Josef Bray-Ali was biking to work recently along the Arroyo Seco near Highland Park when he encountered an interesting sight: a county worker spraying a "neon-green" powder alongside the creek.
Bray-Ali was curious and asked what they were spraying. He was told it was an herbicide.
"They were spraying it on all the concrete and pretty much anywhere where a plant was living," Bray-Ali recalled.
This struck him as a bit odd, with Los Angeles officials in the news recently saying they wanted to revitalize the Los Angeles River and improve its awful water quality. The Arroyo Seco is a major tributary to the river.
So what were they spraying?
A mixture of three common herbicides that go by the brand names Roundup, Gallery and Endurance, according to the county. All are legal.
The latter two are the most interesting. The active ingredient in Gallery is a chemical called Isoxaben, and the main ingredient in Endurance is Prodiamine. Both are listed as possible human carcinogens by the Environmental Protection Agency, based on limited evidence from animal studies.
Anything else interesting about Endurance?
Its label, which states:
"Do not apply directly to water, to areas where surface water is present, or to intertidal areas below the mean high water mark. Drift and runoff from treated areas may be hazardous to aquatic organisms in adjacent areas."
The label also says that in high levels Endurance may be toxic to fish.
And what does the government have to say?
County agricultural commission officials said call the Public Works Department, which said call the public health department, which said call the state.
Bottom line explanation: Public works contracted the spraying, which apparently was being done to prevent weeds from crumbling the Arroyo Seco's concrete flood-control walls.
Public works spokesman Gary Boze also said that one reason his agency contracted the ag folks to spray was to "remove conditions that could create fires."
In an e-mail and phone call, Glenn Brank, a spokesman for the California Department of Pesticide Regulation, said that all three herbicides could be used safely, but added: "I would say that the chemicals are OK when applications do not pose a hazard to waterways."
Brank also said that it was up to the county to follow the directions on Endurance and that it was something of a judgment call on how far it should be sprayed from water.
