Researchers at UCSB have found that certain nanoparticles may have not-so-nano impacts within simple food chains.
Published online in the journal Nature Nanotechnology, the study suggests that the toxic effects of protozoa consuming nanomaterial-containing bacteria could also be found higher up in the food chain at higher concentrations.
Biomagnification occurs when there is an increase in the concentration of certain compounds as a result of predators within a food chain ingesting prey which contain the compound.
According to Patricia Holden, a co-author of the study and a professor of environmental microbiology at UCSB, the team found the results unexpected but useful for understanding the possible effects of nanomaterials on the environment.
“We did not really know what we would find and we were really surprised by the results,” Holden said. “Biomagnification, when it comes to contaminants, is not a plus when it comes to health of ecosystems … It is a concerning result that biomagnification occurs, but it is also good that we discovered this because the field is new. We are all trying to learn as much as we can early in terms of the evolution of nanotechnology.”
The study, funded by the EPA and the UC Center for the Environmental Implications of Nanotechnology, is part of a wider collaboration involving UCLA, UC Davis, UC Riverside, Columbia University and several national laboratories. The project focuses on facilitating the design of safe nanomaterials by better understanding their potentially negative effects in soil, freshwater and marine environments.
Mirroring the UCSB study’s goals is University of Kentucky plant and soil sciences professor Paul Bertsch’s nanomaterial research.
“Certainly the whole area of looking at potential environmental impacts is important,” Bertsch said. “It is good to be thinking of potential negative effects.”
The question still remains if similar effects, like the uptake and biomagnifications of nanomaterials in larger-scale environments, will be observed. The scientists seek to understand the potential effects of nanomaterials in order to prevent possible problems before they occur, Holden said.
“We are really on the cutting edge of studying these new issues, trying to understand these environmental implications before we have disasters,” Holden said. “Let’s learn what we can in the lab and experiment in order to avoid having a crisis. We can say, ‘Okay, we do not have a problem yet,’ but this research is anticipatory in order to prevent such a problem.”
Katherine Santizo, a second-year chemical engineering major currently involved in nanomaterials research, said one of the main goals of nanotechnology studies is ensuring safety for both the environment and the consumer.
“Since nanotechnology is new, it is obviously going to keep on being tested for a while because we want to find the long term effects of the nanoparticles,” Santizo said. “In order to make the field the best that it could possibly be and continue making materials and products that people use in everyday life, we want to make products whose benefits outweigh their negative impacts.”
Bertsch said while the study is important for understanding biomagnification of nanomaterials, it is not necessarily a cause for alarm.
“As organisms pick up contaminants, they are pretty good at eliminating them as well,” Bersch said. “Efficiency of elimination seems to be a key factor.”