Low concentrations of silver nanoparticles in biosolids cause adverse ecosystem responses under realistic field scenario.
Abstract
A large fraction of engineered nanomaterials in consumer and commercial products will
reach natural ecosystems. To date, research on the biological impacts of environmental
nanomaterial exposures has largely focused on high-concentration exposures in mechanistic
lab studies with single strains of model organisms. These results are difficult to
extrapolate to ecosystems, where exposures will likely be at low-concentrations and
which are inhabited by a diversity of organisms. Here we show adverse responses of
plants and microorganisms in a replicated long-term terrestrial mesocosm field experiment
following a single low dose of silver nanoparticles (0.14 mg Ag kg(-1) soil) applied
via a likely route of exposure, sewage biosolid application. While total aboveground
plant biomass did not differ between treatments receiving biosolids, one plant species,
Microstegium vimeneum, had 32 % less biomass in the Slurry+AgNP treatment relative
to the Slurry only treatment. Microorganisms were also affected by AgNP treatment,
which gave a significantly different community composition of bacteria in the Slurry+AgNPs
as opposed to the Slurry treatment one day after addition as analyzed by T-RFLP analysis
of 16S-rRNA genes. After eight days, N2O flux was 4.5 fold higher in the Slurry+AgNPs
treatment than the Slurry treatment. After fifty days, community composition and N2O
flux of the Slurry+AgNPs treatment converged with the Slurry. However, the soil microbial
extracellular enzymes leucine amino peptidase and phosphatase had 52 and 27% lower
activities, respectively, while microbial biomass was 35% lower than the Slurry. We
also show that the magnitude of these responses was in all cases as large as or larger
than the positive control, AgNO3, added at 4-fold the Ag concentration of the silver
nanoparticles.
Type
Journal articleSubject
BiomassEcosystem
Metal Nanoparticles
Microscopy, Electron, Transmission
Plants
Silver
Silver Nitrate
Permalink
https://hdl.handle.net/10161/15714Published Version (Please cite this version)
10.1371/journal.pone.0057189Publication Info
Colman, Benjamin P; Arnaout, Christina L; Anciaux, Sarah; Gunsch, Claudia K; Hochella,
Michael F; Kim, Bojeong; ... Bernhardt, Emily S (2013). Low concentrations of silver nanoparticles in biosolids cause adverse ecosystem responses
under realistic field scenario. PLoS One, 8(2). pp. e57189. 10.1371/journal.pone.0057189. Retrieved from https://hdl.handle.net/10161/15714.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Emily S. Bernhardt
James B. Duke Distinguished Professor
Emily Bernhardt is an ecosystem ecologist and biogeochemist whose research is principally
concerned with tracking the movement of elements through ecological systems. Dr. Bernhardt's
research aims to document the extent to which the structure and function of aquatic
ecosystems is being altered by land use change (urbanization, agriculture, mining)
global change (rising CO2, rising sea levels) and chemical pollution. Ultimately this
information is necessary to determine whether and how
Claudia K. Gunsch
Professor in the Department of Civil and Environmental Engineering
Claudia Gunsch is a Professor of Civil and Environmental Engineering and holds secondary
appointments in the Nicholas School of the Environment and the Department of Biomedical
Engineering. She joined the Duke Faculty in 2004 after obtaining her PhD from the
University of Texas at Austin, her MS from Clemson University and her BS from Purdue
University. Currently, she serves as the Director for PreMiEr, the National Science
Foundation Engineering Research Center for Precis
Curtis J. Richardson
Research Professor of Resource Ecology in the Division of Environmental Science and
Policy
Curtis J. Richardson is Professor of Resource Ecology and founding Director of the
Duke University Wetland Center in the Nicholas School of the Environment. Dr. Richardson
earned his degrees from the State University of New York and the University of Tennessee.
His research interests in applied ecology focus on long-term ecosystem response to
large-scale perturbations such as climate change, toxic materials, trace metals, flooding,
or nutrient additions. He has specific interests in phosphor
Justin Prouty Wright
Professor of Biology
My research focuses on understanding the causes and consequences of patterns of biological
diversity across the planet. I am particularly interested in two broad questions:
1)How does the modification of the environment by organisms affect community structure
and ecosystem function? and 2) what aspects of biodiversity matter most in the regulation
of ecosystem function? While much of my research has focused on wetland plant communities,
I am willing to study any organism and work in any ecosys
Alphabetical list of authors with Scholars@Duke profiles.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info