Elemental composition of PM2.5 aerosols in Queens, New York: Solubility and temporal trends

As a part of the PM2.5 Technology Assessment and Characterization Study-New York (PMTACS-NY), concentrations of sulfate and 15 trace elements were determined in daily PM2.5 samples collected from July 2001 to September 2002 at a site in urban Queens, NY. The elements were Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Cd, Sb, and Pb. Over the first 12 months these elemental concentrations were measured in both a water extract and in a total acid digestate so that the solubility of the aerosols bearing the above trace elements could be evaluated. This is important as elements with high solubility can be more readily bio-activated in the lungs and thus may be potentially more harmful to humans. An overview of the elemental composition of PM2.5 aerosols at the Queens, NY site over the 15-month period is presented. This includes a comparison of seasonal changes in aerosol composition and solubility at the sites along with an evaluation of the impacts on aerosol composition of the collapse of the World Trade Center Towers in Manhattan on 9/11/2001 and the smoke from Quebec wildfires in early July 2002.