The use of dose equivalency as a risk assessment index in behavioral neurotoxicology.

This article reports changes with graduated dosage of alcohol on a standardized set of cognitive and psychomotor performance tests and refers to the approach as dose equivalency. Subjects (N = 20) were tested until their performance was stable on 10 tests from a microcomputer test battery. After administration of sufficient alcohol to achieve .15 blood alcohol level (BAL), using breath as the independent variable, the descending branch of the BAL curve was followed by measuring performance at set levels of alcohol. A dose-response relationship was confirmed in all performance tests (p less than .01), and multiple regression was used to select performance subtests that maximally predicted alcohol level. Four subtests were combined into a linear composite that related well to alcohol levels above 0.05 BAL (shrunken R = .75), which was used in a power function to approximate the roughly linear relation above 0.05, as well as the clearly nonlinear function between 0.05 and zero. It is suggested that alcohol, a powerful central nervous system depressant, can be a useful metric in communicating risk in neurotoxicological research.