Acid aerosols in the Pittsburgh Metropolitan area

This article presents data on ambient concentrations of selected acidic aer osols at four existing monitoring sites in the Pittsburgh PA metropolitan a rea, The data were collected by staff of the Allegheny County Health Depart ment, Division of Air Quality during the summer and fall of 1993, The sampl ing protocol was focused on obtaining 24 h-average ammonia, ammonium, acidi c sulfates, and particle strong acids data on a 2 to 3 day cycle. The data were obtained using Harvard University School of Public Health's "Short-HEA DS" annular denuder sampling train. The Pittsburgh area is of interest beca use it is downwind of a major regional source of sulfur and nitrogen emissi ons from coal-burning power plants: the Ohio River Valley. The data present ed here indicate that ground-level concentrations of acidic aerosols in Pit tsburgh are highly correlated spatially and that many pollutants are higher on days when ground-level wind direction vectors indicate that wind is com ing from the southwest rather than from the Pittsburgh source area itself. The monitoring site that is most upwind of the Pittsburgh source area - Sou th Fayette - has particle strong acid levels about twice those of sites clo ser in to the Pittsburgh central business district. (C) 1999 Published by E lsevier Science Ltd. All rights reserved.