It has been established that organic aerosol (OA) makes up for a major fraction of fine particulate matter in all region of the atmosphere. This fraction accounts approximately for half of the total PM2.5 dry mass.1,2 Primary OA is directly emitted in the troposphere from anthropological and natural sources whereas secondary OA (SOA) is formed in-situ in the atmosphere from the oxidation of biogenic or anthropogenic gas-phase precursors and subsequent partitioning of the less volatile products into the particle phase. The current number is that, on a global scale, SOA would represent around 60% of the overall OA.3 However, recent global mass-balance estimations for the removal of volatile organic compounds (VOC) suggest that this number could under-predicts SOA production.4 Recent field measurements in urban locations are also in support of a larger share, indicating that SOA is the dominant fraction of OA, with amounts considerably 20 greater than models predictions.
By Chromatotec Group based in Val de Virvée, FRANCE.
The environmental challenges require internationally accepted standards, in which limits and test methods are defined. Metrohm instruments and applications comply with a lot of international environmental standards. Substances introduced into the environment are distributed among the environmental compartments water, soil (sediment), and air, as well as among the organisms living in them (biosphere). Only if we know the type and quantity of these contaminants can we protect the environment and its inhabitants.
By Metrohm AG based in Herisau, SWITZERLAND.
Fine dust is generated by industrial exhaust gases but in particular due to traffic. Environmental pollution is therefore caused particularly by exhaust gases of diesel-engined vehicles (diesel soot) but on the other hand also by abrasion of street, tyres and brakes and its resuspensions.
By Palas GmbH based in Karlsruhe, GERMANY.
The principle cause of regional and urban haze, or visibility impairment, is light extinction caused by fine particles, sulfates, organic and elemental carbon, nitrates and crustal matter. Particles between 0.1 and one micrometers in size are most effective at scattering light, in addition to being of greatest concern for human health.
By Ecotech Pty Ltd based in Knoxfield, AUSTRALIA.
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