Marijuana Smokers Have Higher Levels of Toxic Metals in Tests, Study Suggests
forbes.com
forbes.com
i dont think ive met any grower that is not highly selective, about soils and amendments used for culture.
so far i see no mention of regionality regarding user demographic, or source of cannabis.
heres a couple links from the submitted article:
https://www.psu.edu/news/research/story/cannabis-may-contain...
https://www.tandfonline.com/doi/full/10.1080/15569543.2021.1...
> They predicted that because marijuana is known to accumulate metals, individuals would have higher metal biomarker levels than those who did not use the drug, and the study confirmed that marijuana is a source of cadmium and lead exposure.
but to your point it would also make a difference in how and where the plant were grown.
the article lacks a lot of details that would make the study useful. or not.