Quantifying Urban Spatial Variations of Anthropogenic VOC Concentrations and Source Contributions with a Mobile Sampling Platform.

Peishi Gu,Yi Tan,Hugh Z Li,Albert A Presto,Timothy R Dallmann

doi:10.3390/ijerph16091632

Abstract

Volatile organic compounds (VOCs) are important atmospheric constituents because they contribute to formation of ozone and secondary aerosols, and because some VOCs are toxic air pollutants. We measured concentrations of a suite of anthropogenic VOCs during summer and winter at 70 locations representing different microenvironments around Pittsburgh, PA. The sampling sites were classified both by land use (e.g., high versus low traffic) and grouped based on geographic similarity and proximity. There was roughly a factor of two variation in both total VOC and single-ring aromatic VOC concentrations across the site groups. Concentrations were roughly 25% higher in winter than summer. Source apportionment with positive matrix factorization reveals that the major VOC sources are gasoline vehicles, solvent evaporation, diesel vehicles, and two factors attributed to industrial emissions. While we expected to observe significant spatial variability in the source impacts across the sampling domain, we instead found that source impacts were relatively homogeneous.

Highlights

Volatile organic compounds (VOCs) are emitted to the atmosphere by both natural and anthropogenic sources [1]
An advantage of this approach is that we identify a common set of sources for the entire domain, which improves the overall robustness of the performed matrix factorization (PMF) solution [57]
Industrial emissions are important for benzene and m/p-xylene

Summary

Introduction

Volatile organic compounds (VOCs) are emitted to the atmosphere by both natural and anthropogenic sources [1]. They are an important part of the atmospheric oxidation processes that generate ozone and secondary organic aerosols (SOA) [2,3]. Important anthropogenic sources of VOCs include vehicular emissions, oil and gas operations, industrial processes, evaporation of volatile organic solutions, and consumer products [5]. Two important classes of anthropogenic VOCs are aliphatic hydrocarbons (such as alkanes, alkenes, etc.) and aromatics (such as benzene, toluene, ethylbenzene and xylenes, known as BTEX) [6,7,8,9]

Methods

Results

Conclusion