Reply #4: I was just reading this to find out more myself...

[Kadie]

2009 Chinese drywall controversy
From Wikipedia, the free encyclopedia

The 2009 Chinese drywall controversy is an alleged health and safety issue involving defective drywall manufactured in China and imported by the United States starting in 2004. Laboratory tests of samples for volatile chemicals have identified emissions of the sulfurous gases carbon disulfide, carbonyl sulfide, and hydrogen sulfide.<1> These emissions, which have the odor of rotten eggs, worsen as temperature and humidity rise.<1> Homeowners have reported respiratory tract infections, sinus problems and nosebleeds.<1>

In homes with the defective drywall, copper surfaces such as pipes, wiring, and air conditioner coils corrode, turning black and powdery, a chemical process indicative of reaction with hydrogen sulfide.<1>


http://en.wikipedia.org/wiki/2009_Chinese_drywall_controversy