12. Dangers and
Problems, Real and Alleged [1]
Is Marijuana Dangerous?
While
there is no such thing as a completely safe drug, marijuana is one of the least
toxic substances known to modern medicine. The Shafer Commission, appointed by
President Richard Nixon, concluded that "a careful search of literature
and testimony by health officials has not revealed a single human fatality in
the U.S. proven to
have resulted solely from the use of marijuana." It has been calculated
that the amount of marijuana required to make up a lethal dose is so great that
it is virtually impossible for any human being to consume it; after smoking
large amounts of marijuana over a concentrated period, the smoker would suffer
a fate no worse than falling asleep.
In 1970, a team of American researchers went to Jamaica to conduct a
two-year study on the long-term effects of marijuana use. Sponsored by the
Center for Studies of Narcotic and Drug Abuse and by the National Institute of
Mental Health, the study was published in 1975 as Ganja in Jamaica. It indicated
that there were no significant differences between ganja smokers and a control
group with respect to chromosome damage or organic brain damage; in fact, there
were no significant differences in any medical, psychiatric, or psychological
areas between the two groups. The sole exception was an indication of
functional hypoxia (low oxygen level in body cells) among long-term heavy
cannabis smokers.
The modern period of marijuana research began with the
Weil-Zinberg experiments at Boston University in 1968;
since that time thousands of human subjects and many thousands of laboratory
animals have smoked or otherwise ingested huge amounts of marijuana or THC, as
scientists have attempted to learn more about the effects of cannabis. The
amount of marijuana research carried out during the 1970s has made marijuana
one of the most widely studied drugs in history, and what is now known is
radically different from what was believed in the 1960s.
Not all the evidence is in, but the claims that marijuana is
dangerous to human health have not been accepted by most researchers. The
public depends upon the news media to provide information about science and
medicine; unfortunately, media coverage tends to give more attention to
dramatic reports about marijuana's alleged dangers than to reports that suggest
that the drug is relatively harmless. In the seventies, a series of
controversies arose over medical reports on the possible effects of marijuana;
some of the more significant are summarized here.