The Partnership for Environmental Research and Community Health (PERCH) Phase III, Part 2: Source apportionment analyses for fine particulate matter, ozone, and mercury in greater Pensacola, Florida

The Partnership for Environmental Research and Community Health (PERCH) is a comprehensive, multi-partner, and multi-disciplinary study to determine if a connection exists between elevated levels of illness in Northwest Florida and the levels of ambient air pollutants. Initial phases of the project investigated regional scale threats to public health and welfare by reviewing existing information on emissions sources and air quality, and subsequently deploying mobile air monitoring equipment to collect data on ambient pollutant concentrations on a local scale in the greater Pensacola, Florida area. These seminal analyses found that high levels of fine particulate matter likely pose the greatest risk to human health, and that sulfates, organic carbon, and secondary organic aerosols dominate the PM2.5 mass distribution. Locally high concentrations of certain air toxic pollutants appear to result from gasoline combustion, suggesting that mobile sources contribute significantly to potentially dangerous levels of both fine particulate matter and toxic air pollutants. Phase III of the PERCH continues the investigation of air quality in Northwest Florida in two parts: (1) community-scale risk assessment for toxic pollutants and (2) source apportionment of PM2.5, ozone, and mercury.

This paper presents an update on continuing efforts to develop an understanding of emissions sources that contribute to poor air quality and related health effects in the greater Pensacola area using contemporary source apportionment techniques. The Community Multiscale Air Quality (CMAQ) model is used in concert with ambient monitoring data from the Pensacola area for summertime (July 2001) and wintertime (January 2002) conditions to relate the ambient distribution of fine particulate matter (PM2.5), ozone, and mercury to anthropogenic and biogenic sources of precursor emissions (i.e., oxides of nitrogen [NOX], sulfur dioxide [SO2], volatile organic compounds [VOC], and particulate matter [PM]). This analysis is informative to evaluate the likelihood of success of recent U.S. EPA regulatory initiatives such as the Clean Air Interstate Rule, Clean Air Visibility Rule, and Clean Air Mercury Rule, as well as establish priorities for future emissions control requirements that may be necessary on a local scale.