Engineered Nanomaterials in the Air We Breathe

Time: Wednesday, April 9, 2014 - 4:00pm - 6:00pm
Type: Seminar Series
Presenter: Prof. Linsey C. Marr
Room/Office: 211 Mason Laboratory
Mason Laboratory
9 Hillhouse Avenue
New Haven, CT 06511
United States

Our experience with asbestos and combustion-related ultra-fine particles raises concerns about the potential for exposure to engineered nanomaterials in air.  Engineered nano-materials are being released into the4 atmosphere, and the factors affecting their transformation and fate are not well known. This research focuses on nanosilver, which is used as an antimicrobial agent in a variety of products, and C60 fullerenes, which hold promise for use in medical and energy applications.  We have characterized aerosol emissions from nanotechnology-based consumer products.  The spray products emitted 0.24-56ng of  silver per spray action., and the plurality of aerosols were 1-2.5 µm in diameter, a size that readily deposits in the respiratory system.  Both the products’ liquid characteristics and the bottles’ spraying mechanisms played roles in determining the aerosol size distributions, but the size of silver-containing aerosols was largely independent of the liquid-phase size distributions.  In the atmosphere,  nanomaterials are subject to transformations that my alter their transport properties and toxicity.  We have investigated the reaction between aerosolized C60 was oxidized by ozone and formed a variety of  oxygen-containing functional groups on the aerosol surface, including C60O, C60O2, and C60O3.  The reaction was limited to the aerosol surface and may have resulted in oligomerization.  Exposure to ozone increased the oxidative stress exerted by C60 aerosols as measured by the dichlorofluorescein assay, but not by the uric acid,  ascorbic acid, glutathione, or dithiothreitol assays.  This research will advance knowledge of the risks of inhalation exposure to nano-materials, and results will be complement studies in the aqueous phase to enable improved prediction of the environmental impacts of engineered nanomaterials