No citation for this. Do they mean a larger than intended dose or a dose that results in a serious toxic reaction or death?
Better source:
Median lethal THC dose for a 70kg human estimated to be 4g [0], which is slightly over 1300 full joints (at 3mg per joint) [0]. I won't link them here, but a cursory web search showed me stores claiming to sell edibles with up to 1000mg of THC.
Also a good read [1] [2]
0. https://www.tandfonline.com/doi/abs/10.3109/0095299930900161...
1. https://www.nature.com/articles/srep08126
3. https://www.cbc.ca/news/canada/calgary/cannabis-overdose-tox...
For example the Sriracha company settled in the middle of nowhere, the north San Jose water treatment facility was in the middle of nowhere but now you have housing next to them and people complaining about smells or pollution.
To avoid this you’ll need better more stringent zoning laws with bigger buffer zones.