Maximum tolerated dose refers to the highest dose of a radiological or pharmacological treatment that will produce the desired effect without unacceptable toxicity . The purpose of administering MTD is to determine whether long-term exposure to a chemical might lead to unacceptable adverse health effects in a population, when the level of exposure is not sufficient to cause premature mortality due to short-term toxic effects. The maximum dose is used, rather than a lower dose, to reduce the number of test subjects (and, among other things, the cost of testing), in order to detect an effect that might occur only rarely. This type of analysis is also used in establishing chemical residue tolerances in foods. Maximum tolerated dose studies are also done in clinical trials.