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The latest on an environmental mystery in Minnesota from Fred De Sam Lazaro of KCTA-St. Paul-Minneapolis.

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FRED DE SAM LAZARO: For the past several months field workers and interns from Minnesota's Pollution Control Agency have waded through hundreds of wetlands, ponds, and other frog habitats.

MAN: And this one is 4.8 centimeters.

FRED DE SAM LAZARO: Each of these survey locations has had reports of deformed frogs, usually called in by people living nearby.

MAN: And the back right leg, the digits are both shortened, and it is actually missing the first digit.

FRED DE SAM LAZARO: When deformities are spotted, both animals and a sample of water from their environment are taken to the lab for analysis. The exhaustive scientific survey had an unlikely beginning two years ago with a field trip led by Cindy Reinitz of the New Country Day School in Le Sueur, Minnesota, a small agriculture community.

ELAINE FARLEY: We were just catching frogs just because it would be neat, and we caught one, and I thought I broke its leg because it was sticking straight out. And someone else caught a fire and they go you broke its leg too, so we just started catching more frogs, and they all had broken legs, we thought.

FRED DE SAM LAZARO: Until they began looking more closely at frogs in this pond. The limbs were not broken but grossly deformed or nonexistent. Some animals lacked an adult or had reached adulthood without shedding their tails.

GIRL: See this leg's pretty normal, but then this one is totally screwed up.

MAN: Here's one with no legs on one side and a bunch on the other.

WOMAN: They just can't swim. We've got some with no hind legs at all.

FRED DE SAM LAZARO: The Minnesota Pollution Control Agency's Dr. Judy Helgen was called to investigate. First, it seemed like a local problem, perhaps a pesticide leak from a nearby farm.

DR. JUDY HELGEN, Pollution Control Agency: Then we had a news piece went out from the local newspaper. A teacher in Lichfield in September read this to her class, and a boy came in with a bucket of deformed frogs in Meeker County, which is a long distance, hour and a half drive away from the original locations of the deformed frogs. So it started even then last summer and fall to expand. And every time I'd get one of these calls I'd get this chill up my back because at first we thought, well, it's just this one wetland, and there's some problem there.

FRED DE SAM LAZARO: To date, Dr. Helgen's agency has received reports of malformed frogs from almost all Minnesota counties. There have also been similar reports from several states--from Oregon to Vermont. Problems with amphibians are not confined to North America. Frog populations worldwide have declined in recent years. Urban development is partly responsible, but there have also been reports from undeveloped regions in South America, in Australia, where frogs have died in large numbers. A parasite is suspected in those occurrences, one that's likely not implicated here in Minnesota. But one thing in common is the role of the frog as a sentinel animal, the proverbial canary in the coal mine, according to University of Minnesota cell biologist Dr. Robert McKinnell.

DR. ROBERT McKINNELL, University of Minnesota: That frogs have detoxifying mechanism just as we have a detoxifying mechanism--that is our good old liver--that will metabolize and metabolically change toxic substances and get rid of those toxic substances. The frog does it essentially the same way as we do it. And if the abnormalities are due to something that we will get exposed to, then you have to ask the question: Will we be able to manage? Will we be exposed to the same chemical, and it will affect our progeny, much as it has affected the frog? Well, I can't say that it will or not. These are the Mott frogs--hold still, fellas--that are missing their yellow pigment.

SPOKESMAN: We've got some important news to talk with you about today.

FRED DE SAM LAZARO: In early October Pollution Control Agency scientists, working with the National Institute of Environmental Health Sciences, released a preliminary finding that narrowed at least the location of the likely cause or causes of deformities in Minnesota frogs.

DR. GEORGE LUCIER, Institute of Environmental Health Sciences: Everything we have indicates that there's a 100 percent chance that this is in the water.

FRED DE SAM LAZARO: The researchers placed frog eggs in water samples drawn from ponds where deformed animals had been sighted. The resulting larvae showed signs of malformations. But more surprising, they got the same result: deformities using tap water from two homes adjacent to the ponds, water the households draw from their own private wells, not a municipal supply.

DR. JUDY HELGEN: The other part is not something we expected. That's why we didn't even plan to do, for instance, studies on the hydrology of the sites. Now, we're talking about how we need to look at is the water going from the pond into the groundwater, or is it going from groundwater into the pond? You know, is this just a very local thing? We're beginning to think now that we have to look at the hydrology of the sites in a very important way.

FRED DE SAM LAZARO: The Pollution Control Agency is offering bottled water to the affected homeowners. Director Peder Larson stopped short of making any firm recommendations.

PEDER LARSON: We don't have anything today that makes it any more certain or less certain that there's a human health impact. So we're just going through a rigorous process to find out where the impacts are and then giving people the opportunity to make the decision themselves and whether they want to have some bottled water.

FRED DE SAM LAZARO: So far at least the number of homes affected is not high. Most affected frog habitats are in rural areas, and state officials are keeping their surveillance sites confidential at the homeowners' requests, they say. The researchers say it will be next spring at the earliest before enough data emerges to help narrow or pinpoint causes to explain not just the frog deformities but also why they happened in vastly different geographic reasons and all apparently at the same time.

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