Each week we write about the science behind environmental protection. Previous Science Wednesdays.
Nearly a decade ago when I was approaching my 40th birthday, I decided to confront mid-life crisis by taking up long-distance running. Specifically, I set my sights on running a marathon. Before making this decision, I had never run more than three or four miles. So 26.2 was an intimidating prospect. I run in about one-yard strides, so a quick calculation told me that it would take me 46,112 of those choppy strides to cross the finish line.
It seemed overwhelming.
But on Thanksgiving day, 1999, I began with a three-mile run, a week later extended it to four miles, and so on until – one year later – I finished my first marathon. I’ve since run four more. It was all about building up endurance, one stride at a time.
This idea of one-step-at-a-time progression is pretty much the same when it comes to trying to understand the possible environmental impacts of nano-sized particles—tiny manufactured particles that are 100 nanometers or smaller. (A nanometer is 1 billionth of a meter, or about 100,000 times smaller than the width of a human hair.) You start with a little bit of knowledge – say, for example – that you know the size and shape of the particle – and build on that to understand whether the size and shape of the particle at the nanoscale makes the particle behave any differently than a larger-sized particle of the same material.
Let’s take, for example, silver, even though I will never win a medal of that color (and surely not gold and, sigh, not even bronze) in any of my marathons. Nano-sized versions of silver are being made for use in clothing, medical equipment, and other things because it is very good at killing bacteria.
Some of our first steps in the nanosilver marathon are to understand if nanosilver behaves differently than larger-sized silver (which we already know quite a bit about). Then we build on that to learn if any differences we find make nanosilver more (or less) toxic than larger silver. And we keep going from there, pushing the limits of our understanding to learn still more.
Be sure to keep an eye on Science Wednesday next month for training tips and things we’re picking up along the nanotechnology course. To learn more about how Jeff Morris is taking the long view of tiny particles, visit EPA’s Nanotechnology Research web site.
About the author: When he’s not running marathons or training for one, Jeff Morris is National Program Director for Nanotechnology in EPA’s Office of Research and Development.