Ozone versus Ozone Reaction Products: Which Is Responsible for Cardiorespiratory Effects?
When outdoor ozone is transported indoors, a substantial fraction is removed by reactions with indoor surfaces. These reactions generate products that can be inhaled together with ozone. In a panel of 89 healthy workers, we measured ozone concentrations outside and inside offices and residences and collected time-activity data. We used ozone loss - the difference between outdoor and indoor concentrations - as a proxy of exposure to ozone reaction products. Biomarkers of cardiorespiratory pathophysiology were measured 4 times for each participant over a period of 6 weeks. We compared the effects of ozone versus “ozone loss” exposures. We found that ozone loss was more strongly associated with several biomarkers than was ozone itself. Adverse effects were stronger for shorter periods of ozone loss but for longer periods of ozone exposure.
