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- Essay Name : 581.txt
- Uploader : Mike Galagher
- Email Address :
- Language : English
- Subject : Drugs
- Title : Effects Of Pot
- Grade : 12th
- School System : High School
- Country : US
- Author Comments : Good Paper. 4 pages long
- Teacher Comments : B+
- Date : 11/1/96
- Site found at : From a Link
- --------------------------------------------------------------
-
- The Health Effects of Marijuana on Humans
-
-
-
-
- Tim Murphy
-
-
-
-
- Introduction
-
- Marijuana has been used as a drug since the beginning of
- time, yet there are still many mysteries about its health
- effects on humans. Marijuana, or cannabis sativa, is a
- preparation of the crushed flowers and buds of female hemp
- plant. The existence of the plant has been reported as
- early as 1500-1200 BC. in China, and cannabis has been
- described as an analgesic as early as 200 AD .
- Since then, an overwhelming number of studies have attempted
- to explain the physical and psychological effects of
- cannabis on humans.
-
- Physical Effects
-
- Physically, cannabis is relatively harmless. Studies
- have observed interesting results, including that it causes
- structural changes in the brain, depresses male sperm
- counts, causes chromosome damage, lowers testosterone
- levels, and damages the lungs. Most of these claims,
- however, have been unreplicated in humans or have been
- contradicted by other work. This section will address each
- of these reported negative side-effects.
-
- Various studies have claimed that cannabis destroys brain
- cells. However, several other studies found no structural
- or neurochemical atrophy in the brain at all. Furthermore, it
- should be noted that Heath's work was sharply criticized for
- avoiding safeguards of bias and reporting "changes" that
- occur normally in the mammalian brain.
- Wu et al. found a correlation between cannabis use
- and low sperm counts in human males. This is misleading
- because a decrease in sperm count has not been shown to have
- a negative effect on fertility and because the sperm count
- returns to normal after cannabis use has stopped..
-
- Another claim made was that cannabis causes chromosome
- breakage. The primary source for this are studies that were
- conducted by Dr. Gabriel Nahas in the early 1980s. Nahas
- observed abnormalities in somatic (not sex) cells of rhesus
- monkeys in vitro (i.e., in test tubes and petri dishes) and
- then made the unjustified conclusion that these changes
- would occur in human bodies in vivo (in the body). Nahas'
- work was criticized by his colleagues and, in 1983, he
- backed away from his own conclusions.
-
- A widely held claim has also been that cannabis lowers
- male testosterone levels. This theory has
- been challenged by several studies that found no
- correlation at all. Marijuana and Health, also, after
- reviewing literature at that time, concluded that "Due to
- conflicting and incomplete evidence, it is not possible to
- conclude at the present time whether marijuana smoking has
- a significant effect upon gonadotropic and testosterone
- concentrations in humans."
-
- The most serious physical danger of using cannabis is in
- smoking it. Inhaling any sort of burnt plant matter is not
- very good for the lungs. Tashkin et al. reports
- decreased gas exchange capacity and the existence of
- particle residue in the lungs of marijuana smokers several
- times greater than for tobacco smokers. Wu noted that marijuana
- is several times more carcinogenic than tobacco. These findings,
- though, must be interpreted with caution. In both studies,
- smoked marijuana was not filtered, while smoked tobacco was.
- Tashkin notes that, "these differences could largely account for
- more than twofold greater tar yield from marijuana than tobacco that
- was measured using syringe-simulated puffs of similar volume
- and duration." Smoking cannabis through a water-pipe will
- filter out water soluble carcinogens and will also greatly
- cool down the smoke. Furthermore, cannabis need not be
- smoked: In Middle Eastern countries, it has been consumed
- through teas and food for centuries, avoiding the
- carcinogenicity of smoke altogether.
-
- Despite cannabis' known negative effects to lung
- function, it has never been reported to cause a single
- instance of lung cancer. Tobacco, though, is expected to
- kill 400,000 people this year. If cannabis is
- so much more dangerous to a user's lungs than tobacco and is
- so much more carcinogenic, why aren't there stacks of
- reports of cannabis-induced lung cancer? One interesting
- theory is that it's because tobacco tars are significantly
- radioactive, while marijuana tars aren't at all. Winters
- found that a pack-and-a-half-a-day smoker of
- tobacco is exposed to 8000 mrem of radiation a year, equal
- to the dose of 300 chest x-rays. A more recent study
- indicates that a pack-and-a-half-a-day smoker receives 16000
- mrem of radiation more than a non-smoker, annually. It
- could also be noted that the mere contents of
- carcinogenic chemicals doesn't necessarily indicate an
- extreme health hazard. For example, roasted coffee
- contains 800 volatile chemicals, of which only 21 have
- been tested on rodents, and of those, 16 were
- carcinogenic. Coffee has never been considered
- a great cancer-causing substance, though.
-
- Cannabis has also been known for its many therapeutic
- uses, including the treatment of open angle glaucoma,
- asthma, and the nausea associated with chemotherapy. It has
- also been described as a tumor retardant, an antibiotic, a
- sleep-inducer, and a muscle relaxant.
-
- Psychological Effects
-
- The psychological effects of cannabis use have been
- described quite many years before the physical effects, yet
- are as accurate today as they were 100 years ago. Following
- is an early account of its intoxicating properties made by
- Dr. John Bell in 1857:
- "I had taken the drug with great skepticism
- as to its reputed action, or at any rate with the
- opinion that it was grossly exaggerated, and I
- accordingly made up my mind not to be 'caught
- napping' in this way again, and to keep a careful
- watch over my thoughts. But while enforcing this
- resolution as I supposed, I found myself, to my
- own astonishment, waking from a reverie longer and
- more profound than any previous. From skepticism,
- to the fullest belief of all I had read on the
- subject, was but a step. Its effects so far
- surpassed anything which words can convey, that I
- began to think I was on the verge of narcotic
- poisoning; yet, strange to say, there was not the
- slightest feeling of inquietude on that account.
- I resolved to walk into the street. While rising
- from the chair, another lucid interval showed that
- another dream had come and gone. While passing
- through the door, I was aware of having wandered
- again, but how or when I had permitted myself to
- fall into the reverie I was perfectly unconscious,
- and knew only that it seemed to have lasted an
- interminable length of time."
- The user of cannabis feels the onset of the "high"
- between 7 seconds (when smoking) and up to 30 minutes (after
- eating). This involves a relaxed and peaceful, yet
- sometimes euphoric state of mind. At high doses, it can
- cause hallucinations. The effects last from 2 to 4 hours
- after the drug is ingested, and it usually leaves the user
- in a relaxed state for several hours after the high. One of
- the main intoxicating properties is that short term memory
- is inhibited for the duration of the high. Thoughts may
- seem unclear, and it might be difficult for a user to
- concentrate on logical-complicated concepts like
- mathematics.
- Long-term effects have been argued for many years. There
- are claims of an "amotivational syndrome" where users are
- said to withdraw from society and lose ambition. In
- reviewing evidence for and against the theory of this
- "syndrome," however, Marijuana and Health concluded that:
- "Such symptoms have been known to occur in the
- absence of marijuana. Even if there is an
- association between this syndrome and the use of
- marijuana, that does not prove that marijuana
- causes the syndrome. Many troubled individuals
- seek an 'escape' into use of drugs; thus, frequent
- use of marijuana may become one more in a series
- of counterproductive behaviors for these unhappy
- people."
- Other studies have found another interesting correlation:
- Shedler reported these results in a longitudinal survey
- of adolescents:
- "Adolescents who engaged in some drug
- experimentation (primarily with marijuana) were
- the best adjusted in the sample. Adolescents who
- used drugs frequently were maladjusted, showing
- distinct personality syndrome marked by
- interpersonal alienation, poor impulse control,
- and manifest emotional distress. Adolescents who,
- by age 18, had never experimented with any drug
- were relatively anxious, emotionally constricted,
- and lacking in social skills."
- Among other findings, Utah Power and Light spent $215.00 per
- year less on health insurance benefits for drug users than
- on the control group, and employees who tested positive for
- cannabis at Georgia Power Co. had a higher promotion rate
- than the company average, and were absent 30 percent less
- (Morris, 1991).
-
- Conclusion
-
- Whether cannabis use causes permanent physical or
- psychological changes in its users is still under question.
- The most serious concern is its effects on the pulmonary
- system, yet, studies have often used poor controls (i.e., no
- filtration) and their results can mislead an uncareful
- reader. Smoking the drug with a different apparatus or
- ingesting it without smoking at all could greatly effect the
- results of these studies.
- The acute psychological effects of cannabis that cause
- its intoxicating properties are no mystery, as any user can
- report. Long term effects of cannabis use could possibly
- lead to the so-called "amotivational syndrome," but
- scientific evidence is lacking.
-
-
-
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