Fuels for urban transit buses: a cost-effectiveness analysis.
Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental cost-effectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG (dollar 270 000 per QALY for ECD vs dollar 1.7 million to dollar 2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates.
Harvard Center for Risk Analysis, Department of Health Policy and Management, Harvard School of Public Health, Harvard University, Boston, Massachusetts 02115, USA. cohenj@hsph.harvard.edu
Joshua T
JT
Cohen
James K
JK
Hammitt
Jonathan I
JI
Levy
D000393:Air Pollutants / Q000009:adverse effects* / Q000191:economics*; D000397:Air Pollution / Q000191:economics* / Q000517:prevention & control*; D003362:Cost-Benefit Analysis; D005579:Fossil Fuels / Q000009:adverse effects*; D005742:Gasoline / Q000009:adverse effects*; D006801:Humans; D008962:Models, Theoretical; D011634:Public Health; D019057:Quality-Adjusted Life Years; D001335:Vehicle Emissions / Q000009:adverse effects* / Q000517:prevention & control
D000393:Air Pollutants; D005579:Fossil Fuels; D005742:Gasoline; D001335:Vehicle Emissions