Development and evaluation of a mobile laboratory for collecting short-duration near-road fine and coarse ambient particle and road dust samples

This study used fine and coarse PM concentrator technology in a Mobile Particle Concentrator Platform (MPCP) designed and built to allow the collection of large amounts of ambient PM, enabling time-resolved speciation analysis, which would not be feasible using conventional methods. One hour of sampling yielded sufficient sample loading for trace elemental analysis using X-Ray Fluorescence (XRF). In addition, the authors developed a novel Road Dust Aerosolizer (RDA) sampler in order to collect PM₂.₅ and PM₁₀ surface road dust in situ. This sampler aerosolizes dust from the road surface, simulating ambient road dust resuspension, resulting in measured PM composition and size more appropriately (and less labor-intensive) than those obtained from studies using bulk road dust sieved and re-suspended in the laboratory. Overall, the authors' modified fine and coarse particle concentrators yielded good reproducibility between co-located samples and sufficient loading for trace elemental analysis. For particle mass concentration, the authors observed a relative error of 3% and 4% among pairs of filters for fine and coarse concentrators, respectively; confirming that the mass collected on an unweighted quartz filter in parallel with a Teflon filter will have the same PM mass as the weighed Teflon filter. For samples with elements that are well above the LOD, relative uncertainty values were between 5% and 10% for the fine and 3% and 10% for the coarse. The authors' results show that the RDA system has an excellent precision for mass and elements as well. The relative error for mass is 7% for PM₁₀ and 3% for PM₂.₅ within pairs and ranged from 2 to 10% for elements. In conclusion, the authors developed a method for collecting PM₁₀ and PM₂.₅ near-road air and surface road dust for short durations, which allows investigation of the composition of direct (airborne) and indirect (resuspended road dust) non-tailpipe vehicular emissions. Implications: The methods the authors developed in this study allow the collection f one-hour PM₁₀-₂.₅ and PM₂.₅-₀.₂ samples from near-road ambient air at several distances from the same roadway in 1 day, and collection of road dust directly from the road surface, with sufficient loading for trace elemental analysis. This will allow investigation of the composition of direct (airborne) and indirect (resuspended road dust) vehicular emissions.

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  • English

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  • Accession Number: 01765336
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 5 2021 3:02PM