Estimation of Inhalation Exposure on the Basis of Airborne Nanomaterial Release Data and Propagation Modeling

The
lack of data for inhalation exposure concerning the handling
of nanostructured materials is limiting the current nanomaterial risk
assessment. However, there are numerous studies dealing with the origin
of exposure, i.e., the release. The link between release and exposure
are transport and transformation phenomena. Thus, propagation modeling
was used to simulate transport from source to breathing zone in order
to estimate quantitative exposure levels from measured release data
for selected scenarios. On the basis of three ventilation and five
release scenarios, exposure levels were calculated with and without
human thermal plumes for both the nearfield and the farfield. Results
show that the often neglected human-induced convective airflow can
have a strong impact on the level of exposure, especially for natural
ventilation or non-well-designed technical ventilation systems as
typical for nonindustrial consumers or handicraft businesses.