Carbon nanotubes remain attached to materials for years while titanium dioxide and nanozinc are rapidly washed out of cosmetics and accumulate in the ground. Researchers from the National Research Programme "Opportunities and Risks of Nanomaterials" (NRP 64) have developed a new model to track the flow of the most important nanomaterials in the environment.
How many man-made nanoparticles make their way into the air, earth or water? In order to assess these amounts, a group of researchers led by Bernd Nowack from Empa in St. Gallen has developed a computer model as part of the National Research Programme "Opportunities and Risks of Nanomaterials" (NRP 64).(*) “Our estimates offer the best available data at present about the environmental accumulation of nanosilver, nanozinc, nano-tinanium dioxide and carbon nanotubes”, says Nowack.
Cosmetics and tennis racquets
In contrast to the static calculations hitherto in use, their new, dynamic model does not just take into account the significant growth in the production and use of nanomaterials, but also makes provision for the fact that different nanomaterials are used in different applications. For example, nanozinc and nano-titanium dioxide are found primarily in cosmetics.
Roughly half of these nanoparticles find their way into our waste water within the space of a year, and from there they enter into sewage sludge. Carbon nanotubes, however, are integrated into composite materials and are bound in products such as which are immobilized and are thus found for example in tennis racquets and bicycle frames. It can take over ten years before they are released, when these products end up in waste incineration or are recycled.
39,000 metric tons of nanoparticles
The researchers involved in this study come from Empa, ETH and the University of Zurich. They use an estimated annual production of nano-titanium dioxide across Europe of 39,000 metric tons – considerably more than the total for all other nanomaterials. Their model calculates how much of this enters the atmosphere, surface waters, sediments and the earth, and accumulates there.
In the EU, the use of sewage sludge as fertiliser (a practice forbidden in Switzerland) means that nano-titanium dioxide today reaches an average concentration of 61 micrograms per kilo in the affected ground.
Knowing the degree of accumulation in the environment is only the first step in the risk assessment of nanomaterials, however. Now this data has to be compared with ecotoxicological test results and the statutory thresholds, says Nowack. A risk assessment has not been carried out with his new model until now. Earlier work with data from a static model showed, however, that the concentrations determined for all four nanomaterials investigated is not expected to have any impact on the environment.(**)
But in the case of nanozinc at least, its concentration in the environment is approaching the critical level. This is why this particular nanomaterial has to be given priority in future ecotoxicological studies – even though nanozinc is produced in smaller quantities than nano-titanium dioxide. Furthermore, ecotoxicological tests have until now been carried out primarily with freshwater organisms. The researchers conclude that complementary investigations using soil-dwelling organisms is a priority.
(*) T. Y. Sun et al.: Dynamic probabilistic Modelling of Environmental Emissions of Engineered Nanomaterials. Environmental Science & Technology (2016); doi: 10.1021/acs.est.5b05828
(**) C. Coll et al.: Probabilistic environmental risk assessment of five nanomaterials (nano-TiO2, nano-Ag, nano-ZnO, CNT, and fullerenes). Nanotoxicology (2016); doi: 10.3109/17435390.2015.1073812
(Journalists can obtain PDF versions of both publications from the SNSF: firstname.lastname@example.org)
Opportunities and Risks of Nanomaterials (NRP 64)
The Swiss National Science Foundation was commissioned by the Federal Council to run the National Research Programme ‘Opportunities and Risks of Nanomaterials’ (NRP 64). Its goal is to bridge the gaps in our current knowledge of nanomaterials with regard to their manufacture, use and disposal. The overall final recommendations of NFP 64 will be published in summary reports in 2017. www.nfp64.ch
Prof. Dr. Bernd Nowack
Environmental Risk Assessment and Management Group
CH-9014 St. Gallen
Tel.: +41 58 765 76 92
http://www.snf.ch/en/researchinFocus/newsroom/Pages/news-160512-press-release-ho... - Press release online
http://p3.snf.ch/project-131241 - Project in the SNSF research database P3
http://www.nfp64.ch/en/projects/module-environment/project-nowack - NRP 64 - Modelling of nanomaterials in the environment
Media - Abteilung Kommunikation | Schweizerischer Nationalfonds SNF
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy