ARE [NITROPOLYCYCLIC AROMATIC HYDROCARBON]/[POLYCYCLIC AROMATIC HYDROCARBON] RATIOS INDICATORS FOR CONTRIBUTORS OF AIRBORNE PARTICULATES ? Publication Attachment: 05-112.pdf Authors: Hayakawa, Kazuichi, Tang, Ning, Hattori, Tetsuyuki, Igarashi, Kazuhiko, Yang, Xiao-Yang, Toriba, Akira Year: 2005