Impact of legalized recreational marijuana in Washington State Brianna Peterson, PhD, F-ABFT Washington State Patrol Toxicology Laboratory Division

History of marijuana in WA Medical marijuana legalized in 1998 Removes state-level criminal penalties on the use, possession and cultivation of marijuana by patients who possess "valid documentation" from their physician affirming that he or she suffers from a debilitating condition and that the "potential benefits of the medical use of marijuana would likely outweigh the health risks." No established state registration program

WA State Initiative-502 Public initiative; November 6, 2012 general ballot Approved by popular vote (~56%) Defined and legalized small amounts of marijuana and marijuana-infused products Regulated marijuana production, distribution, and sale DUI laws amended to include a per se level for blood THC Possession by anyone <21 years, possession in larger amounts, & unlicensed/unregulated production of marijuana remains illegal

Driving Under the Influence (RCW 46.61.502/3) (1) A person is guilty of driving while under the influence …     (b) The person has, within two hours after driving, a THC concentration of 5.00 or higher as shown by analysis of the person's blood … ; or     (c) While the person is under the influence of or affected by intoxicating liquor, marijuana, or any drug; 4(b) Analyses of blood samples obtained more than two hours after the alleged driving may be used as evidence that within two hours … a person had a THC concentration of 5.00 or more … and … above 0.00 may be used as evidence that a person was under the influence of or affected by marijuana … (under 21 years): … has, within two hours … a THC concentration above 0.00

Toxicology testing in WA Only one toxicology lab for entire state Receive approximately 15,000 cases a year Case types: Death investigation, DUI, DRE, sexual assault 39 counties Testing is a free service funded by the state

Toxicology Testing All cases are tested for ethanol All cases are screened for the following drug/drug class(es): Amphetamines Barbiturates Benzodiazepines Cannabinoids (cutoff for positive: carboxy THC at 10 ng/mL) Cocaine metabolite Methadone Opiates PCP Tricyclic antidepressants Enzyme Multiplied Immunoassay Technique

Total # DUI/DRE cases received THC Results Year Total # DUI/DRE cases received # of positive THC cases % of positive THC cases 2009 4,809 877 18.2% 2010 5,012 974 19.4% 2011 5,132 1,036 20.2% 2012 5,298 988 18.6% 2013* 5,468 1,362 24.9% 2014 6,270 1,759 28.0% 2015 7,044 2,311 32.8% 2016 (Jan-April) 2,842 977 34.4%

Carboxy-THC Results 2009 4,809 1,267 26.3% 2010 5,012 1,413 28.2% 2011 Year Total # DUI/DRE cases received # of positive Carboxy-THC cases % of positive Carboxy-THC cases 2009 4,809 1,267 26.3% 2010 5,012 1,413 28.2% 2011 5,132 1,460 28.4% 2012 5,298 1,515 28.6% 2013* 5,468 2,187 40.0% 2014 6,270 2,279 36.3% 2015 7,044 2,693 38.2% 2016 (Jan-April) 2,842 1,108 39.0%

Marijuana-related driving cases (%)

Demographics of marijuana positive cases Year Percent Male Age, Range Age, Median 2009 80 % 14 - 76 years 25 years 2010 78 % 15 - 74 years 2011 81 % 14 - 70 years 2012 77 % 16 - 85 years 2013 79 % 14 - 78 years 26 years 2014 15 – 74 years 2015 13 – 73 years 27 years

Summary of THC blood concentrations Year # cases positive for THC THC concentration range Average THC concentration Median THC concentration 2011 1,036 1-58 ng/mL 6.4 ng/mL 4.8 ng/mL 2012 988 1-90 ng/mL 8.0 ng/mL 6.2 ng/mL 2013 1,362 2-77 ng/mL 7.2 ng/mL 5.2 ng/mL 2014 1,759 1-100 ng/mL 6.1 ng/mL 3.9 ng/mL 2015 2,311 1-69 ng/mL 5.7 ng/mL 3.8 ng/mL 2016 (Jan-April) 977 1-66 ng/mL 5.8 ng/mL 3.7 ng/mL

THC cases at or above 5 ng/mL Year # cases positive for THC # cases positive for THC below 5 ng/mL # cases (%) positive for THC above 5 ng/mL 2011 1,036 530 506 (49%) 2012 988 378 610 (62%) 2013 1,362 642 720 (53%) 2014 1,759 1,056 703 (40%) 2015 2,311 1,389 922 (40%) 2016 (Jan-April) 977 593 384 (39%)

Beyond the tox results

Missouri v. McNeely 2013 US Supreme Court decision “Police must generally obtain a warrant before subjecting a drunken-driving suspect to a blood test”

Prosecutor’s perspective Affected by cases easier to prove before I-502 passed Since implementation things have gotten more difficult: Under 5 ng/mL cases, prosecutors must review police video Over 5 ng/mL cases usually involve more impairment so it is easier to charge on the affected by prong Many DUI’s are dealt when under the per se level even with good signs of impairment and poor field sobriety tests Exigent circumstances cases are usually thrown out Increased ethanol and marijuana combined driving cases

Internal procedural changes Normalize data in an attempt to eliminate effect of changes Reporting limits THC: changed from 1 to 2 ng/mL Carboxy-THC: changed from 5 to 10 ng/mL 2009-2012, often no EMIT/drug screen if blood alcohol > 0.10% Exceptions: vehicular assault/homicide, drug specifically mentioned or requested, circumstances suggest drug use, DRE cases

Percentage of cases (BAC >0 Percentage of cases (BAC >0.10%) with EMIT positive results, Jan-Apr 2008, N=548 Unconfirmed EMIT results, however, conservatively decided to assume that 25% of untested high BAC cases ‘might’ be positive for cannabinoids 25% of cases with BAC > 0.10% were removed from 2013 dataset

Data interpretation Reliable information regarding traffic accidents and traffic deaths to correlate with toxicology results Information regarding time course of incident: time of stop and time of blood draw. THC has a short half life Uncertainty of Measurement 26% for THC at k=3 (99.7% confidence) Result of 6.7 ng/mL is reported at 6.7 ± 1.7 ng/mL

Things to remember Establish a reliable baseline of data Benefit of having years of comparison data Be aware of any changes in testing practices Lower limit of reporting Increasing number of cases tested Be aware of what is scope of data Regional – different labs testing, different reporting guidelines, different uncertainty measurements Are all cases being screened for marijuana use?

Brianna.peterson@wsp.wa.gov 206-262-6100 Questions? Brianna.peterson@wsp.wa.gov 206-262-6100