Abstract
A previous mathematical model of air pollutant concentration, averaging time, and frequency gave results close to actual measurements for the relatively short averaging times for which it was used. However, recent calculations show that mathematically unsound results are obtained with the model for averaging times longer than one month. A new mathematical model, described herein, gives mathematically sound results for all averaging times. The two dominant features of this new model are derived from observations that indicate: (1) air pollutant concentrations are approximately lognormally distributed for all pollutants in all cities for all averaging times; and (2) median concentration is proportional to averaging time to an exponent. Applications to problems air pollutant effects and air quality standards are shown.