>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.<<

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...