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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Die Brücke, die sich dehnen kann

Brücken verformen sich, daher baut man normalerweise Dehnfugen ein. An der TU Wien wurde eine Technik entwickelt, die ohne Fugen auskommt und dadurch viel Geld und Aufwand spart.

Wer im Auto mit flottem Tempo über eine Brücke fährt, spürt es sofort: Meist rumpelt man am Anfang und am Ende der Brücke über eine Dehnfuge, die dort...

Im Focus: Eine Frage der Dynamik

Die meisten Ionenkanäle lassen nur eine ganz bestimmte Sorte von Ionen passieren, zum Beispiel Natrium- oder Kaliumionen. Daneben gibt es jedoch eine Reihe von Kanälen, die für beide Ionensorten durchlässig sind. Wie den Eiweißmolekülen das gelingt, hat jetzt ein Team um die Wissenschaftlerin Han Sun (FMP) und die Arbeitsgruppe von Adam Lange (FMP) herausgefunden. Solche nicht-selektiven Kanäle besäßen anders als die selektiven eine dynamische Struktur ihres Selektivitätsfilters, berichten die FMP-Forscher im Fachblatt Nature Communications. Dieser Filter könne zwei unterschiedliche Formen ausbilden, die jeweils nur eine der beiden Ionensorten passieren lassen.

Ionenkanäle sind für den Organismus von herausragender Bedeutung. Wenn zum Beispiel Sinnesreize wahrgenommen, ans Gehirn weitergeleitet und dort verarbeitet...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Erste integrierte Schaltkreise (IC) aus Plastik

Erstmals ist es einem Forscherteam am Max-Planck-Institut (MPI) für Polymerforschung in Mainz gelungen, einen integrierten Schaltkreis (IC) aus einer monomolekularen Schicht eines Halbleiterpolymers herzustellen. Dies erfolgte in einem sogenannten Bottom-Up-Ansatz durch einen selbstanordnenden Aufbau.

In diesem selbstanordnenden Aufbauprozess ordnen sich die Halbleiterpolymere als geordnete monomolekulare Schicht in einem Transistor an. Transistoren sind...

Im Focus: Quantenbits per Licht übertragen

Physiker aus Princeton, Konstanz und Maryland koppeln Quantenbits und Licht

Der Quantencomputer rückt näher: Neue Forschungsergebnisse zeigen das Potenzial von Licht als Medium, um Informationen zwischen sogenannten Quantenbits...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

VideoLinks
Industrie & Wirtschaft
Veranstaltungen

Digitalisierung auf dem Prüfstand: Hochkarätige Konferenz zu Empowerment in der agilen Arbeitswelt

20.02.2018 | Veranstaltungen

Aachener Optiktage: Expertenwissen in zwei Konferenzen für die Glas- und Kunststoffoptikfertigung

19.02.2018 | Veranstaltungen

Konferenz "Die Mobilität von morgen gestalten"

19.02.2018 | Veranstaltungen

VideoLinks
Wissenschaft & Forschung
Weitere VideoLinks im Überblick >>>
 
Aktuelle Beiträge

Highlight der Halbleiter-Forschung

20.02.2018 | Physik Astronomie

Wie verbessert man die Nahtqualität lasergeschweißter Textilien?

20.02.2018 | Materialwissenschaften

Der Bluthochdruckschalter in der Nebenniere

20.02.2018 | Biowissenschaften Chemie

Weitere B2B-VideoLinks
IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics