(USA Today) A previous version of this story named sulfur dioxide as one of the primary drivers of health-related complaints linked to Chinese drywall. Hydrogen sulfide is the main chemical of concern. Also, the U.S. Consumer Product Safety Commission, not the U.S. Agency for Toxic Substances and Disease Registry, sent staff to China to investigate the issue.
Chinese-made drywall used in more than 20,000 homes in the United States could have caused nosebleeds, headaches, difficulty breathing and asthma attacks in tens of thousands of Americans exposed to it, the federal government said in a long-awaited report released Friday.
The drywall was installed in mostly Southern homes since 2005, and it has been the subject of multiple lawsuits. In addition to health-related complaints, homeowners have also alleged sulfur dioxide and other chemicals found in the drywall caused foul odors and corroded pipes and wiring. There have been five settlements totaling more than $1 billion, but it's not clear how much of the drywall was replaced.
"The bottom line is that this modeling data suggests that levels of sulfur dioxide and other sulfur compounds found in the Chinese manufactured drywall were sufficiently high to result in the health effects people have been reporting," said Vikas Kapil, chief medical officer with the U.S. Agency for Toxic Substances and Disease Registry at the Centers for Disease Control and Prevention.
The health research began in 2011 but was not finished until now because of the work necessary to create scientifically valid models that allowed researchers to estimate what the sulfur emissions from the drywall samples "might mean for people in a room in a house" containing that drywall, Kapil said.
The report's release had been promised in 2012. Florida Sen. Bill Nelson sent a letter to the CDC more than two months ago urging it be made public.
"Thousands of Floridians continue to wait and wonder if they will ever see this critical taxpayer-funded research on the possible health impacts of problem drywall. This is unacceptable," he wrote.
Why some Chinese-made drywall contained high levels of sulfur compounds is unknown, said Kapil.
Sulfur dioxide is linked to respiratory problems when inhaled, according to the Environmental Protection Agency. Most people are exposed to it in industrial settings.
As of Jan. 20, owners of 20,244 properties had registered for compensation in a multistate settlement program overseen by the New Orleans federal court where all the lawsuits were consolidated. Claims have been filed by homeowners, home builders, contractors and construction material distributors.
For some homeowners, however, a cash settlement still has not been made.
"They should be receiving it by the end of this year. We're still hopeful," said David Durkee, a lawyer with Roberts and Durkee in Coral Gables, Fla. The firm has more than 300 clients whose homes were built with the drywall.
Homeowners' complaints to the U.S Consumer Product Safety Commission include recurrent headaches, irritated and itchy eyes and skin, difficulty breathing, persistent cough, runny noses, sinus infections, frequent nosebleeds and asthma attacks.
The homes smelled like rotten eggs, many reported. Appliances and electronics failed as their wiring corroded and metal in the homes tarnished and pitted.
The only way to deal with the problem is to rip out and replace the faulty wallboard, said Durkee.
The CDC report said the level of emissions from wallboard it tested dropped over time, but Durkee said he has not seen contamination levels fall in affected buildings.
"Every home that I have dealt with, if they have not fixed their home, it's still causing air conditioners to break, copper to corrode. My experience is I have not seen a Chinese drywall home that gets better," he said.
The drywall, sometimes called wallboard, was imported from China beginning in 2005, after the record-breaking hurricane seasons of 2004 and 2005 created a shortage of U.S.-made wallboard.
Drywall is made of gypsum plaster pressed between two thick sheets of paper, and is used to make interior walls and ceilings.
The U.S. Agency for Toxic Substances and Disease Registry sent staff to China, where they obtained samples of wallboard manufactured there in 2005, 2006 and 2009.
The samples were tested by the Lawrence Berkeley National Laboratory in Berkeley, Calif. Results from those samples were then used to estimate how much of the chemicals would be present in the air of a home with the defective wallboard.
High levels of sulfur dioxide were found in the samples of Chinese wallboard, as well as hydrogen sulfide, carbon disulfide, methyl mercaptan, dimethyl sulfide, carbonyl sulfide and ethyl mercaptan.
Samples of U.S.-made wallboard had very low or undetectable amounts of those chemicals.
The samples gave off the highest amounts of chemicals when they were exposed to hot, humid conditions — much like those found in Florida and Louisiana, two states with the largest number of cases linked to the wallboard.
The levels ranged from 220 to 657 micrograms of hydrogen sulfide per cubic meter of air, the models found.
Tainted Chinese drywall is no longer sold in the United States since the 2012 passage of the Drywall Safety Act, which set chemical standards for domestic and imported drywall.