The Centers for Disease Control and Prevention is recommending that the Federal Emergency Management Agency relocate people from travel trailers and mobile homes in the Gulf Coast as quickly as possible based on formaldehyde testing in more than 500 of the temporary housing units.

CDC and FEMA released the preliminary results of testing in 519 occupied travel trailers and mobile homes Thursday, which showed that the average unit had about 77 parts per billion of formaldehyde — much higher than normal indoor air levels of 10 to 20 ppb. Levels ranged from 3 ppb to 590 ppb in the temporary units.

“We know that if we took the same snapshot in the summer, when the weather is warmer that we would probably see even higher levels in some of these trailers,” said CDC Director Julie Gerberding. “So we’re making the recommendation that all of the people in these situations be relocated to safer, permanent housing as quickly as possible and certainly before the warm summer months arrive.”

The travel trailers and mobile homes were tested between Dec. 21 and Jan. 23.

“With formaldehyde, the degree of risk from chronic exposure is still somewhat uncertain, but it is classified as a carcinogen and we do want to be sensitive to the fact that people who spend a lot of time in their trailers could be at risk for cumulative exposure effects,” Gerberding said.

In the wake of the results, FEMA will work to expedite the relocation of residents. “Along with the aggressive approach we’ve been taking, we are going to take a more aggressive approach,” FEMA Administrator R. David Paulison said.

After having nearly 144,000 households in the temporary housing units following hurricanes Katrina and Rita, Paulison said the number is down to about 38,000.

The priority groups for relocation will be people expressing health concerns and those most susceptible to health risks associated with formaldehyde, including families with children, the elderly and those with respiratory problems, according to Paulison.

“CDC is recommending that we try to get as many people out as we can by the summer time, and we are going to shoot for that,” Paulison said.

FEMA had already planned to relocate people from group sites by June 1.

“We have offered consistently over the past two years if you want to move out we will move you out immediately and we’ve done that,” Paulison said. “A lot of people have called about health issues, we’ve offered to move them and they’ve refused. I think with this information . . . when we ask them to move out of these travel trailers . . . they will do so.”

As part of the plan to relocate travel trailer and mobile home residents, FEMA has taken or will take a numbers of steps including:

• Establishing direct contracts with hotels and motels to get the necessary capacity.

• Establishing direct leases with landlords.

• Using contract resources to help facilitate local relocation.

• Offering food vouchers and stipends.

• Providing for the boarding/care of pets for families relocated to hotels/apartments that don’t allow animals.

Going forward, Paulison said FEMA will never again use travel trailers. “We may use mobile homes just like we’re doing in Arkansas and California, but we will not use trailers again,” he said. “They’re too small. We saw they do not work well, particularly in large group sites when you put families in them.”

Unlike travel trailers, which are made for short-term housing, Paulison said mobile homes are designed for people to live in for an extended period of time. “There are HUD standards [relating to formaldehyde] that go into the materials that go into mobile homes that are not applied to travel trailers,” he said. “So we feel like the mobile homes are a safe place to put people.”

Formaldehyde is a chemical used in the manufacturing of building materials.

But Paulison noted that the testing of the 519 units, including 79 mobile homes, also raised some concern about the mobile homes. “We had some mobile homes tested very high here, which was a surprise to us, so we’re going to make sure that we test any of our mobile homes before putting them on the ground and putting people in them,” he said.

After reviewing the report, Sen. Mary L. Landrieu, D-La., said she plans to launch an investigation into “FEMA, the Department of Homeland Security and this administration’s dismal and failed housing strategy.”

She said FEMA has been in a pattern of “deny and delay and ignore” with regard to the trailers for more than two years.

“FEMA is acting somewhat surprised by this announcement, but I am not surprised and it should be surprise to no one,” said Landrieu, who chairs the Senate Homeland Security and Governmental Affairs’ Subcommittee on Disaster Recovery.

“When families complained that their children were getting sick over a year and a half ago, FEMA and other federal agencies turned a blind eye,” she said. “When the agency’s own tests said that these trailers were dangerous, FEMA ordered its own personnel to stay out of them, but failed to warn the people living inside them.”

Sen. Mark Pryor, D-Ark., said he intends to introduce legislation requiring FEMA to enumerate its housing needs, create a plan to meet those needs, adhere to the plan and then report back to Congress.

Landrieu and Pryor, who chairs the Homeland Security and Governmental Affairs’ Subcommittee on State, Local and Private Sector Preparedness and Integration, announced that their subcommittees will hold a joint March 4 hearing on formaldehyde in trailers.

Pryor said the report is “alarming, but it’s also incomplete. We still don’t know the whole story.”

House Homeland Security Chairman Rep. Bennie Thompson, said, “It is simply unacceptable that the administration allowed trailer occupants to be exposed to these health risks at all, let alone for years.”

Thompson, a Mississippi Democrat, said he expects FEMA to “comply with CDC’s recommendation and begin moving people out of the affected trailers immediately.”

Joseph I. Lieberman, I-Conn., chairman of the Senate Homeland Security and Governmental Affairs Committee, said the results are “deeply troubling, not just for the disturbing news they contain for thousands of victims already knocked off their feet by Hurricane Katrina, but also because it has taken FEMA so long to finish the testing, despite longstanding concerns.”

Daniel Fowler can be reached at dfowler@cq.com.

Rob Margetta contributed to this story.