Occupational exposure to LTA Nanozeolites: strategies of exposure monitoring and toxicity evaluation

Abstract

Nanozeolites (NZs) are increasingly used in several sectors, but very few data are available on their toxicity. Therefore in this study we aimed to apply a standardized strategy to assess the occupational exposure integrated to an in vitro model useful to evaluate potential toxic effects in the case study of LTA-NZs.

Particle number concentration (PNC) values greater than the background significant level were highlighted during the production process phase of LTA NZs. The increase of PNC in the typical size range of produced NZs (around 100nm) and the presence of airborne NZs and their agglomerates in the workplace were confirmed by both real-time (CPC and FMPS) and off-line (ICP-MS and SEM-EDX) data analysis.

We also investigated the potential cyto-genotoxicity of NZs produced in the factory, on human alveolar cells (A549) exposed to 10-100μg/mL. We evaluated cell viability/apoptosis by cytofluorimetric assay, membrane damage by LDH release and DNA damage by Fpg-comet assay. We found a slight increase of apoptotic cell % at 50 and 100μg/mL. We found slight, statistically significant, direct DNA damage and slight oxidative DNA damage.

These findings represent the first data integrating exposure characterization and potential genotoxicity of NZs and highlight the need to perform further studies to confirm such results.