Oh, poor 71GTO! I didn't mean to frighten anyone, but ya know--It's better to know what to protect yourself from than not know and lose your health. Just use the mosquito dunks like people do. I'm going to try that.
When I was in my 20s, we kept a cardboard drum of diatomaceous earth in our garden shed for some friends. We got a minor flood in the neighborhood and the water didn't get into the house, but it got into the outbuildings and the diatomaceous earth soaked up the water and turned into a giant column of toothpaste-like substance, which split itself right out of that cardboard drum it was in. That was sure something to see! We got rid of it because it was no good anymore. That spring, I was sweeping out the shed and I got into the dust that was left from the diatomaceous earth. I didn't realize it, but the next day, I came down with something like a really bad cold, but I realize it was a reaction to the diatoms in the dust. Am I in trouble from that? Don't know, but I know it's not good to inhale. There are masks you can use to protect yourself from irritants and it's a good idea to use them.
So, not all natural things, like diatomaceous earth, are harmless! Dang! Arsenic is natural and it'll kill you real well.
Know what you are using and use it appropriately and you'll likely be all right.
noss.