# Is marijuana harmful, and if so, how much? **URL:** \ **Category:** Factual Questions\ **Created:** [October 21, 2012, 7:56pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450 "2012-10-21T19:56:58Z")\ **Posts on this page:** 11\ **Page:** 3
**Author:** ![Kizarvexius](https://avatars.discourse-cdn.com/v4/letter/k/da6949/32.png) [@Kizarvexius](https://boards.straightdope.com/u/Kizarvexius)\ **Post date:** [October 23, 2012, 6:11pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/41 "2012-10-23T18:11:51Z")
Back in high school I wrote a paper on the necessity for drug testing in the transportation industry. One of the most powerful arguments I had at my disposal was an article I found that described the results of short-term marijuana effects on airline pilots. (Please note that I wrote this paper in 1988, and tracking it down might be a little difficult.) A sample group of qualified airline pilots started out the test by running through standard landing procedures in a flight simulator. In the next phase, the pilots were given a joint apiece, then, after an hour, repeated the landing procedures – with predictable results. But here’s the kicker. The final phase was to have each pilot “land the plane” 24 hours later. Even after a full day’s recovery, most of them failed to land their planes safely (one pilot missed the runway altogether)…yet none was aware during that final test of any impairment to their judgement or reaction time. So if you wanna smoke a joint in the privacy of your home or pass the pipe at a party, I’ve no objections. Just don’t expose me to your second-hand smoke (I’m allergic, thank you very much) or plan on piloting a plane within the next 48 hours. ---
**Author:** ![The\_Dord](https://avatars.discourse-cdn.com/v4/letter/t/3be4f8/32.png) [@The\_Dord](https://boards.straightdope.com/u/The_Dord)\ **Post date:** [October 23, 2012, 6:56pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/42 "2012-10-23T18:56:52Z")
> [@VanIsleScott](#): > > In the first pic…under the coffee table…is that a gravity BONG?:eek: > ETA: your post about biting urself made me laugh Self harm isn’t funny. 😕 ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [October 23, 2012, 8:01pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/43 "2012-10-23T20:01:05Z")
> [@The\_Dord](#): > > Self harm isn’t funny. 😕 …to you. It is to someone else. ---
**Author:** ![dataguy](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dataguy](https://boards.straightdope.com/u/dataguy)\ **Post date:** [October 23, 2012, 8:41pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/44 "2012-10-23T20:41:15Z")
> [@C6541](#): > > So I guess the body was designed for morphine, pethidine, and diacetylmorphine since they are ligands of the mu-opiate receptor? Alas it is not, no matter how wonderful dope is. Well I could persist and say that yes, the body is designed for opiods. But my intention was to show that because there are cannabis receptors that’s why it’s non-toxic. That doesn’t appear to be true. So, I may have taken a step too far on this one. Let me just back up to the part where I say it’s non-toxic and leave it there. ---
**Author:** ![misling](https://avatars.discourse-cdn.com/v4/letter/m/3ab097/32.png) [@misling](https://boards.straightdope.com/u/misling)\ **Post date:** [October 23, 2012, 8:59pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/45 "2012-10-23T20:59:25Z")
When I lived in Alaska in the 70s, growing your own supply was legal, and carrying a small amount as well (as best I remember - it’s been a long time). Selling was illegal. Did anybody do any studies on that period in Alaska? were there more illnesses of any type, more car wrecks with mj implicated, anything like that? I new some people who grew pot plants in their living rooms under grow lights. It never seemed to do much harm, though my parents were pissed when my brother’s friend’s parents would let the boys (teen age) light up at their house. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [October 23, 2012, 9:03pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/46 "2012-10-23T21:03:23Z")
The harm caused to individuals consuming marijuana is nothing compared to the harm created by it’s prohibition. ---
**Author:** ![C6541](https://avatars.discourse-cdn.com/v4/letter/c/90db22/32.png) [@C6541](https://boards.straightdope.com/u/C6541)\ **Post date:** [October 23, 2012, 9:04pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/47 "2012-10-23T21:04:02Z")
> [@dataguy](#): > > Well I could persist and say that yes, the body is designed for opiods. But my intention was to show that because there are cannabis receptors that’s why it’s non-toxic. That doesn’t appear to be true. > > So, I may have taken a step too far on this one. Let me just back up to the part where I say it’s non-toxic and leave it there. Yep, it’s pretty benign and there is no denying that. But it’s not because of endogenus receptors, perhaps it has a ceiling effect like LSD, buprenorphine, and the sort. Also, as they say\* “The dose makes the poison.”\* ---
**Author:** ![dataguy](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dataguy](https://boards.straightdope.com/u/dataguy)\ **Post date:** [October 24, 2012, 12:05pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/48 "2012-10-24T12:05:09Z")
> [@Jragon](#): > > In addition, if you’re smoking it as a joint (meaning, instead of taking the psychoactive component in pill form), you are **inhaling burning smoke**. This is not good for you. At all. It will cause tissue damage. > … > It’s at best as harmless as inhaling smoke is ever going to be, and at worst as damaging as alcohol. This just in: [Media Ignored Expert’s Shocking Findings That Marijuana Helps Prevent Lung Cancer](http://www.alternet.org/drugs/media-ignored-experts-shocking-findings-marijuana-helps-prevent-lung-cancer-now-its-med-school?akid=9578.225201.54UyMZ&rd=1&src=newsletter732160&t=10&paging=off) ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [October 24, 2012, 12:36pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/49 "2012-10-24T12:36:47Z")
I’m surprised that no-one has mentioned the [Dunedin Study](http://www.pnas.org/content/early/2012/08/22/1206820109.abstract) - this is a longterm study of 1037 babies in NZ started in 1973. Neuropsychological testing was conducted at age 13, and again at 38. Interviews (including questions on use of cannabis and other drugs) were carried out at intervals from 18. The study concludes that persistent cannabis use does produce measurable neuropsychological decline, and that adolescent onset use produces greater impacts. These impacts cannot be mitigated by reducing or stopping use at a later date - the some of the damage is permanent. This is a well regarded study with solid longterm research behind it. Si ---
**Author:** ![dataguy](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@dataguy](https://boards.straightdope.com/u/dataguy)\ **Post date:** [October 24, 2012, 1:09pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/50 "2012-10-24T13:09:05Z")
> [@si\_blakely](#): > > I’m surprised that no-one has mentioned the [Dunedin Study](http://www.pnas.org/content/early/2012/08/22/1206820109.abstract) - this is a longterm study of 1037 babies in NZ started in 1973. Neuropsychological testing was conducted at age 13, and again at 38. Interviews (including questions on use of cannabis and other drugs) were carried out at intervals from 18. > > The study concludes that persistent cannabis use does produce measurable neuropsychological decline, and that adolescent onset use produces greater impacts. These impacts cannot be mitigated by reducing or stopping use at a later date - the some of the damage is permanent. > > This is a well regarded study with solid longterm research behind it. > > Si I file this under Common Sense. We don’t condone drinking, tobacco use, some prescription medications, during the early, formative years. Once you are an adult, you’re allowed to pick your poisons. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [October 24, 2012, 2:32pm UTC](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450/51 "2012-10-24T14:32:22Z")
Earlier [thread](http://boards.straightdope.com/sdmb/showthread.php?t=663601) on the New Zealand study. [Previous page](https://boards.straightdope.com/t/is-marijuana-harmful-and-if-so-how-much/638450.md?page=2)