Pesticides
and Insecticides
By Dervla O'Kane (Y11
TA Oct 2002).
These substances kill insects that harm crops. They bring benefit by greatly increasing the yield of produce from the farmer's field. It was once thought that they were harmless and presented no serious risk to humans. However, it is now apparent that they do! Should we then be worried about wind/air borne pesticides and insecticides? Of course we should!!
Pesticides and insecticides have the potential to produce cancers in exposed individuals and mutations in their children. The mutation happens because these substances have adverse effects on our reproductive system. They damage the genes on our chromosomes. These genes are essential because they determine our characteristics and those of our offspring. The material that makes the genes is DNA. It is also used day and daily to make thousands of different enzymes and hormones, each of which have vitally important roles to play in our bodies. When our DNA is altered it begins to make mistakes in building some of these enzymes and hormones. Diseases of the body are then likely to result. If the doctor cannot give you a medicine to overcome the deficiency your body has - then it's 'curtains' for you I'm afraid!
The chemicals also show sub clinical indications of biological damage.
Occupational exposure to fine powders and some organic chemicals have
been found to produce allergies and inhalation can lead to fatal lung cancer.
Treatment consists of minimizing the body’s absorption of the poison.
Cholinesterase inhibitors cause symptoms related to parasympathetic over
activity – chest tightness, wheezing, blurring of vision, vomiting, diarrhea,
abdominal pain, and in severe cases respiratory paralysis.
50% of human poisoning cases involve the use of insecticides, along with
aspirin, cosmetics and barbiturates. Symptoms
of disease include reports of pain, visible conditions, body temperature,
fatigue, loss or gain of weight, pain or tenderness of muscles or internal
organs and high blood pressure. However, sometimes there are no symptoms at al
until it is too late.
The pesticide DDT can cause nausea, irritability, weakness, muscle pain
and convulsions.
Of course one needs to take a balanced view in this debate. Although pesticides and insecticides cause harm to
people they also help to protect people from life-threatening diseases as well.
They are used to guard against the disease malaria, by killing the parasites
that carry the disease, namely mosquitos. Insecticides
have eliminated malaria in most of the western hemisphere.
Around 200 million people are affected by malaria in tropical areas and in
sub-Saharan Africa. Around 1million children under the age of 5 die annually
because of malaria. Some parasites like the mosquito that carries plasmodia have
become resistant to the chemicals and new, more effective chemicals are being
searched for. It is estimated that
over ˝ of the human race harbours one or more species of parasites.
Malaria parasites affect up to 500 million people and kill over 2 million
annually. Malaria symptoms include
chills, sweating and fever.
Pesticide precautions:
§
Use protective clothing and respirators
§
Monitor contamination of equipment and clothing
§
Keep workers out of recently sprayed areas
§
Workers must wash thoroughly after being exposed.
Pesticides and insecticides are both harmful but they are
needed to prevent diseases such as malaria and to protect crops that we need for
food. Although they cause diseases
like cancer it is hard to imagine life without these chemicals, as they are part
of our everyday life!!
Hopefully we will find safer pesticides and safer ways of using them. This way we can still benefit from the fact that they save lives indirectly, through increasing food production and guarding against killer diseases.
Mosquito carrying malaria virus.
Click
here to see how multiple applications of pesticides are typically necessary on
various crops.
Onions and orchard crops receive the greatest number of insecticide applications
due to onion thrip and codling moth pressures. Field corn and small grains
average only one insecticide application each season.
Click here to see how multiple applications of herbicides are typically necessary on various crops.
Click here to see how multiple applications of fungicides are typically necessary on various crops.
Environmental Officers need to be
watchful of DRINKING WATER WELLS.
Wells located in pits, or without grout or a cap, can allow
surface water to carry bacteria, pesticides, fertilizer, or oil products into
your drinking water supply. Proper well design reduces the risk of pollution by
sealing the well from anything that might enter it from the surface.
Controversially, some scientists believe
there is a link between ICI's nerve gas insecticide and CJD.
Click here to read more on
this particular viewpoint.
The ranges in average number of pesticide applications for 11 crops in one survey were 1 to 6 for herbicides, 1 to 5 for insecticides, and 0 to 4 for fungicides.
As well as being carried in the air, these pesticides (and insecticides) can enter into water supplies and present a significant health risk.
What do
you think the cartoonist's message is in the following cartoon?
By
Chuck Asay.
