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Myth: Marijuana Prohibition Improves Public
Safety
There is no evidence that the prohibition of
marijuana reduces the net social risk of accidents. On the
contrary, recent studies suggest that marijuana may actually be
beneficial in that it substitutes for alcohol and other, more
dangerous drugs. Research by Karyn Model found that states with
marijuana decrim had lower overall drug abuse rates than others;
another study by Frank Chaloupka found decrim states have lower
accident rates too[17] In Alaska, accident
rates held constant or declined following the legalization of
personal use of marijuana[18] In Holland,
authorities believe that cannabis has contributed to an overall
decline in opiate abuse. Recent government statistics showed that
the highest rates of cocaine abuse in the West were in Nevada and
Arizona, the states with the toughest marijuana laws.
Myth: Drug Urinalysis Improves Workplace
Safety
There has never been a single, controlled
scientific study showing drug urinalysis improves workplace
safety. Claims that drug testing works are based on dubious
anecdotal reports or the mere observation of a declining rate of
drug positives in the working population, which has nothing to do
with job performance. Such scientific studies as have been
conducted have found little difference between the performance of
drug-urine-positive workers and others. The largest survey to
date, covering 4,396 postal workers nationwide, found no
difference in accident records between workers who tested positive
on pre-employment drug screens and those who did not[19]
The study did find that drug-positive workers had a 50% higher
rate of absenteeism and dismissals; put another way, however, drug
users had a 93.4% attendance record (versus 95.8% for non-users)
and fully 85% kept their jobs for a year (versus 89.5% for
non-users)! An economic analysis of postal workers in Boston
concluded that the net savings of drug testing were marginal, and
that there could be many situations where it is not cost-effective[20]
Another survey of health workers in Georgia found no difference in
job performance between drug-positive and drug-negative workers[21]
Myth: Random Urinalysis is Needed in
Safety-Sensitive Transportation Jobs
Government rules mandating random drug
testing were promulgated without any prior statistical evidence
that illicit drugs constituted an inordinate safety hazard. Not a
single commercial passenger airline accident has ever been
attributed to marijuana (or, for that matter, alcohol) abuse[22]
Drug tests on rail workers found no elevated incidence of drug use
among workers involved in accidents[23]
Random drug testing of transportation
workers was enacted as a hysterical reaction to a single 1987
train collision, in which 16 Amtrak passengers were killed by a
Conrail train that failed to stop. The engineer and brakeman of
the Conrail train at fault were found to have recently smoked
marijuana, though it was never firmly proven that marijuana caused
the accident. The Conrail engineer had an extensive record of
speeding and drunken driving offenses and was known by management
to have drinking problems. Critical safety equipment that would
have averted the accident was missing or disabled. A subsequent
investigation by the National Transportation Safety Board
recommended that Conrail improve both its management and
equipment, but did not recommend random testing. Nonetheless,
Congress responded by mandating random drug testing on the entire
transportation industry, from airline flight attendants to gas
pipeline workers.
Myth: A Single Joint Has Effects That
Linger for Days and Weeks
While it is true that THC and other
cannabinoids are fat-soluble and linger in the body for prolonged
periods, they do not normally affect behavior beyond a few hours
except in chronic users. Most impairment studies have found that
the adverse effects of acute marijuana use wear off in 2-6 hours,
commonly faster than alcohol[24] The one
notable exception was a pair of flight simulator studies by Leirer,
Yesavage, and Morrow, which reported effects on flight simulator
performance up to 24 hours later[25] The
differences, described by Leirer as "very subtle" and
"very marginal," were less than those due to pilot age.
Another flight simulator study by the same group failed to find
any effects beyond 4 hours[26] Similar
"hangover" effects have been noted for alcohol[27]
Chronic users may experience more prolonged
effects due to a build-up of cannabinoids in the tissues. Some
heavy users have reported feeling effects weeks or even months
after stopping. However, there is no evidence that these are
detrimental to safety.
References on Accidents and Drug Testing:
Alcohol, Drugs and Driving: Abstracts and Reviews Vol. 2 #3-4
(Brain Information Service, UCLA 1986); Dale Gieringer,
"Marijuana, Driving, and Accident Safety," Journal of
Psychoactive Drugs 20 (1): 93-101 (Jan.-Mar 1988); Dr. John
Morgan, "Impaired Statistics and the Unimpaired Worker,"
Drug Policy Letter 1(2): May/June 1989, and "The 'scientific'
justification for drug urine testing," The University of
Kansas Law Review 36: 683-97 (1988); John Horgan, "Test
Negative: A look at the evidence justifying illicit-drug
tests," Scientific American, March 1990 pp. 18-22, and
"Postal Mortem," Scientific American, Feb. 1991 pp.
22-3; Dale Gieringer, "Urinalysis or Uromancy?" in
Strategies for Change: New Directions in Drug Policy (Drug Policy
Foundation, 1992).
Myth: Pot is Ten Times More Potent and
Dangerous Now Than in the Sixties
The notion that pot has increased
dramatically in potency is a DEA myth based on biased government
data, as shown in a recent NORML report by Dr. John Morgan[28]
Samples of pot from the early '70s came from stale, low-potency
Mexican "kilobricks" left in police lockers, whose
potency had deteriorated to sub-smokable levels of less than 0.5%.
These were compared to later samples of decent-quality domestic
marijuana, making it appear that potency had skyrocketed. A
careful examination of the government's data show that average
marijuana potency increased modestly by a factor of two or so
during the seventies, and has been more or less constant ever
since.
In fact, there is nothing new about
high-potency pot. During the sixties, it was available in premium
varieties such as Acapulco Gold, Panama Red, etc. , as well as in
the form of hashish and hash oil, which were every bit as strong
as today's sinsemilla, but were ignored in government potency
statistics. While the average potency of domestic pot did increase
with the development of sinsemilla in the seventies, the range of
potencies available has remained virtually unchanged since the
last century, when extremely potent tonics were sold over the
counter in pharmacies. In Holland, high-powered hashish and
sinsemilla are currently sold in coffee shops with no evident
problems.
Contrary to popular myth, greater potency is
not necessarily more dangerous, due to the fact that users tend to
adjust (or "self-titrate") their dose according to
potency. Thus, good quality sinsemilla is actually healthier for
the lungs because it reduces the amount of smoke one needs to
inhale to get high.
Myth: Pot Kills Brain Cells
Government experts now admit that pot
doesn't kill brain cells[29] This myth came
from a handful of animal experiments in which structural changes
(not actual cell death, as is often alleged) were observed in
brain cells of animals exposed to high doses of pot. Many critics
still cite the notorious monkey studies of Dr. Robert G. Heath,
which purported to find brain damage in three monkeys that had
been heavily dosed with cannabis[30] This work
was never replicated and has since been discredited by a pair of
better controlled, much larger monkey studies, one by Dr. William
Slikker of the National Center for Toxicological Researc[31]
and the other by Charles Rebert and Gordon Pryor of SRI
International[32] Neither found any evidence
of physical alteration in the brains of monkeys exposed to daily
doses of pot for up to a year. Human studies of heavy users in
Jamaica and Costa Rica found no evidence of abnormalities in brain
physiology[33] A 15-year study of 1,318
chronic marijuana users by Johns Hopkins University found no
evidence of long-term decline in mental function[34]
Even though pot does not appear to cause permanent brain damage,
users should be aware that persistent deficits in short-term
memory have been noted in chronic, heavy marijuana smokers after 6
to 12 weeks of abstinence[35] It is worth
noting that other drugs, including alcohol, are known to cause
brain damage.
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