An example of environmental sampling from his aforementioned 2014 speech:

So if you go—in Iraq, we learned in Iraq—it was on the U.S. side that it was developed. And we used to call it—we take the urine test of Iraq, just like to take urine test of drug addicts—we could go and take a little water in the river and then test it and you will see. You could take some samples or leaves or sand or whatever and you could find it. So that was a new technique that was developed during the Iraqi affair and which then went into this.