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The distribution of mutagenic activity and nitroaromatic components of polycyclic organic matter (POM) in ambient air at industrial, urban, suburban, rural, and remote sites was studied using organic extracts from high volume aerosol samples. Direct-acting mutagens including 1-nitropyrene (1-NP), dinitropyrenes (DNP), and hydroxynitropyrenes (HNP) were measured by high performance liquid chromatography while the mutagenicity was determined in the Salmonella bioassay with strain TA-98. Benzo(a)pyrene (BaP), one of the possible precursors of nitroaromatic compounds in POM, was also measured. In comparing samples from a range of sites, TSP and the concentration of BaP per mass of particulate matter decreased, as expected, at greater distances from urban and industrial combustion sources. However, the concentrations of polar nitroaromatic POM compounds per mass of particles were higher at a remote site than in nonindustrial urban and suburban areas. The mutagenicity in particulate matter extracts from the remote area was predominantly (>90 percent) in the very polar fractions. There were also high atmospheric levels of nitroaromatic compounds and mutagenicity in heavily industrialized areas. These observations may reflect the influences of source emissions, atmospheric transformations of POM compounds, and ther atmospheric processes on the composition of ambient suspended particulate matter.  相似文献   
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A biomonitoring survey using the moss species Hypnum cupressiforme Hedw. was conducted in the surroundings of two steel plants located in the North of Spain. Levels of V, Cr, Ni, Cu, Zn, As, Cd, Hg, Pb and N were determined. Very high concentrations in the areas of study were detected when compared to nearby unaffected regions. Similar trends were observed for all the elements in the differently orientated transects, showing an appreciable influence of the NW prevailing winds of the region in the dispersion of pollutants, as well as a clear decreasing gradient in the concentrations of metals in mosses within a distance of 1500 meters from the facilities. A differentiation between the elements emitted by the chimney as result of the industrial activity (V, Cr, Ni, Cu and As) and those with a high presence in steel slag deposits (Zn, Cd, Hg and Pb) was observed. The range of contamination was also established by means of the Contamination Factor, indicating a category 4 out of 6 categories, which shows the high levels reported in the areas of study. A different dynamic was registered for nitrogen regarding the rest of the heavy metals analysed except for Hg, probably due to the elevated volatility and mobility of both elements, as well as their high persistence in the atmosphere.  相似文献   
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Abstract

A total of 77 On-Board Diagnostics II (OBDII)-equipped vehicles with illuminated malfunction indicator lights (MILs) and non-evaporative codes were tested before and after repair. The test cycles included the Federal Test Procedure (FTP), IM240, and steady-state cycles. A total of 17 vehicles were found with emissions greater than 1.5 times their respective FTP emissions standards. Repair of these vehicles resulted in dramatic reductions in overall emissions for all the cycles. A majority of the remaining vehicles were found to have emissions below the certification standard for the FTP both before and after repair. Repairs for the vehicles with emissions <1.5 times the standard resulted in some smaller but quantifiable emission reductions over the FTP and IM240 but larger reductions over the steady-state driving tests. Misfires, bad oxygen sensors, and exhaust gas recirculation (EGR) problems were the most common non-evaporative causes for triggering the MIL. The results show some fundamental differences between identifying malfunctioning vehicles using OBDII as opposed to more traditional dynamometer tests. In particular, for many systems, OBDII identifies components that are operating outside their design specification rather than for a specific emissions threshold.  相似文献   
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Sand dunes are complex systems that contain several habitats, often as mosaics or transitions between types. Several of these habitats are afforded protection under European Legislation and in the UK nationally within Special Areas of Conservation (SAC) and Sites of Special Scientific Interest (SSSI). Natural England has a statutory duty to report to Europe on the conservation status and condition of sand dunes; and is required to report to the UK Government on designated sites. To achieve this we have sought ways of capturing, analysing and interpreting data on the extent and location of sand dune habitats. This requires an ability to be able to obtain data over large areas of coastline in an efficient way. Natural England and Environment Agency Geomatics have worked collaboratively for over 16 years, sharing data and ecological knowledge. In 2012 work started to evaluate the use of remote sensing to map UK BAP and Annex I sand dune habitats. A methodology has now been developed and tested to map sand dune habitats. The key objective was to provide an operational tool that will help to map these habitats and understand change on sites around England. This has been achieved through analysis of LIDAR and Compact Airborne Spectrographic Imager (CASI) data using Object Orientated Image Analysis. Quality Control (QC) and accuracy assessments have shown this approach to be successful and 11 sites have been mapped to date. These techniques are providing a new approach to monitoring change in coastal vegetation communities and informing management of protected sites.  相似文献   
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Book reviews     
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A total of 77 On-Board Diagnostics II (OBDII)-equipped vehicles with illuminated malfunction indicator lights (MILs) and non-evaporative codes were tested before and after repair. The test cycles included the Federal Test Procedure (FTP), IM240, and steady-state cycles. A total of 17 vehicles were found with emissions greater than 1.5 times their respective FTP emissions standards. Repair of these vehicles resulted in dramatic reductions in overall emissions for all the cycles. A majority of the remaining vehicles were found to have emissions below the certification standard for the FTP both before and after repair. Repairs for the vehicles with emissions <1.5 times the standard resulted in some smaller but quantifiable emission reductions over the FTP and IM240 but larger reductions over the steady-state driving tests. Misfires, bad oxygen sensors, and exhaust gas recirculation (EGR) problems were the most common non-evaporative causes for triggering the MIL. The results show some fundamental differences between identifying malfunctioning vehicles using OBDII as opposed to more traditional dynamometer tests. In particular, for many systems, OBDII identifies components that are operating outside their design specification rather than for a specific emissions threshold.  相似文献   
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