite analysis was performed on DNA extracted from the isolated, maternal, paternal and placental cells after PCR amplification. Recovery of the trophoblasts was confirmed in 13/14 cases (93%) by the identification of an identical microsatellite pattern for fetal and placental cells. Further evidence was the presence of heterozygous alleles of both maternal and paternal origin. The correct prediction of gender in all five male fetuses was an additional confirmation of trophoblast recovery. We conclude that trophoblasts can be effectively isolated from maternal blood in the first trimester, and by using polymorphic microsatellite markers to confirm sample purity, this method has potential future application in prenatal diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.     

Volatile Organic Compounds Selection for Incorporation in Photochemical Mechanisms and the Development of Secondary Pollution Reduction Strategies

In the present work a method for the evaluation of the importance of the VOCs species is presented, aiming to provide criteria for the incorporation of these species into atmospheric photochemical mechanisms and for the successful application of secondary pollution reduction strategies. According to the method presented here, the species can be divided into more important and less important ones, taking into account their mixing ratios and emission values in combination with their reactivity. For this classification three quantitative and one qualitative criteria were introduced. Overall, it is concluded that alkenes with more than a few carbon atoms in their chain appear to be more important in urban and suburban areas, while in background conditions the alkanes, having the smaller chain (ethane, propane), become more important. In the case of alkenes there is no clear species classification, except for the biogenically emitted compounds, isoprene and limonene. In general, more important alkenes appear to be those with the smaller chain (ethene, propene, butene). Most abundant aromatics are benzene, toluene, and xylene. In background conditions higher aromatics are also important, especially 1,2,3-, 1,3,5-, and 1,2,4-trimethylbenzene. The most important carbonylic compounds are formaldehyde, acetaldehyde, and acetone. Finally, taking into account the results mentioned above, a new photochemical mechanism was developed. The species and species groups used in the proposed mechanism are: ethane, higher alkanes, ethene, propene, 2- butene, 1-alkenes, 2-alkenes, higher alkenes, benzene, toluene, m-, o-, p-xylene, 1,3,5-, 1,2,3-, 1,2,4-trimethylbenzene, higher aromatics, formaldehyde, acetaldehyde, higher aldehydes, isoprene, limonene, and other biogenic VOCs.     

The Importance of Mixing Height in Characterising Pollution Levels from Aerosol Optical Thickness Derived by Satellite

In the present study the horizontal distribution of columnar aerosol optical thicknessderived at high spatial resolution from Earth observation satellite data in the Lombardy area (Italy) was converted to the horizontal distribution of optically effective aerosols concentration at the ground level. This was achieved by incorporating information on atmosphere's mixing height, at which pollutants released at ground level are vertically dispersed by convection or mechanical turbulence. The resulted fields compared favourably to pollutant concentration measurements provided by the ground stations. These results show that it is possible to calculate mean concentration fields by using the spatial distribution of aerosol optical thickness (AOT) measured by satellite normalized by the atmospheric mixing height. The advantage of satellites in measuring AOT is that they can capture all actual emissions compared to the models, which are based on inventoried data.     

Evaluation of EHS hazard and sustainability metrics during early process design stages using principal component analysis

A principal component analysis (PCA) based methodology accounting for EHS hazard and sustainability metrics has been recently proposed in literature (Srinivasan and Nhan, 2008) to deal with the subjective weighting problem of existing index-based methods. In this study we evaluate the potential use of the PCA-based method during early phases of process design in the problem of selection between various synthesis paths, also called chemical routes, for the production of chemical compounds. The study also focuses on the impact of the methodology settings on the obtained chemical route rankings and their interpretation. Two case studies have been performed regarding the production of 4-(2-methoxyethyl)-phenol (MEP) and methyl methacrylate (MMA) using fifteen different evaluation categories capturing various sustainability metrics. The PCA-based method identified the most promising chemical routes as well as the most important evaluation categories. The necessity for normalization of the raw data was demonstrated, without the method being very sensitive to the type of normalization. Moreover, the effect of the transition approach from chemical step to chemical route scores is discussed. The results of the PCA-based method are also compared with an index-based method (Koller et al., 2000) sharing the same evaluation categories, as well as with other index-based frameworks in order to reveal the extent of similarities.     

A Multidisciplinary Decision Support System for Forest Fire Crisis Management

A wildland fire is a serious threat for forest ecosystems in Southern Europe affecting severely and irreversibly regions of significant ecological value as well as human communities. To support decision makers during large-scale forest fire incidents, a multidisciplinary system has been developed that provides rational and quantitative information based on the site-specific circumstances and the possible consequences. The systems architecture consists of several distinct supplementary modules of near real-time satellite monitoring and fire forecast using an integrated framework of satellite Remote Sensing, GIS, and RDBMS technologies equipped with interactive communication capabilities. The system may handle multiple fire ignitions and support decisions regarding dispatching of utilities, equipment, and personnel that would appropriately attack the fire front. The operational system was developed for the region of Penteli Mountain in Attika, Greece, one of the mountain areas in the country most hit by fires. Starting from a real fire incident in August 2000, a scenario is presented to illustrate the effectiveness of the proposed approach.