The Bren School-based authors of a study published Jan. 20 in the journal PLoS ONE have observed toxicity to marine organisms resulting from exposure to a nanoparticle that had not previously been shown to be toxic under similar conditions.
Lead author and assistant research biologist Robert Miller and co-authors Arturo Keller and Hunter Lenihan – both Bren School professors and lead scientists at the UC Center for Environmental Implications of Nanotechnology (UC CEIN) – Bren Phd student Samuel Bennett, and Scott Pease, a former UCSB undergraduate and current graduate student in public health at the University of Washington, found that the nanoparticulate form of titanium dioxide (TiO2) exposed to ultraviolet radiation (UVR) can be toxic to marine organisms.
"Application of nanomaterials in consumer products and manufacturing is quickly increasing, but there is concern that these materials, including nanoparticles, may harm the environment," says Miller. "The oceans could be most at risk, since wastewater and factory discharges ultimately end up there."
Nano-titanium dioxide is highly reactive to sunlight and other forms of ultraviolet radiation (UVR,) the authors write, adding that TiO2's property of generating reactive oxygen species (ROS) when exposed to UVR makes it useful in antibacterial coatings and wastewater disinfection, and potentially valuable as an anti-cancer agent.
Until now, they say, no research has demonstrated that photoactivity causes environmental toxicity of TiO2 under natural levels of UVR.
"Previous experiments have suggested that TiO2 does not affect aquatic organisms, but these experiments used artificial lighting that generated much lower levels of UVR than sunlight," Miller explains. "In these new experiments, we used lights simulating natural sunlight."
But now, the authors say, "We show that relatively low levels of ultraviolet light, consistent with those found in nature, can induce toxicity of TiO2 nanoparticles to marine phytoplankton, the most important primary producers on Earth.
"With no exposure to UVR, the TiO2 had no effect on phytoplankton, but under low-intensity UVR, ROS in seawater increased with increasing concentrations of nano- TiO2."
The concern is that rising concentrations of nano- TiO2 "may lead to increased overall oxidative stress in seawater contaminated by TiO22, and cause decreased resiliency of marine ecosystems."
The authors suggest, therefore, that UVR exposure should be considered when conducting experiments to determine the ecotoxicity of nanomaterials having photoactive potential.
James Badham | EurekAlert!
Signaling Pathways to the Nucleus
19.03.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
In monogamous species, a compatible partner is more important than an ornamented one
19.03.2018 | Max-Planck-Institut für Ornithologie
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
19.03.2018 | Event News
19.03.2018 | Information Technology
19.03.2018 | Interdisciplinary Research