Identification of sites with elevated PM levels along an urban cycle path using a mobile platform and the analysis of 48 particle bound PAH

Using a multidisciplinary approach, this study provides insight into everyday exposure scenarios of urban commuters to aerosol particles and their associated polycyclic aromatic hydrocarbons. It combines high spatiotemporal resolution particle measurements, used to determine the distribution of particulate matter in the urban environment, with the chemical analysis of the health-relevant particle fraction (< 2.5 mu m) at higher polluted sites. In September 2019, multiple test rides were conducted using a mobile platform along an urban cycle path in Aachen, Germany. With this, particle number and mass concentrations were recorded. Based on this data, five sites with elevated levels of particulate matter concentrations were identified. At these locations, the airborne respirable particles (PM2.5) were collected using a high-volume sampler. These were then quantified for an extended set of PAH and alkylated PAH by GC-MS. The alkylated distribution pattern of PAH in the samples all exhibited a typical pyrogenic pattern. A more detailed assessment of toxicity was possible because PAH such as dibenzo[a,l]pyrene or 7H-benzo[c]fluorene could be taken into account. The non-EPA PAH contributed up to 81% to the total toxicity of the particles expressed in toxic equivalents. The measurement of an extended set of PAH was beneficial and is highly recommended for future studies.