Size Distribution, Mercury/Lead Concentrations, and Stochastic Analysis of Suspended Particulates in Ambient Air

摘要

Particulate concentration, particle size distribution, and mercury and lead concentrations in atmospheric particulates on Wright-Patterson Air Force Base (WPAFB), Ohio, were determined. Particulates were fractionated as follows: greater than 7.0, 3.3 to 7.0, 2.0 to 3.3, 1.1 to 2.0, and less than 1.1 microns in equivalent aerodynamic diameter. The distribution of the particulate concentrations was analyzed using the Reverse Arrangements test to establish randomness, the Kolmogorov-Smirnov test to compare ten proposed probability density functions, and the Likelihood Ratio test to isolate the function best describing the data. The average lead concentration during a 24-hour sampling period was 1.25 micrograms/cu m. Mercury concentrations in particulates averaged 6.9 nanograms/cu m, however, due to inconsistencies in the analytical method no correlation could be established between mercury concentration and particle size.