Products Generated Indoors by Outdoor Ozone: Occupant Exposures and Urban Air Impacts

Abstract:

Outdoor ozone is transported indoors via infiltration and ventilation. It subsequently reacts with chemicals on indoor surfaces and in the air generating gas-phase and condensed-phase oxidation products, including secondary organic aerosols (SOA). Occupants inhale these gas-phase oxidation products, condensed phase products constituting the SOA, and ozone itself. Substantial fractions of the gas-phase oxidation products and SOA are ultimately transported outdoors. In this way, indoor chemical processing transforms outdoor ozone to a complex mix of outdoor oxidation products, some of which would not be otherwise present in outdoor air. To what extent do the products of indoor ozone chemistry contribute to the well-established associations between ozone monitored at outdoor sites and morbidity and mortality? Do these oxidation products, produced indoors, have any impact on urban air quality?