Canadian and U.S. sources impacting the mercury levels in fine atmospheric particulate material across New York State

An extensive atmospheric sampling and analysis program has been completed in order to identify and apportion the sources of mercury associated with fine atmospheric particulate material (d(a) < 2.5 μm). Samples of fine atmospheric particulate material were collected daily, at five remote sites in New York State, over a period of 2 years. The trace element composition of 1200 of these samples was determined by Instrumental Neutron Activation Analysis. Results of both meteorological and statistical analyses of the data indicate that approximately 55% of the fine particulate mercury originated from smelters in Ontario and Quebec, and 25% originated from a mixture of regional sources in the Midwestern United States. A decline in the average measured particulate Hg concentration, beginning in February 1993, has been attributed to reduced emissions from one or more of the major Canadian smelters.