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 The oceans can’t take any more
03.07.2015 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Improved veterinary service for livestock is significant for leopard conservation
02.07.2015 | Georg-August-Universität Göttingen

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: Forschungsschiff Heincke seit 25 Jahren im Dienst der Wissenschaft

Ein Vierteljahrhundert alt, über 900.000 Kilometer (488.842 nautische Meilen) gefahren und trotzdem auf dem neuesten wissenschaftlichen und technischen Stand: Die Indienststellung des Forschungsschiffes Heincke jährt sich am 8. Juli 2015 zum 25. Mal.

Wissenschaftler des Alfred-Wegener-Instituts, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), das die Heincke betreibt, nehmen ebenso regelmäßig an...

Im Focus: Solardächer produzieren Strom für Fahrzeuge

Studentische Industriekooperation zwischen HAW Hamburg und Webasto erarbeitet Ergebnisse für EU-Zertifizierungsprozess von Solardächern zur Verbesserung der Öko-Bilanz von Fahrzeugen.

Unter der Leitung von Dr.-Ing. Volker Skwarek, Professor für technische Informatik an der HAW Hamburg, erarbeiteten sechs Studierende des...

Im Focus: Viaducts with wind turbines, the new renewable energy source

Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.

The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...

Im Focus: Aus alt mach neu - Rohstoffquelle Elektroschrott

Der Markt für Unterhaltungselektronik boomt: Rund 60 Millionen Fernsehgeräte wurden im letzten Jahr in Europa verkauft. Früher oder später werden sie zurückkehren – als Elektroschrott.

Die Recycling-Industrie hat darauf reagiert: Kupfer, Aluminium, Eisen- und Edelmetalle sowie ausgewählte Kunststoffe werden bereits wiederverwertet. Allerdings...

Im Focus: Radar schützt vor Weltraummüll

Die Bedrohung im All durch Weltraummüll ist groß. Aktive Satelliten und Raumfahrzeuge können beschädigt oder zerstört werden. Ein neues, nationales Weltraumüberwachungssystem soll ab 2018 vor Gefahren im Orbit schützen. Fraunhofer-Forscher entwickeln das Radar im Auftrag des DLR Raumfahrtmanagement.

Die »Verkehrssituation« im All ist angespannt: Neben unzähligen Satelliten umkreisen Weltraumtrümmer wie beispielsweise ausgebrannte Raketenstufen und...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Flurförderzeuge im Zeichen der Zeit

03.07.2015 | Veranstaltungen

Aktuelles aus Forschung und Betrieb: 27. Deutscher Flammentag

02.07.2015 | Veranstaltungen

Call for ideas: Gute Ideen für bessere Städte

02.07.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Siemens erhält Auftrag für Offshore-Windkraftwerk in Großbritannien

03.07.2015 | Unternehmensmeldung

Flurförderzeuge im Zeichen der Zeit

03.07.2015 | Veranstaltungsnachrichten

Kompakter Time Converter für zuverlässigen Einsatz in rauen Umgebungen

03.07.2015 | Energie und Elektrotechnik