by Nancy Price
I was stunned to read that Bapu Vaitla, who is a candidate for Davis City Council in District 1, is considering overturning the City’s phase out of glyphosate (manufactured and commonly sold as Roundup by Monsanto) instead of improving and strengthening the City’s Integrated Pest Management (IPM) program. (see Question #2). None of the other candidates made this audacious proposal.
Here is some background. The City decided to phase out glyphosate in 2017; finally discontinuing its use in 2020. The process involved three City citizen-advisory commissions: Natural Resources, Recreation and Parks, and Open Space & Habitat. It took over a year and a half and involved a widely attended public citizens forum, a city-wide citizen survey, many individual Commission meetings, and a 3-way joint Commission meeting. Despite considerable stonewalling from staff, who attempted to derail and water down THIS [the] citizen-based effort, the measure was finally unanimously approved by the City Council. What passed in 2017 wasn’t perfect, but it was well-received by citizens. (For more details, see here).
Around the same time, the city forced out its popular and highly respected IPM specialist (see here). Regrettably, that position still hasn’t been filled. But given the clear desire expressed by many staff to continue using non-organic pesticides over other less toxic weed management strategies, it is hard to see the ongoing long-term failure to fill the position as an unintended accident.
Instead of advocating for hiring an IPM Specialist, Vaitla thinks we should go back to glyphosate because, he says, — “we cannot reasonably resort to mechanical weed management.”
There are several problems here. One is Vaitla offering an opinion that either ignores or is ignorant of this recent controversial history of pesticide use by the City. A second problem is his complete dismissal and disregard of the work of the public and three citizen-advisory commissions which collectively devoted many hundreds of hours of work to this effort, most of which occurred prior to Mr. Vaitla’s most recent move to Davis.
A third problem is that, although Mr. Vaitla gives lip service to the Precautionary Principle, he doesn’t follow it. Notably, just this past June, the Ninth Circuit Court of Appeals rejected EPA’s analysis for determining that glyphosate is likely not carcinogenic to people and ordered EPA to conduct “further analysis and explanation.” The science is far from settled, and since there are valid reasons to think that glyphosate is a human carcinogen supported by respected international authorities and agencies, we should avoid using it especially since we have other methods at our disposal.
Vaitla’s position is hasty, overlooks a long City history and the latest Court rulings, and lacks respect for the citizen and commissions-led process in Davis. And, most importantly, it fails to protect our health. This attitude generally does not bode well for the sort of Councilmember he would make.
Mr. Vaitla’s comments were accurate and well-considered. Given the late-season increase in hazardous weeds that the city just had to deal with manually, we can see the results of the current policy.
The city council needs to revisit their weed management policies.
Focusing on one specific weed control product, without a full evaluation of the alternatives and the impacts of cessation of glyphosate, has led to increased risk to city workers due to exposure to traffic, 2-cycle engine exhaust, dust and pollen from increased use of mechanical weed removal, and less effective weed control. It’s simple: they have to visit a site 3 – 4 times to remove weeds manually, compared to 1 – 2 visits with an effective weed killer.
The safety of city personnel from should have been more carefully examined. Workers have to visit weedy sites, often along roadsides or even in traffic, more often than they did when glyphosate was being used. Some of the “organic” alternatives, which are top-kill products (not systemic) actually pose greater risk to the staff applying them than glyphosate. They can cause serious eye and skin injury. That includes acetic acid and those containing pelargonic acid. It needs to be stated clearly, since some people don’t seem to understand this, that a product being ‘organic’ does not make it safer.
Prior to the decision to stop using glyphosate, the city’s IPM adviser had helped staff implement policies that significantly reduced the usage by combining it with faster-acting but non-systemic products such as Scythe. Prioritizing the use of glyphosate strategically for hard-to-kill perennial weeds and those that posed a risk to the public (foxtails, starthistle), identifying problem areas and working to reduce the weed populations there long-term would be an effective strategy that reduces real and perceived risks and ultimately could reduce costs. But this would entail some higher budget approvals up-front for new plant materials, irrigation modification, and labor.
A proper IPM strategy for weeds will likely include continued use of systemic herbicides.
Such a strategy would also evaluate methods for reducing weed problems proactively.
Example: Consider plant installations to suppress weeds.
• Grasses that spread by rhizomes and which can be mowed at long intervals can readily suppress the growth of many annual, and some perennial weeds.
o The fine fescues are well-adapted to lower-water landscapes, have good drought recovery, and can shade out many herbaceous weeds. They are also popular with the public. There actually are native strains of Festuca rubra and Festuca idahoensis that have different foliage colors and textures. Repetitive overseeding can be done with fall and winter rainfall to establish a dense stand.
o Some sedges have been tested as lawn alternatives and may achieve sufficient density, especially with periodic mowing, to suppress weeds. Use caution: these tend to be a permanent decision.
• Some herbaceous ground covers get dense enough to crowd out weeds. Lippia and the new sterile version called Kurapia spread rapidly and achieve good densities.
• Unfortunately, wildflowers and annual natives will not compete with the grasses and thistles, so they are not viable alternatives.
Some woody plants with prostrate growth habits can be effective at suppressing weeds.
Examples:
• Artemisia Powis Castle
• Baccharis Twin Peaks
• Myoporum parvifolium
• Ribes viburnifolium (good for shadier areas)
• Rosemary, especially the intermediate-height spreaders such as Irene.
• Salvia clevelandii, S. sonomensis, S. ‘Pozo Blue’
Making it work:
• Larger plants installed on 3 to 6’ centers are easier to establish than small rooted cuttings. They allow manual weed management (hoeing, careful spraying) between the plants as they root in and start to grow. Pre-emergent herbicides are often used to prevent annual grasses and other seasonal weeds. Thick mulch such as arborist wood chips can be installed around the new plantings for further weed suppression. Additional labor costs would need to be budgeted in the first 2 to 3 years.
Foxtails, starthistle, and other thistles are weeds that can cause serious injury. Current weed management policies appear to be leading to increases in these weed species, as well as others. A balanced weed management strategy is likely to include use of some herbicides like glyphosate, but in a proper IPM strategy those would be the last option and would need to be fully justified.
The costs of the current strategy are undoubtedly higher, the exposure of the city workers to hazards is greater, and the weed control has been less effective. Increasing the city budget for weed management should have been a logical outcome of the decision to stop using glyphosate. More important, the impact of the policy should have been addressed more fully before implementation and it should certainly be reviewed now that the outcomes can be evaluated. Unfortunately, the NRC is clearly not the commission to evaluate this topic.
The overwhelming scientific evidence is that glyphosate is very low toxicity:
the LD50 is very high (it is practically non-toxic via ingestion),
it does not cause birth defects,
it showed no toxic effects in long-term feeding studies at high doses,
and glyphosate itself caused no skin irritation and limited eye irritation (though some formulations of RoundUp do, because of the detergent-like material used).
The consensus of every regulatory agency (at least 10 to date) that has exhaustively evaluated the carcinogenicity is that exposure to glyphosate does not increase your risk of cancer. No regulatory agency in the world considers glyphosate to be a cancer risk.
No intake of glyphosate in diet or exposure by occupation has been clearly linked to any cancer at any statistically significant level.
The IARC, whose monograph on glyphosate asserting it is a ‘probable human carcinogen’ is the basis of the lawsuits and the Prop 65 listing in California, does not assess risk; that is not the mandate of that agency. The small number of studies that formed the basis of the IARC’s decision do not reflect realistic field dosages or exposures, even over a very long period of time by those who work with these materials.
The decisions of legislatures and recent jury cases are not based on the scientific evidence. The current city council policy regarding glyphosate is not based on scientific evidence. It should be re-evaluated.
Don – Your analysis here completely ignores the Precautionary Principle that states that if there is doubt or uncertainty in the risk of a chemical causing harm then it’s use should be avoided. Clearly if a chemical is classified by a reputable international agency as a “Probable Human Carcinogen”, we should avoid all risk associated with its use because we simply can’t define the “risk” with any degree of certainty – especially since a dose:response relationship cannot be established for sensitive populations such as immuno-compromised individuals, young people, and elderly people.
The whole question of proper weed control is one of weed management and not necessarily whether or not glyphosate is used. As an example, the City discontinued use of ALL herbicides in parks since 2018 even though only glyphosate was banned. Simultaneously, the City cut way back on ALL forms of mechanical weed management. So yea, duh, weeds stated growing. But the weed growth was due to the stoppage of almost all weed management activities and had almost nothing to do with the ban on glyphosate which was almost never used in neighborhood parks anyhow.
In our very small neighborhood park this past year, we had one time when a crew came by with a weed eater and cut the weeds around the edges of the park requiring less than 45 minutes time. There was absolutely no other form of weed management practiced. But they City waited to cut the weeds until all the weeds had gone to seed so the soil seed bank was replenished virtually guaranteeing a healthy weed stand the following year.
Weed whacking used to be done 3 times per year in the past. Personal protective equipment required is a set of hearing protectors, eye goggles, and a OSHA-approved dust air filter (costing about $35 and can be reused). So presumably weed-whacking the weedy area several times during the year would only require a few extra hours of time per year and, if done during normal mowing and clean-up activities by the contract crews, would not even require special trips to do that.
That is what was done from 2017 up until the pandemic stated in 2020 and it was acceptable to the neighborhood users compared to being sprayed with chemicals. Then ALL weed control was stopped completely during 2020 and we had only one time in 2021 and one time in 2022 when a person came by and cut down the weeds. So the weeds got out of hand and the pesticide proponents all started the drum beat of “we need more chemicals and glyphosate because we can’t control the weeds”. Well it was a self-fulfilling prophecy.
And the statement that mechanical weed control is always more expensive is not borne out by any cost-benefit analysis by the City – or anywhere else I have seen. For instance, spraying in a park requires an email notice to be first sent out to all parties that request notifications. Then a special trip needs to be made to post the areas planned to be sprayed. Then on the scheduled day of the spray a licensed pesticide applicator needs to assemble the materials to be sprayed and mix them and make a special trip to the site to spray them all the while wearing a hazmat suit with a respirator – try doing that when it is hot outside). Then the spray equipment needs to be triple rinsed. Then another special trip needs to be made to the site to take down the postings. Then a special report needs to be filled out and sent to the County Ag Commissioner within a specified number of days. The costs of doing all of this for one spray are exorbitant compared to the costs of using a weed whacker several times a year in the normal course of park maintenance.
I also question the statement that one spray per year will glyphosate will do the trick inferring that no other weed management activities are necessary. That MAY be true if there is a single type of weed present and the spray is timed exactly to precede the time when the weed goes to seed. But these conditions rarely occur in the real world and when the City was actively spraying for weeds with glyphosate along bike paths or at the waste water treatment plant they would spray at least several times per year to get the weeds that grow or bloom at different times of the year. And they would do mechanical weed management in the intervening periods. So the statement that glyphosate use need be only once per year is a far stretch from reality based on the City’s own history of use.
What the City really needs is a new IPM manager who is committed to weed management using the smallest amount of chemicals possible. That’s what we had during the tenure of our previous IPM specialist and folks loved him for minimizing pesticide use while achieving adequate weed control in a cost effective manner.
Just opening up the floodgates of glyphosate usage again by claiming that weeds aren’t being controlled when almost all weed management activity was stopped is disingenuous and misleading and, like I said, a self-fulfilling prophecy. Chemical pest management has it’s place but it should be done ONLY when absolutely necessary after other treatment options have been exhausted. Stopping all weed treatment is not the same as exhausting all treatment options. Our problem is we have absolutely no one on City Staff who knows what they are doing in terms of weed control so they stopped doing everything. So yea, duh, weeds stated growing.
The IARC, whose monograph on glyphosate asserting it is a ‘probable human carcinogen’ is the basis of the lawsuits and the Prop 65 listing in California, does not assess risk; that is not the mandate of that agency.
That is precisely what regulatory agencies do and have done with regard to glyphosate, both before and after the IARC monograph was released. All of them have concluded that it is not a cancer risk. Literally no regulatory agency in the world has considered the IARC publication to be relevant to field-realistic applications of glyphosate, even for those with lifetimes of exposure in landscaping or agriculture. They do, in fact, evaluate for all levels of risk. The regulatory agencies use that evaluation to determine the wording on the product labels.
Health Canada did it twice!
After their second evaluation:
….
Your analysis isn’t detailed enough with respect to the costs of spraying vs mechanical management for me to really reply to that. I am familiar with the paperwork and posting requirements. I would need to see an actual cost-benefit analysis to evaluate your assertion. But more to the point, I’d leave that to experts.
I neither said nor “inferred” that. I have observed the process and have training on this topic, and can confirm that mechanical control requires more site visits than chemical control. But we know that a combination of strategies including mulching, planting, some mechanical removal, strategic use of pre- and post-emergent pesticides will be the most effective approach, especially with careful monitoring of the most hazardous weeds.
For the record, the method adopted on recommendation of the city’s IPM specialist was a mix of glyphosate with a top-kill product such as Scythe. That reduced glyphosate usage by 50% in each application. I’m not sure why the NRC and your subcommittee decided to press for banning glyphosate given that usage had already been reduced based on expert recommendation.
Agreed.
Yes. And his recommendations included using some glyphosate, while you personally spearheaded the process that got the city to stop using it. We concur that an IPM manager with some degree of line authority could significantly improve the city’s weed abatement practices.
All of the Commissions clearly heard the IPM specialist claim that alternatives to glyphosate usage were available if properly managed and that the public clearly indicated its desires to get rid of glyphosate.
And BTW – The vast majority of the glyphosate usage was also not in Parks but by the wastewater treatment plant and by the stormwater maintenance crews and the street maintenance crews over which the IPM specialist had no control over what pesticides were used. They told him what they were going to use and then used it. Take a look at any of the annual IPM reports at the time that were reviewed by the NRC and you can verify that there was VERY little glyphosate usage at the parks themselves which is now the source of most of the complaints about weeds from citizens. The problem is not because glyphosate was banned from the parks…the problem was because almost ALL weed management activities were stopped in 2020 and beyond. Bringing glyphosate back and greatly incresing its use is Parks is not going to solve that problem.
Based on the notices of intent to spray on the city’s calendar, there were applications in the city limits of glufosinate in May and June of 2020, multiple applications in March 2021, and glufosinate and a mix of isoxaben and trifluralin were applied in late spring 2022. In addition, I can confirm that work crews were manually removing weeds during 2020 and 2021, despite the impact of the pandemic.
Don – I do not recall you being at any of the multiple City meetings when this information was discussed nor submitting any comments when the matter was then considered. There was actually a wealth of studies and information presented for discussion and evaluation at that time.
It otherwise seems that the basis for your claim that the phase-out of glyphosate is not based on scientific information is based on your perception that if we cannot prove it causes cancer then we should be able to use it. This is hardly consistant with the Precautionary Principle which, in stark contrast to your view, states that if we cannot prove it is safe we should not use it.
Additionally, it is not just scientific evidence that was the basis for the phase-out of glyphosate. It was also based on the likelihood that there could be legal liability downstream for the City. For instance, one of the first mega-awards by a jury for lymphoma caused by glyphosate was for a SF park employee who was awarded millions of dollars after showing exposure to glyphosate over decades of work in their Parks Dept. It was on this basis that the DJUSD discontinued glyphosate use on their premises – that is, who needs the potential future liability if there are alternatives to glyphosate.
Also, it is not just a question of whether ot not scientific evidence supports the banning of glyphosate because it is or is not a cancer-causing agent; or whether or not there is any legal liability to the City by using it. It was also partially based on the express political will of the people. The City did an extensive survey of people’s attitudes toward pesticides in the Davis City parks and there was a decided and clear preference by the respondents that they would prefer no pesticides in their parks and they were willing to accept a litlle scruffiness in the parks to accomplish that. But the City Parks staff has obviously gone way beyond just reducing or minimizing pesticide use to doing almost no weed control at all – either chemical or mechanical or cultural. So yea, duh, weeds stated growing.
I have found the debate over Roundup fascinating. The people most at risk from exposure to Roundup are the applicators who in the case of the city are some of its employees. Minor exposure to treated areas is not a cancer risk to ordinary citizens. Bayer, who bought out Monsanto, has paid out huge claims from Roundup exposure and has set up a billion dollar fund for future claims.
When the issue came before the city I was shocked that the city parks people, the ones responsible for the workers most at risk, were also the ones most resistant to giving up Roundup as a weed management tool.
What we have seen since removing Roundup as a management tool is that weed abatement is much more difficult problem than simply bringing in an IPM expert.
I don’t know if taking the cancer risks to employees seriously and reducing Roundup use to the most difficult situations while at the same time making sure that applicators use state of the art protections would be enough but I’m open to a discussion about it.
When people objected to putting fluoride in the water the opponents came up with a way to get kids the fluoride they needed without adding it into the water. Maybe the opponents of Roundup could create a volunteer organization that goes out and tackles weed abatement. Much like Tree Davis maybe we should have Weed Davis.
I’m thinking that the volunteers who show up for that might be disappointed when they find out what you’re actually proposing.
And you are basing this on Monsanto’s word? What about hypersensitized or immunocompromised citizens? Do you have any evidence to support this claim?
We actually had such a thriving volunteer program at a number of larger parks in town (Mace Ranch, Slide Hill, etc.) run by our previous IPM manager. He worked directly with volunteers at the parks and they loved him and worked with him to minimize pesticide use in those parks. The program has functionally completely stopped once he was fired for not obeying an order to apply a pesticide he was not licensed to apply which would have otherwise been a direct violation of California law.
I’m basing it on what I’ve read in the media about who was getting cancer and settlements from Monsanto. If you look it up you can find out about the cases and settlements and the fund for future claims. The cancer risks are real and the courts have awarded judgments. But my understanding has been that the people getting sick have had high levels of exposure for long periods of time.
Do you have contrary evidence about immunocompromised people being injured by Roundup from casual exposure?
The City probably needs to reconsider strategic use of Round up. However, the greater danger is not to human health, but rather to pollinators that support our local ecology and agricultural economy. Glyphosate has been identified as a likely hazard to bees, although the mechanism hasn’t been clearly identified:
https://beyondpesticides.org/dailynewsblog/2021/04/roundup-shown-to-kills-bees-but-not-how-you-might-expect/
https://www.science.org/content/article/common-weed-killer-believed-harmless-animals-may-be-harming-bees-worldwide
https://www.theguardian.com/environment/2022/jun/02/glyphosate-weedkiller-damages-wild-bumblebee-colonies
The environmental impacts of all weed abatement practices would best be evaluated by an integrated pest management specialist. For example, mulching is a very effective way to suppress annual weeds. But mulching also impedes nesting by ground-dwelling bees. So some open areas should or could be retained for that purpose with extra attention to weed management on those sites.
Every weed management practice selects for some weeds, against others, and has some kind of secondary impact. Glyphosate isn’t unique in having adverse consequences but it may be less environmentally harmful, in some cases, than alternatives. Top-kill products such as pelargonic acid, citric acid, acetic acid, fatty acids, etc., are also likely very harmful to beneficial insects that are present at the time of spraying, so time-of-day standards may be necessary. Those things are best evaluated by experts.
Any weed abatement plan would consider the mix of species on different sites, the most effective and safest method of managing that population mix (with special attention to the presence of flowering plants and a strategy to treat, if needed, before they flower), the safety to the general public, the safety to staff/applicators, and so on.
Which the City has no access to once our beloved IPM specialist was canned.
If city workers are at risk from traffic, change the traffic. Slow down the relevant streets, permanently or during operations.
If city workers are at risk from gasoline two-cycle equipment, replace the equipment.
If workers are at risk from exposure to any substance, make sure they are wearing appropriate equipment.
Or just get rid of the substance….what a concept! Or should we also have our public park visiors also where protective equipment.
As a person who has often tried to protect public services and city council members from unfair criticism, I am not convinced the city public works management wants to find an alternative.
On a very limited scale, I notice that where mulch material is applied 5 to 6 inches deep, there is very little weed growth. It works around my home. It works in places along greenbelts where the mulch somehow found its way there in sufficient quantity. I also notice that when the city removes trees, etc., and run the branches through the chipper, that they inexplicably haul it away. Along the Covell Blvd. overpass three or four years ago, there were three or four large trees that blew over in high wind. The city chopped them up and hauled away all those great chips that should have been spread in the same vicinity. Saves transportation costs, reduces weeds. Or is this just too simple?
When I look at the mountains of mulch sitting along Second Street below the Dave Pelz overcrossing, I wonder why all this mulch is sitting there instead of being spread around especially at problematic and difficult to access weedy locations. It feels as if the city wants to punish the citizenry for forcing them to do something they didn’t wanna do. “Okay, you won’t let me use my convenient weed control method, so I’ll just let it go to hell and wait for you to cry uncle and let me go back to doing it the way I want to. I know if I don’t do anything to fix the weed situation, there will be an outcry and I will win the fight.”