Pilot estuarine mesocosm study on the environmental fate of Silver nanomaterials leached from consumer products

Although nanosilver consumer products (CPs) enjoy widespread availability, the environmental fate, leaching, and bioaccumulation behaviors of silver nanoparticles (AgNPs) from these products are not well understood. In this work, three nanosilver CPs, two AgNP standards, and an ionic silver (Ag+) standard were studied in estuarine mesocosms. The CPs exhibited long-term release of significant amounts of silver over a 60 d residence time in the mesocosms, and ultimately released 82 - 99% of their total silver loads. Measurements of total silver as a function of time, by inductively coupled plasma mass spectrometry (ICP-MS), indicated that the silver was transferred from the water column and accumulated in the estuarine biota, including hard clams, grass shrimp, mud snails, cordgrass stalks and leaves, biofilms, intertidal sediment, and sand. The ICP-MS results and calculations of bioconcentration and trophic transfer factors indicated that significant amounts of silver were taken up by the organisms through trophic transfer. Silver was also adsorbed from the seawater into the biofilms, sediment, and sand, and from the sand into the clams.

Photograph taken during high tide in the mesocosm that was treated with the toy bear.Figure optionsDownload as PowerPoint slideHighlights
► Pilot study on the fate of nanosilver from consumer products in estuaries.
► Consumer products leached 82 to 99% of their total silver loads over 60 d.
► Silver accumulated in the biota, including clams, shrimp, snails, cordgrass, biofilms, and sediment.
► Adsorption and trophic transfer processes probably contributed to the fate of the nanosilver.