BETTY ANN BOWSER: It's probably the most unique dumpsite on earth: Refrigerators stacked side by side for as far as the eye can see. By the time the Environmental Protection Agency completes its part of the clean up job in New Orleans, more than 300,000 of them will be emptied of rotten food, drained of environmentally hazardous Freon, and crushed for recycling.
But the "Big Fridge Yard" represents just a fraction of what the EPA is facing in New Orleans, in the largest environmental clean up in the agency's history.
There are 22 million tons of debris -- enough to fill the Superdome 43 times. More than 350,000 cars, trucks, and 60,000 boats have to be hauled away. And tens of millions of tons of hazardous waste will have to be disposed of.
BETTY ANN BOWSER: The EPA has conducted hundreds of tests all over New Orleans to see if the environment is safe. With a staff of over a thousand in the area, water samples have been taken, soil and sediment have been tested, and hundreds of air samples have been gathered and analyzed.
John Cardarelli is a health physicist with the EPA.
JOHN CARDARELLI: We're concerned about particulates -- things go in and deposit just about the bulk of your neck and we're also looking at specific particulate matter that can do deeper into your lungs.
BETTY ANN BOWSER: But now after all of the tests, including independent ones done by environmental groups, there is great disagreement over whether the city is safe or not for residents to return for a short time, or on a long term basis.
Meanwhile, local officials are allowing thousands of residents back into their homes: People like Betty LeBlanc who worries what she's being exposed to.
BETTY LEBLANC: It's all mold and spores break from that and get out into the air that I breathe.
BETTY ANN BOWSER: Because of the mold and presence of other potentially dangerous substances, the 77 year old retired nurse is taking her house down to the studs.
BETTY LEBLANC: Everything must come down. The walls, the ceilings -- everything in this house has to come down to the bare wood.
BETTY ANN BOWSER: LeBlanc and her helpers are taking precautions. They wear gloves and face masks.
BETTY LEBLANC: I'm telling you that it's very unhealthy -- mostly the breathing because of the lungs. I know this isn't good. We have hand sterilizer over there; we're washing out hands constantly. Our gloves we change every day and our masks we change every day. So that's all we can do to protect ourselves.
BETTY ANN BOWSER: The EPA has not done any tests inside private homes or on yards. Instead, they've concentrated their efforts in public areas. The agency has posted results of all its tests on its Web site, and they show few dangerous levels of toxins for short-term exposure, meaning 24 hours or less.
EPA's partner, the Louisiana Department of Environmental Quality says its tests have produced "unremarkable" results. An official told the NewsHour that "people have nothing to worry about." But at the same time both agencies have warned residents not to come in contact with flood sediment.
Stephen Johnson is the EPA's administrator.
STEPHEN JOHNSON: What certainly the EPA has said is that as you are dealing with debris that you need to take prudent precautions whether that is gloves or in some cases dust filters or boots and those kinds of things.
BETTY ANN BOWSER: Erik Olson, senior attorney for the Natural Resource Defense Council, thinks the EPA is confusing people with a mixed message.
ERIK OLSON: How can it be safe and then in the next sentence you say that you've got to wear protective equipment? It's not safe for people to be running around and traipsing around in these toxic chemicals and in these clouds of dust and in houses that are soaking with toxins. There are a lot of toxic chemicals, a lot of bacteria that are still in the environment there. There's dust that is toxic that is sprinkled across the city and it's kicked up every time there's demolition or cars driving by.
BETTY ANN BOWSER: The NRDC and a Louisiana environmental group each did their own tests and found similar results as EPA, but reached very different conclusions about what the data meant.
Instead of using EPA's short-term exposure measurement, the NRDC and the Louisiana Environmental Action Network used what they considered a more realistic barometer, exposure for two weeks or longer.
Chemist Wilma Subra is with the Louisiana group.
WILMA SUBRA: There's no difference in the data. It's in the interpretation of what does this mean. And we know the chemicals that are there are also long-term exposure threats. It's not acceptable for people to be allowed to return to their homes and live.
This sedimenty sludge -- which now has turned to this dry sediment that when they go out and start working in their yard, when they walk through it they're stirring it up -- they're coming in contact with it on their skin and they're inhaling the dust -- and it's the toxic heavy metals and the polynuclearomatic hydrocarbons both of which are cancer causing agents.
BETTY ANN BOWSER: EPA Administrator Johnson says whether contamination is measured in short- or long-term standards the government's warning is the same.
STEPHEN JOHNSON: We know that that sediment contains bacteria. We know that in certain parts it contains high levels of petroleum products. People shouldn't come into contact with that. So whether its 24 hours or 48 hours or two weeks still the message is: avoid contact with those kinds of materials.
BETTY ANN BOWSER: But are you saying it is or it isn't safe?
STEPHEN JOHNSON: Well, unfortunately it's not a yes or a no answer because, again, what we're seeing in the sediment area is that we're seeing some of those sediments highly contaminated with petroleum products and for those areas that have high contamination you really shouldn't be coming in contact with it. For those areas with very low contamination there's probably not a health consequence with but still prudent advice would be - common sense advice would be to avoid exposure, take precautions.
BETTY ANN BOWSER: Environmental groups say the EPA could be more definitive about safety if it did tests in private yards and houses.
ERIK OLSON: People are living inside homes. People are moving back into homes. You've got to test inside the homes. This is where people are going to be.
BETTY ANN BOWSER: A scientist from Louisiana State University is doing his own tests in residential neighborhoods.
John Pardue agrees with environmental groups that the EPA should be taking samples inside homes, because they are filled with mold, sewage and dust.
JOHN PARDUE: Not knowing what's in that dust, that just seems to me with the likelihood of there being asbestos, other kinds of things in that dust, that seems to me to be a terrible risk for people to take. If nothing else, the state, city, or EPA should be out there handing out that respiratory equipment or gloves just to strongly encourage people to use those.
BETTY ANN BOWSER: Why aren't you doing testing inside of people's homes?
STEPHEN JOHNSON: Well, first of all the responsibility for testing inside homes is not within the purview of EPA. And so EPA does not have any statutory responsibility for indoor air, for example. And issues such as mold are the responsibility of and advice and counsel from the Centers for Disease Control, Health and Human Services.
BETTY ANN BOWSER: But a spokesman for HHS said the agency has no statutory responsibility for what's inside a private dwelling. A spokesperson for the CDC said it's not a regulatory agency and must be asked as part of a public health response to enter private homes.
The EPA has tested inside homes before. In 1994 it took samples in 9,000 houses in Lorain and Elyria, Ohio, after a highly toxic pesticide was illegally sprayed there. The EPA eventually decontaminated 1,000 dwellings. But in New Orleans the agency says its role is to supply data to officials like Mayor Ray Nagin, who's called all the shots about when its safe to return.
ERIK OLSON: We unfortunately feel that EPA has fallen down on the job. EPA has all sorts of authority if they want to use it to declare an imminent and substantial endangerment under most of its laws just to say it's really not safe for people to be here, we are going to bar people from re-entering or we're going to order certain clamps or certain activity to happen before people enter. EPA really has been unwilling to use those authorities.
BETTY ANN BOWSER: The EPA has declared imminent and substantial endangerment before. In 1978, it used that authority at Love Canal, to relocate an entire upstate New York community when toxic wastes were found there.
But in New Orleans the EPA says its up to local and state officials to make decisions about safety.
STEPHEN JOHNSON: It's not the EPA's decision. It's the responsibility of the state and local officials to make the decision. You know they're the ones that made the decision to evacuate. They're the ones appropriately to make the decision to come back in.
BETTY ANN BOWSER: The NRDC recently conducted yet another set of tests, including ones inside private homes; the results are expected to be made public soon.