DOSAGE PROBABILITIES AND AREA COVERAGE FROM INSTANTANEOUS POINT SOURCES ON GROUND LEVEL

Assuming that the dosage probability distribution in the core" region of a diffusing cloud is log-normal a number of probabilistic results are derived for point-source generated clouds diffusing near ground level. The results also apply to the distribution of concentration (over a given sampling period) in the wake of a continuous source. The topics treated include: "overdose factors" necessary to ensure a given dosage at a fixed point with a given probability; equal dosage probability contours; the area covered by a certain dosage with a given probability; the mean and the variance of the area covered in individual trials by a given dosage; the effect of meandering on the dosage probabilities at fixed points; and the ratio of an appropriately defined "peak" dosage to the local mean. © 1969."