Many studies have shown that the heavy metal content in (Chinese) rice exceeds food safety standards, especially levels of cadium (Cd) and lead (Pb) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9754602/

Yea I mean I would not be surprised about this either. See also: sketchy cooking oil (sometimes literally transported in fuel tankers?), sketchy milk, etc etc. Food safety in China is still getting up to speed.

Though if we're talking specifically about heavy metals, iirc northeastern China has better (lower) heavy metal levels compared to a lot of other parts of China

Chinese would never agree with you. The best rice comes from the South. (I dont necessarily agree but it’s a strong stereotype that I often heard in my 6 years there).

There is an old Chinese saying that goes Live in Hangzhou, marry in Suzhou, dine in Guangzhou, and die in Luzhou.

My grandpa's side grew up in southern China, so that's what I originally thought.

But my wife is from way northeast, and I had to begrudgingly admit that I do like the rice from up there better.