New technology improves marijuana detection in drivers

CCTV News

Marijuana legalization may lead to increased traffic accidents

In the recent U.S. presidential election, voters in California, Massachusetts and Nevada all approved recreational marijuana initiatives joining the states of Colorado and Washington, which have already legalized the drug.

CCTV America’s Mark Niu reports.

Marijuana legalization may lead to increased traffic accidents

Marijuana legalization may lead to increased traffic accidents

In the recent U.S. presidential election, voters in California, Massachusetts and Nevada all approved recreational marijuana initiatives joining the states of Colorado and Washington, which have already legalized the drug. CCTV America’s Mark Niu reports.

But, authorities are now warning the legalization of the drug could lead to an increase in traffic accidents and are looking for new technologies to combat the danger.

The American Automobile Association found that since the state of Washington legalized marijuana, fatal crashes involving drivers under the influence of the drug have doubled. Despite that, the only way for police to reliably detect marijuana’s psychoactive agent THC in a driver is through a time-consuming blood test.

“To pull over a driver and try to assess whether they have certain levels of THC in their system is really practically impossible right now,” said Cynthia Harris, Spokesperson, American Automobile Association, adding “by the time for instance an officer takes a sample, first of all there has to be a warrant involved, transportation of the sample taken to a lab. All of this will last at least two hours or more.”

At Stanford University, researchers are working with THC samples like these that are 200,000 times the legal amount to drive with. Professor Shan Wang from Ningbo, China is developing a detection method based on magnetic nanotechnology– the same technology he’s worked with for years in screening for diseases like cancer and hepatitis.

All that is needed is a suspect’s saliva sample that’s squeezed onto a chip containing a nanoparticle solution that reacts to THC. From that sample, an officer can then read the results on a mobile app.

“Turns out that it works like charm. We can do this test as fast as three minutes altogether. Because if you don’t do the test fast enough, the concentration of saliva and blood will drop so you may not be able to deter the driving under the influence,” Professor Wang said.

Even though recreational marijuana has become legal in many states, there’s still no consensus on how much THC in the bloodstream should be considered illegal. But, Wang says his test is sensitive and quantifiable—both extremely important factors for cases taken to court.

Across town in Oakland, California, a startup called Hound Labs is also developing a test that would be even less invasive—a breathalyzer—for marijuana. But Wang says measuring breath is more difficult because the THC content is much lower.

“Sincerely wish all startups out there will be successful because there’s really no tools for police officers to use right now. So anybody who can do it is really great for society and in terms of technical challenges. I think the concentration of THC and saliva right after use is very high, so for us, it’s relatively easy to do fast and quantitative detection,” Professor Wang said.

Wang hopes to have a prototype for field-testing ready in several months and a product on the market in about a year’s time.

Police officers have already warned him about the imminent danger on the roads and of their hopes that science can come to the rescue.


Shan Wang discusses testing drivers for marijuana


Cynthia Harris on the shortfalls of testing drivers for marijuana

  • Social Conservative

    Well then, if accidents increase by a marginal amount then by all means, keep throwing adults in cages on a daily basis for the simple act of consuming a plant.

  • Paul Rosen

    The Drug and Alcohol Crash Risk report, DOT HS 812 117 February 2015, produced by the Department of Transportation’s National Highway Traffic Safety Administration, found that while drunken driving dramatically increased the risk of getting into an accident, there was no evidence that using marijuana heightened that risk. In fact, after adjusting for age, gender, race and alcohol use, the report found that stoned drivers were no more likely to crash than drivers who were not intoxicated at all.