ABSTRACT
Figure 28.1 Design of existing and future studies.The greatest interest of industrial hygienists and toxicologists is in the release of synthesized ENPs during production (synthesis), handling or application (treatment) of nanostructured materials containing ENPs and use, recycling and littering (treatment) of products containing ENPs into the environment. The case of ENP release during synthesis is best described by an emission factor (EF), which is defined as number, surface area and/or mass (volume) per unit of time released to the environment. One can also consider relating the amount of ENP release to the amount of nanostructured material produced. The ENP release per unit of mass of produced or treated nanostructured material is best described by a release factor (RF), defined as number, surface area and/or mass (volume) per unit of mass of nanostructured material. This is depending on properties of the nanostructured materials and the amount and kind of energy input during the different kinds of treatment of the material. The ENP emission and release factors can be considered to be important process and
material properties, since with no emission and release there is no exposure and therefore no risk.Recently a literature review [4] about workplace situations was published, covering the work done thus far to determine the release of ENPs from different synthesis and treatment process-es of ENPs as well as treatments of nanostructured materials like composites. In all studies, more or less defined exposure measurements for different materials in combination with different practical treatment or stress processes were performed. An ENP re-lease versus exposure measurement relationship was not derived.
