As states in the U.S. begin to experiment with marijuana (cannabis) legalization, society is seeing the need for a test similar to the "breathalyzer" used to detect blood alcohol levels in drivers.
The main pharmacologically active constituent of cannabis, Δ9-tetrahydrocannabinol (THC), has been shown to decrease psychomotor performance significantly in single doses for up to 3 hours under actual driving conditions (and up to 24 hours in lab studies). Still, the ideas persist that marijuana is "natural, not harmful," and "not as bad as alcohol"—especially among young people.
This summer, Holomic LLC demonstrated the Holomic Substance Abuse Test Assistant (HSTA), an economical, quantitative smartphone-based test assistant for photonics-enabled assessment of intoxication by marijuana, among other substances.
If you know how current tests work to measure marijuana use, and you know that THC remains detectable in the body for weeks, you might wonder how roadside testing with instantaneous results is possible. Holomic's system exploits the fact that THC in saliva indicates recent use.
Because of societal and legal issues, implementation of such systems has a long road ahead. But at least developers like Holomic have got us on that road.
