Moving towards UFP – Chemical and Toxicological Characterization of Brake Wear Particles below PM1

Over last decades the presence of nanoparticles in human environment is continuously growing. This trend can be observed in several fields, ranging from industrial sector to medicine, thus reflecting on the environment. Lingering on the last one, the continuous increase of nanoparticles in the environment is mostly related to anthropogenic activities. Among contributors, transport sector is well known to be a relevant source to the diffusion of nanoparticles in the environment [1]. In particular, particular matters (PMs) are known to be hazardous and poorly affected by countermeasures. As far as toxicological hazard of environmental PMs is concerned, it is well known that sub-micrometric and nanometric fractions exhibit stronger effects [2]. However, few investigations are currently available in literature looking specifically at nano-particles generated by brakes. For this reason, nanometric PMs generated by the brake wear of passenger cars components were collected at the dynamometric bench, simulating standard driving and braking conditions. Filters with particulate matter in the range between 400 – 450 nm coming from three different brake wears emissions, namely M1, M2 and M3, were collected. Their chemical composition was assessed through SEM/EDXS and Raman Spectroscopy measurements. The main difference between emissions is related to the presence of Copper in the M2 emission. Following to chemical characterization, toxicological test, such as cells viability was conducted on A549 alveolar cells and on monocytic leukemia THP-1 cells, both in submerged conditions. Cell viability of A549 cells is less sensitive compared to the THP-1 cells, which is variable over a wider range.