I know there's an issue with lead in cinnamon - but that seems to be more an issue of adulteration than of the ground the tree is grown in (what the French might call teroir). By 'convenience sample' do you mean acquired at a convenience store? I've read that the lead in cinnamon was first found in apple sauce packaged for children - and discovered because of developmental issues those children were having.
Without getting into how the FDA is beyond overstretched and really can't secure all the food being imported I do consider food from mainland China risky, avoid it when there's an alternative. I was made aware of the safety issue back in the 90s (long story omitted, but it was a woman *from* mainland China who was warning me in somewhat broken English in an Asian store - so I eventually did a bit of research, was shocked). They have food safety laws, but the people enforcing them stand to make money when they're not enforced, so...