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BioMed Research International
Volume 2013 (2013), Article ID 494671, 7 pages
http://dx.doi.org/10.1155/2013/494671
Research Article

Stepwise Embryonic Toxicity of Silver Nanoparticles on Oryzias latipes

Risk Assessment Division, National Institute of Environmental Research, Kyungseo-Dong, Seo-gu, Incheon 404-170, Republic of Korea

Received 11 March 2013; Revised 3 May 2013; Accepted 7 May 2013

Academic Editor: Weibo Cai

Copyright © 2013 Jae-Gu Cho et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The developmental toxicity of silver nanoparticles (AgNPs) was investigated following exposure of Oryzias latipes (medaka) embryos to 0.1−1 mg/L of homogeneously dispersed AgNPs for 14 days. During this period, developmental endpoints, including lethality, heart rate, and hatching rate, were evaluated by microscopy for different stages of medaka embryonic development. To compare toxic sensitivity, acute adult toxicity was assessed. There was no difference in acute lethal toxicity between embryo and adult medaka. Interestingly, we found that the increase in stepwise toxicity was dependent on the developmental stage of the embryo. Lethal embryonic toxicity increased from exposure days 1 to 3 and exposure days 5 to 8, whereas there was no change from exposure days 3 to 5. In addition, 7 d exposure to 0.8 mg/L AgNPs resulted in significant heart beat retardation in medaka embryos. AgNPs also caused a dose-dependent decrease in the hatching rate and body length of larvae. These results indicate that AgNP exposure causes severe developmental toxicity to medaka embryos and that toxicity levels are enhanced at certain developmental stages, which should be taken into consideration in assessments of metallic NPs toxicity to embryos.