Problems of
Pesticide Residues
Pesticide: Any substance intended for prevailing,
repelling, attracting any pest including unwanted plant as animal during production
transport and processing of food and animal food.
Residue: Residue is a term applied when any pesticide
applied to soil, plant or broadcasted in soil and due to the physico- chemical parameters
(environmental parameter) it is subjected to change in chemical form. Thus some toxic
substances remains as such or its metabolites. Residue is a reminenant of the chemical
including its degraded products with a span of time or time factor when exposed to
environment including degraded products of adjuvant.
In environment
pesticide residue obtained from plants. Out of which 20% remains on plant and 80% fall in
soil and when you irrigate the crop and then soluble amount go into water and this leached
water is collected at some place and it will pollute ground water.
When fodder
Alpha-alpha is grown for the fodder purpose and given to animals, then in milk of those
animals residues of organochlorine pesticide are found and are lipophilic in nature which
causes harm. When Pesticide 25kg a i/ha applied, residue after harvest of crop is found in
PPM.
Pesticide residue is
major problem in chlorinated and organophosphorus compounds, as they are not easily
degraded. In chlorinated hydrocarbon bio-magnification occurs i.e., pesticide residue goes
into the soil then into water and enter in organism or in food chain these molecules get
accumulated in fats and therefore their concentration increases. Which has long term
effect like teratogenic (birth defect), carcinogenic effect which is seen particularly in
birds whereby thickness of shell is reduced. Sometimes lethal mutation also occurs.
A concern more
specific to pesticides is any danger attached to chronic regular intake of small
quantities as residues in our food. Like radioactivity, pesticide levels decrease with
time along a hollow curve. If half the pesticide has gone in 5 days, the ¼ will still be
there after 10 days, 1/8 after 15 days, 1/16 after 20days, and so on. Great alarm followed
the discovery in the 1940s that post-mortems of, for example, accident victims revealed
measurable quantities of DDT in the body fat of nearly all inhabitants of developed
countries and that no restaurant meal could be found free of DDT residues in such
countries. The alarm was heightened by the linear increase of these DDT residues in body
fat year after year. However, it could later be shown that man eventually attained a
plateau level of about 10 parts per million (ppm) DDT in body fat, and that thereafter
further intake was balanced by elimination from the body. More modern pesticides also lead
to residues in our food, but are much more quickly broken down and lost from our bodies. |
Ag.
Technologies
(Pest Mgmt.)
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