Transport of Reactive Gas-Phase Outdoor Air Pollutants Indoors

Abstract
This paper considers the homogeneous and heterogeneous chemistry affecting the transport of outdoor gas-phase nitrogen oxides, ozone and nitric acid indoors. Mathematical models are developed and applied to predict indoor air concentrations resulting from this transport, and integral expressions are pre sented that may be used to estimate model parameters (e.g. deposition veloci ty) from dynamic measurements of contaminant concentration. The approach to model development and parameter identification is general and may be applied to other cases. Comparisons of predicted results and measured data indicate that (a) homogeneous chemistry can significantly impact transport at times and may be predicted using simplified models, (b) accurate prediction of nitric acid generation may demand more complete models and (c) homoge neous and, possibly, heterogeneous generation of these pollutants may be expected to impact the conventional measurement of deposition velocities placing the accuracy of earlier measurement in doubt.