Source apportionment of dry deposited and airborne coarse particles collected in the Chicago area

Long-term dry deposition and dichotomous coarse particle samples vc ere col lected between November 1993 and October 1995 in Chicago, IL, as part of th e Lake Michigan Mass Balance Study (LMMBS). In addition, short-term dry dep osition and airborne coarse particle (Noll Rotary Impactor) samples were co llected during the Atmospheric Exchange Over Lakes and Oceans Study (AEOLOS ), These samples were analyzed for trace metals and modeled using the U.S. EPA's Chemical Mass Balance (Ch IB) Model (Version 7) to determine the sour ces of these particles. The modeled source contributions were similar, The results indicate that light duty unleaded vehicles, soil dust, and heavy du ty diesel vehicles were the major sources of ambient coarse and dry deposit ed particles in Chicago. The other sources found were lime kilns, coke dust , aluminum foundry-reverberatory furnace, coal-fired power plant, paint spr ay booth, and municipal incineration. The results from this study indicate that the CMB approach can be used to determine the source of deposited part icles.