Nanomaterials at the workplace: measuring and modelling inhalation exposure

Abstract

At the nanoscale (<100 nm), materials can exhibit properties that differ physically, chemically, and biologically from their larger counterparts. These new sizedependent properties offer huge possibilities to make materials effectively stronger, lighter, better electrical conductive, flexible, water resistant, dirt repellent, etc. The distinctive size-related properties of nanomaterials are applied by incorporating them in a wide range of products. However, increasing production and use of nanomaterial embedded products raises concerns and questions about the potential health risks of these nanomaterials. The extremely small dimensions of nano-objects increase their ability to cross cell membranes and reach the organs through the blood stream. Due to the greater surface to volume ratio of nanoobjects compared to their larger counterparts, a certain mass concentration of nano-objects will have a higher reactivity than the same mass concentration of larger particles of the same composition. Workers who are frequently handling nanomaterials or products they are incorporated in, run the risk of being exposed to nano-objects and their agglomerates and aggregates (NOAA). Information about the potential for occupational exposure to NOAA is therefore essential for determining whether there is any potential risk of adverse health effects and for the implementation of risk management measures to reduce exposure at the workplace. This thesis aimed to 1) get an overview of the occupational NOAA exposure scenarios and the levels of occupational exposure to NOAA across the various life cycle stages, 2) gain insight into the determinants affecting NOAA exposure, and 3) provide a scientific basis for future modelling of worker exposure to NOAA.