When San Franciscans hike up Twin Peaks or stroll through Glen Canyon Park, they could be exposing themselves to an herbicide that some studies have linked to cancer. But thanks to growing concerns about public health and liability, their risks are substantially lower than they were five years ago, when the city used 20 times as much of the chemical.
That herbicide is glyphosate, the key ingredient in Monsanto’s top-selling weedkiller, Roundup. Monsanto owner Bayer agreed in June to pay more than $10 billion to plaintiffs in thousands of pending lawsuits over claims Roundup caused cancer.
As legal victories against the company pile up, several Bay Area cities have faced a tough choice — keep using a chemical that evidence increasingly shows is dangerous and exposes them to legal risks, or switch to other, often less effective methods. San Francisco has limited its risk through a strategy known as integrated pest management and its move to scale back dramatically on glyphosate since 2015.
By 2020, most Bay Area cities and counties had prohibited use of Roundup in public spaces. San Francisco’s decision to keep using a tiny amount — just 5% of what it used to regularly spray on plants in parks and street medians — still makes it an outlier.
Chris Geiger, director of the integrated pest management program at the San Francisco Department of the Environment, said despite the city’s drastic cutback, it won’t ban glyphosate because it has yet to find a more efficient or safer alternative for controlling some weeds. “In habitat management, there are certain plants you cannot remove from a natural area by hand,” he said.
Environmental activists also urge the public to take a nuanced view that weighs the relative health risks of various chemicals.
“Banning a single pesticide isn’t going to achieve what they think it’s going to, particularly if they move along to another chemical that’s not so widely studied and that — years from now — we may find health issues with it,” said Nathan Donley, a senior scientist at the Center for Biological Diversity, a Tucson-based nonprofit advocacy group.
In 2018, German pharmaceutical giant Bayer bought Monsanto for $63 billion. Just weeks later, a San Francisco jury awarded a Bay Area school groundskeeper $289 million, tying his non-Hodgkin lymphoma to long-term use of Roundup. Bayer’s stock price sank 10.6%. The groundskeeper’s settlement was later reduced to $21 million, a decision affirmed by the state Supreme Court.
Over the next year, two more San Francisco juries awarded plaintiffs suffering from cancer millions of dollars. All three suits relied on a 2015 report by the International Agency on Research on Cancer, an arm of the World Health Organization, that found glyphosate to be a probable human carcinogen.
These court decisions spurred a number of Bay Area cities, including Benicia, Richmond and Sonoma, to ban Roundup use in parks and public facilities. Costco and other retailers pulled the product from their shelves, some under threat of class-action lawsuits.
Despite the rulings and bans and usage cutbacks by cities, Bayer stands by glyphosate’s safety. “There is no evidence that municipalities moving away from glyphosate for vegetation management, including invasive and noxious weed control, are enhancing safety, given there is an extensive body of research on glyphosate that confirm these products are safe when used as directed,” said company spokesman Bob Chlopak.
As part of Bayer’s June settlement with plaintiffs, the company did not admit any wrongdoing. The legal agreement initially called for the establishment of a five-member science panel (See “Scientists Split Over Glyphosate Risk, Leaving Public in Lurch”) to deliver a more definitive verdict as to whether Roundup’s active ingredient causes non-Hodgkin lymphoma, but the judge has indicated he will likely not allow that part of the settlement to move forward.
As early as July 2015, before the lawsuits concluded, San Francisco’s Department of the Environment raised the hazard rating of Roundup and other glyphosate products to the highest level, restricting use but continuing to apply it, provided other alternatives had been exhausted. None of the recent court decisions will change how the city uses this herbicide, Geiger said.
Undoing the ban
San Francisco took a much more rigid stance several decades ago. It banned all pesticides and herbicides from use on city properties in the mid-1990s. That made it difficult to address common pest problems. “Pesticides are a very broad category of products,” Geiger said.
Any commercial chemical applied to kill another organism is registered with the U.S. Environmental Protection Agency as a pesticide. That includes disinfectants in hospitals, agents to control mosquitoes and chemicals to kill weeds. During the ban, city employees refrained from spraying, Geiger said. Weeds, rodents and mosquitoes proliferated. The ban was unworkable because hospitals had fewer ways to disinfect, and public works crews had limited options to control vermin to protect public health.
“When you ban things, as some cities have done, they’re having some impacts on their landscape or on public safety,” said Jen Jackson, who manages San Francisco’s toxics reduction and healthy systems program.
What followed that early, ban-everything approach was integrated pest management, adopted in 1996, which emphasized using the least harmful approaches. That included weeding by hand, blowtorching, weed whacking and using goats to graze weed-infested areas. If none of these work, managers can select substances from a list of reduced-risk chemicals that is reviewed each year.
Those chemicals are classified according to a three-tiered system based on the hazard they pose to the person applying the chemical and to endangered species. Department managers wanting to use tier 1 products must justify the need at an annual public hearing. Tier 3 chemicals, such as soaps and oils, are the least hazardous and face the fewest restrictions.
Tier 2 chemicals are considered not as dangerous as tier 1 chemicals like the U.S. EPA-regulated herbicide dicamba. The city placed Roundup and other glyphosate-based products under tier 2 until mid-2015.
Tracking every ounce
San Francisco tracks chemical use by the fluid ounce of the active ingredient, not the entire formulation of the product applied. But determining risk to public employees and residents from continued use is hotly contested — even among expert scientific institutions.
All city departments, including Recreation and Parks, the Public Utilities Commission, the Department of Public Works and the Airport Commission, file monthly reports detailing chemical use, which the Department of the Environment aggregates and posts on its website.
The department provided the Public Press records of San Francisco’s use of restricted chemicals from 2001 to the present. Over this time, San Francisco has phased out certain herbicides. Dicamba, a Monsanto product found to drift in the air and kill non-target plants, was on San Francisco’s restricted-use list until 2010.
Dicamba was classified as a tier 1 chemical, with instructions that it be used only in spot applications when hand weeding would not work for the golf greens where it was applied. By 2011, the chemical was off the list for approved use because the city found equally reliable products that did not cause the harm to non-target plants dicamba did. (The U.S. Ninth Circuit Court of Appeals ruled in June that dicamba use is illegal, though the U.S. EPA said farmers could still use up their stocks. Bayer agreed to pay $400 million to settle claims against dicamba as part of its Roundup settlement.)
According to Department of the Environment records, the city has continued to use several formulations of herbicides containing glyphosate made by Monsanto, including Aquamaster, Roundup Pro, Roundup Pro Dry and Roundup Promax. City records detail a steep reduction in the herbicide use across San Francisco by all departments from 2010 through 2019 on public areas including Golden Gate Park, ballfields and Natural Areas Program properties such as Twin Peaks, Glen Canyon Park and Bayview Park, where many people walk along paths with their dogs and children, and where they pick and eat blackberries. In this period, overall use on city-managed lands declined by 98%.
A pivotal year
When the World Health Organization classified glyphosate as a probable human carcinogen in 2015, it based that decision on a review of publicly available scientific studies by a group of scientists from around the world. The panel said there was only limited evidence linking exposure in humans to cancer, but sufficient data on cancer in lab animals to warrant cautioning users.
Prior to this report, San Francisco departments did not have to submit their glyphosate use for annual review. From 2010 to 2015, San Francisco used 64,444 fluid ounces of glyphosate, or 504 gallons, enough to fill two medium-size hot tubs.
Because San Francisco is both a city and a county, it maintains lands and facilities outside city limits. These include the San Francisco International Airport and Crystal Springs and Hetch Hetchy reservoirs. The Public Press calculated the overall San Francisco use to include application within city limits and at the airport. Glyphosate use at lands controlled by the San Francisco Public Utilities Commission outside the city were excluded because they are subject to state and federal regulations for habitat restoration and other agreements for herbicide use.
From 2010 to 2015, San Francisco applied just over half of its glyphosate at the airport. The Federal Aviation Administration does not allow groundskeepers to use weed whackers on grassy areas around runways and taxiways.
Within city limits, most of the glyphosate was applied by the Department of Public Works, which maintains the greenways where people walk, drive scooters or skate. The department applied most of its glyphosate on medians and thoroughfares throughout the city. Another major user was the Recreation and Parks Department.
In the years following publication of the WHO report— 2016 through 2019 — San Francisco cut glyphosate use at SFO and San Francisco public areas by 50%, with the steepest decline, 82%, seen within city limits, according to the data.
Glyphosate is not completely out of the picture. From 2016 to 2019, glyphosate was the second-most-used herbicide, making up 20% of all products, after the weed killer quinclorac, which the city started using in 2014.
The change in glyphosate’s hazard level from a tier 2 to a tier 1 chemical in 2015 triggered additional training and other measures, said Jackson of the Department of the Environment. “We have many, many restrictions put in place on the use of glyphosate that protects workers as well as the public.”
The area that has seen the most consistent use is Bayview Park, which occupies a portion of Bayview Hill. Between 2016 and the end of 2019, the city used 165 fluid ounces of glyphosate there to get rid of fennel and French broom, among other measures to preserve natural areas.
The city’s Board of Supervisors in 2018 established biodiversity preservation as a citywide goal. Bayview Hill is home to coastal grassland habitat, and Geiger said glyphosate allows maintenance crews to apply enough to make a perimeter defense to stave off invasive plants that would otherwise crowd out native species.
Monsanto pummeled in court, and cities take action
Following the WHO report, thousands of people who had used Roundup for years and suffered from non-Hodgkin’s lymphoma and other cancers began suing Monsanto, which had long maintained that its herbicide was safe even for home use, as implied by a 2009 TV ad.
All three of the lawsuits to go to trial resulted in multimillion-dollar judgments against the company. The first forced Monsanto to release reams of documents showing how it manipulated the science and suppressed studies questioning glyphosate’s safety. The company also hired a vast public relations army to discredit the report and journalists and activists investigating Monsanto.
The scientific warnings and lawsuits combined to give city governments plenty of reasons to revisit their use of glyphosate.
The East Bay city of Richmond had adopted a pest management program in 2012, based in part on San Francisco’s. Glyphosate was to be used in an emergency. Trouble was, city maintenance staff “didn’t stop using glyphosate,” conceded Mayor Tom Butt. “To them, everything was an emergency.”
Butt got calls from residents complaining about Roundup spraying. So the vote by the City Council in 2015 to ban glyphosate was easy. Now, he said, residents are no longer complaining about the weeds, but “Richmond looks terrible.”
The city’s Department of Infrastructure and Maintenance complained about budget-related staffing cuts and not having glyphosate as a tool. It recently estimated that it would need an additional 8,400 person-hours to restore the landscape to its pre-ban condition.
Other jurisdictions reported similar trade-offs. The East Bay Municipal Parks District voted in July 2019 to ban glyphosate in picnic areas and other public zones while phasing out use in developed areas by the end of 2020. “We’re going to take a hit in the general fund as we have to do more manual weeding,” said spokesman Dave Mason.
The city of Sonoma’s public works staff had already cut back on use of Roundup to 6 gallons in 2017, from 18 gallons in 2000. The department looked to Roundup as a last resort in tough-to-reach areas for large mowers along fence lines and bike paths, and in areas too dangerous for hand weeding.
But Mayor Amy Harrington and her fellow City Council members had been getting an earful from residents for years, saying they didn’t want Roundup used to manage weeds on any city property because of concerns about cancer and other health risks. Not only did the WHO report factor into this pressure, but also a 2016 study finding glyphosate in the region’s top cash crop — wine grapes.
Harrington and the council did not want to ban one chemical and then turn to another that might be worse. So, at first they took the middle ground, voting in December 2018 to continue the last-resort use for four months, while requiring a follow-up report on where it was being used.
The report showed weed killer being applied near waterways, a cemetery and other places to avoid labor-intensive hand weeding. This was not a good argument for continued use, Harrington said. “You can’t just take a chemical and spray it all over the place just because it’s easier.”
The council voted unanimously to ban Roundup on city property in April. “All entities that are requiring employees to apply this chemical have liability,” Harrington said. “We’re a small agency.”
Other cities are not formally banning, but declaring areas glyphosate-free zones, like Novato, in Marin County. There, Mayor Josh Fryday acknowledged the increased burden on the public works department and called for volunteers to step up — or perhaps stoop over — to help clear weeds.
The first legal decision against Monsanto in August 2018 — involving former Benicia Unified School District groundskeeper Dewayne Johnson — led Benicia to discontinue its use of Ranger Pro, a generic equivalent of Roundup. The school district stopped using Roundup and Ranger Pro in 2018.
Not bowing to an internet petition
Jill Fehrenbacher recalled spotting a flyer in San Francisco’s Glen Park neighborhood in the summer of 2015 that made her worry about the health and safety of her two young sons. The notice, posted by the city around the baseball field, advised that Roundup would be used to get rid of eucalyptus stumps. “I thought, ‘Why are they doing this? Roundup is dangerous and I don’t want my kids around it,’” she said.
Like many residents, Fehrenbacher regards city parks as her own backyard. Discovering that Roundup was being sprayed there made her take action. She posted her own flyers next to the city’s, alerting others to an online petition she started, calling on San Francisco to once again ban Roundup. The petition got news coverage when it had 7,000 signatures, and Fehrenbacher said this support eventually doubled.
But the city scoffed at the effort. “That was an internet petition,” said Geiger, noting that not every signature was from a San Francisco resident.
Fehrenbacher attended meetings at which city officials discussed Roundup use. She said they told her they were meeting to rank the relative risks of various pesticides. Fehrenbacher and others had looked to the city for certainty about their safety, but what she said she got was much less. “I felt they were being dismissive,” she said. “It was such a nonanswer to the concerns.”
To Geiger, the Department of the Environment’s actions in reclassifying glyphosate and restricting its use just months after the WHO report was proof that his agency took safety seriously. He said it was in line with the city’s decade-plus mandate to be cautious when changing its practices.
Standing on precautionary principle
San Francisco’s Board of Supervisors in 2003 voted to adopt the precautionary principle, a philosophy that urges caution in adopting new practices when data affirming their safety are not yet available, to guide its work on policy and purchasing. The resolution makes up the first chapter of the city’s environmental code. It acknowledges the role that the integrated pest management system and other Department of the Environment issues played in the supervisors’ move to make it a citywide policy.
Geiger said the decision to continue using glyphosate is justifiable under this principle. San Francisco has reduced its use and added measures to train and protect workers. It has examined alternatives and asks land managers to exhaust other options before turning to chemicals for pest and weed management. Public disclosure is also managed consistently, he said, through signs indicating chemical use across the city, at public meetings and in records.
But Geiger said one part of the precautionary principle is tough to apply because of the way the U.S. regulates chemicals. To protect trade secrets, manufacturers do not have to reveal all ingredients, so city officials lack some certainty about safety. Also, the U.S. EPA requires companies like Monsanto to show only that a chemical doesn’t pose any unreasonable risk to people or the environment. The agency also considers the economic, social and environmental costs against the benefits that could come from the chemical’s use.
The EPA certifies that glyphosate products are safe when used according to labeled guidelines. But California, using information from the WHO, has issued a safety warning. That places some responsibility on Monsanto. “In the absence of conclusive proof that something is harmful, the burden lies with the producer to prove that it is safe,” Geiger said.
The Department of the Environment oversees many environmental initiatives, including efforts to get to zero waste, sustainability in transit and buildings, and the reduction of toxic substances such as nail salon chemicals and paints. The lack of clarity around products like Roundup creates a burden for local governments.
“In this country we don’t have full transparency on chemical data and chemicals in products,” Geiger said. “If we had a good chemicals policy, we wouldn’t have to have so many people working here.”
Meanwhile, Glen Park neighborhood activist Fehrenbacher has noticed some changes, five years removed from her petition drive. Last fall, she said she saw workers spraying in the park. But on a hike through Glen Canyon one recent morning, she said she spotted a group of workers on the hillside, pulling weeds. “It made me feel good — they are tapering off.”
But she said she would feel better with the certainty that a ban would bring.