Roseville, CA: Neither the detection of THC in blood nor in breath is correlated with impairment of performance or recency of cannabis exposure, according to data published in the journal Nature Scientific Reports.
Scientists quantified THC levels in the blood and in the breath of regular cannabis consumers prior to smoking and thereafter. Researchers also assessed the duration of subjects’ impairment following inhalation.
Consistent with other studies, investigators reported that a majority of subjects possessed residual levels of THC in their blood (at levels of 5ng/ml or higher) at baseline. Authors acknowledged that THC was present in these subjects’ blood despite “the absence of any impairment.”
Following subjects’ inhalation of cannabis, authors identified an “inverse relationship” between THC blood levels and impairment of performance – a finding that is also consistent with prior research.