« Previous AbstractQuantification of nitromethane in mainstream smoke using gas chromatography and tandem mass spectrometry    Next Abstract"Personal, indoor, and outdoor exposure to VOCs in the immediate vicinity of a local airport" »

Chemosphere

Title:		Oxidation capacity changes in the atmosphere of large urban areas in Europe: Modelling and experimental campaigns in atmospheric simulation chambers
Author(s):		Jung D; Soler R; de la Paz D; Notario A; Munoz A; Rodenas M; Vera T; Borras E; Borge R;
Address:		"Environmental Modelling Laboratory, Department of Chemical & Environmental Engineering, Universidad Politecnica de Madrid (UPM), C/ Jose Gutierrez Abascal 2, 28006, Madrid, Spain. Electronic address: daeun.jung@upm.es. EUPHORE Labs., Atmospheric Chemistry Area, Fundacion Centro de Estudios Ambientales del Mediterraneo (CEAM), 46980, Paterna, Spain. Environmental Modelling Laboratory, Department of Chemical & Environmental Engineering, Universidad Politecnica de Madrid (UPM), C/ Jose Gutierrez Abascal 2, 28006, Madrid, Spain. Universidad de Castilla-La Mancha, Physical Chemistry Department, Faculty of Chemical Science and Technologies, Ciudad Real, Spain"
Journal Title:		Chemosphere
Year:		2023
Volume:		20230821
Issue:
Page Number:		139919 -
DOI:		10.1016/j.chemosphere.2023.139919
ISSN/ISBN:		1879-1298 (Electronic) 0045-6535 (Linking)
Abstract:		"Air pollution is a major concern for human health and the environment. Consequently, environmental standards have become stricter to improve air quality. Thanks to this, the ambient levels of O(3) precursors such as VOCs and NO(X) have decreased. However, O(3) levels in Europe, especially during winter, have increased, potentially impacting on atmospheric oxidation capacity and the associated chemistry of tropospheric oxidants. In this work, we focus on recent changes in the oxidation capacity of urban atmospheres. The study is conducted with the results of the CMAQ modelling system with a regional resolution with 12 x 12 km(2) across the entire European continent for the winter (January) and summer (July) of 2007 and 2015. The 2015 meteorological data is used for both years to emphasise emission changes during the studied period. We scrutinise the changes in ambient concentration levels of the main tropospheric oxidants (O(3) and HO(X) radicals) in five representative cities, Valencia, Madrid, Milan, Berlin, and The Hague. The enhanced O(3) formation in winter seems to be due to the low VOC/NO(X) ratio, while the opposite trend in summer may be related to a relatively high ratio. Additionally, photooxidation experiments are carried out in the EUPHORE chambers to study the effect of changes in NO(X) concentration and NO/NO(2) ratio on the variation of the given oxidants at constant VOCs concentrations. For the baseline experiments, two scenarios are selected based on the model results of 2015: two representative winter and summer days of low and high pollution in Berlin and Madrid, respectively. The role of VOC/NO(X) and NO/NO(2) ratios on atmospheric reactivity is discussed. As a result, it is first suggested that further decreases in ambient NO(X) levels are required to reduce ambient O(3) levels. Moreover, additional factors should be considered when designing local-specific emission abatement strategies"
Keywords:		Humans *Air Pollutants/analysis *Ozone/analysis Nitrogen Dioxide *Volatile Organic Compounds/analysis Environmental Monitoring/methods *Air Pollution Atmosphere Oxidants Europe China Aoc Cmaq Euphore Lif-fage Ozone Tropospheric radicals Urban atmosphere;
Notes:		"MedlineJung, Daeun Soler, Ruben de la Paz, David Notario, Alberto Munoz, Amalia Rodenas, Milagros Vera, Teresa Borras, Esther Borge, Rafael eng England 2023/08/24 Chemosphere. 2023 Nov; 341:139919. doi: 10.1016/j.chemosphere.2023.139919. Epub 2023 Aug 21"