Exposure to common herbicide could threaten global amphibian population

(UPI) -- Research has shown that frogs exposed to the herbicide atrazine are more susceptible to fungal disease, a discovery that could help explain the decline of the global amphibian population.

Biologist Jason Rohr of the University of South Florida said that when frogs are exposed to atrazine early in life and then confronted with the pathogen chytrid fungus, their mortality rate increases.

"Understanding how stressors cause enduring health effects is important because these stressors might then be avoided or mitigated during formative developmental stages to prevent lasting increases in disease susceptibility," Rohr said.

Atrazine is one of the most common herbicides in the world. Researchers found that once frogs were exposed to atrazine, they showed few signs of recovery.

"These findings are important because they suggest that amphibians might need to be exposed only to atrazine briefly as larvae for atrazine to cause persistent increases in their risk of chytri-induced mortality," Rohr said. "Our findings suggest that reducing early-life exposure of amphibians to atrazine could reduce lasting increases in the risk of mortality from a disease associated with worldwide amphibian declines."

Scientists now know a little more about how early-life exposures can affect amphibians later in life.

"Identifying which, when, and how stressors cause enduring effects on disease risk could facilitate disease prevention in wildlife and humans, an approach that is often more cost-effective and efficient than reactive medicine," Rohr said.