TRACE-METAL PARTICULATE EMISSION TEST-RESULTS FROM A NUMBER OF INDUSTRIAL AND MUNICIPAL POINT SOURCES

As part of a Purdue University [West Lafayette, Indiana, USA] study of the environmental flow of Cd and other trace metals, source emission sampling for particulates was conducted at a number of industrial and municipal plants. The emission samples from each plant were analyzed for Cd, Pb, Zn, Cu, and in some cases Fe and Ni by atomic absorption spectroscopy. Atmospheric mass emission rates and emission factors were reported for total particulates and for each metal. Cd emission factors were substantially different from those estimated by Davis in an earlier report. Aerodynamic particle size distributions were measured at each source using an Andersen impactor. A comparison of the total particulate size distributions with the trace metal size distributions revealed that the metals were not evenly distributed among the particle sizes. In every case the trace metals were found predominantly in the respirable particulate fraction even when the bulk of the emissions were non-respirable.