Toxicology
ScienceDefinition
The branch of science that studies the harmful effects of chemical, biological, and physical agents on living organisms. It examines how toxins enter the body, what dose causes harm, and how the body processes and responds to these substances.
Examples
- Determining safe exposure limits for lead in drinking water (EPA sets the action level at 15 ppb)
- Studying how pesticide residues on food affect human health over long-term exposure
- Forensic toxicologists testing blood samples to determine cause of poisoning
Key Fact
The dose makes the poison — Paracelsus's principle means any substance can be toxic at a high enough dose (LD₅₀ measures the lethal dose for 50% of a test population).
Study This Concept
Practice toxicology with free review games in these units: