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AAA Study: Blood THC Levels After Smoking Pot Are Useless In Defining 'Too High To Drive' (arstechnica.com)
An anonymous reader quotes a report from Ars Technica: Blood tests that try to quantify marijuana use are in fact useless at assessing how impaired a driver is, according to a study by the AAA Foundation for Traffic Safety. The study found that people with low blood amounts of THC -- or delta-9-tetrahydrocannabinol, the main psychoactive component of pot -- may still act as if they're really stoned. On the other hand, some people may have THC measurements off the charts yet still act normally. The finding is critical because several states have already set legal limits for the amount of THC a person can have in their blood while driving. AAA concluded that such limits are "arbitrary and unsupported by science, which could result in unsafe motorists going free and others being wrongfully convicted for impaired driving." The conclusion echoes that of other researchers that also noted no correlation between blood THC levels and impairment. Still, there is a need to deter people from smoking pot while driving, AAA argues, as it can impair driving. It recommends that until scientifically valid measures of impairments are put into place, law enforcement should use a combination of behavior and psychological tests to assess whether drivers who use marijuana are safe to drive.
The officer plays an Amy Schumer skit. If the person laughs they are to high to drive.....
The same things could be said about Blood Alcohol levels. Someone unaccustomed to drinking can become severely impaired even with low amounts of alcohol while long time alcoholic reaction times might still be reasonably ok even when way over the limit.
When only "55.5 percent of drug-free people passed the walk-and-turn test," the test is defective.
I used to very successfully know when my friends were stoned by their pupils.
Ann ipad with a front facing camera capturing and analyzing eye movement and pupil dilation during a series of flashes and moving objects should be perfectly suitable for calculating fitness to drive.
It would work for testing whether people who may be in shock should drive too. I am pretty sure it would block most politicians from driving though. Has anyone noticed how many politicians are a bit slow to focus their eyes... as if things like sound are confusing?
Am I driving OK?
Have gnu, will travel.
The hippie going 45 in a 65 zone is high.
The dude sitting there waiting for the stop sign to turn green is high.
I'm all for the legalization of pot nation wide, but I'm also against impaired drivers being allowed to menace the roads. Smoke to your hearts content, but don't smoke and drive.
Time is what keeps everything from happening all at once.
I don't understand, in the modern world where we have complex handheld game devices, why a functional test can't be administered to detect impaired drivers.
If it couldn't be a handheld device, it could be something built into the the back seat of a squad car, or something in a police van. Sort of a virtual reality booth to detect reaction times, etc.
Stoners in a state where they shouldn't be on the road would be identified and could be processed for arrest. People with a buzz on that doesn't impair their driving could be released.
Now the law is made by randomly pulling a number out our a$$.
And now cops are suppose to diagnose being high with physiological test.
Great.
I'll take the random number.
Problem solved.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Same with alcohol we go with lowest safest value - so ZERO. If you want to drink or smoke fine - but have designated driver!
Agreed. And while we are at it, how about we just start enforcing current laws to ticket people that simply drive like shit? Or people that are driving cars that are just too damn dangerous to be on the road? I know...crazy talk. But I see it all the time on the So Cal freeways. People that cant drive at all and frankly the 'driving assist' stuff has made them worse....they couldn't drive for shit but now they have a car that keeps them in their lane or from rear-ending a car...so they use those systems for daily driving and not as a 'last resort' to save their ass. And we also have a ton of crap buckets with shocks that were shot decades ago, bald tires, windows you cant see out of, etc. But nope. The big problem is dealing with the weed folks although I doubt we have more weed folks on the road these days. They were always there. Now its legal. No real change except the jail population. I guess they gotta make up that shortfall somehow.....
Back in the day, I'd cruise down Halsted with a joint in my hand, a beer between by thighs and black beauties in my blood stream with my Ramones cassette blasting. And I never had a problem with impaired driving.
Of course, there was the time I broke an axle and sheared off the entire exhaust system on my '68 Caprice while doing donuts in the snow in the mall parking lot at 3am, but it was only because I was distracted by the fact that none of the snowflakes hitting my windshield were exactly the same.
Goddamn nanny state wants to take away my right to drive fucked up. Not that I get fucked up any more. I'm too old for that now. But every so often, just for kicks, I crank up Rocket to Russia on my mp3 player and do donuts in my mobility scooter down the paper goods aisle at the Wal-Mart.
https://youtu.be/CVQfVtzFd4U
You are welcome on my lawn.
These laws tend to bust casual users, not the long-term abusers who seem to cause the most grotesque accidents.
Instead, rely on the judgment of police officers -- we may have to raise standards in some areas -- as to who is driving safely or not.
If they cause an accident, or get a ticket, allow the officers to demand a breath or blood test. This can be used as evidence at the trial.
Those who cause wrecks while intoxicated will find themselves uninsurable because the insurance companies will not risk the liability.
Actually, there isn't a lot of science behind the BAC limits.
Way back when, when they were looking for an objective test (because field sobriety tests are notoriously subject to bias) they asked the AMA for a recommendation, and they said "well, 0.10 seems a nice round number, and most people at that level are clearly impaired"
then you have neo-prohibitionist organizations like MADD driving the limit lower and lower.
Betcha the legalize pot when self-driving cars become the norm.
C|N>K
I think you might be confusing THC with THC metabolites.
The study found that people with low blood amounts of THC -- or delta-9-tetrahydrocannabinol, the main psychoactive component of pot -- may still act as if they're really stoned. On the other hand, some people may have THC measurements off the charts yet still act normally.
This just in! The reaction of a person to a drug can vary from person to person. Also... not everyone starts with the same level of driving ability before they ingest the substance. So it's not really possible to do a fair "one size fits all" law. This goes for alcohol, too.
Oh, wait, do you know why alcohol and marijuana have an effect on the body? It's because the body is receptive to it's presence. Have you thought about why the body is receptive to these substances? It's because the body produces these same substances on its own.
This line of reasoning is flat out wrong in general. Plenty of receptors in the human body will react to many different molecules, including many that do not normally exist in the body but may have other molecules with similar shapes (or even just similar in one part that sticks out from the molecule).
Ethanol is a pretty simple chemical and appears in a lot of places in biology, including human metabolism. However, the CB1 and CB2 receptors that respond to THC are not in the body because the body has THC, but because of endocannabinoids like AG2 and others. And the body doesn't react the same, as different endocannabinoids will affect the two different receptors in a different ratio and affect additional receptors that THC doesn't.
Citation needed, if you would. Injecting 10mL of any oil into your bloodstream is probably not a good idea, but the LD50 studies I've read put the level somewhere north of 130 mg/kg of pure THC (citing Rosencrantz 1983). Hash oil is potent, but it's unlikely to be better than 60% THC at best, and the higher the potency, the less suitable it would be for injection, since THC is basically a resin. As far as I have been able to determine, hash oil has a density about the same as water, so all told the average person would probably have to shoot up ~14 mL of very pure oil, and even then most of the effects would be due to physical effects of the oil rather than the neurological effects of the drug.
I can definitely see someone dying from injecting oil into their veins. However, as long as you're willing to argue fine technical points, is it still a death from cannabis if the cannabis was immaterial to the cause of death?
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
If I'm not impaired, there is no justification for arresting me. Your argument would make sense if there were no safe level of consumption. Not being able to determine a safe level of consumption via a blood test is not equivalent to not being able to determine impairment. There are lots of drugs which can impair driving for which there is no blood test. Frankly there aren't a lot of good legal or moral arguments for zero tolerance here. It would be a special exception to the rules about impaired driving, and it's not like the potential for harm by pothead drivers is great enough to offset the harm resulting from arresting unimpaired drivers. And I'm not going to argue strongly that it applies in this case, but there is some level of potential to harm others which is inherent to living in a free society. You have a very high bar to meet before broaching the subject of 'zero tolerance', considering we don't necessarily apply that rule even in the use of deadly force. I'm not so sure you've really though this through...
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
A Danish driver was convicted forDUI after sharing a smoking area with marijuana smokers. In Denmark, the acceptable level is the detection limit, and blood tests are really really effective for marijuana. He was sentenced to lose his license for 3 years and 6 months.
However, it is worth noting that the police had stopped him for suspected drunk driving, and then decided to do a drug test since the alcohol level was below the legal limit and he seemed to be impaired.
Finally! A year of moderation! Ready for 2019?
That's interesting, and close enough! I'm currently studying some IPv6 features!
Slashdot, fix the reply notifications... You won't get away with it...
I think the politics of legalization almost requires a believable and workable DUI measurement system.
One of the many false narratives against legalizing marijuana for recreational purposes is the "ZOMG, STONED DRIVERS11!!" scare tactic. The idea that if you legalize it for recreational purposes, the roads will suddenly be flooded with stoned drivers, threatening the safety, moral purity and precious bodily fluids of God-fearing Christians and their children driving down the road.
It's a scare tactic because it presumes that having pot illegal means nobody is doing this now, and pretty much anyone who smokes marijuana knows that's laughable as everyone *I* know who smokes pot is willing to drive when high, although most have some kind of responsibility threshold where they won't drive past some point. One hit in the last hour? OK. Two joints and then rush hour? Maybe not.
And for legalization advocates, it has to be something other than a zero tolerance policy. Because THC is detectable weeks after smoking pot, a zero tolerance policy is almost the same as continued criminalization. If you can only smoke pot and then not drive for 4 weeks until you test clean, what's the point? And of *course* cops that hate the idea of legalizing pot (one less harassment tool in their toolkit), will selectively enforce pot DUIs against the same people they selectively enforce pot laws against now -- minorities, young people, anyone they think they can harass. A white suburban woman in a late model SUV doing 11 MPH over the limit will need a dashboard bong to get tested, a black man in a 15 year old Cadillac pulled over for the same offense will get tested.
For legalization advocates, having a believable system means the ability to discount the argument that legalization will lead to a surge in pot DUIs, accidents and chaos. Note I said believable, not necessarily scientifically valid. Without it, there are reasonable people who will buy into the stoned driving epidemic fears and vote against it, as well as politicians who will use it as a wedge. So long as the policy is both credible enough to silence fear mongers and reassure the public AND loose enough that it can't be used as a harassment tool (ie, enough false negatives to balance false positives) it's *politically* workable.
I think the best thing would be to focus on a scientifically valid test of impairment that suspected stoned drivers would need to fail before any THC level test could be used. It would let some stoned drivers off the hook, but my sense is that most mildly stoned drivers are still within the normal range of general driving safety skills anyway. I drive more than average (25k mi per year) and there are an awful lot of just plain bad drivers out there, and I'd suspect that most average and better drivers are still more competent mildly stoned than a lot of unimpaired drivers with poor skills.
From the Ars article:
"55.5 percent of drug-free people passed the walk-and-turn test perfectly"
Only 55% of the sober people passed the test? That's the scary part.
If you post as Anonymous Coward, don't expect a reply.
Here we have definitive proof of how slow pot smokers move.
I come here for the love
get your munchies. get your redbox. get everything you want together BEFORE you get high. We should just have PSAs to educate novice stoners about planning ahead so they don't have a reason to drive after they get high because once you're there, it takes something pretty major to get you up and moving until it wears off. At least that's been the case for me.
Makes the little veins in the eyes go red, but visine takes care of that.
LSD and shrooms, those dilate the pupils. And massively fscked with my driving to the point I didn't even try.
Best Slashdot Co
Try this: Federal Obstruction of Medical Marijuana Research
... have trouble selecting and interpreting medical tests.
And it turns out cops with no medical training whatsoever are even worse. Who'd have thunk it?
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Thank You!!!
At least someone tries to validate. We need more source citings.
Now more people can form a better view and demand government check and balances.
if you see me, smile and say hello.
Exactly the same is true with blood-alcohol level. The current .08 level and proposals to drop it to .05 or lower has nothing to do with the 0.15 level proposed by doctors. It is all by politicians seeking votes and pressure groups like MADD.
The whole question that is commonly asked is a bit of a mistake.
What people don't seem to realize is alcohol has some very specific features that have nothing to do with reaction times; and it is quite evident in some of the studies on pot and driving.
Quite simply, drunk people, when asked to rate how impaired they are, consistently underestimate their impairment and, this problem gets worst as they drink more.
Most other psychoactive chemicals don't do that. Marijuana users do not underestimate their impairment. Users of most drugs, other than alcohol, are generally able to compensate adequetly. Its alcohol that specifically has a problem with this.
"I opened my eyes, and everything went dark again"
If they can't figure out an threshold that objectively represents a dangerous level of impairment, then just disallow it entirely when one is driving.
Are you aware that this means that nobody who consumes THC would effectively ever be able to drive and are just trolling, or are you ignorant of the fact that you can show up as a user a month later and just flapping your head?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The big problem is dealing with the weed folks although I doubt we have more weed folks on the road these days. They were always there. Now its legal.
Use has gone way up now that it's legal, because of availability and lack of concern over prosecution. Over the years, many people told me that they would use it more if it were legal... and now it is. So color me unsurprised.
Tons more people are going into the weed business every day. That's not because there's a lack of demand.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I am suggesting that after a sufficient period has elapsed, their THC levels would likely be sufficiently close to zero that it would not be practically measurable, particularly with field equipment that is generally going to be much cruder than what you would be able to use in a proper lab facility.
File under 'M' for 'Manic ranting'
I am suggesting that after a sufficient period has elapsed, their THC levels would likely be sufficiently close to zero that it would not be practically measurable, particularly with field equipment that is generally going to be much cruder than what you would be able to use in a proper lab facility.
Sadly, in most states (including California) you agree to a blood draw when you drive. If you refuse it, guess what happens?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Between 2 and 7 days for a blood test. So you are basically saying that if you regularly use marijuana you can no longer drive.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
What that THC lingers in your blood for up to a week? That is not a fairy tale, it is reality. (the month is for urine tests which do not test for THC but the byproducts created when your body breaks it down).
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
Blood tests can show a positive result for THC for up to a week after use (for regular users). So basically you would be barred from driving all week long if you were a weekend smoker.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
Zero tolerance works adequately for alcohol and driving in some jurisdictions, or when a person has that restriction on their driving license. Why wouldn't it work for THC?
File under 'M' for 'Manic ranting'
Well that rules pretty much everyone out.
We all have some level of ethanol in our systems. The same is true of THC, CBDs, and various alkaloids, opioids, and various other psychoactive substances.
I think that the poster who suggested that everyone be incarcerated and not ever be allowed outside because "danger" is really on to something... if we want to continue to live in a constant state of paranoia.
Or... we could require sobriety tests, reaction tests, and those tests should be compared against a baseline (because everyone's reaction time varies), or maybe consider 250ms reaction time to be acceptable. However even that is unacceptable, because stuff like vertigo, ear infections, migraines, etc. can impair balance even though someone so afflicted is absolutely fine to drive.
The solution is to presume innocence until proven guilty, but deal with reckless driving (and I don't mean speeding; I mean failure to yield, failure to stop at stop signals (be it signs, lights, etc.), causing others to brake or evade collision when they otherwise should not have had to, etc.) harshly and get rid of all other superfluous laws... and perhaps implement real driving tests (such as having to drive through two cities during rush hour) rather than the current "drive around a block with no traffic" driving test that most communities use, then we can actually start using our highways at speeds for which they were originally designed (120-130mph based on 1960s-era suspension and brakes... which would essentially mean unlimited speed today).
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
If you read the Journal of Studies on Alcohol and Drugs, you'd know that marijuana didn't even increase the risks of crashes and fatalities.
http://www.ncbi.nlm.nih.gov/pm...
J Stud Alcohol Drugs. 2014 Jan; 75(1): 56â"64.
PMCID: PMC3893634
Drugs and Alcohol: Their Relative Crash Risk
Eduardo Romano, Ph.D.,a,* Pedro Torres-Saavedra, Ph.D.,b Robert B. Voas, Ph.D.,a and John H. Lacey, M.P.H.a
Abstract
Objective: The purpose of this study was to determine (a) whether among sober (blood alcohol concentration [BAC] = .00%) drivers, being drug positive increases the drivers' risk of being killed in a fatal crash; (b) whether among drinking (BAC > .00%) drivers, being drug positive increases the drivers' risk of being killed in a fatal crash; and (c) whether alcohol and other drugs interact in increasing crash risk.
Method: We compared BACs for the 2006, 2007, and 2008 crash cases drawn from the U.S. Fatality Analysis Reporting System (FARS) with control drug and blood alcohol data from participants in the 2007 U.S. National Roadside Survey. Only FARS drivers from states with drug information on 80% or more of the drivers who also participated in the 2007 National Roadside Survey were selected.
Results: For both sober and drinking drivers, being positive for a drug was found to increase the risk of being fatally injured. When the drug-positive variable was separated into marijuana and other drugs, only the latter was found to contribute significantly to crash risk. In all cases, the contribution of drugs other than alcohol to crash risk was significantly lower than that produced by alcohol.
Conclusions: Although overall, drugs contribute to crash risk regardless of the presence of alcohol, such a contribution is much lower than that by alcohol. The lower contribution of drugs other than alcohol to crash risk relative to that of alcohol suggests caution in focusing too much on drugged driving, potentially diverting scarce resources from curbing drunk driving.
Hey is that a stop sign way up there better slow down or the cops are gonna pull us over.
A friend of mine tested positive during preselection for clinical tests. very small amount, but still tested positive. All because he was at a party where people smoked the week before. What about if my downstairs neighbors smoke on their balcony? I'm gonna have traces too. There are no ways (yet) to measure the inability to drive based on THC in bloodstream. One could argue the same for alcohol, as me drinking 8 beers won't have the same effect as someone else drinking 8 beers, even if same BAC, but Ethanol won't stay in the body for weeks like THC. Besides, kinda hard to inhale second-hand beer compared to someone smoking next to you.
I've got better things to do tonight than die.
" A white suburban woman in a late model SUV doing 11 MPH over the limit will need a dashboard bong to get tested, a black man in a 15 year old Cadillac pulled over for the same offense will get tested."
Amen to that. Ex girlfriend driving her bimmer? driving while black. Me driving the *exact same* car? no problem whatsoever, she's just the dude's GF.
I dunno how it compares in other major cities, but in Montreal there IS such a thing as racial profiling...
"there are an awful lot of just plain bad drivers out there, and I'd suspect that most average and better drivers are still more competent mildly stoned than a lot of unimpaired drivers with poor skills."
Or cellphone using drivers, but those get a free pass here...
I've got better things to do tonight than die.
True, in reality, tired driving is evey bit as dangerous as stoned driving and can even reach the danger level of drunk driving. The reason why you are impaired is far less important than the fact you are impaired. The problem mainly is objectivity when it comes to enforcement since, sadly, with many cops, whether you're brown or have tattoos will likely be as much of a factor as your actual impairment if it is left to the cops' judgement. I don't have a good solution for this.
"Be particularly skeptical when presented with evidence confirming what you already believe." -
Because unlike alcohol, testing how much THC is in blood tells you nothing about the impairment of the driver. One could have smoked the previous weekend, been sober for several days and then get a DUI for something they did a week ago. Because everyone's metabolism is different you would have no way of knowing when your system has purged all readable amounts of THC.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
Actually BAC has a pretty direct correlation to impairment. You may not notice it, but it readily shows up in tests. Your reaction times will be slowed, your judgement will be impaired, whether you think it is or not.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
THC levels might say nothing about impairment, but I think it would still say something about how *recent* the last time was. Regardless of impairment, zero tolerance means that no threshold is considered "safe" (even if one clinically otherwise might be), and that one who uses it should not drive for at least 8 to 12 hours.
File under 'M' for 'Manic ranting'
Sure, there's a more direct correlation, but it's not perfect either. Some people might be unable to stand up at .08 and others will be able to stand up and talk in a coherent fashion at 0.12.
I'm not saying reaction time won't be slower, but an experienced drinker might be able to hide it more. Besides, a good driver (even if slightly impaired) will be safer than a sober bad driver.
I've got better things to do tonight than die.
Here we have definitive proof of how slow pot smokers move.
Tai chi is just kung fu for pot smokers.
Star Trek transporters are just 3d printers.
I once had a layover in an airport and ended up having a beer with a random guy at the airport bar. He turned out to be a big shot at the National Highway and Traffic Safety Administration (NHTSA) and he was on his way to Phoenix for a special cop meet up where police from all over the country descend on one city to do a blitz on drunk drivers. I asked him how come there's no such thing as a breathalyzer for marijuana. He was very quick to answer. The NHTSA has of course done plenty of studies on pot-smoking drivers and pot-smokers who have accidents. The fact is: when people smoke pot they drive slower, and usually more cautiously. He said, it's the opposite of alcohol drinkers. The statistics show that very few accidents are caused by pot-smoking. He said that for these reasons they do not focus much attention on pot-smoking drivers.