I live in the midwest USA, and heard a NPR local program about the Legionella bacteria being virtually everywhere that damp, non-sun exposed soil was. It apparently is nothing new or especially menacing when in it's natural habitat, but when it is enclosed (building crawl-spaces, bagged soil, any areas that are damp and enclosed) it can multiply to dangerous levels. As we make our homes and businesses more "space-capsule"-like, we will discover more of these problems, I'm sure. Fresh air (even in Los Angeles) is superior to getting a lungful of these nasty buggers. Using a breath mask is a sensible precaution when handling any garden chemicals, and now it seems if you use the processed soils it is a good idea also. I love my garden, but I'm not willing to die for it... though, to hear my mother talk, she thinks I grow my chiles to try and kill myself with them :^) George