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Pesticides in Organic Farming (repost)


Organic produce has become increasingly popular in recent years, as consumers
have grown more health conscious and environmentally aware.  Many stores and
supermarkets now have large sections devoted to organic fruits and vegetables.


WHAT MAKES PRODUCE "ORGANIC"? 

Contrary to what most people believe, "organic" does *not* automatically mean
"pesticide-free" or "chemical-free".  In fact, under the laws of most states,
organic farmers are allowed to use a wide variety of chemical sprays and powders
on their crops.

So what *does* organic mean?  It means that these pesticides, if used, must be
derived from natural sources, not synthetically manufactured.  Also, these
pesticides must be applied using equipment that has not been used to apply any
synthetic materials for the past three years, and the land being planted cannot
have been treated with synthetic materials for that period either.  

Most organic farmers (and even some conventional farmers, too) employ mechanical
and cultural tools to help control pests.   These include insect traps, careful
crop selection (there are a growing number of disease-resistant varieties), and
biological controls (such as predator insects and beneficial microorganisms).

ORGANIC PRODUCE AND PERSONAL HEALTH

When you test synthetic chemicals for their ability to cause cancer, you find
that about half of them are carcinogenic.

Until recently, nobody bothered to look at natural chemicals (such as organic
pesticides), because it was assumed that they posed little risk.  But when the
studies were done, the results were somewhat shocking:  you find that about half
of the natural chemicals studied are carcinogenic as well.

This is a case where everyone (consumers, farmers, researchers) made the same,
dangerous mistake.  We assumed that "natural" chemicals were automatically
better and safer than synthetic materials, and we were wrong. It's important
that we be more prudent in our acceptance of "natural" as being innocuous and
harmless.


ORGANIC PESTICIDES VERSUS SYNTHETIC PESTICIDES

Clearly, the less we impact our environment, the better off we all are.  Organic
farming practices have greatly advanced the use of non-chemical means to control
pests, as mentioned earlier.

Unfortunately, these non-chemical methods do not always provide enough
protection, and it's necessary to use chemical pesticides.  How do organic
pesticides compare with conventional pesticides?

A recent study compared the effectiveness of a rotenone-pyrethrin mixture versus
a synthetic pesticide, imidan.  Rotenone and pyrethrin are two common organic
pesticides;  imidan is considered a "soft" synthetic pesticide (i.e., designed
to have a brief lifetime after application, and other traits that minimize
unwanted effects).  It was found that up to 7 applications of the rotenone-
pyrethrin mixture were required to obtain the level of protection provided by 2
applications of imidan.

It seems unlikely that 7 applications of rotenone and pyrethrin are really
better for the environment than 2 applications of imidan, especially when
rotenone is extremely toxic to fish and other aquatic life.

It should be noted, however, that we don't know for certain which system is more
harmful.  This is because we do not look at organic pesticides the same way that
we look at conventional pesticides.  We don't know how long these organic
pesticides persist in the environment, or the full extent of their effects.

When you look at lists of pesticides allowed in organic agriculture, you find
warnings such as, "Use with caution.  The toxicological effects of [organic
pesticide X] are largely unknown," or "Its persistence in the soil is unknown."
Again, researchers haven't bothered to study the effects of organic pesticides
because it is assumed that "natural" chemicals are automatically safe. 


WHY HAVEN'T WE HEARD THIS BEFORE?

For obvious reasons, organic farmers have done little, if anything, to dispel
the myth that "organic = chemical/pesticide-free".  They would only stand to
lose business by making such a disclosure.

Pesticide manufacturers have little concern in the matter.  To them, "synthetic
pesticides sold" and "organic pesticides sold" are both "pesticides sold".

As for conventional farmers, they are not really in a position to be critical.
It would not be in their interest to draw attention to chemical and pesticide
use.


WHAT DOES ALL OF THIS MEAN?

The purpose in writing this article is not to discourage you from buying organic
produce.

It is only meant to let you know what you are or aren't getting when you make
such a purchase.  Unless you know your grower personally, there is no guarantee
that your produce has been grown without pesticides or other chemicals.  It's a
point to consider, given the substantially higher cost of organic foods.

There are many choices and decisions that we, as consumers, are asked to make.
Hopefully, this has provided some new information that you will find helpful.

				* * * * * * *

Hard copies of this article in formatted leaflet form are available (on recycled
paper, of course).  Send your snail mail address to lhom@ocf.berkeley.edu

The data describing the carcinogenicity of natural and synthetic compounds are
referenced in Gold, L.S., et al. (1992) _Science_ Vol. 258, pp. 261-265.

Many thanks go to the Organic Crop Improvement Association for their cooperation
in this study.  The OCIA has chapters in AZ, AR, CA, CO, FL, IL, IN, IA, KS, MD,
MI, MN, MO, MT, NE, NM, NC, ND, OH, PA, SD, UT, and WI.  Thanks are also
extended to the California Certified Organic Farmers, the Ohio Ecological Food
and Farm Association, and Oregon Tilth Certified Organic. (The appropriate
information has not yet been obtained from the Natural Organic Farmers 
Association (NOFA), but it is almost certain that all facts stated here apply
to their products as well.)  The following state Departments of Agriculture
have also been very helpful:  AL, AK, AZ, CA, CO, DE, FL, HI, IA, LA, MD, MI,
MS, MO, ND, OK, SC, TN, VA, and WA.  States with no laws governing organic
products include Alabama, Delaware, Hawaii, Mississippi, and Tennessee.

-- 
______________________________________________________________________________
Lou Hom		        "On that day did they all mingle blood with wine and
lhom@ocf.berkeley.edu    drink it and when they had drunk themselves to mighty
			 drunkenness, they parted." 
					 	-- from _All Men Are Brothers_