Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Silver nanoparticles may adversely affect environment

28.02.2013
In experiments mimicking a natural environment, Duke University researchers have demonstrated that the silver nanoparticles used in many consumer products can have an adverse effect on plants and microorganisms.

Fifty days after scientists applied a single low dose of silver nanoparticles, the experimental environments produced about a third less biomass in some plants and microbes.

These preliminary findings are important, the researchers said, because little is known about the environmental effects of silver nanoparticles, which are found in textiles, clothing, children's toys and pacifiers, disinfectants and toothpaste.

"No one really knows what the effects of these particles are in the environment," said Benjamin Colman, a post-doctoral fellow in Duke's biology department and a member of the Center for the Environmental Implications of Nanotechnology (CEINT).

"We're trying to come up with the data that can be used to help regulators determine the risks to the environment from silver nanoparticle exposures," Colman said. CEINT's research is funded by the National Science Foundation and the Environmental Protection Agency

Previous studies have involved high concentrations of the nanoparticles in a laboratory setting, which the researchers point out, doesn't represent "real-world" conditions.

"Results from laboratory studies are difficult to extrapolate to ecosystems, where exposures likely will be at low concentrations and there is a diversity of organisms," Colman said.

Silver nanoparticles are used in consumer products because they can kill bacteria, inhibiting unwanted odors. They work through a variety of mechanisms, including generating free radicals of oxygen which can cause DNA damage to microbial membranes without harming human cells.

The main route by which these particles enter the environment is as a by-product of sewage treatment plants. The nanoparticles are too small to be filtered out, so they and other materials end up in the resulting wastewater treatment "sludge," which is then spread on the land surface as a fertilizer.

For their studies, the researchers created mesocosms, which are small, man-made structures containing different plants and microorganisms meant to represent the environment. They applied sludge with low doses of silver nanoparticles in some of the mesocosms, then compared plants and microorganisms from treated and untreated mesocosms after 50 days.

The study appeared online Feb. 27 in the journal PLOS One.

The researchers found that one of the plants studied, a common annual grass known as Microstegium vimeneum, had 32 percent less biomass in the mesocosms treated with the nanoparticles. Microbes were also affected by the nanoparticles, Colman said. One enzyme associated with helping microbes deal with external stresses was 52 percent less active, while another enzyme that helps regulate processes within the cell was 27 percent less active. The overall biomass of the microbes was also 35 percent lower, he said.

"Our field studies show adverse responses of plants and microorganisms following a single low dose of silver nanoparticles applied by a sewage biosolid," Colman said. "An estimated 60 percent of the average 5.6 million tons of biosolids produced each year is applied to the land for various reasons, and this practice represents an important and understudied route of exposure of natural ecosystems to engineered nanoparticles."

"Our results show that silver nanoparticles in the biosolids, added at concentrations that would be expected, caused ecosystem-level impacts," Colman said. "Specifically, the nanoparticles led to an increase in nitrous oxide fluxes, changes in microbial community composition, biomass, and extracellular enzyme activity, as well as species-specific effects on the above-ground vegetation."

The researchers plan to continue to study longer-term effects of silver nanoparticles and to examine another ubiquitous nanoparticle – titanium dioxide.

The rest of the team were Duke's Christina Arnaout, Claudia Gunsch, Curtis Richardson, Emily Bernhardt, Bonnie McGill and Justin Wright; Sarah Anciaux of Coe College, Iowa; Michael Hochella and Bojeong Kim of Virginia Tech University; Gregory Lowry and Brian C. Reinsch of Carnegie Mellon University, Pittsburgh; Jason Unrine at the University of Kentucky; and Liyan Yin of Wuhan Botanical Garden, China.

Richard Merritt | EurekAlert!
Further information:
http://www.duke.edu

More articles from Ecology, The Environment and Conservation:

nachricht Engineers purify sea and wastewater in 2.5 minutes
17.04.2015 | Investigación y Desarrollo

nachricht Expanding rubber plantations 'catastrophic' for endangered species in Southeast Asia
17.04.2015 | University of East Anglia

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Forscher verschieben Moleküle auf Oberflächen: Nur halb so viel Kraft nötig wie theoretisch gedacht

Forscher der Universität Regensburg haben ein interessantes Phänomen aus der Welt der Quantenphysik entdeckt: Um ein Kohlenmonoxidmolekül auf einer Oberfläche seitlich zu verschieben, ist nur halb so viel Kraft erforderlich, wie theoretisch zu erwarten wäre.

Ein Team um Prof. Dr. Franz J. Gießibl vom Institut für Experimentelle und Angewandte Physik machte diese Beobachtung bei Versuchen mit einem...

Im Focus: Autoklavierbare LEDs für die Medizintechnik

Das neue Keramik-SMD-Design der Solidur™ TO LED ermöglicht komplexe Chipkonfigurationen in einem einzigen LED-Modul.

SCHOTT stellte vor kurzem seine neue autoklavierbare und hochbeständige Solidur™ LED-Produktlinie für Geräte und Instrumente der Medizin- und Dentaltechnik...

Im Focus: Astronomers reveal supermassive black hole's intense magnetic field

Astronomers from Chalmers University of Technology have used the giant telescope Alma to reveal an extremely powerful magnetic field very close to a supermassive black hole in a distant galaxy

Astronomers from Chalmers University of Technology have used the giant telescope Alma to reveal an extremely powerful magnetic field very close to a...

Im Focus: Eine „Flipper-Maschine“ für Atome und Photonen

Physiker vom MPQ, Caltech und ICFO haben ein neues Konzept entwickelt, durch Kombination von Nano-Photonik mit ultrakalten Atomen Quanten-Vielteilchensysteme zu simulieren und neue Materiezustände zu erzeugen.

Ultrakalte Atome in optischen Gittern, die durch die kreuzweise Überlagerung von Laserstrahlen entstehen, haben sich bereits als die meist versprechenden...

Im Focus: A “pin ball machine” for atoms and photons

A team of physicists from MPQ, Caltech, and ICFO proposes the combination of nano-photonics with ultracold atoms for simulating quantum many-body systems and creating new states of matter.

Ultracold atoms in the so-called optical lattices, that are generated by crosswise superposition of laser beams, have been proven to be one of the most...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Das Kaba Ideen Netzwerk geht in die nächste Runde

17.04.2015 | Veranstaltungen

VDI-Expertenforum: Effiziente Softwareentwicklung in der Medizintechnik

17.04.2015 | Veranstaltungen

Impflücken schließen. Die Europäische Impfwoche beginnt

17.04.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Das Kaba Ideen Netzwerk geht in die nächste Runde

17.04.2015 | Veranstaltungsnachrichten

ERP-Softwarehersteller HS zeigt mit neuer Webpräsenz Gesicht

17.04.2015 | Unternehmensmeldung

Schnelle und unkomplizierte Hilfe von HEIDENHAIN im Servicefall

17.04.2015 | Unternehmensmeldung