[stands2reason]

Not enough information in this survey. One joint can be potent enough for 1-6 people depending on the size and potency. Way too much wiggle room for an accurate result.

[cgbg]

potency

Since marijuana is not regulated in any way (since it is illegal) there could be an incredible variance in potency--a factor of six may be far too low.

So the study is utter garbage--along with about ninety-five percent of the tobacco studies.

Both products are not good for you in excess--both are relatively harmless in moderation.