Chinese Drywall Now Radioactive

A few months ago we got word that the Consumer Product Safety Commission had issued warnings regarding the use of certain Chinese made drywall due to it's smell, corrosive gases and ruining household systems such as air conditioners.

Now some Chinese experts think these problems stem from the use of a radioactive phosphorus substance -- phosphogypsum -- that is banned for construction use in the U.S. but has been used by Chinese manufacturers for almost a decade.

This stuff is radioactive "due to the presence of naturally occurring uranium and radium in the phosphate ore" (Wikipedia), and the EPA has banned most of it's applications. It's been known to cause metal damage and nosebleeds, among other ailments.

We ask the question, where does the blame lie? Chinese manufacturers selling a known radioactive product (although it seems to be legal there)? Builders seeking the cheapest materials? Consumers not being responsible enough to demand higher quality materials?