Tracing nanomaterial hotspots in a changing world
Conference contribution, 2010
The potential risks of nanotechnology and nanoparticles have been outlined along with the importance of assessing these risks before commercial products are out on the market. We here propose a method to detect future hotspots of nanoparticle emissions by estimating the production rate and societal stock of technologies containing nanomaterials at a future stage when the technology can be viewed as mature and fully developed and diffused. This estimate is combined with a characterisation of the nanomaterial. The method is applied to some technologies containing titanium dioxide (TiO2) nanomaterials. The applications of TiO2 nanomaterials investigated in this study are UV absorbers (in sunscreen), pigment (in paint), electron carrier (in Grätzel solar cells) and photocatalyst (in self-cleaning windows and cement). Estimations of the current production and stocks of TiO2 nanomaterials for the technologies are also included for comparison. The TiO2 nanomaterials are characterized in seven steps, which gives valuable information regarding the potential emissions. Results indicate that two TiO2 nanomaterial containing technologies, paint and sunscreen, are already close to their mature stages. Paint is the current hotspot since it has the currently highest production rate and largest stock of TiO2 nanomaterial. In the future, however, in terms of TiO2 nanomaterial turnover, it may be passed by self-cleaning cement, which has the potential to become by far the largest use even if only a minor part of all cement will contain TiO2 nanomaterial. The diversity of types of different TiO2 nanomaterials and their potential emissions makes it problematic to discuss TiO2 nanomaterials as if it was one single nanomaterial in an exposure assessment context.