"A federal investigation into contaminated Chinese-made drywall has been a long, hard tug-of-war for U.S. investigators trying to pry information from Chinese government officials and manufacturers. When a team of investigators traveled to China last year, the tug-of-war became physical, with a Chinese official trying to wrest a piece of drywall from an American’s hands.
The federal probe is the largest defective-product investigation  ever conducted by the Consumer Product Safety Commission. But almost two years after it began, the CPSC still hasn’t been able to figure out what materials in the Chinese drywall are triggering the release of sulfur gases. The gases have a chemical smell and have corroded wiring and appliances in thousands of U.S. homes. They’ve also been linked to respiratory ailments, nosebleeds and sinus problems.
Joaquin Sapien of ProPublica and Aaron Kessler of the Sarasota Herald-Tribune report October 25, 2010.