According to the U.S. Department of Justice, Drug and Crime Facts: Drug Use Among the General Population, approximately 112 million Americans (46 percent of the US population) have experimented with the use of illicit substances, with many operating a motor vehicle while under the influence. But while biological measurement for alcohol intoxication has been around for many years, there is no standard to quickly identify and penalize people who are too high to drive. This is because THC, the mind-altering compound in marijuana, dissolves in fat, whereas alcohol dissolves in the blood. Due to the fact that THC is absorbed in a very different way than alcohol, it is much more difficult to relate behavior to levels of THC in the body or develop a mechanism similar to the breathalyzer to detect levels that impair a person’s ability to drive a car.
Analysis of blood alcohol content can predictably tell you how much is in any part of your body, such as the brain or the liver. The effects of alcohol on the physical condition of the human body can vary greatly, based on the amount consumed, as illustrated by the following chart of Blood Alcohol Concentration or Levels and Effects:
|BAC/BAL||# Drinks Consumed||Effects||Hours needed to metabolize alcohol|
|0.05||1 – 2||Relaxation; decreased inhibition and judgment; decreased reaction time and alertness||2 – 3|
|0.05 – 0.10||3 – 4||Marked decrease in fine motor skills, reaction time, and judgment; may be clumsy; exaggerated behaviors||4 – 6|
|0.10 – 0.15||5 – 7||Vision and perception affected; can be verbally argumentative, emotionally irrational; further impairments in reaction time and judgment||6 – 10|
|0.15 – 0.30||8 – 10||Staggering; slurred speech; blurred vision; sensory and motor skills greatly affected; nausea/vomiting||10 – 24|
|more than 0.30||more than 10||Stuporous; may be conscious but unaware of surroundings; decreased respiration; anesthesia at levels above 0.35; approximately 50% will die at levels above 0.40||more than 24|
There is, however, no similar chart for THC intoxication. The height of a person’s impairment is not determined at the moment when blood THC levels peak; the “high” marijuana produces does not rise and fall uniformly based on how much THC leaves and enters a person’s body and cannot be measured by the same chemical analysis as used with a breathalyzer. Studies prove that THC can still be measureable in the brain even if it is no longer measurable in the blood. Because THC is fat soluble, it moves from the blood to fatty tissues like the brain. There is also a difference in levels of intoxication based on whether weed is smoked or eaten in terms of determining the levels of THC in the body.
These factors pose huge problems for both lawmakers, law enforcement, the scientific community and gadget manufacturers attempting to come up with a biological measurement for marijuana intoxication and laws that parallel the 0.08 BAC/BAL standard for alcohol.