By: Popular Mechanics

Keith Baker noticed sour smells emanating from the walls of his newly built home in Fort Myers, Fla., soon after he took up residence there in March 2008. Then the copper pipes from the water heater turned black, “as though someone threw soot on them.” Soon, Baker and his wife started experiencing sinus problems, dizzy spells and muscle aches. They are among thousands of homeowners in Florida and elsewhere who are blaming such problems on low-quality, imported drywall.

Domestic supplies of the building staple ran short during the building boom of recent years, which was compounded in coastal areas by post-hurricane reconstruction projects. Contractors imported 540 million pounds of drywall from China between 2004 and 2008, according to shipping records surveyed by the Associated Press.

The office of Florida Sen. Bill Nelson estimates that the material may have ended up in as many as 100,000 homes nationwide. Lab analyses obtained by the Florida Department of Health show that the gypsum in some Chinese drywall contains strontium sulfide, a material absent from most samples manufactured in the United States. The EPA tests for this material are still pending, but scientists suspect that this compound, which releases sulfurous gases, could be the cause of homeowner complaints that range from nosebleeds and respiratory ailments to black coatings tarnishing shower fixtures and corroding air-conditioner coils.

Researchers say the evidence isn’t conclusive — and point out that not all Chinese drywall is suspect. However, a number of class-action lawsuits have been filed against plasterboard manufacturers and others. Builder Lennar Corporation has identified dozens of houses containing potentially harmful drywall, and has pledged to fund the only known remedy: removing the drywall, replacing damaged plumbing and wiring and relocating homeowners until new materials are installed. In a sure sign that fear is spreading, con men have started hawking bogus test kits and remedies such as chemical sprays and ozone generators.

Homeowners worried about their own wall material can check for a “Made In” stamp or a manufacturer’s name on exposed board backs. If no name appears, the Florida attorney general’s office recommends an inspection by the builder or a licensed contractor. Meanwhile, the U.S. Consumer Product Safety Commission is investigating.

“We need to see what’s going on,” spokesperson Joe Martyak says. “We will pursue this aggressively but scientifically.”

This article was written by Adam Hadhazy for PopularMechanics.com.