Ask A Scientist General Science Archive

name         gary
status       educator
age          30s

Question -   My son recently brought a one-paged paper home from
school, titled "Marijuana and Cancer", published by Signal Press.  It
states:

"There are more cancer-causing agents in marijuana than in any other
substance presently known to man."

"Marijuana contains more carcinogens (150 more) and in greater
concentration than tobacco."

"Smoking 3 to 5 joints a week is equal to smoking 16 cigarettes a day"

"Three joints smoked per week for 3-6 months carries the same
probability of developing lung cancer as smoking a pack of sigarettes
daily for 20 to 30 years."

I'm sure that it's true that there is a link between marijuana and
cancer.
But some of the statements seem outrageous to me.  Are they true?
-----------------
While I am not advocating the use of marijauna, the "scare" tactics such as
you quote above are ineffective and counterproductive. Moreover, kids
between that ages of about 10 and 20 have "invincibility / immortality"
frame of mind and will reason that the above don't apply to me -- even if
the above is true.
    Your skepticism is, in my opinion, well founded. The best way to address
such an issue is ask the proponent a simple question, "SHOW ME YOUR DATA."
Such data must come from a neutral, peer reviewed source. Just quoting
another polemic is not a credible source since that reasoning is circular.
The sources playing ring-around-the-rosey with one another.
    It is not very useful to try to "convince" the proponents of assertions
as those above. No amount of reasoning will change their minds.

Vince Calder
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Gary,

I'm always rather suspicious of such claims until I see the source research on which the 
claims are based. Nevertheless, I side with those that think smoking marijuana is a bad 
idea for the following reason -- phrased in the form of a question: "Can you think of 
ANY substance which is harmless to health if you set it afire and then inhale the 
smoke?" When I pose the question to my students, I'm greeted with smiles and a nodding 
understanding of my point. In general, smoking anything is sure to be detrimental to 
good health.

Regards,
ProfHoff 696
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