A New Mathematical Model of Air Pollutant Concentration Averaging Time and Frequency

A Study of the Statistical Distribution of Chemical Pollutants in Air

“…The assertion of Larsen 1 that the totality of quantitative determinations of certain chemical pollutants in the air has a log-normal distribution independent of the place and duration of sample collection, is accepted almost unanimously by contemporary practical 2 " 4 and theoretical 5 investigators. During routine investigations on air pollution in Sofia, data that gave rise to some doubt in regard to the universal validity of that hypothesis were obtained.…”

Ambient Air Quality and Automotive Emission Control

“…These histograms show the expected number of 8 hr intervals having CO concentrations within each 1 ppm increment. The histograms were obtained by assuming a lognormal distribution of concentration; 13 consecutive, nonoverlapping intervals; and that the distribution could be scaled between years. The histograms emphasize the fact that the projected curve represents the maximum, once-peryear concentration and that most 8 hr average concentrations, and hence exposures, are much lower, even at this worst case, downtown site.…”

An Air Quality Data Analysis System for Interrelating Effects, Standards, and Needed Source Reductions: Part 4. A Three-Parameter Averaging-Time Model

“…4 Fixed, nonoverlapping averaging times are also used for the averaging-time model. 5 ' 6 All averaging times begin at the first minute of a calendar year and conclude at its last minute. Standard time is always used.…”