A critique of empirical emission factor models: a case study of the AP-42 model for estimating PM10 emissions from paved roads

This paper provides a critical examination of empirical emission factor mod els by considering one model that typifies the class: the model used to est imate PM10 emissions from paved roads. We show that the model can yield hig hly uncertain emission estimates because (1) it lacks a mechanistic basis, (2) its formulation is highly dependent on the data set used to derive it, and (3) the accuracy of the model is completely determined by the methods u sed to measure emissions. The paper also describes a method to relate model performance statistics to statements about the uncertainty in emission est imates. (C) 1999 Elsevier Science Ltd. All rights reserved.