144 Occupational Exposure to Particles Measured by Nanoparticles Tracking Analysis (NTA) in Exhaled Breath Condensate (EBC).

Abstract The production of paints, coatings and construction materials may generate nanoparticles (NP) with potential adverse health effects. We carried out a study aimed at investigating exposure biomarkers reflecting the internal dose of inhaled particles and NP. NTA was used to quantify particle number concentration and size in EBC collected at the end of shift in 81 workers employed in companies producing technological materials. External exposure was characterized in terms of particle number concentration, size and lung deposited surface area (LDSA) in the near operational field by using a set of DiSCmini. Three subgroups were identified: Low-Exposure (LE, n=30), High-Exposure (HE n=35), and non-occupationally exposed (UC, n=16). Comparisons between groups were made using non-parametric analyses. LE and HE workers showed significantly higher number of NP in EBC (p=0.024, p=0.041, respectively) as compared to UC. The HE groups showed higher levels of inflammatory biomarkers, such as IL-1β and IL-10 as compared to LE and UC (p=0.02, p<0.01, respectively). Positive correlations were observed between particle number concentration recorded by DiscMini and NTA data (Rho=0,225, p=0.04) and between the NTA and IL-10 and IL-1β (Rho=0.246, p=0.012; Rho=0.223, p=0.022, respectively). In contrast, LDSA did not correlate with NTA data. These findings provide evidence of the relationship between increasing exposure to NP and the burden of particles in the airways which, in turn, results in sustained inflammation. Given the lack of exposure biomarkers for dusts, these results are promising to investigate the relationship between internal dose of particles and changes in lung pathobiology.