Graphic: MGN Online

The Federal Emergency Management Agency test results, obtained April 1 by the Associated Press, show that three of 32 mobile homes tested for use in Arkansas had levels high enough to put possible residents at an increased risk of cancer and respiratory illnesses. Above half of the homes tested had levels higher than the average home.

The more than 7,500 mobile homes are being stored at Hope Municipal Airport. FEMA had a contractor test some of them to see if they were suitable for storm victims in Arkansas and Tennessee, which were hit by deadly tornadoes on Feb. 5.

Arkansas is still deciding whether to accept any FEMA mobile homes; Tennessee has taken 16, but set a formaldehyde limit.

FEMA announced in February that many of the mobile homes it had provided to victims of hurricanes Katrina and Rita had high levels of formaldehyde, and that it was stepping up efforts for tens of thousands of occupants into different housing.

Formaldehyde, a preservative commonly used in building materials, can cause respiratory problems and has been classified as a carcinogen by the International Agency for Research on Cancer and a probable carcinogen by the U.S. Environmental Protection Agency.

Hurricane victims have complained of headaches and nosebleeds after living in the homes, and some lawsuits have been filed. About 34,000 mobile homes remain occupied by victims of the 2005 hurricanes, down from a peak of more than 143,000, FEMA says.

There is no federal limit for formaldehyde, but officials in Alabama, Arkansas, Louisiana, Mississippi and Tennessee are discussing whether they should set a uniform standard of what an acceptable level of formaldehyde in emergency housing should be.

Matt DeCample, a spokesman for Arkansas Gov. Mike Beebe, said the governor would meet with advisers to discuss whether the state should accept any of the mobile homes.

“Obviously, we want to get some information out to our storm victims as quickly as we can,” Mr. DeCample said.

Jeremy Heidt, a spokesman for Tennessee Emergency Management Agency, said his state decided to only accept homes that had formaldehyde levels below 40 parts per billion. He said the mobile homes offered by FEMA came from their Selma, Ala., holding site.

The average formaldehyde level in tested homes used by hurricane victims was 77 parts per billion, more than five times the amount in an average modern home.

In Oregon, FEMA shipped 21 mobile homes for those affected by December flooding in the logging community of Vernonia, just northwest of Portland, said Jennifer Bailey, a spokeswoman for Oregon Emergency Management. She said the mobile homes had an average formaldehyde level of 22 parts per billion.

“The formaldehyde levels were so low it just wasn’t even an issue,” Ms. Bailey said.

—Jon Gambrell, Associated Press