chemtrail effluent prior to approximately 1990 (thereabouts). Prior to the change to the white spew, there was only clear exhausts and for higher flying stratospheric jets, contrails. Since we all observe the grunge being emitted, I think you are obligated to prove it’s just water vapor. I recall 10 years ago over my property a commercial jet at very low altitude. And flying very slow. I could easily make out every window. That jet was laying down a particularly nasty toxic chemtrail. Water vapor at that level does not occur, period.