Probabilistic Air Pollutant Emission Inventories

Quantification of Variability and Uncertainty in Air Pollution Emissions Estimation

These papers established novel methods for quantifying variability and uncertainty in air pollutant emission inventories, which are crucial for air quality planning and policy. The research provided frameworks to analyze emissions from diverse sources, including lawn and garden equipment, highway vehicles, and large-scale industrial sources like utility power plants. Dr. Frey’s work pioneered a probabilistic approach to developing emission inventories, addressing the challenge of censored data (non-detect values) and providing a more rigorous basis for regulatory decisions by acknowledging and managing the inherent uncertainty in emissions data.

Illustrative papers (selected examples): 

Frey, H.C., and J. Zheng, “Quantification of Variability and Uncertainty in Air Pollutant Emission Inventories:  Method and Case Study for Utility NO_x Emissions,” Journal of Air & Waste Manage. Association, 52(9):1083-1095 (September 2002).

Frey, H.C., and J. Zheng, “Probabilistic Analysis of Driving Cycle-Based Highway Vehicle Emission Factors,” Environmental Science and Technology, 36(23):5184-5191 (December 2002).

Abdel-Aziz, A., and H.C. Frey, “Development of Hourly Probabilistic Utility NO_x Emission Inventories Using Time Series Techniques:  Part II-Multivariate Approach,” Atmospheric Environment, 37:5391-5401 (2003).

Frey, H.C., and Y. Zhao, “Quantification of Variability and Uncertainty for Air Toxic Emission Inventories With Censored Emission Factor Data,” Environmental Science and Technology, 38(22):6094-6100 (2004).