Careful examination of an analytical method for the determination of lead concentrations in atmospheric particulates has confirmed that a low temperature ashing technique is preferable to the ashing of organic matter in a muffle furnace when preparing samples for metals analysis, and that use of the standard additions technique for the avoidance of interferences in the analyses by atomic absorption spectroscopy is justified. Analyses of some 600 samples collected from the air over Morton Grove, Illinois from 1964 through 1967 have revealed average suspended particulate concentrations but rather high lead concentrations for urban areas. Monthly mean lead contents, which were highest in the fall months, showed a gradual increase over the four years.
C. D. Burnham, C. E. Moore, T. Kowalski, and J. Krasniewski, "A Detailed Study of Lead Determinations in Air-Borne Particulates over Morton Grove, Illinois by Atomic Absorption Spectroscopy," Appl. Spectrosc. 24, 411-414 (1970)