Can we trust real time measurements of lung deposited surface area concentrations in dust from powder nanomaterials ?

A laboratory comparison between various methods for real-time measurements of lung deposited surface area (LDSA) using spherical particles and powder dust with specific surface area ranging from 0,03 to 112 m2/g was conducted. Based on these results it appears that there is still currently insufficient reliability and comparability between methods in the measurement of LDSA concentrations. Further development is required to enable use of LDSA for reliable dose metric and regulatory enforcement of exposure to poorly soluble substances.