Cannabis is also in a unique situation given that is in legal gray area due to federal prohibition in the US (and many other countries).
I'm curious if pesticide contamination is as prevalent in markets where cannabis is decriminalized or legalized at the country level.
Vapes aren't that much better, containing different groups of chemicals you wouldn't want to inhale directly, or not in the concentrations used in vaping.
So my 'knowledge' about that stuff is a patchwork of what I've read in the media, concerning the region/changing legislature/over time, and personal experience, be it by consuming it itself, or just smelling it from afar and thinking for myself 'I'd never touch that crap with a ten foot pole!'
I can say that I feel safest with Colorados model, which basically amounts to that all the stuff has to be tested before it is allowed to be sold legally, be it in shops, or online. Not halfassed shit like in the Netherlands, where it is only decriminalized, and the 'Coffeeshops' pay taxes for 'not drunken coffee', while the supply chain is still VERBOTEN and shrugged off, or the recent German model, which is shitty in similar ways, and doesn't even allow 'Coffee-shops'. Georgia, the country? They also messed the supply-chain and shop-thing up, or decided not to bother at all. Just consuming and maybe up to hand full of plants for personal use is legal, and that's it.
Which means anywhere not following Colorados mandatory testing model has a black market, and thus the potential 'quality problems' which they bring with them.