The vertical distribution of Cd

form change and the relation between Cd concentration and pH on paddy soil have been investigated in Zhangshi wastewater-irrigated area. And the sources of Cd in brown rice have been pointed out.

The authors examined the pathway of Cd accumulation in rice grains

and stated methods for reducing its Cd content.

And finally

a mathematical model was established for calculating limiting values of Cd concentration in irrigated water on the basis of tracer experiments.