[Lucky]

In the 50's, our out-door movie theaters were sprayed with DDT and nobody got sick from it. Also other businesses used it with no problems.

[backhoe]

I can recall spraying the stuff around from Flit guns, and people walking through, and even smoking in, the cloud of insecticide without ill effects. By contrast, the "EPA Approved" pyrethrin-based fogging oil I use around here makes me feel sick as a dog- I can taste the stuff for days- if I get one whiff of it.

And it doesn't kill the bugs, either...

[Sungirl]

In the 50's, our out-door movie theaters were sprayed with DDT and nobody got sick from it

What year was DEET developed? How long does it take to see all symptoms?