Article 3-4 Pesticides
by Erwin Rosario, Atami, Holland
Pyrethrum is made from the flowers of an African type of chrysanthemum. Its Latin name is Chrysanthemum Cinerariaefolium. It is very poisonous to insects and bees, because it works on their central and peripheral nerve system. This causes the impulse transference to be disrupted. After convulsions death will follow. An insect that is contaminated by the toxin will drop dead on the spot. If the concentration is high enough, the insects will be dead instantly. Pyrethrum is less poisonous to flies and cockroaches. Fish on the other hand are very susceptible to Pyrethrum. To mammals it is less harmful. The deadly dose for humans lies around 100 grams. Pyrethrum can however also cause allergic reactions, like rash, to those people sensitive to it. Pyrethrum is mostly grown in Kenya. At daylight Pyrethrum disintegrates into innocent inactive compounds, within a few hours.
Because Pyrethrum decomposes quickly, synthetic compounds are sometimes added to the natural product. For instance Pyrethroids and Piperonyl Butoxide. Pyrethroids are synthetic compounds made by the chemical industry. Pyrethroids cannot be decomposed as well as the natural Pyrethrum. Piperonyl Butoxide is not a pesticide, but a booster (synergidae) of Pyrethrum. It inhibits demolition and therefore increases the effect of Pyrethrum. It is however also a synthetic compound. So by far, not all products, which are named Pyrethrum, are in fact "natural" or "environment-friendly".
- Nematocides kills little worms and larva
- 1988 yield per square meter:
Tomatoes 34 Kg; 1998=63 kg
1988 yield per square meter
Paprika 20 Kg; 1998=34 Kg
1988 yield per square meter
strawberry 3.5 Kg; 1998=4.5 Kg
- Reasons why not to use pesticides:
Safety of workers
Inadequate production methods in third world countries
- Explication of nerve gas:
Nerve cells (neurons) contain threadlike ends (axons). The nerve impulses go from the central nerve system (brains, spinal marrow) via the neurons to the different organs and muscles. When an axon ends, the electronic message needs to be transmitted, for instance to the axon of another nerve cell or muscular cell. The gap that needs to be narrowed (around 20 nanometers: nano = millionth) is called the synapse.
Stimulus transfer within the synapse occurs by using biochemical substances. When a stimulus reaches the end of an axon, a small amount of acetylchline is released and then stored inside very small blisters at the very end of the nerve vessel. The released acetylcholine diffuses (diffusion) to the receptor places of for instance a neighboring muscle vessel membrane. After the impulse has been transmitted in this manner, the receptor places are released again.
This occurs under the influence of enzyme cholinesterase, which through the molecular bond of acetylcholine is divided into acetic acid and chorine. These small compounds can no longer bind to the receptor places.
An important group of insecticides are the phosphor ethers. The effect of phosphoric insecticides (parathion, Malathion, dichlorinefox and demeton) is based on the blockade of the enzyme cholinesterase. Because of the blockade an overdose of acetylcholine inside the synapse is created. The consequence is an "over stimulus" of the receptor places and uncontrollable muscle contractions and muscles paralysis can occur. With insects this may lead to paralysis of the respiratory muscles, which can lead to suffocation.
- When residues of synthetic pesticides (parathion included) are heated, a great risk is carried. At the combustion of chemical residues of pesticides, dioxins can be released. These are the most poisonous compounds known up to now. These dioxins are also released when lighting a cigarette or other stimulants, which have been treated with synthetic pesticides. They are very harmful to mankind.
- The use of pesticides has caused numerous problems for the environment. There is no way to keep pesticides out of water sources. This contamination hurts the ecosystem around the water, the wildlife, and the humans who drink the water. Also pesticides cause soil degradation. If we continue to use pesticides, the soil will become less effective and crop yields will begin to drop. Furthermore pesticides add to the depletion of the ozone layer and add to the greenhouse effect (for example methyl bromide).
- When we introduce foreign chemicals into our food, we run the risk of contamination. The food grown using pesticides contains chemical residues. Although these chemicals are constructed to have no adverse effects on humans, it is impossible to know the long term effects of pesticides residues. On a more alarming level, 31 people died from pesticides contaminated bread at a party in the Sudan. This contamination was caused by improper application of pesticides and is very common in third world countries which lack the same application tools.