According to a 66-page report released Monday by the Florida Department of Health Chinese drywall samples give off a sulfur odor when exposed to heat and moisture.

The investigation conducted by Unified Engineering, a private lab was on one sample made in the U. S. by National Gypsum Co.'s GridMarx brand and three samples made in China. The findings by the lab are to be detailed later Monday during a press conference by the department which is analyzing drywall in response to a widening product liability crisis.

The Florida Department of Health is looking into 150 complaints relating to drywall causing metal corrosion and odors in homes while the U. S. Consumer Product Safety Commission is also investigating the extent of the drywall problem.

In a letter Lori Streit, a principal scientist with Unified said, "There is a distinct difference in drywall that was manufactured in the United States and those that were manufactured in China. The Chinese samples contained traces of strontium sulfide inclusions and more organic material than the GridMarx sample (United States). However, it is not yet known if either contributed to the odor."

Streit added that the Chinese samples emitted a sulfur odor when exposed to extreme heat and moisture similar to conditions on a hot day in Florida. "It is clear that exposure to moisture accelerates the release of volatiles from the drywall," she wrote. "Both the outer paper and the gypsum from the drywall had noticeable odors after moisture exposure and were found to release sulfur compounds."

In the recent months homeowners have filed lawsuits alleging that drywall has caused them to suffer health problems and it has also caused the corrosion of copper tubing used in air conditioners. Attorneys have filed class-action lawsuits arguing that defective drywall also has led to problems in homes in Louisiana and Alabama. Similar problems with drywalls are being faced in some homes at The Hampshires at Greenbrier in Chesapeake and in Cromwell Park in Virginia Beach.

The Dragas Companies one of the area's most well-known development companies confirmed Monday that the imported drywall suspected to be Chinese made may have been used in 60 homes built in Chesapeake and Virginia Beach.

In a statement Monday, Dragas said it determined that the imported drywall installed at The Hampshires and Cromwell Park "appears to emit elevated levels of sulfur compounds that may corrode air conditioning coils, and may damage other mechanical and electrical systems over time."

According to the statement the drywall was imported by a U. S. supplier in 2006 and installed by a local subcontractor without Dragas' knowledge. In January, Dragas became aware of an issue with imported drywall from one of its subcontractors and "moved immediately to determine if Chinese drywall had been used in any of our properties."

Chesapeake city and health department officials are investigating as well. Chesapeake spokesman Heath Covey said, top city officials are "studying the various jurisdictional and legal questions" surrounding the drywall issue, and "further action will be taken if the situation warrants."

In an e-mail Dr. Nancy Welch, director of the Chesapeake Health Department said," There is general consensus that the gas that is emitted contributes to corrosion of wiring in appliances and may evoke respiratory or (gastrointestinal) complaints in persons who are particularly sensitive (similar to some persons' responses to fresh paint),". She said the high-risk or permanent health effects are unknown.

According to The Wall Street Journal On Monday, Florida's health department said preliminary tests showed no specific health hazard from gases from the drywall.