Stanford engineers hope a new saliva test will someday be the key to catching drivers who've taken too many tokes. Right now, the only way to detect marijuana in the body is through a blood test or urine sample collected in a hospital -- not exactly a convenient roadside solution.
As states continue to legalize various forms of cannabis use, law enforcement will increasingly be looking for ways to detect impairment from pot. More than 20 states and the District of Columbia already allow some sort of cannabis use, and legalization is on the ballot in five states this November.
Stanford's “potalyzer" is a handheld device that allows officers to conduct a simple field test to determine a driver's concentration of THC, the chemical in marijuana that impairs drivers. In just a few minutes, a traffic cop could swab a saliva sample from a driver's mouth and insert it into a device with magnetic biosensors that can then send the results to a smartphone or laptop.
Although companies such as Cannabix Technologies and Hound Labs have developed breathalyzer tests for marijuana that work like those used to test for alcohol, Stanford researcher Tyler O’Brien Shultz says he’s highly skeptical that marijuana levels can be captured through air.