Effects of Exposure Time and Ozone on Respiratory Diseases and Asthma

We show how spending different amount of time outdoors on weekends and weekdays changes the estimates of the impact of ground level ozone on respiratory diseases and Asthma. Our focus is on the short term effect of air pollution on public health. The American Time Use Survey data are used for the estimation. The measurement errors are corrected by adding the interaction of weekend fixed effect with the pollution level. We also use a reasonable radius around an individual’s residence to assign the pollution level. This considerably mitigates the bias. The findings illustrate that people spend on average 50 minutes outdoors on weekends more than weekdays. We then show that incorporating this difference in estimating the health impact of ozone changes the results significantly, especially for adults ages 20-64. Finally, the specification allows our analysis to find a precise estimate for each day of the week.