Chemical Characterization of Nanoparticle Emissions from Brakes - The nPETS Project

nPETS - nanoParticle Emissions from the Transport Sector - is an EU- funded project within the Horizon 2020 research and innovation program, with the aim of characterizing specifically the emission amount, the chemical composition and the toxicological behavior of nano-particulates produced by different exhaust and non-exhaust emission sources related to the transport sector. Started in June 2021, its final goal is to provide a wide scientific background for informed public health policies aiming to tackle transport-related nano-particulates, while developing sound technologies for their collection, chemical analysis and toxicological characterization. In particular, the chemical characterization of the collected nano-particulates is of fundamental importance in determining the presence of univocal markers for specific emission sources in different environments. Furthermore, it plays a pivotal role in explaining nano-emissions environmental and toxicological interactions, which will be studied during the second half of the project. With specific reference to the non-exhaust nano-particulates generated during braking operations, this paper summarizes the results obtained during the first period of project activities. More specifically, dedicated collection procedures, measurement protocols and physico-chemical characterization of brakes ultra-fine emissions are described and discussed. Notably, a comprehensive study of the chemical composition of brake emissions of nanometric dimensions is still lacking in literature. To this end, this paper reports for the first time a comparative assessment between the chemical composition of the brake emissions from nanometric dimensional fraction (d50 < 150 nm) with respect to those from coarser fractions.