A 72-h exposure study with eastern oysters (Crassostrea virginica) and the nanomaterial graphene oxide
Citation:
Khan, B., A. Adeleye, R. Burgess, R. Smolowitz, S. Russo, AND K. Ho. A 72-h exposure study with eastern oysters (Crassostrea virginica) and the nanomaterial graphene oxide. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 38(4):820-830, (2019). https://doi.org/10.1002/etc.4367
Impact/Purpose:
The overall goal of this work is to evaluate responses of marine organisms to environmental exposures to carbon-based nanomaterials such as graphene oxide (GO). Given the increasing usage of graphene family nanomaterials in the field of electronics, biomedicine, and surface coatings, it is likely that GO will make its way to aquatic ecosystems. Our knowledge of the environmental effects of such nanomaterials is very limited and incomplete. This research aims at understanding the impacts and toxicity of GO exposures using Eastern oysters which are a commercially and ecological important shellfish species.
Description:
Graphene is a two-dimensional nanomaterial with unique mechanical, thermal, electrical, and optical properties. With increasing applications of graphene-family nanomaterials (GFNs) in numerous fields such as electronics, biomedicine, and surface coatings, concern for their impacts on aquatic ecosystems is rising. However, current information on the toxicity of GFNs, including graphene oxide (GO), is scarce. Filter-feeding bivalves, such as Eastern oysters, are good models for nanomaterial exposure studies. We present results from a 72-hour static renewal oyster study which, to our knowledge, is the first study documenting in vivo effects of GO exposures in marine bivalves. Water samples were analyzed after each renewal for GO concentration and particle size assessments. Gill and digestive gland tissues were evaluated for lipid peroxidation, a marker of oxidative damage, and for glutathione-s-transferase (GST) activity, a phase II detoxification enzyme. Additionally, gill tissues were fixed for histopathological analyses. Elevated lipid peroxidation in GO-exposed oysters was noted. No significant changes in GST activity were observed, but reduced total protein levels were found in exposed oysters. Loss of mucous cells, hemocytic infiltration, and vacuolation were observed in the gills. Results indicate that short-term GO exposures can induce oxidative stress, gill epithelial inflammation, and can adversely affect overall health in oysters. Further investigations regarding the fate and sublethal effects of GO are critical to understanding the spectrum of risks associated with a rapidly growing graphene consumer market.
URLs/Downloads:
DOI: A 72-h exposure study with eastern oysters (Crassostrea virginica) and the nanomaterial graphene oxide