An evaluation of atmospheric deposition of trace elements into the Great Lakes

High-volume air samplers were used to collect aerosol samples on Whatman 41 air filters at the Canadian air sampling stations Burnt Island, Egbert, an d Point Petre. Once collected, the samples were analyzed for trace elements by neutron activation analysis. Air concentrations of over 30 trace elemen ts were determined. A special focus was made to utilize Compton suppression gamma-ray spectroscopy and epithermal irradiations to enhance the detectio n limits of neutron activation analysis. These techniques allowed for the d etermination of trace elements at very low levels. Results of the study of the trace-metal dry deposition into Lakes Huron and Ontario indicated that the majority of the total deposition resulted from crustal materials. Howev er, dry deposition is also a significant pathway for many toxic anthropogen ic trace metals into the Great Lakes.