IMPORTANCE OF DOSE

Dose-response modeling is almost always a key component of quantitative human health risk assessment and reflects a central premise of toxicology; namely, that "the dose makes the poison."  This phrase ("the dose makes the poison") was used by Paracelsus in the 16th century when he wanted to use mercury to treat syphilis.  The dose is the amount of chemical or other substance entering the body.  The risk is the probability of a particular chemical agent causing a disease or other response of concern and is a function of the dose received.  The function is called the dose-response relationship or dose-response model.

            Dose-response models are a critical component of quantitative human health risk assessment.  Almost all chemical substances have the potential to be poisonous (toxic) if the dose is sufficiently high.  However, at lower doses many chemicals are harmless and indeed, like drugs and vitamins, may be beneficial to health.  Dose-response models reflect the importance of the size of the dose in determining the probability of a response of concern such as a disease or death.