NEAR ROADWAY DEPOSITION GRADIENTS IN THE BINGHAMTON, NY URBAN CORRIDOR

Atmospheric deposition can be a significant source of pollutants to ecosystems. Networks such as the National Atmospheric Deposition Program (NADP) provide insight into regional patterns of atmospheric deposition. However, the NADP was not designed to assess the potential for elevated deposition rates near urban infrastructure such as roadways.

In order to examine how near roadway ecosystems are affected by spatial and temporal variations in atmospheric deposition, arrays of bulk deposition collectors were deployed at distances from 0 – 150 m at four sites with differing traffic patterns, fetch and vegetation characteristics. These collectors were sampled weekly to biweekly from June 2009 – May 2010. In addition to precipitation volume, pH, and conductivity, samples were analyzed using sector field – mass spectrometry to determine concentrations for over 50 major and minor elements.

Many of the elements exhibit exponential decreases in concentration perpendicular to the roadway corridors. Considerable seasonal depositional variation is also evident with the concentration of many elements several orders of magnitude higher during the winter months. Using multi-element analysis coupled with spatial variation, it is possible to differentiate pollutant signals from deicing salts, road surface degradation, brake and tire wear, and natural sources of organic materials, including canopy interception. Roadway abrasion, as well as vehicular emissions, was found to be significant sources of atmospheric deposition near roadways. The impact of the enhanced deposition to microbial and plant communities near roadways will be assessed in the next phase of the project.