Particulate zinc, cadmium, lead, and copper in the surface microlayer of southern Lake Michigan

Abstract

Bulk water and surface microlayer water samples were collected from the southern and southern central basin of Lake Michigan during the summer of 1975. Samples were filtered through 47 mm diameter nuclepore filters and then tested for trace metal concentrations. Particulate matter of diverse composition and morphology commonly occurred in higher concentrations in surface microlayer samples than in the bulk water samples. Enrichment of zinc, cadmium, lead, and copper in the surface microlayer samples occurred substantially in the particulate phase, especially when surface enrichments were large. Surface enrichment of total particulate matter and zinc, cadmium, lead, and copper was related to the presence of surface accumulated material and film pressure. Chemical analysis indicated that a significant portion of the particulate zinc, cadmium, lead, and copper in the surface microlayer samples may be atmospherically transported anthropogenic particulate matter. (2 graphs, 3 photos, 35 references, 5 tables)