"Good intentions will always be pleaded for every assumption of authority ... the Constitution was made to guard against the dangers of good intentions. There are men in all ages who mean to govern well, but they mean to govern. They promise to be good masters, but they mean to be masters." - Noah Webster

"There is no worse tyranny than forcing a man to pay for what he does not want just because you think it would be good for him."
-- Robert A. Heinlein

Wednesday, May 4, 2011

Chemical Pesticides

Probably the biggest problem with using chemical pesticides is that most of them don't just kill the bad bugs that we want dead.  They often kill beneficial insects as well.  Then there is the issue of secondary and tertiary bad effects to other forms of life.

Let's say you want to kill this one bug that has shown up to dine on your precious lettuce, so you get out some bug spray.  You kill the nasty little goblin that was munching on your romaine, but the same spray you used also killed the ground beetle who would have eaten the cutworms below the soil.  This is just one example.  The same insecticide that you use to kill bad insects also kills green lacewings and honey bees.  I'm not saying that I wouldn't break out some Sevin dust and sprinkle a little just around the base of all my lettuce plants if I discovered that cutworms seemed to be all over the yard, because I definitely would.  But I would seriously think about it.

Back in 1982, an entomologist from Cornell University, by the name of David Pimentel started a study to examine the hidden costs of using man-made pesticides, and found that indirect costs ran as high as $8 billion a year by causing the deaths of honeybees, birds, fish, and even domestic animals.  His results were published in The Way We Grow, in 1993.

Right now, much of the world is beginning to panic over the loss of many bee populations.  Some of the newer insecticides that were developed to have less residues and are thus thought to be safer, are actually causing more poisoning of honeybees.  This actually comes from the law of unintended consequences.  For example; smokers buying low tar cigarettes and then smoking twice as many to get enough nicotine in their system.   Or, people driving more dangerously because they have seat belts and air bags.  You may find that amazing, but it's true.

Those who farm on the commercial scale are under a lot of pressure.  No one who has experienced a bad infestation of worms or beetles eating their crops can deny that the fear of such damage is real.  The problem is compounded by the companies who are legitimately in business making the pesticides that we sometimes need, but who also will use that fear to sell more of their product.  Most all commercial farmers just grow one or two crops.  Some grow multiple crops and also livestock of various sorts, but most commercial level farmers specialize because that's how the industry has developed over the years.  From this development has grown a loss of understanding of the big symbiotic picture of the relationship of all the creatures in a large biological or ecological system.  If all you grow is acres and acres of corn, then all you are going to care about is which chemicals treat for the bugs and fungi that attack corn.  The beekeeper and the trout farm operator downwind and downstream from you might not be your biggest concern.  I'm sure there are plenty of farmers who really do care about their neighbor, but it only takes a few who are only thinking of their own farms to cause a lot of damage.

There are many other great things written on the subject of "wholistic" farming; doing the opposite of highly specialized farming.  This would be too far afield for our subject in this post, but it is well worth looking into.

For now, let's look at some of the most used and widely available insecticides and how they work.

Sevin dust has been around since the sixties.  Sevin is the trade name of the chemical carbaryl.  It is technically a cholinesterase inhibitor, which means that it interferes with the breaking down of acetylcholine a neurotransmitter that exists in pretty much every animal in the animal kingdom.  But the simple way of looking at it is that it's a nerve poison.  It kills insects.  All insects.  Honeybees and butterflies.  It kills crustaceans in the water.  The reason it is preferred for food crops is because vertebrates can more rapidly detoxify and eliminate it from the body and it doesn't store up in fat cells and doesn't get secreted in milk (if cows ingest some of it).  But it is still toxic in large enough amounts and is also considered a carcinogen.

Malathion is also a cholinesterase inhibitor but is much more dangerous because it not only does not break down more easily as carbaryl does, but in the human body it metabolizes into a substance called malaoxon which is substantially more toxic.  Symptoms of exposure to this type of compound include cholinesterase inhibition, miosis, frontal headache, increased bronchial secretion, nausea, vomiting, sweating, abdominal cramps, diarrhea, lacrimation, increased salivation, bradycardia, cyanosis and muscular twitching of the eyelids, tongue, face and neck, possibly progressing to convulsions. Other symptoms include hyperemia of the conjunctiva, dimness of vision, rhinorrhea, bronchoconstriction, cough, fasciculation, anorexia, incontinence, eye changes, weakness, dyspnea, bronchospasm, hypotension or hypertension due to asphyxia, restlessness, anxiety, dizziness, drowsiness, tremor, ataxia, depression, confusion, neuropathy (rare), coma and death from depression of respiratory or cardiovascular systems. Exposure to this type of compound may result in giddiness, nervousness, blurred vision, discomfort (tightness) in chest, papilledema, muscular weakness, loss of reflexes, loss of sphincter control, cardiac arrhythmias, various degrees of heart block and cardiac arrest. It may also result in spasm of accommodation, aching pain in and about the eye, nystagmus, delayed distal axonopathy and parethesias and paralysis of limbs. A decrease in blood pressure may occur. Respiratory failure may also occur.

How do you like that list?

Diazinon works the same way as Sevin and malathion; cholinesterase inhibition.  It's only advantage is faster breakdown, but it was banned from use on golf courses and sod farms in 1988 by the EPA because of damage to bird populations.

Pyrethrin is the organic extract from the seed cases of the chrysanthemum, also commonly called mums.  Interestingly enough, the substance is also essentially a nerve poison, but it behaves completely differently from the cholinesterase inhibitors.  This chemical affects the sodium ion flow out of the nerve cells, essentially causing a rapid fire or "short-circuiting" effect in the insect.  While this means that it could potentially do this in humans or other mammals it would take tremendous amounts of it to do so.  Pyrethrins rapidly disintegrate into inert ingredients when exposed to sunlight and air.  This means that they don't last long and can't build up.  But for all of its advantages, it will still kill other beneficial insects.  Kenya produces about seventy percent of the world supply of pyrethrum from flowers grown by small scale farmers.  Wow.  Something beneficial has come out of Kenya.  Not enough to offset their worst export by far, but we can be thankful for something.

Another problem with reaching first for the sprayer is the fact that insects, as well as many small life forms, have an incredible ability to adapt to life-threatening changes in their environment.  The bugs that somehow survive an attack with chemical pesticides will pass on the genetic information to the next generation, creating a whole new set of problems.  We then have to change chemicals to something that might now kill other beneficial species that we never intended to kill.

It cannot be over-emphasized that the destruction of bees and other pollinating insects puts the food supply in much greater danger than losing even half the crops of a given species in a given year.  When entire bee colonies get wiped out, entire crops of multiple types can and do fail.  There really is no comparison.  Add to this the fact that now we may be finding out that Monsanto's GMO crops may be killing the bees in other ways.  I can't describe how evil I think genetically modified foods are.

Ultimately, wouldn't it make more sense to encourage a balance of good, or predatory insects and animals to avoid using chemicals altogether? If we do have to resort to man-made chemicals, are we using the absolute minimum that we can get away with?  Is this a situation where it would make sense to just "spot" treat the affected area?   We have to remember that what we do on our own property often doesn't just effect us.  The consequences can ripple out from us.  Will it be like a pebble in a pond or tsunami?

My lovely wife, Twyla, writes for Enota Mountain Retreat, and you can go check out that blog.  Most of this post will be edited for publishing over there.

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