July 3, 2008
Study: Wood Released Formaldehyde in FEMA Trailers
The U.S. government released a report on Wednesday saying pressed wood products such as particleboard are the main source of irritating formaldehyde fumes in trailers used to house disaster victims.
The U.S. Centers for Disease Control and Prevention suggests that such temporary housing should be designed with better ventilation and current health and safety standards may not be enough to protect people.
"Even though construction materials meet standards ... you have to be a little bit careful about how you use those construction materials. You could end up fostering high levels of formaldehyde," said CDC spokesman Glen Nowak.
Around 15,000 people displaced by hurricanes Katrina and Rita along the U.S. Gulf Coast in 2005 are still living in such trailers, according to the Federal Emergency Management Agency.
"A few dozen mobile homes were being sent to people displaced by flooding in Iowa, but they had been tested for low formaldehyde levels," said FEMA spokesman James Kaplan.
Several trailers were cut open to measure concentrations of formaldehyde and other irritating chemicals known as volatile organic compounds.
"We refer to it internally as the chain saw study," Nowak said. "We went beyond formaldehyde and looked at levels of other volatile organic compounds.
The CDC contracted with the Lawrence Berkeley National Laboratory in California and found that processed wood products such as particleboard and plywood were the main source of formaldehyde. They did not find other chemicals at significant levels.
Formaldehyde, used to manufacture many building materials, can irritate the skin, eyes, nose and throat. High exposure levels may cause cancer.
Particleboard and plywood were identified by the Department of Housing and Urban Development as one of the largest sources of formaldehyde emissions in 1985 and set standards for manufactured homes to limit them.
"It has implications for FEMA as FEMA looks at emergency housing. One of the factors they need to consider is indoor air quality and the construction materials used in the ventilation systems," Nowak said.
Average formaldehyde levels in trailers and mobile homes were about 77 parts per billion -- high enough to raise the odds of cancer and respiratory diseases, according to an earlier CDC study.
Gypsum board was now used in 95 percent of walls and ceilings in manufactured housing, said the Manufactured Housing Institute.
"The findings only apply to trailers distributed by FEMA in the Gulf Coast Region," said Michael McGeehin, director of the Division of Environmental Health Hazards at CDC.
"However, taken together, the two studies indicate that manufacturers of travel trailers and the government agencies that influence their design, should consider using construction materials that emit lower levels of formaldehyde as well as designs that increase outside air ventilation," McGeehin said.