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
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
Russian researchers together with their French colleagues discovered that a genuine feature of superconductors -- quantum Abrikosov vortices of supercurrent -- can also exist in an ordinary nonsuperconducting metal put into contact with a superconductor. The observation of these vortices provides direct evidence of induced quantum coherence. The pioneering experimental observation was supported by a first-ever numerical model that describes the induced vortices in finer detail.
These fundamental results, published in the journal Nature Communications, enable a better understanding and description of the processes occurring at the...
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
25.06.2018 | Physics and Astronomy
25.06.2018 | Earth Sciences
25.06.2018 | Power and Electrical Engineering