PESTICIDES AND PUBLIC HEALTH

pesticide

A substance or mixture of substances used to prevent, destroy, or control pests, including insects, rodents, fungi, bacteria, and unwanted plants.

Crop protection, food preservation, reduction of vector populations, and prevention of vector-borne diseases.

What are the main uses of pesticides?

target specific systems or enzymes in pests

What is the main action of pesticides?

Herbicides

chemicals that kill weeds.

Nitrofen

give an example of an herbicide

Zinc phosphide, Warfarin

give an example of a rodenticides

Phorate

give an example of a nematicides

Niclosamide

give an example of a molluscicides

Anilazone

give an example of a fungicides

Copper sulfate

give an example of an algaecides

Chlorine, Peroxides

give an example of a bactericides

insecticides

control insects by direct contact or ingestion

organochlorines

non-biodegradable, persist in the soil, accumulate in fatty tissues, and are highly toxic

DDT, endosulfan

give examples of organochlorines

organophosphates

inhibit acetylcholinesterase, causing nerve overactivation, paralysis, and death

Malathion, Temephos

give examples of organophosphates

carbamates

work similarly to organophosphates but have a shorter residual effect

Propoxur, Bendiocarb

give examples of carbamates

pyrethrins

natural extracts with rapid knockdown effects but no residual activity

Extracts from Chrysanthemum cinerariaefolium

give examples of pyrethrins

synthetic pyrethroids

more stable under light and have a longer residual effect

Permethrin, Deltamethrin.

give examples of synthetic pyrethroids

insect growth regulator

Chemicals that disrupt insect development by interfering with hormones.

Pyriproxyfen

give examples of insect growth regulator

Metofluthrin

highly volatile pesticide that does not persist long in the environment

Blocking cellular processes, disrupting metabolism, altering enzymes, and interfering with hormones

What are the main ways pesticides act against pests?

interfere with sodium and chloride channels or acetylcholine signaling, causing paralysis and death

How do insecticides target the nervous system?

prevent the hardening of an insect’s exoskeleton

How do insecticides that act via desiccation work?

emulsifiable concentrates

Liquid formulations that mix with water, commonly used for their ease of application.

liquid concentrates

Diluted in fuel oil or kerosene for thermal fogging applications

dry powder formulations

Powdered pesticides that can be inhaled or ingested, posing exposure risks.

wettable powders

Suspensions used for residual treatments, as their active ingredients are not water-soluble.

granules

Pesticide-impregnated particles applied directly to water or soil.

Direct toxicity, bioaccumulation, environmental pollution, and insect resistance.

What are the major hazards of pesticides?

bioaccumulation

The gradual buildup of pesticides in organisms, leading to toxicity in the food chain.

superpest

Pests that develop resistance to pesticides and have no natural predators.