>>8857192 PB DDT to kill mosquitoes banned...
I seem to remember it was something to do with the environment; maybe birds ...found this
"The ban was intended to prevent the imminent extinction of ospreys, peregrine falcons, and bald eagles, our national bird, among other species; they were vulnerable because DDT caused a fatal thinning of eggshells, which collapsed under the weight of the parent incubating them."
https://e360.yale.edu/features/rachel_carsons_critics_keep_on_but_she_told_truth_about_ddt