https://merryjane.com/health/5-pesticides-wrongfully-used-in-cannabis-cultivation
https://www.smithsonianmag.com/science-nature/modern-marijuana-more-potent-often-laced-heavy-metals-and-fungus-180954696/
Like you, your ex is a clueless jackass
"even “medical” cannabis can be covered in toxic mold, raised in rooms filled with shedding pit bulls, or coated in commercial-grade synthetic fertilizers and insecticides such as phosphate and Diazinon, which can be especially toxic if improperly applied"