During Covid, you could have seen, your house, or street being sprayed with chemicals by the Municipality. Such a thing is quite common in the agricultural field. India being an agricultural-based country, such spraying is a regular and most practised practice in the name of eradicating pests. But what is a pest? Ant that moves around, mosquito that flies around and the rat that consume almost one-third of agricultural produce in the world are all examples of pest.
Pest is anything (chemical, an animal microorganism that is s troublesome or destructive to human/animal or plant. Definitely, you don’t like having them with you, right. How to eliminate them? Apply pesticide. Oh. Is it so simple? Wait. Why? Let us see.
But pesticide causes pollution to the environment and becomes a curse instead of a boon. Do you know a pest that survived long not only of pesticides but even of nuclear blast?. Natural pesticides are more beneficial for the surroundings than human manufactured. Natural insecticides degrade quickly, leaving less residue in the soil, and are less likely to damage humans or animals.
Table of content:
Types of pesticides: Organic pesticides and inorganic pesticides are the two major types of pesticides based on their chemical nature.
Based on chemical structure:
Carbonate- These compounds are esters of carboxylic acid
Example: Sevin. The chemical formula of Sevin is C12H11NO2
Pyrethroids-These compounds are called natural pesticides because they are produced from chrysanthemum flowers.
Example: Decis is one of the example of pyrethroids. The chemical formula of Decis is C12H19Br2NO3
Based on the target:
Based on mode of action:
While manufacturing pesticides few things we must keep in mind, These are,
Raw materials used during manufacturing: Active ingredients and inert ingredients.
Active ingredients - These are natural substances and are also synthesized in the laboratory. The role of active ingredients is to kill the insects. Chlorine, oxygen, and nitrogen are examples of such types.
Inert ingredients - These ingredients vary according to the type of pesticide used. The role of inert ingredients is to prevent the coating of the plants from the harmful effects of pesticides. Kerosene, water, and emulsifiers are examples of such types.
Steps involved: There are three steps involved in manufacturing the pesticides.
Step 1 – Synthesizing the active ingredient: Firstly, the organic molecule which is considered for preparing the pesticide is altered in the laboratory. Reagents and catalysts are used for this purpose, and the reactions occur under specific climatic conditions, pressure, temperature, etc. The active ingredient is obtained after this process.
Step 2 –Formulating the active ingredient: The active ingredient prepared in the previous step is mixed with inert powders to make dust pesticides. Inert powders are those which are chemically inactive. Liquid pesticides are also prepared by mixing the active ingredient with carriers. Carriers are either liquid or solid chemicals which are used to help the active ingredients. In this way, the pesticides are manufactured.
Step 3 –Dilution of dust pesticides: Finally, the farmer dilutes the dust pesticides to get the desired proportion which can then be applied to the plants and crops.
Properties: Most of the pesticides are water-soluble and volatile.
The chemical properties of a pesticide are greatly influenced by environmental conditions like temperature, pH, and moisture.
A pesticide's toxicity refers to its ability to harm a living system, such as a human body
or sections of it (such as the lungs or respiratory system); a pond, a forest, and the organisms
that dwell there.
A pesticide's toxicity is determined by a variety of factors.
1. Dose: The amount of pesticide that is applied to a surface, plant, or animal.
2. Frequency: How frequently the exposure happens.
As a result, how much of the substance is involved and how frequently the substance is
exposed gives rise to this toxicity. Based on this two types of toxicity is present.
1. Acute toxicity, 2. Chronic toxicity
Acute toxicity: The toxicity of a pesticide to a human, animal, or plant after a single short-term exposure is
referred to as acute toxicity. Even if only a small amount is absorbed, a pesticide with high acute toxicity
is lethal. Acute oral toxicity, acute cutaneous toxicity, and acute inhalation toxicity are all examples
of acute toxicity.
Chronic toxicity: Chronic toxicity is the poisonous effect of pesticide exposure that occurs over time.
Pesticide chronic toxicity impacts the general people as well as individuals who work directly with
pesticides because pesticides can be found on/in food, water, and the air.
Q1. What are herbicides?
Solution: Herbicides are chemicals that are used to destroy or hinder the growth or development of plants. Alachlor, butachlor, and metolachlor are some examples of herbicides.
Q2. Name one Organochlorine Pesticide.
Solution: One of the important organochlorine pesticide is polychlorinated derivatives of cyclohexane known as Lindane.
Q3. How toxicity of pesticides are measured?
Solution: Rats, rabbits, mice, guinea pigs, and other animals are used to investigate pesticide toxicity. Toxicology studies are only recommendations for evaluating and comparing pesticide harmful effects due to variances in human and animal bodies work.
Q4. What are algicides?
Solution: Algicides are chemicals that are used to kill or prevent algae growth. Copper sulphate, diuron, isoproturon, oxyfluorfen, and simazine are just a few examples.
Question 1. Do pesticides create air pollution?
Solution: The amount of pollutants in our atmosphere, which includes both indoor and outdoor air, is measured by air quality. Pesticides used in agriculture and urban areas have the potential to pollute our air, impacting the health of humans, animals, and plants.
Question 2. What happens if a child breathes in pesticides?
Solution: Pesticide particles can be quickly taken into the circulation by the lungs, making respiratory exposure extremely dangerous. If enough pesticides are inhaled, they can cause catastrophic harm to the nose, throat, and lungs. The most dangerous substances are vapours and very microscopic particles.
Question 3. What is the odour of pesticides?
Solution: Pesticides often contain a number of chemicals, any of which can emit a foul odour.
Question 4. Can boiling water remove pesticides?
Solution: Boiling water does not remove other impurities such as heavy metals, medicines, herbicides, insecticides, other organics, or inorganics.
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