Keywords: exposure, consumer products, nanoparticles
Summary:Application of nanotechnology in various consumer products such as cleaning supplies, cosmetics, electronics, clothing, and others has yielded products with desired physical and chemical properties. At the same time, there is a concern that nanoparticles could be released from such products during their use resulting in environmental and consumer exposures to nanoparticles and their agglomerates. Such releases and resulting inhalation exposures are especially likely from certain product groups, such as sprays and cosmetics that, due to their nature and intended application, release aerosol particles into the air and often in the user’s breathing zone. Due to these concerns, over the past years, there have been numerous studies looking into the release of particles from various nano-enabled products during their use. Studies also looked into the fate of the released particles, including their transport in indoor spaces as well as resuspension and inhalation risks once the particles settle. Particular attention has been paid to products containing metallic nanoparticles, such as Fe, Ti, and Ag. The latter is of special concern due to its antimicrobial ability. This presentation will review these research efforts by the Mainelis group as well as other researchers and will summarize the main observations as well as remaining and new research questions. Overall, most have demonstrated that nanoparticles and their agglomerates ranging in size from a few nm to 10-20 µm would be released, while the concentration of the released particles varied product-to-product and application-to-application. In certain instances, the mass concentration of the released particles could be as high as tens of mg/m^3 for spray and powder applications. The resuspension of deposited particles also has been demonstrated, with resuspension rates due to the use of Zn-based and Ag-based sprays ranging from 10^-1 to 10^-4 h^-1. At the same time, it is yet unknown if the observed concentrations lead to health and environmental effects. Also, can the employed study designs help us find the answers we seek? What is the best way to connect laboratory-based exposures studies with toxicological studies that use pristine nanoparticles as well as with real-world exposures to nanoparticles? It is hoped that this presentation will give the audience a sense of what has been accomplished so far and will stimulate a discussion on future research directions in this area.