The answer is no; at least not from radiation.
The Sarasota Herald Tribune is reporting that testing by three agencies, the Florida Department of Health, the U.S. Environmental Protection Agency and the Consumer Product Safety Commission, on drywall manufactured in China has found no traces of radioactivity. Why was it being tested in the first place? Apparently, there have been quite a few problems with Chinese drywall: foul smells, metal corrosion and even illnesses reported in people living in houses with it. A radioactive material called phosphogypsum was considered as a possible contaminant in the drywall, but the testing ruled this out.
Phosphogypsum is a byproduct left over from the process that creates fertilizer from phosphate ore. Phosphate ore contains trace amounts of uranium, and therefore its daughter product radium. When phosphate ore is chemically treated with sulfuric acid to create fertilizer, the radium is separated out with the phosphogypsum. As a Health Physics Society “Ask the Expert” answer makes clear, phosphate ore produced by marine deposits has a higher concentration of uranium, and therefore the phosphogypsum produced is too radioactive to use in construction materials. Since it cannot be used, the fertilizer industry has resorted to piling it into stacks. The wikipedia article states that there are 1 billion tons of radioactive phosphogypsum in stacks in Florida and that 30 million more tons are produced each year.
Chinese industries are not prohibited from using phosphogypsum, though. Was it reasonable to suspect that imported drywall laced with phosphogypsum was the culprit? An article in July from the Los Angeles Times found some evidence that phosphogypsum use was widespread in China. The radioactive La-Z-Boy story shows that radioactively contaminated materials can be imported into the US without discovery. However, in that case, the contamination was fairly low level. In order to corrode metal and cause acute illness in humans, a much higher level of radioactivity would be required.
In the United States, phosphogypsum cannot be used if its activity is greater than 370 becquerels/kg. Exposure to phosphogypsum with this activity is estimated to give a dose of 1 mSv/year. However, acute symptoms of radiation poisoning require a dose of around 500 mSv. Considering, that phosphogypsum has a maximum activity of around 1,300 becquerels/kg, even pure phosphogypsum would not come close to that. Of course, cancer can be induced at a much lower dose and therefore the drywall could still pose a significant health hazard. Therefore, it is reasonable to check the safety of the drywall even if the specific complaints listed above are unlikely to be caused by radiation.
In any event, the radioactivity in the drywall was found to be at background levels, and the more likely culprit might be sulfur compounds (which would explain the rotten egg smell described by some residents). But could other household objects be slowly killing you? Stay tuned for a special report that could save your life! (Well, not really. I just always wanted to say that.)
