Abstract View
Successfully Lowering Exposure to Air Pollutants in Public Transport
BORIS GALVIS, Ricardo Morales Betancourt, Daniela Mendez, Yadert Contreras Barbosa, Alejandra Montejo-Barato, Diego Roberto Rojas-Neisa, Universidad de La Salle
Abstract Number: 622
Working Group: Aerosol Exposure
Abstract
Commuters are often exposed to higher concentrations of air pollutants than those reported by urban monitoring sites. Despite the recent transformation of urban transport towards zero or low-tailpipe emission alternatives, the assessment of these transformations over commuter exposure are limited by the paucity of such studies. In this work, we use a unique data-set of personal exposure to traffic related air pollutants (TRAP), collected over the span of 5 years to assess changes due to the new the fleet of Bogota’s Bus Rapid Transit System. The renewal process started in 2019 and up until 2020 replaced 1440 Euro-II and III diesel-powered buses with a mix of Euro-VI compressed natural gas (CNG) and DPF-equipped Euro-V diesel buses. We measured the change in personal exposure to Black Carbon, PM2.5 and ultra fine particles before, during, and after the retirement of the old buses and the introduction of the new ones. We used data collected by the researchers during 2015 and 2017, and new measurements performed over two campaigns between 2019 and 2020. Significant drops in the concentrations of PM2.5 and BC were observed during the 2019 campaign, with a mean 50% decrease for PM2.5(176 to 92ug m−3) and BC (90 to 45ug m−3). Further reductions were observed during the 2020 measurement campaign, even after accounting for effects of the COVID-19 pandemic related mobility restrictions. Nevertheless we found that commuters were exposed to higher concentrations inside the stations and buses and in the central and southern areas of the city and even more if they are inside vehicles with more than 682 x103 vehicle kilometers traveled. This evidence of positive effects of urban transport interventions can be used as input for decision-makers to put forward policies aimed at improving the quality of life of city commuters related to air pollution.