Characterization of PM10 Emission Rates from Roadways in a Metropolitan Area Using the SCAMPER Mobile Monitoring Approach

Abstract

The SCAMPER mobile system for measuring PM10 emission rates from paved roads was used to characterize emission rates from a wide variety of roads in the Phoenix, AZ metropolitan area. Week-long sampling episodes were conducted in March, June, September, and December. A 180 km-long route was utilized and traveled a total of 18 times. PM10 emission rate measurements were made at 5-s resolution for over 3200 km of roads with a precision of approximately 25%. The PM10 emission rates varied by over two orders of magnitude and were generally low unless the road was impacted with dust deposited by activities such as construction, sand and gravel operations, agriculture, and vehicles traveling on or near unpaved shoulders and roads. The data were tabulated into averages for each of 67 segments that the route was divided into. The segment-averaged PM10 emission rates ranged from zero to 2 mg m−1, with an average of 0.079 mg m−1. There was no significant difference in emission rates between seasons. There was a major drop in emission rates over a weekend, when dust generation activities such as construction are expected to be much reduced. By Monday, the PM10 emission rates had risen to the levels of the previous Friday. This indicates that roads quickly reach an equilibrium PM10 generating potential.