One of the scientists on a research team at Trent University (Ontario, Canada) is claiming that safety questions about nanomaterials are not being asked and so the team is embarking on a study of silver nanoparticles and their impact on a lake ecosystem. From the May 2, 2012 news item on Nanowerk,

Dr. Chris Metcalfe, professor and director of the Institute for Watershed Science at Trent University, is the principal investigator on the Lake Ecosystem Nanosilver (LENS) project with Trent researchers, Drs. Maggie Xenopoulos, Holger Hintelmann and Paul Frost, and colleagues from Fisheries and Oceans Canada and Environment Canada.

“This is a high profile project that will have the eyes of the scientific community on Trent,” said Professor Metcalfe. “We’re fortunate that we have four world-class researchers on our team.” Over the past decade, tiny substances called nanomaterials have become part of our daily lives.

It’s possible that the clothes you’re wearing, or the sunscreen you just applied, contain nanomaterials. Because of this growing use, there is now concern that nanomaterials may pose threats to the environment.

“We have seen an exponential growth in the use of nanomaterials,” said Professor Xenopoulos, an associate professor in the Biology department at Trent University. “However, questions of safety are not being asked.” [emphasis mine]

Likely the claim is a little overenthusiasm or a lack of clarity on the speaker’s part since there has been more than one study about nanosilver particles and safety, including one at Purdue University mentioned in a March 4, 2010 posting on the Beyond Pesticides blog. The Purdue study (The effects of silver nanoparticles on fathead minnow (Pimephales promelas) embryos) is behind a paywall.

Here’s a bit more about silver nanoparticles and the LENS study,

While the benefits of nanomaterials are recognized, we know little about their risks to health and the environment. Due to their extremely small size, nanomaterials interact with cells and organic molecules, raising questions about their impact on organisms.

Due to their antibacterial properties, nanosilver particles are among the most widely-used nanomaterials in consumer goods. Clothing, home appliances, paint, bandages and food storage containers are a few of the products which may contain nanosilver. As we use and dispose of these products, there is a risk that nanosilvers will travel through our municipal water systems into our lakes and rivers.

The research team is working to understand the effect of nanosilver particles on the aquatic environment. Initial laboratory research conducted at Trent indicates that nanosilver can strongly affect aquatic organisms at the bottom of the food chain, such as bacteria, algae and zooplankton.

To further examine these effects in a real ecosystem, the team is conducting a study at the Experimental Lakes Area, near Kenora, in northwestern Ontario.

The LENS project will monitor changes in a lake’s ecosystem that occur after the addition of nanosilver. It will follow nanosilver as it travels through the lake ecosystem, track effects through the entire food web, and determine how resulting changes alter ecosystem function.

There’s more about the LENS project on the Trent University LENS (Lake Ecosystem Nanosilver) Project page (excerpt),

Our previous laboratory research has shown that nanosilver in the aquatic environment first affect organisms at the bottom of the food chain, including bacteria, algae and zooplankton. These responses may have devastating effects upon aquatic ecosystems by reducing overall productivity and altering the cycling of nutrients, such as carbon, nitrogen and phosphorus. There may be compensatory mechanisms within aquatic ecosystems that can mitigate these responses, but it is impossible to predict these responses using laboratory studies. Through support from the Strategic Grants Program of the Natural Sciences and Engineering Research Council of Canada and Environment Canada, a team of researchers from Trent University, Environment Canada and Fisheries and Oceans Canada will conduct a study at the Experimental Lakes Area (ELA) in northwestern Ontario by adding nanoform silver to a small lake over two summer field seasons ion 2013-14. During nano-silver additions, we will monitor the lake for changes to nutrient cycling and the biological effects within the entire food chain. However, in 2012, before starting the lake additions, we will refine our approach by determining what happens in mesocosms (i.e. plastic tubes) that are deployed in lakes. ELA has been used for over 40 years as a living laboratory to study the effects of pollutants in the environment, including past studies of the impacts of pollution from phosphorus, acid deposition, mercury and endocrine disruptors. These studies have resulted in policies to reduce the impacts of pollution. While we do not take lightly the impact that this study will have upon a lake in ELA, this approach is the only way to determine ecosystem level impacts and to influence regulatory policy regarding the ecological risks of NMs.

This is a three-year project, which starts this year (2012).