Driving under the influence of drugs (DUID) has become a growing issue nationwide and likewise in Orange County (OC), California. In the USA, the number of alcohol-related crashes has been on the decline, but drug-related crashes have seen an increase.  According to the 2013–2014 National Roadside Survey, approximately 20 percent of drivers are positive for one or more drugs in their blood. This represents an increase from the 2007 roadside survey in which 16.3 percent of drivers tested positive for one or more drugs.  In OC, nearly 5,000 drivers were suspected of DUID from November, 1 2010 through November 30, 2012, which is more than double the number from the same timeframe ten years prior. This study as featured a specific dramatic increase in marijuana usage.

In research published in Journal of Forensic Sciences by K. Declues et al., UCT’s famous Clean Screen® THC SPE cartridges were used to extract cannabinoids from samples of whole blood taken from apprehended drivers in OC over a two-year period. In this study (Part II of a two stage study), a comparison was conducted of examined objective signs, eye examinations and physiological indicators with their relationship to the presence of identified concentrations of THC. Several objective signs were excellent indicators of the presence of THC: red eyes (94%), droopy eyelids (85.6%), affected speech (87.6%), tongue coating (96.2%), and odor of marijuana (82.4%). About 63.6% of THC positive subjects had dilated pupils (room light). THC positive subjects had either rebound dilation or hippus in 88.8 percent of cases. Pulse and blood pressure (BP) were also evaluated to determine any correlation with THC. An increased pulse rate coincided well with the presence of THC (88.5%). BP did not correlate to THC and was also a poor indicator of THC in the blood (50% high). This study demonstrates why when forensic toxicologists working in the field of medical judicial drug testing of samples turn to UCT as their first choice for the finest SPE sorbents. For further information about the Clean Screen® THC sorbent and corresponding methodologies, visit https://sampleprep.unitedchem.com/products/spe/clinical-forensic/clean-screen-thc.