This report documents the findings of a study on the health effects of air pollution. The data on which the study is based were collected in Dayton, Ohio, in the Health Insurance Experiment conducted by RAND for the U.S. Department of Health and Human Services. The authors applied the Whittemore-Korn individual time series analysis to a general population dataset and found it to be a promising method for measuring the short-term health effects of air pollution. The results consistently identify sulfur dioxide and nitrogen dioxide as having significant adverse health effects.