Maybe, maybe not... not if 1 ppm has the potential to cause killing damage. 1,000 ppm would just be over-kill.
And, is that 1 ppm being applied to a single leaf, or ten thousand leaves on a single tree?
Your "1 ppm" made me think of how much fluoride is permitted in municipal water... and I see definite similarities here.
They say, 1 ppm is a safe level for human consumption. However, what is glossed over is, 1 ppm for who and for how long? Is that 1 ppm safe for a five pound infant drinking 16 ounces of water/day, or is that safe for a 250 pound construction worker drinking three gallons/day?
There is also the accumulative effects of that acceptable amount to consider.
I don't want to go off on the fluoride issue, but I think the questions of "acceptable amount" and "accumulative amount" also apply to synthetic auxins in trees.
The growth regulators act at the cellular level and have a detrimental impact on the entire tree, not just the leaves. Don't they?
How is applying these synthetic auxins to a tree any different that genetically modifying a soybean to make it resistant to Round-up... but in reverse?
I found this article... the first paragraph went over my head, but it looks like it might be interesting.
Maybe you can decipher it?
I'll read it tomorrow.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362085/
Here's some more info to support your concerns. You are right to be very concerned about this poisoning trespass and it's long term effects--
Too many of these so-called "below regulatory concern" "acceptable levels" ignore what happens in the real world. The flawed science goes like this: A lot of it kills or sickens most, like the LD-100 dose (lethal to 100%), a lesser amount shows the LD-50, and so-called miniscule amounts appear to not show an effect, so the manufacturer and those poisoning for profit declare "no effect seen, therefore, safe". High doses, or "acute exposures" are harmful, but an alleged low dose threshold is extrapolated, assuming a linear dose response, ans some lower exposure is claimed that is safe, with no response.
Real world experience shows us several things: An amount of poison in one hit can have some effecft, however, the same amount, in low doses or continuous exposure can often have far worse effects. Consider this Yale article, which explains how hormonally active compounds behave quite differently when exposure is spread over time at low levels compared to the same amount in one or a few doses. "
Scientists Warn of Low-Dose Risks of Chemical Exposure" https://e360.yale.edu/features/scie..._risk_of_endocrine_blocking_chemical_exposure
A second aspect of long-term low level exposure is the cumulative effects of exposure. They are usually worse than acute hits. The earlier comments by some that the effects of this drift poisoning are temporary or recoverable implies the poison is cleared (metabolized), like recovering from drinking, and all will be well. Often not true, though the poisons industry would want us to think so, (just like the [false] claim that "the pesticide sticks to the clay" and doesn't migrate.)
The "too little to matter" so the poison "won't hurt you" falsehood is even addressed in this book,
The Myth of the Linear, No-Threshold Dose-Response Relationship for Carcinogens, available from Amazon.
The effect of exposure over time, especially low exposure over a long time, is studied under a science model with a name: "
The Druckrey–Küpfmüller equation established in the early 1960s explains why toxicity may occur after prolonged exposure to very low toxicant levels. In essence, this equation states that the total dose required to produce the same effect decreases with decreasing exposure levels, even though the exposure times required to produce the same effect increase with decreasing exposure levels. Druckrey and Küpfmüller inferred in the late 1940s that if both receptor binding and the effect are irreversible, exposure time would reinforce the effect." (from the excellent site
https://www.farmlandbirds.net/en/taxonomy/term/3)
Another profound and dangerous truth about these poisons is this: we aren't just different in how we handle poisons (biochemical individuality), but how we handle the poison in us--what it's lasting effect is--is shaped by when we are poisoned. Childhood? Puberty? during a growth spurt? Stressful time in our life? At critical times in our growth, from being a neonate to infant to child...and on, poisons can have far more harmful effects at some times than others. If one is concerned about children and their health, download and read lot's more about pesiticides and poisoning kids at
In Harm’s Way: Toxic Threats to Child Development, by the Greater Boston Chapter of Physician's for Social Responsibility https://gbpsr.org/resources/in-harms-way/
or Dr. Philip Landrigan's
Children as a Vulnerable Population.
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I had intended to post on this ongoing topic--pesticides, drift of this poison, and others and how the health effects are very serious and can't be ignored. I'll post more on that later. The connection to the exploding levels of Parkinson's Disease and the link to pesticides is something every poison user should know about, as well as their children and neighbors. Dozens of recent studies show this truth.
I'll post more later, but for those interested, check out this documentary by U of Rochester's School of Neurology, funded by Roche, which follows from the book Ending Parkinson's Disease. Pesticides and solvents are discussed by those harmed:
The Long Road to Hope: Ending Parkinson's Disease
For the record, Parkinson's is progressive, degenerative, and incurable, not reversible. Pesticides and chemicals are proven causes. Rarely do the poisoned show any effects till it's too late...
Stay on this, TNTreeHugger. It's important people know what they are messing with. And if harming others (or their property), they should be held to account.
see also:
Parkinson’s Disease and Pesticides Exposure: New Findings From a Comprehensive Study in Nebraska, USA https://bloximages.chicago2.vip.tow...-54d3-a2a4-51054a68e5d0/56f5b86f91feb.pdf.pdf
https://endingpd.org/about-parkinsons, and
Preventing Parkinson’s Disease: An Environmental Agenda
https://content.iospress.com/articles/journal-of-parkinsons-disease/jpd212922
And if you are new to Parkinson's, here's a brief video that describes early stage symptoms: HAND 
