Skeptical Democrats in Congress are demanding to see internal documents they believe highlight the risks and consequences of the decision. An epidemic of the disease, foot and mouth, which only affects animals, could devastate the livestock industry.
One such government report, produced last year and already turned over to lawmakers by the Homeland Security Department, combined commercial satellite images and federal farm data to show the proximity to livestock herds of locations that have been considered for the new lab. "Would an accidental laboratory release at these locations have the potential to affect nearby livestock?" asked the nine-page document. It did not directly answer the question.
A simulated outbreak of the disease - part of an earlier U.S. government exercise called "Crimson Sky" - ended with fictional riots in the streets after the simulation's National Guardsmen were ordered to kill tens of millions of farm animals, so many that troops ran out of bullets. In the exercise, the government said it would have been forced to dig a ditch in Kansas 25 miles long to bury carcasses. In the simulation, protests broke out in some cities amid food shortages.
"It was a mess," said Sen. Pat Roberts, R-Kan., who portrayed the president in the 2002 exercise. Now, like other lawmakers from the states under consideration, Roberts supports moving the government's new lab to his state. Manhattan, Kan., is one of five mainland locations under consideration. "It will mean jobs" and spur research and development, he says.
The other possible locations for the new National Bio-and Agro-Defense Facility are Athens, Ga.; Butner, N.C.; San Antonio; and Flora, Miss. The new site could be selected later this year, and the lab would open by 2014. The numbers of livestock in the counties and surrounding areas of the finalists range from 542,507 in Kansas to 132,900 in Georgia, according to the Homeland Security study.
The existing lab is 100 miles northeast of New York City in Long Island Sound, accessible only by ferry or helicopter. Researchers there who work with the live virus are not permitted to own animals at home that would be susceptible, and they must wait at least a week before attending outside events where such animals might perform, such as a circus.
The White House says modern safety rules at labs are sufficient to avoid any outbreak. But incidents in Britain have demonstrated that the foot-and-mouth virus can cause remarkable economic havoc - and that the virus can escape from a facility.
An epidemic in 2001 devastated Britain's livestock industry, as the government slaughtered 6 million sheep, cows and pigs. Last year, in a less serious outbreak, Britain's health and safety agency concluded the virus probably escaped from a site shared by a government research center and a vaccine maker. Other outbreaks have occurred in Taiwan in 1997 and China last year and in 2006.
If even a single cow signals an outbreak in the U.S., emergency plans permit the government to shut down all exports and movement of livestock. Herds would be quarantined, and a controlled slaughter could be started to stop the disease from spreading.
Infected animals weaken and lose weight. Milk cows don't produce milk. They remain highly infectious, even if they survive the virus.
The Homeland Security Department is convinced it can safely operate the lab on the mainland, saying containment procedures at high-security labs have improved. The livestock industry is divided. Some experts, including the former director at the aging Plum Island Animal Disease Center, say research ought to be kept away from cattle populations - and, ideally, placed where the public already has accepted dangerous research.
The former director, Dr. Roger Breeze, suggested the facility could be safely located at the Atlanta campus of the Centers for Disease Control and Prevention, or at Fort Detrick in Frederick, Md., home of The United States Army Medical Research Institute for infectious diseases.
Another possibility, Breeze said, is on Long Island, where there is no commercial livestock industry. That would allow retention of most of the current Plum Island employees.
Asked about the administration's finalist sites located near livestock, Breeze said: "It seems a little odd. It goes against the ... safety program of the last 50 years."
The former head of the U.S. Agriculture Department's Agricultural Research Service said Americans are not prepared for a foot-and-mouth outbreak that has been avoided on the mainland since 1929.
"The horrific prospect of exterminating potentially millions of animals is not something this country's ready for," said Dr. Floyd Horn.
The Agriculture Department ran the Plum Island lab until 2003. It was turned over to the Homeland Security Department because preventing an outbreak is now part of the nation's biological defense program.
Plum Island researchers work on detection of the disease, strategies to control epidemics including vaccines and drugs, tests of imported animals to ensure they are free of the virus and training of professionals.
The new facility will add research on diseases that can be transferred from animals to humans. The Plum Island facility is not secure enough to handle that higher-level research.
Leaders of the House Energy and Commerce Committee also are worried about the lab's likely move to the mainland. The chairman, Rep. John Dingell, D-Mich., and the head of the investigations subcommittee, Rep. Bart Stupak, D-Mich., are threatening to subpoena records they say Homeland Security is withholding from Congress. Those records include reports about "Crimson Sky," an internal review about a publicized 1978 accidental release of foot-and-mouth disease on Plum Island and reports about any previously undisclosed virus releases on the island during the past half century.
The lawmakers set a deadline of Friday for the administration to turn over reports they requested. Otherwise, they warned in a letter to Homeland Security Secretary Michael Chertoff, they will arrange a vote next week to issue a congressional subpoena.
A new facility at Plum Island is technically a possibility. Signs point to a mainland site, however, after the administration spent considerable time and money scouting new locations. Also, there are financial concerns about operating from a location accessible only by ferry or helicopter.
The Homeland Security Department says laboratory animals would not be corralled outside the new facility, and they would not come into contact with local livestock. All work with the virus and lab waste would be handled securely and any material leaving would be treated and monitored to ensure it was sterilized.
"Containment technology has improved dramatically since foot-and-mouth disease prohibitions were put in place in 1948," Homeland Security spokeswoman Amy Kudwa said.
Cattle farmers and residents are divided over the proposal to move the lab to the mainland.
"I would like to believe we could build a facility, with the knowledge and technology we have available, that would be basically safe from a bio-security standpoint," said John Stuedemann, a cattle farmer near Athens, Ga., and a former scientist at the Agriculture Department.
Nearby, community activist Grady Thrasher in Athens is worried about an outbreak from a research lab. Thrasher, a former securities lawyer, has started a petition drive against moving the lab to Georgia, saying the risks are too great.
"There's no way you can balance that equation by putting this in the middle of a community where it will do the most harm," Thrasher said. "The community is now aroused, so I think we have a majority against this."
In North Carolina, commissioners in Granville County originally endorsed moving the lab to their area but later withdrew support. Officials from Homeland Security ultimately met with residents for more than four hours, but the commissioners have taken no further action to back the facility.
"Accidents are going to happen 50 years down the road or one year down the road," said Bill McKellar, a pharmacist in Butner, N.C., who leads an opposition group that has formed a research committee of lawyers and doctors.