Lol!! I imagine if you inhale the dust directly, yeah, could be a problem! But I’m pretty sure the plant won’t magically absorb the dust out of the soil through the roots, up the stalk and stems, into leaf and bud (through osmosis?) Somehow manage to make it through the drying then curing process, survive grinding up, put in bowl and fired up into smoke, pass through the water in the bong, and end up causing lung cancer… shit… Maybe I’ve gotta burn this crop now… lol!
In all seriousness, look it up, Wikipedia has an in depth detailed description. I found a ton of stuff- pretty sure it’s approved for food prep areas, hospital, schools… should be good and put your mind to rest. Then, enjoy your bug free smoke!!