Chinese drywall has not been conclusively linked to health issues. That being said, reports are widespread indicating that those living in affected homes have experienced a wide range of health issues. These issues range from severe headaches, nose bleeds, coughing, and irritated eyes and skin to more concerning symptoms associated with neurological issues. Many reports indicated that these symptoms cease when the homeowners leave the home for a period of time.
At least one doctor has advised homeowners with Chinese drywall to "get out" of their home. The key to evaluating the health risks of Chinese drywall is the concentrations and intensity of the toxic gases and the duration of the exposure. Most structures affected are homes, and people are exposed to their homes on a regular and extended basis. The intensity of the exposure depends on how much gas the drywall produces and the level of air exchange.
The gas that appears to be most hazardous to human health is carbon disulfide. The the National Institute for Occupational Safety and Health (NIOSH) limits short term exposure to carbon disulfide to 1 ppm. The exposure limits are designed around risks to the cardiovascular, central nervous system, and reproductive.
The other gas of concern is hydrogen sulfide. Hydrogen sulfide exposure should be limited to 10 ppm for just a 10 minute duration. Long term, lower level exposures have not been adequately studies. Also, the the 10 ppm exposure is based on the acceptable levels for adults. Studies of safe exposure levels for children and infants have not been studied.
Hydrogen sulfide is also responsible for the rotten egg smell associated with Chinese drywall. At just 40 part per billion, most people can smell hydrogen sulfide. The more dangerous of the two gases, carbon disulfide, is typically found at about 1/4th the level of hydrogen sulfide. Because exposure limits for carbon disulfide are dramatically lower, the combination of hydrogen sulfide and carbon disulfide has the potential of significant adverse health effects in the long term.
Some preliminary studies of indoor air quality seemed to indicate that levels of these gases were no higher than in homes with Chinese drywall. For various reasons, these studies have been faulty in their approach.
