The number comes from the Agency for Toxic Substances and Disease Registry out of Atlanta, Georgia, from some of their scientists. Actually, the work is maybe not being done so much for health-related reasons as for security reasons over the last few years, to be able to detect molecules or particles that at a certain....
What we were told at the time we visited is that they were able to detect a substance at 10-18 , which I believe is the quintillionth.... I'm not sure. I'd have to go back and look at my notes. No, it's not a quintillionth; that's only 1-5....