Pesticides are chemical agents that are used to kill or control pests. Pests can include insects, rodents, fungi, and weeds. Pesticides can be natural or man-made. They are usually applied to crops to protect them from pests.
Pesticides work by either killing the pest outright or by making the environment unsuitable for the pest to live in. For example, some pesticides work by preventing the pest from being able to reproduce. This is known as sterilization. Other pesticides work by disrupting the life cycle of the pest so that it cannot develop into an adult and reproduce. This is called growth regulation.
Some pesticides are more toxic than others. The most toxic pesticides are those that kill on contact. These pesticides are also known as acute toxins. Less toxic pesticides may cause illness or death only after repeated exposure over time. These are called chronic toxins.
The effects of pesticide poisoning depend on the type of pesticide, the amount of pesticide that was ingested or inhaled, and how long ago the exposure occurred. Symptoms of acute toxicity include nausea, vomiting, diarrhea, seizures, and coma