Abstract
Public transit buses, which move more than 5 billion passengers annually in the United States (U.S.), can contribute substantially to the environmental health burden through emitted air pollutants. As a leader in transforming to cleaner bus fleets, the Regional Transport Commission of Southern Nevada (RTC) has been transitioning from diesel to compressed natural gas (CNG) transit buses since 1999. By 2017, ~75% of RTC’s buses operating in Clark County, Nevada were CNG-powered. This study assesses the health benefits of the venture using the US Environmental Protection Agency’s (EPA) Co-Benefits Risk Assessment (COBRA) model, considering the emission and exposure changes from the 2017 baseline for two hypothetical scenarios: (1) no transition (CC_D) and (2) complete transition (CC_N). The CC_D scenario shows realized health benefits, mostly due to avoided mortality, of $0.79–8.21 million per year for 2017 alone, while CC_N suggests an additional $0.88–2.24 million annually that could be achieved by completing the transition. The wide range of estimates partly reflects uncertainties in determining diesel bus emissions under business-as-usual. These health benefits were not limited locally, with ~70% going to other counties. Two national-scale scenarios, US_D and US_N, were also constructed to explore the health impact of transitioning from diesel to CNG buses across the U.S. As of 2017, with CNG powering only ~20% of transit bus mileages nationwide, there could be massive unrealized health benefits of $0.98–2.48 billion per year including 114–258 avoided premature deaths and >5000 avoided respiratory and cardiovascular illnesses. Taking into account the health benefits, economic costs, and the inter-state nature of air pollution, expanding federal assistances to accelerate a nationwide transition to cleaner bus fleets is highly recommended.
Highlights
According to the World Health Organization (WHO) [1], air pollution causes more mortality and loss of disability-adjusted life years (DALYs) than any other environmental health issues globally.Motor vehicle emissions contribute substantially to urban air pollution around the world [2,3] and have been a target for mitigation
Conclusions from this study offer a justification to further public investment in cleaner bus fleets at both regional and national levels
The healthbenefits benefits corresponding to four the scenarios, four scenarios, as estimated byareCOBRA, are in
Summary
According to the World Health Organization (WHO) [1], air pollution causes more mortality and loss of disability-adjusted life years (DALYs) than any other environmental health issues globally. Motor vehicle emissions contribute substantially to urban air pollution around the world [2,3] and have been a target for mitigation. While diesel and gasoline remain the dominant transportation fuels used today, newer technologies, such as electric, hybrid, liquefied petroleum gas (LPG), compressed natural gas (CNG), and hydrogen-powered vehicles, are shown to be cleaner options [4]. For public health and sometimes economic considerations, urban mass transportation systems such as transit buses are often the first to adopt these technologies with public investment. The health benefits of transitioning from conventional to cleaner fuels are rarely assessed when carrying out specific transition programs. A recent assessment by Dey et al [5] shows that a complete
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
