This article is adapted with permission from SutroForest.com
UCSF, which owns and manages most of Mt Sutro Forest, recently decided not to use pesticides there. This may make it the only wild land in San Francisco that is reliably free of pesticides. Most of the others fall under the misnamed Natural Areas Program (NAP) of San Francisco Recreation and Parks Department (SF RPD). NAP is responsible for around 1100 acres in San Francisco in 32 parks. It has a very different attitude to pesticides.
NAP’s RISING PESTICIDE USE
We’ve been tracking NAP’s rising herbicide use, compiling reports we obtain under San Francisco’s Sunshine Act. (The report for 2012 is HERE; and for 2011 is HERE.) For a year or two, we hoped the rise was an anomaly. Apparently not. With the 2013 data in, the best things we can say are that the rate of increase is not as high as in the last four year; and that the number of applications fell.
But the volume of toxic herbicides used still rose.
People have asked us: But why complain about NAP? Surely a garden like Golden Gate Park with all those lawns and golf courses uses lots more herbicide than NAP? This year, we tracked that too. NAP also uses more pesticides than the rest of SFRPD put together.
NAP USES MORE HERBICIDES THAN THE REST OF SFRPD
NAP, which manages one-fourth of the area under the SF RPD, uses more pesticide than the rest of SF RPD put together. That counts all the golf courses except Harding, which is apparently under contract to be tournament-ready.
Also, NAP is the main user of the most toxic pesticides. San Francisco’s Department of the Environment (SF DoE) – which watches out for pesticide use on city-owned property – rates the permitted pesticides into three Tiers. Tier III is the least hazardous; Tier II is more hazardous; and Tier I is most hazardous. NAP is the major user of the Tier I pesticide, Garlon.
As we mentioned earlier, NAP’s pesticide use continued to increase in 2013, though the number of applications went down. The lower number of applications slightly reduces the opportunities for exposure to freshly applied toxins. But this is more than offset by the fact that actual amounts of pesticides continued to rise – and that many of these chemicals are the ones that are most toxic and very persistent.
THE FOUR PESTICIDES NAP USES
NAP currently uses four pesticides: Glyphosate (Roundup/ Aquamaster); Triclopyr (Garlon 4 Ultra); Imazapyr (Polaris or Stalker); and Aminopyralid (Milestone VM). They are all of concern. Of these, SF DoE rates Garlon as Tier I (most hazardous); the remaining three are currently rated as Tier II.
Three of the Four on Mt Davidson
Despite the manufacturer’s claims, there is evidence that these herbicides are not safe. Our article summarizing this is HERE: Natural Areas Program: Toxic and Toxic-er.
ROUNDUP/ AQUAMASTER (Glyphosate)
Classified as a Tier II (More Hazardous) chemical by the San Francisco Department of the Environment, this is the most-used pesticide of the four. However, there’s been growing evidence that it’s not a safe herbicide.
- Toxic to human cells, particularly embryonic and placental cells. Here’s an article in Scientific American, about the effect of Roundup on human cells – not just the active ingredient, Glyphosate, but the “inert” one, POEA. (Aquamaster does not contain POEA.)
- Damage to liver, red blood cells, lymph system. Here’s a series of research articles detailing some of illnesses caused by Roundup.
- Link to birth defects. Here’s an abstract of a May 2010 article in the journal Chemical Research in Toxicology.
It indicates that Roundup increased retinoic acid activity in vertebrate embryos, causing “neural defects and craniofacial malformations.” The actual article, which we read elsewhere describes some of the birth defects: microcephaly (tiny head); microphthalmia (tiny undeveloped eyes); impairment of hindbrain development; cyclopia (a single eye in the middle of the forehead); and neural tube defects. Our summary of this article is HERE.
- Linked to cancer, specifically, Non-Hodgkins Lymphoma. A 1999 article on research linking Roundup to cancer, specifically non-Hodgkins lymphoma, and HERE is a follow-up published in 2008 in the International Journal of Cancer.
- Dangerous to amphibians. This article cites University of Pittsburgh research showing Roundup is highly lethal to amphibians.
- Suspected endocrine disruptor. Initial research suggests that it is an endocrine disruptor in human cell lines. It’s on the list of chemicals the EPA is reviewing for endocrine disruption.
NAP accounts for 96% of the use within SF RPD of this Tier I (Most Hazardous) chemical. Garlon kills broad-leaved plants (not grasses or conifers) by sending them a hormonal signal to grow uncontrollably. This weakens the plant until it dies. Its breakdown products are triclopyr acid and then ‘TCP’ – both of which are, fortunately, somewhat less toxic than Garlon. (Imazapyr, by contrast, has a breakdown product that is neurotoxic.)
Our article is based on the Garlon chapter of Draft Vegetation Management from the Marin Muncipal Water District (which can be found here as a PDF file). It was a pretty thorough multi-source review of what was known about the chemical, and it clarified the risks: birth defects; kidney damage; liver damage; damage to the blood. What stood out, though, was how much is not known, particularly about the effects of repeated low-level exposure. There simply isn’t that much research out there, and few human studies. “Although triclopyr has been registered in the US since 1979, there are still very few studies on triclopyr that are not part of the EPA registration process.” Most of the research that exists is on Garlon 4. What NAP uses is Garlon 4 Ultra. It’s similar but isn’t mixed in kerosine. It’s mixed in a less flammable but apparently equally toxic methylated seed oil.
What is known makes uncomfortable reading.
- Birth defects. Garlon “causes severe birth defects in rats at relatively low levels of exposure.” The rats were born with brains outside their skulls, or without eyelids. “Maternal toxicity was high” and exposed rats also had more failed pregnancies.
- Damage to kidneys, liver, blood. Rat and dog studies showed damage to the kidneys, the liver, and the blood. It’s insidious, because there’s no immediate effect that’s apparent. If someone’s being poisoned, they wouldn’t even know it. In a study on six Shetland ponies, high doses killed two ponies in a week, and two others were destroyed.
- Skin absorption. About 1-2% of Garlon falling on human skin is absorbed within a day. For rodents, its absorbed twelve times as fast.
- Dogs may be particularly vulnerable; their kidneys may not be able to handle Garlon as well as rats or humans. “The pharmacokinetics of triclopyr is very different in the dog, which is unique in its limited capacity to clear weak acids from the blood and excrete them in the urine.” Dow Chemical objected when EPA said that decreased red-dye excretion was an adverse effect, so now it’s just listed as an “effect.”
- Insufficient information. There was insufficient information about Garlon’s potential effect on the immune system, or as an endocrine disruptor.
- Not quite carcinogenic. It isn’t considered a carcinogen under today’s more lenient guidelines, but would have been one under the stricter 1986 guidelines.
- Probably alters soil biology. “There is little information on the toxicity of triclopyr to terrestrial microorganisms. Garlon 4 can inhibit growth in the mycorrhizal fungi…” (These are funguses in the soil that help plant nutrition.) No one knows what it does to soil microbes, because it hasn’t been studied.
- Dangerous to aquatic creatures: fish (particularly salmon); invertebrates; and aquatic plants.
- Some effect on honey bees. It doesn’t generally kill adult honeybees, but there are no studies of other insects. Some studies show slight “acute toxicity” to honeybees.
- Garlon can persist in dead vegetation for up to two years.
Given all the information we do have on this chemical (and all the information we don’t have ) we have to question why native plant restoration is worth spraying poisons on some of the highest points in our city. Garlon must be used when the weather is wet; if the plants don’t have water, they will not grow and the chemical won’t work. But the runoff from these hills is enormous during the rain – it washes down in rivulets and streams, and it will end in the reservoirs, the groundwater, and the bay.
Classified as a Tier II (More Hazardous) chemical by the San Francisco Department of the Environment, this is another pesticide used mainly by NAP. In 2013, NAP accounted for 97% of the imazapyr used by SFRPD. NAP started using Imazapyr even before the SF DoE had approved its use. Now it’s being used in Sutro Forest. Here’s our article on Imazapyr.
The main issues with it are that plants push it out through their root system, so that it can spread and affect other plants; it is very persistent. Its breakdown product is neurotoxic. It’s banned in Europe.
According to a BASF Safety Data Sheet from Europe, it’s “Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment.” However, a BASF Material Safety Data Sheet from the US says, “There is a high probability that the product is not acutely harmful to fish. There is a high probability that the product is not acutely harmful to aquatic invertebrates. Acutely harmful for aquatic plants.”
MILESTONE VM (Aminopyralid)
SF DoE originally classified this chemical as Tier I, Most Hazardous, because of its uncanny persistence. In 2013, it was reclassified as Tier II – More Hazardous. At the time, we protested that the down-classification would increase its use; SF DoE didn’t think so. But this year, NAP’s use of Milestone has risen 200% from 2012. (Only NAP uses Milestone in the SF RPD.)
Milestone is even more persistent that Imazapyr, and can survive being ingested by animals. Thus, if it is used to treat plants and animals eat and excrete them, they spread the poison. It is banned in New York for fear it will get in the groundwater, and was for a time banned in the UK.
For purists, we also calculated NAP’s pesticide usage based on “Active Ingredient” and based on “Acid Equivalent.” (The post explaining those measure is HERE.) By those calculations, it’s gone up even more.
The graph above shows index numbers of the various indicators, with a base of 2008 (i.e, 2008 = 100). After a dip in 2009, NAP’s pesticide use has trended upward for four years. We cannot quite understand the need for the continuous rise in pesticide use in NAP. We can only wonder if it correlates to budget availability.
We call upon SF RPD to stop all Tier I and Tier II herbicide use in Natural Areas. It would make the Natural Areas more … natural. And it would halve SF RPD’s herbicide consumption, and nearly eliminate their use of Tier I pesticides.