In cooperation with key stakeholders including EPA, local and state environmental agencies, industry, and academia, the U.S. Department of Energy (DOE) has established the Upper Ohio River Valley Project (UORVP), a network for monitoring and characterizing PM2.5 in the Upper Ohio River Valley. This region was chosen because it has a high density of coal-fired electric utilities, heavy industries (e.g. coke and steel making), light industry, and transportation emission sources. It is also ideally situated to serve as a platform for the study of interstate pollution transport issues. This region, with its unique topography (hills and river valleys) as well as a good mix of urban and rural areas, has a high population of elderly who are susceptible to health impacts of fine particulate as well as other related environmental issues (e.g., acid rain, Hg deposition, ozone). A world-class medical research/university system is also located in the region, which will facilitate the subsequent use of the air quality data in studies of PM2.5 health effects.

The UORVP, operated by Advanced Technology Systems, Inc. (ATS) under contract to DOE, includes two urban and two rural monitoring sites that were part of existing local and/or state air quality programs. The primary urban site, located in the Lawrenceville section of Pittsburgh, PA, is an air quality monitoring station operated by the Allegheny County Health Department. The primary rural site is co-located with a station operated by the Pennsylvania Department of Environmental Protection near Holbrook, Greene County, PA. The Lawrenceville and Holbrook sites both contain several types of filter-based PM monitoring equipment, continuous samplers for co-polluting gases (CO, SO₂, NOx, NH₃, etc.) and surface meteorological stations. Sampling at Lawrenceville and Holbrook consists of one filter-based sample every sixth day throughout the year, along with month-long intensive (four samples daily at Lawrenceville and one sample daily at Holbrook) periods during the summer and winter of 1999 through 2001. A "satellite" urban site is co-located at a West Virginia Division of Environmental Protection monitoring station at the Morgantown, West Virginia, airport, while a satellite rural site is co-located at a site operated by the Ohio Environmental Protection Agency near Athens, Ohio. Samplers at Morgantown and Athens collect one filter-based PM2.5 sample every sixth day. Measurements under the UORVP began in early 1999 and will continue through the summer of 2001.

Preliminary analysis of data collected during the first 18 months of the UORVP show that: (1) the median mass and composition of PM2.5 are similar for both Lawrenceville and Holbrook, suggesting that the sites are impacted more by the regional than by local effects; (2) there was no significant difference in the particulate trending and levels observed at both sites between Summer 1999 and Summer 2000; (3) sulfate levels predominate at both sites during winter intensive sampling; and (4) PM2.5 and PM10 mass concentration levels are consistently higher in summer than in winter, with intermediate levels being observed in the fall. As the UORVP progresses, data analysis will focus on relating the aerometric measurements to local and regional scale emissions of sources of primary and secondary fine particles using receptor-based air quality models.

In May, 1999, the Holbrook, PA site of the UORVP was augmented with a precipitation gauge and collector to measure the wet deposition of mercury. Precipitation samples are collected weekly and analyzed for mercury content as part of the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). The purpose of the network is to collect nationwide data on the chemistry of precipitation for monitoring of long-term spatial and temporal trends. Mercury deposition data from the Holbrook site (National site designation PA37), and all other similar sites, are available on the Mercury Deposition Network portion of the NADP/NTN website.