why low cadmium rock phosphate such as wonarah

Chinese agricultural researchers believe as much as 10% of China's rice may be tainted by cadmium.

www.marketwatch.com/story/chinas-rice-contaminated-with-heavy-metals-2011-02-14

The researchers believe cadmium is finding its way into rice paddies from heavy metal discharge in mine and industrial sewage.
A lot of high cadmium rice is being consumed by farm families or sold in areas of the nation's food market beyond the reach of government safety regulators.
Rice is a staple food for 65% of the population in China.

Cadmium is found in rock phosphate at different concentrations depending on rock source. It is removed to acceptable levels during phos acid production. (see my post No. 4931620 12/01/10)

Developing countries such as China will have to spend more time and effort and cost in dealing with cadmium in fertiliser or alternatively source rock phosphate from deposits such as Wonarah. Another reason why this deposit is world class.