According to a report released by the U.S. government on Wednesday, the construction material used by FEMA in the trailers, used to house disaster victims, is the main source of formaldehyde fumes.

Federal Emergency Management Agency says, that around 15,000 people are still living in such trailers. These people were displaced by hurricane Katrina and Rita along the U.S. Gulf coast in 2005.

Several FEMA trailers were cut open to measure concentrations of formaldehyde and other irritating chemicals, and it was found that the average formaldehyde level in trailers and mobile homes was about 77 ppb, high enough to cause a risk of cancer and respiratory diseases. It can also cause irritation in the skin, eyes, nose and throat.

Particleboard and plywood were already included in the list of largest sources of formaldehyde emissions, by the Department of Housing and Urban Development.

The manufacturers of travel trailers and the government agencies have already been advised to use construction materials with lower levels of formaldehyde and better outside ventilation.