Evaluating Atmospheric Pollutants from Urban Buses under Real-World Conditions: Implications of the Main Public Transport Mode in São Paulo, Brazil

Thiago Nogueira,Maria Andrade,Adalgiza Fornaro,Pamela Dominutti,Marcelo Vieira-Filho

doi:10.3390/atmos10030108

Abstract

The broad expanse of the urban metropolitan area of São Paulo (MASP) has made buses, the predominant public transport mode for commuters in the city. In 2016, the bus fleet in the MASP reached 56,354 buses and it was responsible for more than 12 million daily trips. Here, we evaluate for the first time, the emission profile of gaseous and particulate pollutants from buses running on 7% biodiesel + 93% petroleum diesel and their spatial distribution in the MASP. This novel study, based on four bus terminal experiments, provides an extensive analysis of atmospheric pollutants of interest to public health and climate changes, such as CO2, CO, NOx, VOCs, PM10, PM2.5 and their constituents (black carbon (BC) and elements). Our results suggest that the renovation of the bus fleet from Euro II to Euro V and the incorporation of electric buses had a noticeable impact (by a factor of up to three) on the CO2 emissions and caused a decrease in NO emissions, by a factor of four to five. In addition, a comparison with previous Brazilian studies, shows that the newer bus fleet in the MASP emits fewer particles. Emissions from the public transport sector have implications for public health and air quality, not only by introducing reactive pollutants into the atmosphere but also by exposing the commuters to harmful concentrations. Our findings make a relevant contribution to the understanding of emissions from diesel-powered buses and about the impact of these new vehicular technologies on the air quality in the MASP.

Highlights

In 2015, pollution was responsible for 16% of all premature deaths worldwide
The findings reported that about ten thousand deaths per year are associated with air pollution in the metropolitan area of Sao Paulo (MASP) [2,3]
It must be highlighted that June is typically dry but it rained 131 mm for five days, from 3 to 7 June 2016

Summary

Introduction

In 2015, pollution was responsible for 16% of all premature deaths worldwide. Atmospheric pollutants, in particular, have been responsible for the deaths of more than four million people [1]. The road transport sector has been responsible for air quality degradation in urban areas, the public transit sector can be an essential agent in the control of emissions, mainly by using. Atmosphere 2018, 9, x FOR PEER REVIEW Atmosphere. Of emissions, mainly by using alternative fuels and more current bus engines. Commuters are exposed to air pollution in different ways, depending on the mode of transport, the position of the commuter in relation to the pollutant concentration gradients, and the alternative fuels and more current bus engines [4]. Commuters are exposed to air pollution in different microenvironmental conditions for pollutant dispersion [5]

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Results

Conclusion