sand versus shot in speaker stands

I used garden pebbles (also called beach pebbles or river pebbles). You can get many different types. You can even use Pea gravel although it needs a good washing first, but it's super cheap. anyway, you can get garden pebbles pretty cheap, and you can get mixed or quartz or whatever and you can get very small ones -- the small ones are very dense and are no mess to work with, pour easily, more desnse than kitty litter, don't retain moisture, don't make any dust.

Interesting issues regarding shot and lead. We have loaded our own shotgun shells in all 4 gauges for 60 years. 12, 20, 28, and 410. We use MEC 650 loaders, and we are competive internationally ranked skeet and trap shooters. At any given time, we have 300-500 pounds of bagged lead shot on hand, and have yet to have a 3 headed baby, nor have we glowed in the dark.
Now if I can just get rid of this nasty eye twitch...

Lead shot is just fine (the real tiny stuff from the gun store)- much better/heavier than sand in my experience. I have filled a Target stand with it, along with a pair of speaker stands- I did not have any 'dust' when I was filling mine- wore gloves while doing so; then sealed the holes with black electrical and/or duct tape- don't see how this would be a problem, as it is all inside the stand(s)...

all of lead's toxic charms are still being discovered. i do not think any manufacturers are recommending it anymore.

Would there be an issue in using lead if once installed it were potted in place using expanding foam or other 'goo'?
How about using some kind of epoxy resin to fill the stand/voids after filling w/shot? No way will it ever come out or get to atmosphere.

Wear gloves / long sleeves / and a particle/dust mask when handling it?