Police say people who smoke weed have 'green tongues,' though there's no scientific evidence


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Sep 19, 2009
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Mariposa County CA
From The Journal Sentinel
Police say people who smoke weed have 'green tongues,' though there's no scientific evidence

Police officers across the United States have used the observation as one of several signs to justify probable cause and make arrests in criminal cases.
Dylan Segelbaum, York Daily Record Published Nov. 7, 2019
YORK, Pa. – In the early morning hours of May 2, 2018, Amanda Guimond was driving through York County when the red and blue flashing lights came on. She was going more than 15 mph over the speed limit.

The Northern York County regional police officer smelled marijuana coming from inside her vehicle. Guimond, he wrote in an affidavit of probable cause, had glassy, bloodshot eyes, lethargic speech and a dazed and confused appearance.

The police officer requested that Guimond stick out her tongue and noticed there was a "green film" on it.

Guimond was arrested on DUI charges after failing standardized field sobriety tests. She said she hadn't smoked in about four hours. More than one year later, she said she's still bothered about the allegations concerning her tongue.

"Not once has my tongue ever changed to green,” said Guimond, 20, a cook and manager who's a medical marijuana patient and lives in Frederick, Maryland. “I was extremely shocked. I was very angry.”

Police officers across the USA alleged in some DUI cases that people who recently smoked marijuana had green tongues. Law enforcement is told to look for a "possible green coating" in one specialized training program that's taught all over the world.

Police point to no scientific studies that show marijuana causes someone's tongue to turn green.

“If someone is going to be convicted, it should be based on facts proven beyond a reasonable doubt,” said Bradley Myerson, a defense attorney in Vermont. “Green tongue has nothing to do with marijuana ingestion, let alone impairment.”

‘As sound as the science behind the earth being flat or that lying makes your nose grow’

The York Daily Record/Sunday News analyzed more than 1,300 DUI cases that reached the York County Court of Common Pleas in 2018 and found at least 28 that mentioned phrases such as "green coating," "green film" and "green tint.”

The research led to a national look at the phenomenon.

Critics, including Scott Harper, a defense attorney in West York, describe it as “kind of junk science.”

Harper argued in a DUI case in York County that there’s “no evidence that a ‘green tongue’ is indicative of any specific degree of marijuana impairment (assuming it actually is evidence of anything at all).”

“I don’t even think it’s real,” Harper said. “They can take pictures of these things. I’m still waiting to see a green tongue someday.”

The National Organization for the Reform of Marijuana Laws was more blunt.

“The science behind marijuana consumption turning your tongue green is about as sound as the science behind the earth being flat or that lying makes your nose grow,” Erik Altieri, executive director of NORML, said in an email.

In 2000, the Washington Court of Appeals upheld a ruling to throw out a case that arose from a traffic stop in which a state trooper partly used the observation of a green tongue to justify a request to search the vehicle.

Even if a green tongue indicates that someone used marijuana, Judge Elaine Houghton wrote in the opinion, the absence of other observations and the many innocuous ways that could happen showed that there was a lack of reasonable suspicion.

“Although we assume the officer's assertion to be true for purposes of this opinion, we are nevertheless skeptical as to its accuracy,” Houghton said. “We find no case stating that recent marijuana usage leads to a green tongue.”

The Utah Court of Appeals ruled in 2004 that a state trooper arrested a man on a hunch when he used observations including a green tongue.

In the opinion, Judge William Thorne wrote that the circumstances in the case and the trooper’s training and experience weren’t enough to support probable cause.

Thorne specifically addressed the green tongue. He noted that the state had “presented nothing, no scientific studies and no case law or other authority, to support the reliability of the trooper's concern.”

It 'just doesn’t seem to go away’

Nick Morrow said he knows the origin of the green tongue phenomenon.

From 1984 to 1995, Morrow worked in the Los Angeles County Sheriff’s Department, where he was a certified drug-recognition expert and instructor. He was a self-described "complete drug nerd" who sought to learn as much information as possible about the subject.

Morrow traced the green tongue back to a handbook called “Identifying the Marihuana User," which was published in 1986.

Forest Tennant, the physician who wrote the guide, included a picture of a person with a green tongue in the handbook. He dedicated it to the California Highway Patrol.

Morrow works as a court-qualified expert witness and testifies for the defense.

Morrow said he doesn’t doubt that police officers are trained to look for a green tongue. It’s been in the law enforcement culture for decades. The phenomenon, he said, “just doesn’t seem to go away.”

He said he’s seen only one credible instance in his career – and it was on St. Patrick’s Day.

Where’s the evidence?
Law enforcement and traffic safety advocates point to the same two peer-reviewed articles, neither of which concludes that marijuana causes someone's tongue to turn green.

The first article was published in the Journal of the American Optometric Association in 1998. Two of the five authors worked in law enforcement: Oregon State Police Lt. Charles Hayes and Senior Trooper Richard Evans.

The paper states, without a citation, that people who've recently smoked marijuana "might have a greenish coating" on the back of their tongues.

In an interview, Karl Citek, an optometry professor at Pacific University in Forest Grove, Oregon, who's one of the authors, said they reported on what police officers were taught in the Drug Evaluation and Classification Program.

The Drug Evaluation and Classification Program is an intensive training course that educates police officers on how to recognize if people are under the influence of drugs and determine what substance is causing impairment.

If optometrists have knowledge of the program, the article concludes, that could allow them to serve as consultants to the police and testify as expert witnesses.

Citek said the authors weren't conducting original research to determine whether marijuana causes someone's tongue to turn green – though he's personally witnessed the phenomenon.

“It was intended to be more educational than anything else,” Citek said. “And, hence, it’s a review paper.”

The second article was published in the Journal of Forensic Sciences in 2017.

Researchers tested blood samples from people who were suspected of driving under the influence.

Police officers documented that 185 drivers had a "coating on the tongue." When the toxicology came back, 96.2% of them had THC in their system. That’s the ingredient in marijuana that causes a high.

“The objective signs of red eyes, droopy eyelids, affected speech, coating on the tongue, and the odor of marijuana are very reliable in indicating the presence of THC in the blood,” the study reads. “This is not surprising as they represent the most common symptoms of consuming marijuana."

Researchers looked at any mention of a coating on the tongue – not specifically a green one. The paper contains the following note on the first page, “Authors all work for The Orange County Crime Laboratory testifying on driving under the influence cases, specifically in regard to marijuana, which represents a possible conflict of interest.”

Ariana Adeva, supervisor of toxicology and one of the authors, said researchers didn't draw any conclusions about whether marijuana causes a coating on the tongue.

Instead, she said, they looked at trends that police officers saw in the field to see whether they corresponded to THC in the blood.

"I think it is a common finding," Adeva said of a coating on the tongue. "We did see a good number of cases including it."

More than one indicator of drug impairment should be considered, experts say
The 2018 Drug Recognition Expert Course instructor guide states that “a greenish coating on the tongue has been documented in two peer‐reviewed articles.” Those two peer-reviewed articles? The same ones from 1998 and 2017.

*This article is too long to post in this forum. read full story here. ~ Burnin1*


Mad Scientist
Mar 5, 2012
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Yeah...it probably from drinking the mountain dew