Evaluación a la exposición peatonal a Nox vehícular en el casco urbano del cantón San Pedro de Pelileo

Abstract

The aim of this technical work was to evaluate the pedestrian exposure to atmospheric pollutants (NOx) from automobiles that travel through the urban area of “San Pedro de Pelileo” county, which is characterized for being a commercial area; First of all, 25 monitoring points were determined, the ones which were randomly chosen within a radius of 3,200 m, the NOx (Nitrogen Oxides) presence was measured through the passive sampling technique with the use of collecting tubes with triethanolamine, n-butanol and distilled water; the study was carried out from October to November 2020 and the samples were taken weekly. With the use a UV spectrophotometer it was possible to measure the absorbance values which were read before the construction of a calibration curve in order to determine the NOx concentration through several formulae, then some thematic maps were made with the use of ArcGIS Software in order to visualize the areas with the highest amount of NOx; in this way, it was possible to obtain high concentrations which exceed the permissible limits established by the Air Quality and Control 2015 Regulation, taking p20 as a referential point which presents the highest weekly average concentration of NOx with a value of 3483,072 μg / m3, this evidences air pollution by NOx in the studied area; therefore, it needs to be treated as fast as possible. Finally, an exposure analysis was carried out through PTV VISSIM program; for this, a vehicular and pedestrian simulation was carried out by counting people and automobiles at peak traffic hours and also taking into account the type of vehicle as well as the time of its entry and exit, this allowed us to determine that the NOx emissions are not only related to road traffic but also to the pedestrians overcrowding at certain points.