You are quite correct.
That said, does anyone suspect that the chinese would "waste" the grain?
I'm guessing that it the Cd will end up in various exported foods, perhaps after being fed to livestock or by being diluted with uncontaminated grain so the Cd levels are lower, but still measurable.
Oh, and if the rice is contaminated, what about wheat? (IIRC, china exports a lot of wheat gluten, etc.)
.
The plastic rumor is about them “cutting” the product so they dont waste the contaminated rice.
Fold in enough filler so that the stuff doesnt seem so toxic.