Lynette Hooks sat on the narrow bed of her FEMA trailer, gazing out the window at the house where she lived until Hurricane Katrina wrecked it. The three-bedroom shotgun remains uninhabitable, but the news she got Thursday made her wonder if she might have to move back in.

The Federal Emergency Management Agency announced that it wants to quickly move 35,000 Gulf Coast hurricane victims from their disaster trailers after the Centers for Disease Control and Prevention found unsafe levels of formaldehyde in the dwellings. Earlier FEMA had downplayed health concerns.

Hooks blames the formaldehyde for her headaches and sinus problems, and many others displaced by hurricanes Katrina and Rita have similar complaints. But far from feeling vindicated, they worry that the government’s newfound urgency could leave them in an even worse housing situation.

The market is already tight, and fair-market rent has increased by 40 percent since the 2005 hurricanes.

FEMA Administrator R. David Paulison said the agency hopes to get people out of the trailers and into hotels, motels, apartments and other temporary housing by the summer, when the heat and stuffy air could increase the formaldehyde levels inside the trailers.

“The real issue is not what it will cost but how fast we can move people out,” Paulison said.

A hotel room has no appeal to Hooks.

“If they (FEMA) can help me get in an apartment, I’ll go. If they can’t, I’ll go right back in my house,” the 48-year-old said. “It’s not much, but it’s something.”

Hooks, a former nurse’s assistant on a medical disability, said her assistance check would not cover the costs of the city’s climbing rents. She said unscrupulous contractors ran off with the money she received from the state’s Road Home rebuilding program.

Observers say the already beleaguered disaster agency will face an uphill climb in finding housing for trailer residents who are often strapped for resources.

Dr. Irwin Redlener, a pediatrician who co-founded The Children’s Health Fund philanthropic organization, said FEMA’s plan leaves many in a “no-win situation,” potentially ill while they scramble for a new roof over their head.

“It’s a real dilemma for people with limited means to begin with,” said Redlener, a professor at the School of Public Health at Columbia University.

The CDC said fumes from 519 tested trailers and mobile homes in Louisiana and Mississippi were, on average, about five times what people are exposed to in most modern homes. Formaldehyde, a preservative commonly used in construction materials, can lead to breathing problems and is also believed to cause cancer.

The CDC findings could also have disturbing implications for the safety of other trailers and mobile homes across the country, Homeland Security Secretary Michael Chertoff said on Capitol Hill on Thursday. The CDC study did not look beyond the FEMA housing.

Paulison vowed that the agency will never again use flimsy, cramped trailers to shelter disaster victims. The formaldehyde levels in some trailers were found to be high enough to cause breathing problems in children, the elderly or people who already have respiratory trouble, CDC Director Dr. Julie Gerberding said. About 5 percent had levels high enough to cause breathing problems even in people who do not ordinarily have respiratory trouble, she said.

Hooks lives in her trailer with a 16-year-old son and 9-month-old granddaughter. Cockroaches climbed the walls as she spoke, and supports for the three beds in the cramped dwelling were collapsing. They have lived there since October 2006.

“Am I angry at FEMA? Of course I am. They should have started moving people out of these trailers once they first started finding problems,” she said.

Gerberding said the tests could not draw a direct link between formaldehyde levels and the wide range of ailments reported by trailer occupants. But the CDC urged people to move out.

As early as 2006, trailer occupants began reporting headaches, nosebleeds and difficulty breathing. But as recently as last spring, a FEMA spokesman said the agency had no reason to question the safety of its trailers. Just last month, congressional investigators accused FEMA of suppressing and manipulating scientific research to play down the danger — an accusation the agency denied.

“I don’t understand why FEMA bought trailers in the first place that were dangerous,” said Henry Alexander, 60, who has been living in a trailer since February 2006. “You would hope they would test them for formaldehyde before.”

Chertoff said at a Senate committee hearing that the government has been trying since last summer to prod people to move out of the trailers, but it has been difficult to get them to do so because the housing shortage means they might have to move far away. Residents live in the trailers rent-free.

Louisiana has 25,162 occupied FEMA trailers and mobile homes, while Mississippi has 10,362, according to FEMA. Other states also have hundreds of trailers. At one point, FEMA had placed victims of the 2005 hurricanes in more than 144,000 trailers and mobile homes.

Formaldehyde fumes can cause burning of the eyes and nose, shortness of breath, wheezing, coughing and tightness in the chest.

“It seems like I have had more respiratory problems since I have been in the trailer,” Roger Sheldon, 60, said in Pascagoula, Miss. Grateful for the trailer, he was not ready to blame formaldehyde. “You know you can walk into any new trailer, or house for that matter, and things like new carpet can cause irritation,” he said.

Ernest Penns of the crippled Lower Ninth Ward said he too was grateful, if only for one reason: “I got nowhere else to go.”