In a scientific meeting convened by the Environmental Protection Agency (EPA) today, scientists for Syngenta presented data they say more closely replicate real-world exposure and support the safety of atrazine.

One of the studies measured the potential effects of atrazine on animals using two delivery methods: 1) after distributed doses or 2) after a large, single dose.

Because rats in studies received atrazine in distributed doses over time, data from this study are more applicable to how humans may be exposed to minute quantities of atrazine in reality, the scientists say. Doses delivered in a distributed manner showed no effects up to and including the highest dose given, which was 500 parts per million in the diet.

“This highest dose was tens of thousands of times higher than the current EPA water standards for atrazine. People would never be exposed to this level in the environment,” says Tim Pastoor, principal scientist with Syngenta. “Yet even at this extreme dose, atrazine had no effect.”

Syngenta is also providing what it calls "significant new data" that will support the EPA’s efforts to understand the internal dose metric for atrazine and its metabolites — or what happens to these compounds once they enter the body. This information will aid the EPA in applying animal exposure scenarios to humans.

“As the EPA continues its re-evaluation of atrazine, we want to continue to provide the most relevant data, showing that the extremely small levels found in water are safe,” Pastoor says.