PLoS One
(NHI Nanoblog) Swedish researchers have found that ultra-tiny particles can survive through the food chain — from algae to zooplankton to fish — raising questions about the long-term impact of the increasing use of nanoparticles in everyday products.
In a study recently published in the journal PLoS ONE, researchers found that polystyrene nanoparticles were taken up by algae, then absorbed by the zooplankton that feed on the algae. When the zooplankton were subsequently fed to fish, the metabolism of the fish was affected — and they were much less interested in eating at all.
The research team, from Sweden’s Lund University, conclude that their work might offer a way to measure the potential environmental effects of a variety of nanomaterials before they’re introduced into the market.
Nanotechnology leverages the often-unique properties of super-small particles (a nanometer is a billionth of a meter) to create products with amazing qualities. These materials can make better batteries or lighter and stronger bike frames, as well as new medical instruments and medicines that can save lives. They’re increasingly common in consumer products, from “mineral-based” sunscreens to stain-repellent pants to boat paints that resist algae growth.
Nanomaterials are believed to hold great promise for a wide variety of applications. Their ultra-tiny size also gives them different properties; scientists are struggling to figure out whether that can make them dangerous in the process, and how and why it happens.
As the Swedish team points out, the issue is a serious one because of the potential for nanomaterials to survive the sewage treatment process and stick around to impact aquatic plants and marine life. Other scientists, for example, have already found nanosilver particles in end-stage sewage sludge. Nano-sized zinc oxide has been shown to negatively affect the growth and survival of mussels.
Other products that are designed to be washed away at some point — such as sunscreen, detergents and cosmetics—increasingly contain super-small boosters to make them more effective or more aesthetically pleasing.
Toxicologists are pushing for more studies that examine the whole life cycle of a nanomaterial, from manufacture to application to disposal. Studies like this one show why they’re needed.
The co-authors of the paper are Tommy Cedervall, Lars-Anders Hansson, Maercy Lard, Birgitta Frohm and Sara Linse.