SACRAMENTO, Calif. (AP) — Researchers and U.S. authorities are finding what they say is an alarming increase in the use of a powerful banned pesticide at illegal marijuana farms hidden on public land in California.
The pesticide residue is showing up in about 30 percent of the plants themselves, researcher Mourad Gabriel told The Associated Press. U.S. and state authorities will announce Tuesday that they will use $2.5 million in federal money to target the illegal grows.

danger before legalization in California was the uncertainty of what was in pot products, but authorities say the rise in Carbofuran use poses an increased danger. Gabriel’s research found that traces of the chemical are showing up in pot but did not attempt to quantify how much was in each sample or its effects on people.The chemical is intended for use as an insecticide but is so powerful that a quarter of a teaspoon can kill a 300-pound (136-kilogram) bear, Gabriel said.
Research by Gabriel and colleagues previously showed that the use of pesticides at illegal marijuana farms is poisoning significant numbers of California’s few hundred remaining fishers, a threatened weasel-like mammal.