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Quantifying the Release of Silver from Nanotechnology-Based Consumer Products for Children
Citation:
Vance, M., N. Tulve, R. Willis, K. Rogers, T. Thomas, AND L. Marr. Quantifying the Release of Silver from Nanotechnology-Based Consumer Products for Children. QEEN Workshop, Arlington, VA, July 07 - 08, 2015.
Impact/Purpose:
The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
We assessed the potential for children’s exposure to bioavailable silver during the realistic use of selected nanotechnology-based consumer products (plush toy, fabric products, breast milk storage bags, sippy cups, cleaning products). All products had at least one component containing silver. Silver in particulate form was visible in the spray cleaning product, the interior foam and exterior fur of the teddy bear, the baby blanket, and in components of a sippy cup. Silver particles ranged from nanoscale up to 10 μm in size and appeared to be located on the surface and interior of fabric fibers and embedded in the components of the cup. We measured the release of ionic and particulate silver from products into water, orange juice, milk formula, synthetic saliva, sweat, and urine (1:50 product to liquid mass ratio); into air; and onto dermal wipes. Sweat and urine yielded the highest amount of released silver, up to 38% of the silver mass in products; tap water yielded the lowest amount, ≤1.5%. Leaching from a blanket into sweat plateaued within 5 min, with less silver released after washing. Between 0.3 and 23 μg m–2 of silver transferred from products to wipes. Aerosol concentrations were not significantly elevated during product use. Fabrics, a plush toy, and cleaning products were most likely to release silver. Silver leached mainly via dissolution and was facilitated in media with high salt concentrations. We predict that children may potentially be exposed to low concentrations of silver during the normal use of these consumer products, and bioavailable silver is expected to be in ionic rather than particulate form.
