Does size matter when regulating nanomaterials? As I’ve noted (more than once), I waffle on this issue. Earlier this week, I featured my thoughts on Health Canada’s definition of nanomaterial (Oct. 24, 2011) and posted an interview with Dr. Andrew Maynard (Oct. 24, 2011) where he expressed reservations about basing nanomaterial regulations on definitions which rely on nanoparticle size.
Hours after posting my thoughts and the interview with Andrew, I came across this Oct. 24, 2011 news item on Nanowerk titled, Nanoparticles and their size may not be big issues. From the news item,
If you’ve ever eaten from silverware or worn copper jewelry, you’ve been in a perfect storm in which nanoparticles were dropped into the environment, say scientists at the University of Oregon.
Since the emergence of nanotechnology, researchers, regulators and the public have been concerned that the potential toxicity of nano-sized products might threaten human health by way of environmental exposure.
Now, with the help of high-powered transmission electron microscopes, chemists captured never-before-seen views of miniscule metal nanoparticles naturally being created by silver articles such as wire, jewelry and eating utensils in contact with other surfaces. It turns out, researchers say, nanoparticles have been in contact with humans for a long, long time. [emphasis mine]
“Our findings show that nanoparticle ‘size’ may not be static, especially when particles are on surfaces. For this reason, we believe that environmental health and safety concerns should not be defined — or regulated — based upon size,” said James E. Hutchison, who holds the Lokey-Harrington Chair in Chemistry. [emphasis mine] “In addition, the generation of nanoparticles from objects that humans have contacted for millennia suggests that humans have been exposed to these nanoparticles throughout time. Rather than raise concern, I think this suggests that we would have already linked exposure to these materials to health hazards if there were any.”
This discussion is becoming quite interesting.