A year ago, the active ingredient in Roundup, the nation’s most widely used weed-killing herbicide, was added to California’s official list of chemicals known to cause cancer.
But Roundup’s critics say it’s hypocritical for one state agency to say the herbicide is a likely cancer hazard while another sprays it into a place where drinking water is pulled.
According the state, the IARC “found that glyphosate is an animal carcinogen and probable human carcinogen” based primarily on studies in which “rodents exposed to glyphosate developed tumors at higher rates than rodents not exposed glyphosate.” However, several other government agencies, including the U.S. Environmental Protection Agency, have concluded there is no evidence that glyphosate causes cancer.
Following the international agency’s listing, hundreds of lawsuits alleging glyphosate causes cancer were filed in state and federal courts across the country.
In addition, the custom blend of Roundup the state uses for aquatic weeds “is absorbed by the plants,” Madsen said.
It’s only active when it’s on the foliage of the plants.” Madsen and other scientists say the herbicide treatments will never completely remove the weeds, but they’re critical for keeping water flowing through the Delta’s 60,000-acre spiderweb of sloughs and river channels stretching from south of Sacramento and west of Stockton to the San Francisco Bay.
Chopping up the plants can harm native species while spreading seeds and other debris that can re-establish the plant elsewhere.
Fish habitats Clear channels for boats and water deliveries aren’t the only reasons for the herbicide treatments.
“Instead of providing good rearing habitat (for young fish), we’ve just got predator habitat,” said Sommer, the Department of Water Resources scientist.
“The rates that they’re using are not going to cause any fish kills.