Determinación de la concentración de NOX a la que se encuentran expuestos los peatones en el terminal terrestre de Riobamba

Abstract

The concentration of nitrogen oxide (NOx), to which the pedestrians around the bus terminal area were exposed was determined through passive samplers and (Arc Gis, PTV Vissim and Viswalk) specialized software. Some sampling points were considered taking into account the vehicles that are driven during peak hours, the ones which were classified into automobiles, buses, vans and motorcycles as well as pedestrians at the same hour during a week in entrances and exits of the study area. The passive sampler analyzes carried out through spectrophotometry reflect that the absorbance of 26 monitoring points has a maximum value of 8,246 ug/m3 and a minimum value of 1,456 ug/m3. It was determined that the average concentration of nitrogen dioxide emissions (NO2) was 27.71 +/-4.61 ug/m3 with a minimum of 14.92 ug/m3 and a maximum of 56.56 ug/m3, considering that the World Health Organization (WHO) allows a permissible value of 40 ug/m3, it can be established with a 95% of confidence that the true mean of sampled NO2 is between 23.54 and 31.87 ug/m3. Although the samples do not launch alertness, there is a possibility to reach a concentration which is out of the norm. The medium exposure dose of NOx was 93963.375 people per g/m3, while there is a maximum exposure of 171888.24 people per ug/m3 and a minimal exposure of 18157.44 people per ug/m3, which according to the pedestrian counting carried out in half of cases exceeds the pedestrian average traffic of each monitored hour. It is recommended to have a permanent monitoring in the study area, considering that this is a heavy traffic area of both, vehicles and pedestrians.