Bus commuter exposure and the impact of switching from diesel to biodiesel for routes of complex urban geometry

Targino, Admir Créso; Krecl, Patricia; Cipoli, Yago Alonso; Oukawa, Gabriel Yoshikazu; Monroy, David Andrés

doi:10.1016/j.envpol.2020.114601

Cited by 29 publications

(11 citation statements)

References 65 publications

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“…The absolute eBC and PM 2.5 decrease observed in our study are 9 and 4 times bigger, respectively. Targino measured reductions of 16 μg m –3 in eBC exposure concentrations inside buses when diesel was changed to biodiesel. They found similar exposure PM 2.5 concentrations, 31.6 and 29.0 μg m –3 , for diesel and biodiesel in the BRT of Curitiba, Brazil.…”

Section: Resultsmentioning

confidence: 99%

“…46 In-bus exposure to TRAP in the city of Curitiba, Brazil, was studied before and after the bus fleet switched fuel from diesel to biodiesel, finding a decrease in BC, but no change in PM 2.5 exposure, and a slight increase in UFP after biodiesel was used. 5 In this work we focus on quantifying the impact that reducing emissions in a BRT system by adopting Euro V and Euro VI emission standards in a new bus fleet has on TRAP exposure for its users. We do so for the Transmilenio system in the city of Bogota, where 1152 diesel-powered buses with obsolete emission standards were recently replaced with 1441 newer vehicles, abiding to stricter emission standards by including emission controls systems or fuel change from diesel to compressed natural gas (CNG).…”

Section: ■ Introductionmentioning

confidence: 99%

“…Traffic-related air pollutants (TRAP) drive the overall personal exposure to air pollution, particularly for people living in urban environments or in areas with high traffic density. − Among the most prevalent TRAP are fine (PM 2.5 ) and ultrafine particles (UFP), and soot or black carbon (BC), coming from internal combustion engines or in the case of UFP mostly formed inside and outside tailpipes . Concentrations of these pollutants are usually higher within transport microenvironments compared to ambient levels. − Furthermore, even the short-term exposure to TRAP can have observable health outcomes .…”

Section: Introductionmentioning

confidence: 99%

“…Researchers analyzed the change in exposure to TRAP when the BRT started operation in Mexico City, observing a reduction in exposure to carbon monoxide, benzene, and PM 2.5 after its implementation . In-bus exposure to TRAP in the city of Curitiba, Brazil, was studied before and after the bus fleet switched fuel from diesel to biodiesel, finding a decrease in BC, but no change in PM 2.5 exposure, and a slight increase in UFP after biodiesel was used …”

Section: Introductionmentioning

confidence: 99%

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Toward Cleaner Transport Alternatives: Reduction in Exposure to Air Pollutants in a Mass Public Transport

Betancourt

Gálvis

Mendez-Molano

et al. 2022

Environ. Sci. Technol.

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Commuters are often exposed to higher concentrations of air pollutants due to its proximity to mobile sources. Despite recent trends in urban transport toward zero-and low-tailpipe emission alternatives, the assessments of the impact of these transformations on commuter exposure are limited by the low frequency of such studies. In this work, we use a unique data set of personal exposure concentration measurements collected over the span of 5 years to analyze changes due to the introduction of a new fleet for Bogota's Bus Rapid Transit System. In that system, over a thousand Euro-II and -III diesel-powered buses were replaced with Euro-VI compressed natural gas and filter-equipped Euro-V diesel buses. We measured personal exposure concentrations of equivalent black carbon (eBC), fine particulate (PM 2.5 ), and ultra fine particles (UFP) during and after the retirement of old buses and the introduction of new ones. Observations collected prior to the fleet renewal were used as baseline and later compared to data collected over two follow-up campaigns in 2019 and 2020. Significant reductions in the concentration of PM 2.5 and eBC were observed during the 2019 campaign, with a 48% decrease for mean in-bus eBC (89.9 to 46.4 μg m −3 ) and PM 2.5 (180.7 to 95.4 μg m −3 ) concentrations. Further reductions were observed during the 2020 follow-up, when the fleet renovation was completed, with mean in-bus eBC decreasing to 17.7 μg m −3 and PM 2.5 to 42.3 μg m −3 . These observations imply nearly a 5-fold reduction in eBC exposure and a 4-fold decrease in PM 2.5 . There was a much smaller reduction of in-bus UFP concentration between 2019 and 2020, indicating a persistent presence of high particle number concentrations in the near-road environment despite the fleet renovation process. In-bus UFP concentrations ranged between 65 000 and 104 500 cm −3 during the follow-up campaigns. The results in this work illustrate the immediate benefits of reducing personal exposure through the adoption of vehicles with more stringent emission standards.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Toward Cleaner Transport Alternatives: Reduction in Exposure to Air Pollutants in a Mass Public Transport

Betancourt

Gálvis

Mendez-Molano

et al. 2022

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The lower heating value of B00 was 41.77 MJ/kg for B10 and B20 it was 41.17 and 40.58 MJ/kg, respectively. While the changes in fuel properties were small, the literature reported that even these small changes can notably affect engine performance and emissions [53][54][55]. The lower calorific value and higher density of biofuels have negative impacts on engine power and increase fuel consumption [56].…”

Section: Methodsmentioning

confidence: 99%