Roundup ban in Sonoma parks?

Weedkillers containing glyphosate, a substance that may be linked to cancer, could be banned in Sonoma city parks if the City Council sets the process in motion at its upcoming meeting Monday.|

Weedkillers containing glyphosate, a substance that may be linked to cancer, could be banned in city-maintained areas if the City Council sets the process in motion at its upcoming meeting Monday.

The city in 2001 and 2014 already sharply limited the use of glyphosate, a systemic herbicide known more commonly under the brand name Roundup, to kill weeds. Workers only used six gallons in 2017, according to Colleen Ferguson, the city’s public works director.

Ferguson is recommending that the city extend the restriction to all city parks but stop short of a total ban. Presently, there are few places city workers can use glyphosate-based herbicides; for example, the weedkillers aren’t used in the Plaza.

“The Public Works Department and city contractors use products containing glyphosate as a last resort to control weeds on city property,” Ferguson said in her staff report. If it’s used in currently approved areas such as city parks, landscape areas and bike paths, signs are posted with information such as the material applied, with a contact phone number.

Glyphosate was designated “probably carcinogenic to humans” by the International Agency for Research on Cancer, a unit of the World Health Organization, in 2015.

It’s worth noting that this designation means the evidence that it causes human cancer is “limited” and that explanations including “chance, bias or confounding (meaning an unrelated factor) could not be ruled out,” but that some evidence also exists from animal experiments.

In a conflicting study, glyphosate was “not statistically significantly associated with cancer at any site,” according to a November 2017 analysis based on the Agricultural Health Study, a federally financed cohort study that has monitored 57,000 pesticide users in Iowa and North Carolina since the 1990s.

It’s also worth noting that more than 76,000 pounds of the herbicide in its various forms were applied to wine grapes in 2016 in Sonoma County, according to the state Department of Pesticide Regulation.

“I’m just surprised that it (growth) hasn’t been stronger and faster,” Chris Benziger, vice president of trade relations at Benziger Family Winery in Glen Ellen, told the Santa Rosa Press Democrat in November, speaking of the adoption of organic products by the wine industry.

Benziger’s family founded the winery in 1980 and has since been known as one of the top producers of wines made from organically grown grapes from its vineyards in the Sonoma Valley.

The Sonoma Valley Unified School District, meanwhile, says it hasn’t used glyphosate in years.

“We do not use Roundup, and we haven’t used it in almost five years,” said Andrea Deely, clerical coordinator at the district.

The City Council has the choice of banning the weedkiller altogether, banning it in city parks, sending the idea back to city staff for further research, or doing nothing.

Ferguson isn’t recommending a total ban. For one thing, the warnings on glyphosate-based herbicides have a “Caution” rating from the U.S. Environmental Protection Agency.

This means the product is slightly toxic if eaten, absorbed through the skin or inhaled – as opposed to the “Warning” rating, which applies to organic herbicides and means the product is moderately toxic if ingested. “As a more hazardous product that is only effective with repeat applications, use of organic herbicides by City and contractor staff has financial impacts,” Ferguson wrote in the staff report.

Also, organic herbicides cost almost 20 times as much, she said.

If glyphosate is banned in city parks, Ferguson said, “The ban would be most successful if the community develops a greater tolerance for weeds … and if park visitors take the initiative to pull weeds they find offensive.”

Reach Janis Mara at

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