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Identifying the Ozone Weekend Effect in the air quality of the northern Andean region of Ecuador

2016; WIT Press; Volume: 1; Linguagem: Inglês

10.2495/air160161

1746-448X

René Parra, E. Franco,

Air Quality and Health Impacts

The Weekend Effect (WE) is a phenomenon that occurs in some urban areas, characterized by increased concentrations of O 3 and decreased emissions of its precursors (NO x and VOC) during weekend days, in comparison to weekdays.The study of the WE is relevant for understanding the behavior of pollutants; and hence, for air quality control.We analyzed the hourly records of the period 2005-2012, from 8 stations of the air quality network from the Distrito Metropolitano de Quito (northern Andean region of Ecuador).Both for each station and year, 3 mean-daily profiles were obtained for CO, NO 2 , PM 2.5 and O 3 , corresponding to weekdays, Saturdays and Sundays.The CO, NO 2 and PM 2.5 profiles from Centro (historic center of Quito) and Belisario (center-north) stations, declined on Sundays.However the O 3 profiles were higher on Saturdays and Sundays.The O 3 8-h mean concentrations of Sundays were higher in Belisario (19.7-31.1%)and Centro (11.7-18.4%), in comparison to weekdays.These results indicate the presence of the WE around these 2 stations, which probably are located in a VOClimited region for photochemical O 3 production.