Estudio de la distribución espacial y temporal del material particulado en concentración y por rangos de tamaños en el Distrito Metropolitano de Quito entre 2009 y 2019.

Abstract

This work presents the spatio-temporal analysis of the size distribution of particulate matter less than 10 µm between 2009-2019 through the statistical analysis of concentration data series recorded by the Metropolitan Atmospheric Monitoring Network of Quito.

The size distribution was evaluated by the percentage contribution of six fractions to PM10, defined by the impactor used for sampling. The possible sources of origin of PM2.5 and PM10 were determined by the ratio PM2.5/PM10. Inferential statistics were used to identify significant temporal and spatial differences in the concentration of fractions less than 10 µm, PM10 and PM2.5. For the year 2019, the spatial distribution of PM2.5 and PM10 was represented considering the population density of each monitored point.

It was found that particles (0.30-0.95 µm) contribute between 50-63% to the annual PM10, while particles (3.00-7.20 µm) contribute between 13-19 %. Particles between (0.30-0.95 µm) are caused by vehicular emissions, and those between 3.00-7.20 µm are caused by road erosion and the extraction of stone materials. The lowest concentrations of PM2.5 were identified between (June-September) and the maximums between (January-May and September-December), while for PM10 the maximums were between (August-September). In 2019, the national annual limit of PM2.5 is exceeded in most stations, being Cotocollao, Centro and Camal where the largest number of people exposed to the highest concentrations is housed, in the case of PM10, Carapungo is the critical point of maximum concentration