R1 AM Nanotechnology Environmental and Health Impacts
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in Ballroom 1

(RIN-1117-833304) Characterization of nanoparticle risks in aquatic organisms.

Ringwood, A¹, Gonsalves, K², Khambhammettu, S², ¹ Deparment of Biology, UNC-Charlotte, Charlotte, NC, USA² Department of Chemistry, UNC-Charlotte, Charlotte, NC, USA

ABSTRACT- There are numerous potential environmental risks of engineered nanoparticles that are not yet well-characterized or understood. Nanoparticles may be introduced into aquatic environments during production processes and also as a result of release following their use in electronic and biological applications. The purpose of these studies was to characterize the behavior of quantum dots (QD) in seawater, and the accumulation of and toxicity to potential biological receptors. There are natural differences in environmental factors that may affect the degradation rates of QDs, including salinity and pH conditions, as well as seasonal differences in temperature. To determine the effects of salinity on degradation rates, nonfunctionalized QDs composed of a Cd/Se core surrounded by layers of Zn (Evident Technologies) were added to 0.22 filtered seawater samples of different salinities (10, 20, and 30 parts per thousand), and the changes in emission spectra over time were determined; likewise, the potential effects of pH were evaluated under a range of environmentally realistic pH conditions (e.g. pH 7, 7.5, and 8); and the impacts of temperature (10, 20, and 30 degrees centigrade) were determined. The accumulation and potential toxicity of QDs was evaluated using oysters, Crassostrea virginica. For these studies, oyster embryos as well as isolated hepatopancreatic cells were used. Fluorescent confocal microscopy and electron microscopy were used to verify the accumulation and cellular localization. Toxicity to embryos was evaluated using the bivalve embryo development assay, and toxicity to hepatopancreatic cells was determined using the lysosomal destabilization assay. These kinds of basic studies are essential for addressing the potential impacts of nanoengineered particles on aquatic organisms.

Key words: nanoparticles, oysters, estuarine