Authors' reply

摘要

We appreciate the opportunity to respond to Crane's comments on our article, "Parsing Pyrogenic Polycyclic Aromatic Hydrocarbons: Forensic Chemistry, Receptor Models, and Source Control Policy" (O'Reilly et al. 2014a). Dr. Crane raises a number of interesting points, but these serve to support, not distract from, the conclusions of our paper. In our paper, we describe the challenges of using multivariate approaches, such as EPA's Chemical Mass Balance (CMB) model and principal component analysis (PCA), to identify sources of pyrogenic polycyclic aromatic hydrocarbons (PAH) in urban sediments. We also discuss why it is critical that, when these methods are used to promote source control policy, technical specialists accurately describe the uncertainty inherent in the results.