Long-term Exposure to Gold Nanoparticles Accelerates Larval Metamorphosis Without Affecting Mass in Wood Frogs (Lithobates sylvaticus) at Environmentally Relevant Concentrations

Student Authors

Andrea J. Sitton '14, Gettysburg College

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Department 2



Nanoparticles are environmental contaminants of emerging concern. Exposure to engineered nanoparticles has been shown to have detrimental effects on aquatic organisms. We synthesized gold nanoparticles (18.1 ± 3.5 nm) and tested their effects on time to and weight at metamorphosis in wood frog (Lithobates sylvaticus) tadpoles, a species known to be sensitive to environmental stressors. Continuous exposure to all concentrations of gold nanoparticles (0.05, 0.5, and 5 pM in particles) for up to 55 days significantly reduced time to metamorphosis by as much as an average of three days (p < 0.05). However, exposure to gold nanoparticles had no effect on tadpole mass at metamorphosis. The ∼18 nm gold nanoparticles used in this study were metastable in dechlorinated tap water resulting in a change in surface charge and aggregation over time leading to negatively charged aggregates that are on the order of 60–110 nm. Nanoparticle aggregation could exacerbate the effect on time to metamorphosis. To our knowledge, this is the first report on the effect of engineered nanoparticles of any kind on life history variables in an amphibian, a taxonomic group that has been declining globally for at least 25 years.


Original version is available from the publisher at: http://onlinelibrary.wiley.com/doi/10.1002/etc.3396/full



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