Found 10544 publications. Showing page 76 of 422:
2006
Substantial efforts and improvements in air quality across Europe lowered levels of air pollutants including particulate matter (PM) in the last decades. However, significant proportion of the European population still lives in areas exceeding WHO recommendations, especially in Northern Italy, Balkans, and Eastern Europe, including Serbia. Targeted PM mitigation strategies require extensive air quality monitoring and modelling including source apportionment (SA) studies. In the past, numerous SA studies were conducted for Belgrade city, capital of Serbia. Nevertheless, comparisons across the results are difficult, as they encompass different datasets of pollutants contained in PM fractions such as elements and/or ions and/or PAHs. Here, the aim is to offer a broader insight on PM 10 sources at an urban background site in Belgrade by including 34 species as input variables for SA (carbonaceous aerosols, elements, ions and specific organic tracers). For SA, the USEPA PMF 5.0 software was applied. The factor that dominated PM 10 mass was biomass burning (21 %), primarily during heating season, followed by ammonium sulphate (18 %) and mineral dust (17 %). A mixed traffic and industrial activity accounted for 15 % of PM 10 mass while contribution of factors from biological origin, primary biological aerosol particles and biogenic secondary organic aerosols from isoprene, was 10 % each. Mixed factor of long-range transport and road salt/local combustion contributed to the PM 10 mass 9 %. This analysis provides more detailed perspective on the composition and sources of PM 10 in Belgrade, both from anthropogenic and natural, including biological origin. These findings are valuable for defining targeted PM 10 mitigation strategies.
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2006
Chemical properties of Arctic aerosol particles collected at the Zeppelin station during the aerosol transition period in May and June of 2004. Report series in aerosol science, No. 92
2008
2008
This scoping study proposes a methodology to develop indicator(s) on the risk of chemicals on various types of ecosystems, habitats and species. This indicator is designed to answer the very different needs coming from environmental policy and strategies. Its aim is to reflect the consequences of human activities (e.g., farming) on ecosystems taking into account different protection goals that can cover specific or protected habitats (or the relevant communities or species in these habitats) or intensively used areas such as agricultural landscapes, which are very relevant in terms of representativity.
In order to develop such an indicator, the methodological approach retained to calculate maps showing a specific risk, illustrated as different degrees of exceedance of tolerable effect thresholds, is to combine different layers of information on which areas/habitats/ecosystems, contain which species, that are exposed to which amounts of chemicals. Information on the sensitivity of the species towards different toxicological effects, and how sensitive the species are to the applied chemicals, is used as ‘connectors’ between the different layers of spatial information.
The report highlights the data required for the development of such an indicator and their availability through a review of existing databases. A case study illustrates the applicability of the indicator and the need for further development.
European Topic Centre on Human Health and the Environment (ETC HE)
2022
Chemical speciation of fine airborne particles in Abu Dhabi. NILU OR
PM2.5 was sampled at two urban background sites in Abu Dhabi (Khalifa in the city of Abu Dhabi and Bida Zayed) and analysed chemically for further source identification and quantification. Understanding of source contributions to PM2.5 is a prerequisite for the formulation of effective control strategies for PM2.5 emissions.
For both sites, five source factors were identified. Long-range transported aerosol is the largest contributor (~41%) to average PM2.5 mass concentrations at both sites. It gradually forms from SO2, which is possibly emitted into ambient in the Arabian Gulf area, while it is transported to the sites. Mineral dust was found to be the second most important source, contributing ~25% at both sites. It represents an ubiquitous natural contribution of mainly regional origin to particulate matter in Abu Dhabi.
Other source contributions to particle concentrations found at Khalifa identified were: local traffic (15.1%), shipping/industry (10.5%) and sea salt (4.0%). The latter is a natural contribution.
At Bida Zayed, a mixed traffic/industry factor (13.2%) was found, as well as another two factors of natural origin, explaining 11.4% and 8.7%
2013
Chemical speciation of fine airborne particles in Abu Dhabi. NILU OR
Chemical speciation results of PM2.5 filter samples from eight sites in Abu Dhabi are discussed. This is the third interim report, covering a total of 40 filter samples. As one aim of this sampling study was to use the speciation results for health impact studies, samples with high particle loads and high degree of blackness were selected for analysis, and compared to samples with typical particle loads. Particles with diameters less than 2.5 µm were analysed for elements, inorganic ions and carbonaceous fractions.
The most abundant elements were found to be crustal elements, contributing on average 14% to PM2.5 mass. Reconstructing the mass of crustal oxides, approximately 44% of the fine particle mass was estimated to be associated with mineral dust. The concentrations of most heavy metals were below limit values for annual averages at all sites. For nickel, it was found that the Guideline Value may be exceeded at one traffic site.
Inorganic ions (sulphate, nitrate, ammonium, sodium, chloride) explain on average 34% of the PM2.5 mass in Abu Dhabi. Remarkably high sulphate concentrations account for the major part (on average 26%). Particulate sulphate in Abu Dhabi is likely to have both natural (as a result of the local composition of mineral dust) and anthropogenic sources which cannot be separated with the applied analytical methods. An anthropogenic contribution of ~6% comes from the secondary inorganic ions nitrate and ammonium.
Total carbon, which consists of elemental carbon, organic carbon and carbonate carbon contributed on average 14% to PM2.5 mass. About 30% of total carbon was estimated to be carbonate of likely natural origin. Elemental carbon and most organic carbon are expected to be of anthropogenic origin.
PM in Abu Dhabi has a strong signature of natural sources (mineral dust). A detailed apportionment of sources requires further analyses.
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