Evaluation of the Effectiveness of Ozone Precursor Emission Reduction Strategies in the Northeastern/Mid-Atlantic USA
Q. Sun, V.M. Vyas, and P.G. Georgopoulos (EOHSI, UMDNJ - R.W. Johnson Medical School and Rutgers University)
Precursor emission reduction strategies are required for attaining compliance with regulation mandated air quality levels for pollutants like O3 and fine PM. Due to the complexity of the processes involved, the effect of emission reductions on reducing ambient secondary pollutant concentration levels is not linear. Furthermore, emission reduction strategies must demonstrably succeed in reducing the number of people potentially exposed to air pollutants. Consequently, it is necessary to develop appropriate metrics that can help evaluate the effectiveness of emission reduction strategies.
This study used US EPA's Community Multiscale Air Quality (CMAQ) model, a component of the Models-3 system. Simulations were carried out for the period of July 11-25, 1999 with two levels of nested grids. The Sparse Matrix Kernel Estimator (SMOKE) was used to process emissions, and the Meteorological Model 5 (MM5) was used to model meteorology. In addition to the base case (no emissions reductions), four simulations were performed corresponding to "across the board" emission reductions of 25%, 50% and 75% VOC and/or NOx reductions in combination.
The effectiveness of these emission reductions was analyzed through the use of direct air quality metrics that include daily domain maxima of 1-hour and 8-hour running averages of O3 concentrations, episode pervasiveness, and episode severity; as well as through potential population exposure metrics. These outcomes demonstrate the benefits of both NOx-intensive reduction strategies and of implementing the 8-hour O3 standard.
ACKNOWLEDGEMENTS: Support for this work has been provided by the USEPA funded Center for Exposure and Risk Modeling (CERM) at EOHSI (EPAR-827033), and the State of New Jersey Department of Environmental Protection (NJDEP) funded Ozone Research Center (ORC) at EOHSI. The views expressed in this work are solely the responsibility of the authors and do not necessarily reflect the views of the funding agencies.