USF researchers question safety of widespread lawn spray


By LINDSAY PETERSON | The Tampa Tribune
Published: May 22, 2012

TAMPA — 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.

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.

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