Pesticides are poisons designed to kill pests. A pest could be an insect, other type of animal, or plant that threatens to destroy an agricultural crop, food, or livestock; but a pest could also be an unwanted presence in your home, such as a family of rats in your attic, or weeds in your garden.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/are-pesticides-harmful-to-humans