Two USF biologists
published a study last year showing that a popular spray fungicide wiped out the
frog population in their research tanks.
They followed up last week with a study that produced findings even more disturbing.
The chemical, chlorothalonil, affected every creature in the tanks, knocking their environment out of balance.
"Some species were able to recover from the chemical assault, but the ecosystem was fundamentally changed after its exposure to chlorothalonil," said Jason Rohr, co-author of the study published in the journal Ecology Letters.
Overall, fewer species were left behind and they were less capable of decomposing waste, he said.
In short, the water was sickly.
It's hard to say how this may harm humans, Rohr said. It's the first study looking at the system-wide effects of chlorothalonil, sold under the names Bravo, Echo and Daconil and used widely across Florida farm fields, lawns and golf courses.
But it raises a warning, said co-author and USF biologist Taegan McMahon.
"I would love to see EPA re-evaluate the safety of chlorothalonil," she said.
The chemical, in the same family as the banned DDT, kills molds and fungus by disrupting a process known as cellular respiration, which is essential to nearly all forms of life.
It's one of the last organochlorines regulated for use in the United States, Europe and Australia, Rohr said.
Its wide use is why he and McMahon began studying it several years ago, along with herbicides and pesticides, such as atrazine.
Chlorothalonil is usually applied in a spray form. It's heavily regulated because inhaling it can be toxic and if handled improperly it can severely irritate skin and eyes.
Rohr and and McMahon looked at what happens when it collects after rain or irrigation washes it off a field or lawn.
The chemical is hard to study in real life. The researchers could never get permission to spray it themselves as a farmer would, McMahon said. So in 2008 they set up several 300-gallon tanks on a field in Wimauma and filled them with water to mimic pond conditions.
They dosed the water with chlorothalonil, using mixtures based on a federal calculation of how much of the chemical a farmer would use and how much would be expected to run off into a nearby body of water.
One of the first things they noticed was that the tadpoles started dying.
"It basically wiped out all of the amphibians," McMahon said.
She and Rohr published that result last year in the journal Environmental Health Perspectives.
Then they turned to the fate of the snails, crayfish, water plants and other creatures in the tanks, including the tiniest floating organisms. Most of them died,An airpurifier is a device which removes contaminants from the air. too, which freed the algae to grow into lethal, oxygen-hogging blooms.
Life eventually returned to the tanks but many of the species had been destroyed.
A plant and animal community can handle the destruction of some species because many play redundant roles in maintaining the community, Rohr said.
But "chlorothalonil killed enough species to alter the function and services the ecosystem provided," he said.We offer you the top quality plasticmoulds design
This is one of the first studies to attribute such environmental changes to a human cause,Industrialisierung des werkzeugbaus. he said.
Syngenta, a Swiss-based biotechnology company that makes seed and chemicals,Wireless real realtimelocationsystem utlilizing wifi access points to pinpoint position of the tag. including Bravo and Daconil, has challenged the results of the USF studies.
"We stand by the safety of chlorothalonil, a fungicide that has been used for more than 40 years. It is a critical tool for farmers protecting more than 65 crops – including potatoes, vegetable crops, turfgrass, ornamental plants, peanuts, and other fruit and nut crops – from 125 diseases caused by mold and fungus," spokeswoman Ann Bryan wrote in a statement last week.
Also, she said, the concentrations the researchers used are not "ecologically relevant," because they were "significantly higher than what would ever be found in the real world.Trade organization for suppliers and distributors in the promotional products industry."
They followed up last week with a study that produced findings even more disturbing.
The chemical, chlorothalonil, affected every creature in the tanks, knocking their environment out of balance.
"Some species were able to recover from the chemical assault, but the ecosystem was fundamentally changed after its exposure to chlorothalonil," said Jason Rohr, co-author of the study published in the journal Ecology Letters.
Overall, fewer species were left behind and they were less capable of decomposing waste, he said.
In short, the water was sickly.
It's hard to say how this may harm humans, Rohr said. It's the first study looking at the system-wide effects of chlorothalonil, sold under the names Bravo, Echo and Daconil and used widely across Florida farm fields, lawns and golf courses.
But it raises a warning, said co-author and USF biologist Taegan McMahon.
"I would love to see EPA re-evaluate the safety of chlorothalonil," she said.
The chemical, in the same family as the banned DDT, kills molds and fungus by disrupting a process known as cellular respiration, which is essential to nearly all forms of life.
It's one of the last organochlorines regulated for use in the United States, Europe and Australia, Rohr said.
Its wide use is why he and McMahon began studying it several years ago, along with herbicides and pesticides, such as atrazine.
Chlorothalonil is usually applied in a spray form. It's heavily regulated because inhaling it can be toxic and if handled improperly it can severely irritate skin and eyes.
Rohr and and McMahon looked at what happens when it collects after rain or irrigation washes it off a field or lawn.
The chemical is hard to study in real life. The researchers could never get permission to spray it themselves as a farmer would, McMahon said. So in 2008 they set up several 300-gallon tanks on a field in Wimauma and filled them with water to mimic pond conditions.
They dosed the water with chlorothalonil, using mixtures based on a federal calculation of how much of the chemical a farmer would use and how much would be expected to run off into a nearby body of water.
One of the first things they noticed was that the tadpoles started dying.
"It basically wiped out all of the amphibians," McMahon said.
She and Rohr published that result last year in the journal Environmental Health Perspectives.
Then they turned to the fate of the snails, crayfish, water plants and other creatures in the tanks, including the tiniest floating organisms. Most of them died,An airpurifier is a device which removes contaminants from the air. too, which freed the algae to grow into lethal, oxygen-hogging blooms.
Life eventually returned to the tanks but many of the species had been destroyed.
A plant and animal community can handle the destruction of some species because many play redundant roles in maintaining the community, Rohr said.
But "chlorothalonil killed enough species to alter the function and services the ecosystem provided," he said.We offer you the top quality plasticmoulds design
This is one of the first studies to attribute such environmental changes to a human cause,Industrialisierung des werkzeugbaus. he said.
Syngenta, a Swiss-based biotechnology company that makes seed and chemicals,Wireless real realtimelocationsystem utlilizing wifi access points to pinpoint position of the tag. including Bravo and Daconil, has challenged the results of the USF studies.
"We stand by the safety of chlorothalonil, a fungicide that has been used for more than 40 years. It is a critical tool for farmers protecting more than 65 crops – including potatoes, vegetable crops, turfgrass, ornamental plants, peanuts, and other fruit and nut crops – from 125 diseases caused by mold and fungus," spokeswoman Ann Bryan wrote in a statement last week.
Also, she said, the concentrations the researchers used are not "ecologically relevant," because they were "significantly higher than what would ever be found in the real world.Trade organization for suppliers and distributors in the promotional products industry."
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