Cytotoxicity of filtering respiratory protective devices from the waste sorting industry: A comparative study between interior layer and exhalation valve

Filtering respiratory protection devices (FRPD) are mandatory for workers to wear in the Portuguese waste-sorting industry. Previous results regarding microbial contamination found on FRPD interior layer raised question of whether from exhalation valve would also have cytotoxicity effects. Since valves very close workers’ nose and mouth, they represent a source exposure bioburden by inhalation. This study aimed evaluate present valves. For this purpose, effects were determined through MTT assay two different cell lines (human A549 epithelial lung cells, swine kidney cells) compared with previous obtained layers. The presented some suggesting inhalation route as potential use Half-maximal (50%) inhibitory concentration (IC50) values lower than overall when (z = ?4.455, p 0.000). Higher bacterial counts TSA correlated IC50 values, thus, higher effect cells. No statistically significant differences detected among workplaces.