What is a pesticide?
Simply put, a pesticide is any substance used to control pests. It’s a broad term, and includes herbicides, which are used to control unwanted plants. When most people think of pesticides, they probably assume that they’re used to kill pests; however, effective pest control often involves repelling pests.
Ancient Pest Management
As technology and science improves, pesticides have become more effective and easy to distribute, but the idea of pesticides is not new. In fact, humans have been using pesticides for thousands of years to protect their crops.
- Sulfur was used as early as 2,500 BC in ancient Sumer (near the modern-day Persian Gulf) to control insects and mites.
- The ancient Chinese controlled body lice with mercury and arsenic.
- Many cultures have used salt and/or sea water to control weeds (or to render soil useless in times of war).
- The Romans burned sulphur to kill insect pests.
- Persians used pyrethrum powder, made from dried Chrysanthemum flowers, to protect stored grain.
- In the third century BC, the Chinese burned herbs to repel mosquitoes.
- Farmers began to resort to more toxic chemicals in later centuries, and treated crops with substances like arsenic, mercury, and lead. Natural insecticides included pyrethrum and rotenone.
The Pesticide Century
If one century can be remembered as the century of pesticides, it is the 20th. Researchers developed numerous synthetic pesticides of varying effectiveness; some were branded and sold without any information about the active ingredient(s). Eventually concerns about misuse led to new restrictions on the manufacture and application of pesticides, enforced by the Environmental Protection Agency (EPA), which was founded in 1970. Numerous pesticides have since been banned to protect the environment and human health, though the EPA has frequently been accused of making decisions based on politics rather than science.
The 21st Century and Beyond
In this era of strict regulations, the most popular pesticides include organophosphates, carbamates (e.g., Sevin dust), deltamethrin, fipronil, and pyrethrins (e.g., Talstar). As opposed to banned pesticides that remained active for years, many of these break down within months. Manufacturers continue to research and develop new pesticides, with the goal of making them safer and more effective.