INTRODUCTION In March 1972@ Copley International Corporation was awarded contracts by the Coordinating Research Council (CAPM-11-71 (1-71)) and the Environmental Protection Agency (68-02-0349) to participate in a coordinated series of epidemiologic studies planned for the Los Angeles Basin. These studies form a part of the Community Health and Environmental Surveillance System (CHESS) program being conducted in several various sized metropolitan areas across the nation. They are designed to be performed under standardized procedures to measure simultaneously sensitive health and environmental quality indicators in sets of communities representing exposure gradients to common air pollutants such as oxidants. The purpose of these studies@ and of the CHESS program as a whole@ is to permit an evaluation of existing environmental standards and@ in light of new health intelligence obtained@ to develop new standards and improved understanding of the effects of air pollutants on human health. CIC's primary responsibility under the awarded contracts is to measure selected health characteristics of persons residing in three communities of the Los Angeles Basin. Simultaneous measurements of ambient air characteristics in the same communities is the responsibility of the Statewide Air Pollution Research Center@ University of California@ Riverside@ under a separate contract with the Environmental Protection Agency. Additional CIC responsibilities include critiques of the data collection and analysis procedures designed by the EPA for the performance of the CHESS studies and of the Federal Intramural Technical Reports in which the subsequent data analysis performed by the EPA is described. This volume covers the progress achieved by CIC in performing its project responsibilities during the first contract year. It is divided into five sections: an outline of the studies already undertaken and those to be undertaken@ a description of the study locations@ the details of data collection surrounding the studies already undertaken@ a description of the supporting air monitoring facilities@ and concluding comments. Volume II@ to be published at a later date@ describes the subsequent data analysis performed by the EPA.