We use ‘nano’ stuff in everything these days (as I’ve discussed earlier here). However, we still really don’t know what happens when this stuff eventually gets into our water, soil, and air. One very simple example published recently in Environmental Science & Technology (subscription required to see abstract here) demonstrated this point by showing that silver nanoparticles (used as antimicrobial agents) in socks can come off in fairly large quantities in the laundry. After getting flushed down your pipes, the nano-silver could then restrict the efficiency of wastewater treatment plants by killing necessary bacteria, among other consequences.
This study, among others, prompted several consumer groups to petition the U.S. Environmental Protection Agency to ban all products containing nano-silver until further research is conducted (see Washington Post article here).
I guess I am a little on the fence here on how I feel about strategies such as this that some may consider alarmist. On one side, I really think EPA needs to step up and address the fact that nanoparticles are different and may present different health/toxicity hazards than their larger-sized counterparts (i.e. nano-nonsense). But on the other hand, some nano-silver products are quite important, including those used in medicine. Banning all of them is certainly not the answer either. How do we as scientists (or goverments, funding agencies, etc) fill in the knowledge gaps without creating a backlash against nanotechnology? The Science Progress blog recently compared it to the backlash against genetically-modified foods. Funding projects that study the environmental impact of ‘nano’ stuff is certainly one place to start, but the U.S. has a ways to catch up. For example, in 2006 the U.S. only spent $13 million on studying the risks of nanotechnology whereas Europe spent $24 million. This will certainly need to go up (in both regions as well as other emerging nano-tech leaders in Asia) if we hope to balance the science with the backlash.