1990 Diesel Particulate Matter (PM) Concentrations Across Maine's Census Tracts   

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Short Description: 1990 Concentrations of modeled diesel particulate matter (PM) air toxics emissions from road sources for each US Census Tract in the lower one-third of the state of Maine.

Data Details: The basemap polygons are 1990 US Census Tract boundaries. The 1990 air toxics emissions particulate matter (PM) dataset was obtained from the offices of the Northeast States for Coordinated Air Use Management (NESCAUM) as they obtained it from the Environmental Protection Agency's Cumulative Exposure Project (CEP). The data was originally modeled under the Assessment System for Population Exposure Nationwide (ASPEN) in order to predict US Census Tract level diesel PM concentrations as micrograms per cubic meter (µ/m3). Emissions data for 1990 was inputted to the ASPEN dispersion model by the Environmental Protection Agency (EPA), which subsequently produced the estimated concentrations. The legend is classified in quantiles. The cities with a population of over ten-thousand residents was obtained from the 1990 US Census cities shapefile. The companion Names of Cities page listing the names of the enumerated cities was also derived from the 1990 US Census cities shapefile. As a letter-sized landscape print out, the scale is approximately 23 miles to an inch. Magnetic north is up.

Credits: Map prepared by Carlos M. Jusino at West Harlem Environmental Action, Inc. (WE ACT) with assistance from the Northeast States for Coordinated Air Use Management (NESCAUM), using ArcView® GIS v3.1 software from the Environmental Systems Research Institute, Inc. (ESRI).

Support: Funded in part by the former W. Alton Jones Foundation (now Blue Moon Fund) and by the National Institute of Environmental Health Sciences (NIEHS).

Map Maker’s Notes: While a distinction exists between data for non-road sources such as airplanes, farm equipment, boats, construction equipment, etc, (vehicles that don't generally go on roads) and road sources such as cars, trucks, buses, etc., only the latter data (road sources) was used to generate this map.