Two recent research reports explain why blood tests are ineffective for determining driving impairment by marijuana, and why impairment-based DUI per se blood level limits for marijuana are useless.
Rebecca Hartman’s team (R.L. Hartman et al. http://dx.doi.org/10.1016/j.drugalcdep.2015.06.015 ) led the groundbreaking Iowa driving simulator study that showed, “During drive blood THC ≥8.2 ?g/L increased SDLP similar to notably-impairing alcohol concentrations.” She followed up with a report in Clinical Chemistry this year (R.L. Hartman et al. … READ MORE