They increase crop production while saving time and labor. But pesticides can show up where they're not wanted, such as in groundwater or surface water. The greatest concern with using pesticides is the health risk they pose to humans and animals.
Pesticides can cause acute or chronic health effects.
Acute effects occur almost immediately after exposure to large amounts of a pesticide. Symptoms include nausea, dizziness, vomiting, skin rashes, lung and eye irritation, and even death. Chronic effects develop over time from exposure to low levels of pesticides. Cancer, birth defects, organ damage, and disorders of the nervous system are examples of chronic health effects. The Arizona Department of Environmental Quality has detected some pesticides in groundwater through-out the state.