serious reservations about the zero-tolerance driving restrictions for teenagers
@23) Untrue. There's no science to back up the claim that someone who smoked marijuana would remain above the 5 ng/mL cut-off after 12 hours. The vast majority of users fall well below that level within a few hours. Furthermore, under current law, people are routinely prosecuted for less than the 5ng/mL cut off.
The study by Gisela Skopp et al. found that none of them exceeded the 5 ng/mL cutoff. The highest was 6.4 ng/mL of blood serum. (Note: That test measured blood serum, in which THC concentrations are roughly double their levels in whole blood. In whole blood, Grotenhermen explains, the equivalent would be 3.2 ng/mL, well below the cutoff for drivers in I-502.)