I believe there are real long term 'concerns'. The truth is, we don't know the long term consequences of smoking/vaping certain poisons. Even beyond the expected pesticides, one of the biggest concerns is pgr's (plant growth regulators). They are only supposed to be used on nonfood crops. Most either shorten growing time or add bulk. The most commonly used pgr's are paclobutrazol, chlormequat chloride and daminozide. Paclobutrazol IUPAC name: (2S,3S)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ol Molecular Formula: C15H20ClN3O Commercial Trade names: Cultar, Astar, Bonzi, Clipper, Holdfost, Klipper, MET, Parlay, PP333 Consumer products: Bushmaster, Gravity, Phosphoload, Flower Dragon Daminozide IUPAC name: N-(Dimethylamino)succinamic acid Molecular formula: C6N2H12O3Commercial trade names: Alar, Kylar, B-NINE, DMASA, SADH, B 995 Consumer Products: Flower Dragon, Top Load, Phosphoload The manufacturers intentionally omits info, mislabels products, hides ingredients and markets as if totally natural/organic. This is how Humboldt countys gravity is marketed: "Our uniquely prepared kelp extract and phosphorous based additive will harden your flowers from top to bottom. Use once or twice about 3 weeks before the end of a plant's cycle. Adds size and weight to flowering plants." Here is the link for 'stop sales' orders on products in Oregon. Some are strictly labeling/money games w/ the fda, others are more serious: http://www.oregon.gov/ODA/pest/Pages/stopsales.aspx Many familiar manufacturers are on there. Many growers don't even understand the process well enough to get beyond the sales pitch and determine for themselves what is in a product. Many in the medical mj community have compromised immune systems and should be more aware of what they are putting in their bodies. If one is health conscious enough to vape, wouldn't it stand to reason that they should be health conscious enough to avoid ingesting poison?