Healthy soil and sustainable growing

[Harvey Ussery <huboxwood@earthlink.net>]

An important point to add to the discussion about pesticide residues and 
their potential threats post-Carson: I heard Sandra Steingraber address 
the issue at PA Assoc for Sustainable Ag annual conf this year. She said 
that 400 years after Paracelsus, we still accept his dictum "The dose 
makes the poison." That is, even quite poisonous substances are harmless 
below a certain dosage--indeed, could even be used beneficially. 
(Paracelsus used small doses of mercury to treat syphilis, even tho it 
was know that mercury is quite toxic.) This assumption that has come 
down from Paracelsus still informs our absurd notion of "threshold" 
levels of toxins in the environment, below which they're "okay."

Steingraber referred to numerous studies that should make us conclude 
that it is not "the dose makes the poison," but rather "the timing makes 
the poison." That is, there are four windows of vastly increased 
vulnerability in the developmental stages--in utero, the first months of 
explosive growth, the time of rapid growth and great hormonal changes in 
puberty, and the emergence into old age. At these points the body is 
undergoing many changes, quite rapidly, and is thus more sensitive to 
influence by what would be "below threshold" doses at other stages of 
life. Thus an embryo in utero might develop birth defects from the water 
her mother is drinking, even tho said water is having no demonstrable 
deleterious effects on the mother.

Another change in the nature of toxics used now as opposed to when 
Carson wrote is that so many of them are hormone analogs/mimics, and the 
body can react to them as if they were hormones triggering certain 
responses--but responses that are entirely inappropriate to the body's 
actual state of development. One especially insidious thing about 
hormone mimicking toxins is that they can be even *more* dangerous at 
extremely small doses than in larger ones. This would be 
counter-intuitive to Paracelsus, but it makes sense: Hormones are active 
in the body to initiate potent changes at extremely small 
concentrations. That is the way the body is accustomed to getting that 
information--in small amounts--and in larger doses it has the wisdom to 
say, "oh no, that *can't* be right--no way" and discount the information 
and refuse to unleash the cascade of changes.

I don't know how much attention Carson gave to synergistic effects of 
the toxins she studied, but of course there are hundreds or thousands 
more individual chemicals released into the environment today than in 
her day. Safety studies on these chemicals individually are inadequate, 
but almost *no* attention has been paid to the later compounds emerging 
from their combination "in the wild" in completely unpredictable ways. 
Truly, we have *no idea* what the chemical stew we dump into the 
environment is doing, or what effects it is having on us.

As Wendell Berry said: "We think we are in the environment. We are 
wrong: The environment is in us."

~Harvey

--
Harvey in northern Virginia
www.themodernhomestead.us