BayCEER Workshop 2023

Microplastics and associated leachates in the atmospheric deposition of Bayreuth, Germany

Microplastics (MPs) are small pieces of synthetic polymers, typically smaller than 5 mm, which can be directly released in the environment as primary MPs or by the degradation of larger plastic objects as secondary MPs. The most abundant polymer types of atmospheric MPs have been reported to be polyethylene terephthalate (PET), polyethylene (PE), polystyrene (PS), polypropylene (PP), and recently also tire wear road particles (TWRP). Carried through the air, MPs can potentially travel far away from their sources, and subsequently be deposited, leading to contamination in even remote areas. MPs are suspected to be of high relevance in the context of public and ecological health. To date, the relative importance of wet and dry deposition in the MP removal from the atmosphere remains poorly understood. To address this research gap, we collected monthly atmospheric deposition samples, both wet and total, over one year from March 2022 till February 2023, at Bayreuth Center of Ecology and Environmental Research (BayCEER) and analysed them for MPs and TWRP leachates. Close to this urban site, we have monitored meteorological parameters such as temperature, wind direction and velocity, and precipitation. Here we report the abundance of MPs in the atmospheric fallout, their size, shape, and polymer type obtained by analyzing our samples using micro-Fourier transform infrared spectroscopy (µ-FTIR). We analyzed the composition and concentration of TWRP related leachates using high-performance liquid chromatography with mass spectrometry and fluorescence detection (HPLC-MS/FLD), namely the N,N′-Substituted p-phenylenediamines (PPDs) and their derived quinones (PPDqs), and the 1,3-diphenylguanidine (DPG).

The link between MP deposition and meteorological factors merits our investigation and would assist to understand better their environmental fate.

This project is financed by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project nr. 391977956 – SFB1357.