1. reliable standards for correlating impairment (or time of use) with the amount of THC, the psychoactive substance in marijuana, found in a blood test-much less a real understanding even of what "impairment" means when applied to THC use;Ellen M Kelman;AM. BAR ASS'N,2018
2. Matthew Berger, Why It's Difficult to Develop a Roadside Test for Marijuana, HEALTHLINE;See generally Marilyn A. Huestis & Michael L. Smith, Cannabinoid Markers in Biological Fluids and Tissues: Revealing Intake, 24 CELL PRESS,2018