"INTRODUCTION This report describes the work performed by Scott Research Laboratories@ Inc. and its sub-contractor Bolt@ Beranek and Newman@ Inc. on APRAC Project No. CAPA-7-68@ ""Atmospheric Reaction Studies in the Los Angeles Basin"" (Contract No@ CPA-22-69-19). This project was sponsored jointly by the National Air Pollution Control Administration and the Coordinating Research Council@ Inc. This report is contained in two volumes. Volume I includes a complete description of the study methodology as well as a thorough representation of the quantitative and qualitative results obtained. Volume II displays all of the relevant raw data which were collected in the test operations and processed by manual or machine techniques."