THC and Cannabis Dosages: "THC is the major psychoactive constituent of cannabis. Potency is dependent on THC concentration and is usually expressed as %THC per dry weight of material. Average THC concentration in marijuana is 1-5%, hashish 5-15%, and hashish oil ³ 20%. The form of marijuana known as sinsemilla is derived from the unpollinated female cannabis plant and is preferred for its high THC content (up to 17% THC). Recreational doses are highly variable and users often titer their own dose.
Statistics and data relating to operating a vehicle while under the influence of an intoxicant (DUII), also referred to as drugged driving, drunk driving, driving under the influence (DUI), or driving under the influence of drugs (DUID).
"Cannabis use impairs cognitive, memory and psycho-motor performance in ways that may impair driving.10 Recent data suggest that approximately 5% of Canadian drivers/adults report driving after cannabis use in the past year.39 Large-scale epidemiological studies using different methodologies (e.g., retrospective epidemiological and case control studies) have found that cannabis use acutely increases the risk of motor vehicle accident (MVA) involvement and fatal crashes among drivers.40,41 Recent reviews have found the increase in risk to be approximately 1.5
"We identified cohorts of individuals hospitalized in California from 1990 to 2005 with ICD-9 diagnoses of methamphetamine- (n = 74,170), alcohol- (n = 592,406), opioids- (n = 68,066), cannabis- (n = 47,048), cocaine- (n = 48,949), or polydrug-related disorders (n = 411,175), and these groups were followed for up to 16 years. Age-, sex-, and race-adjusted standardized mortality rates (SMRs) for deaths due to MVAs were generated in relation to the California general population.
DRUID Project Evaluation of Oral Fluid (Saliva) Testing Devices for DUI Enforcement
"To combat drug-driving, most countries either operate a zero tolerance policy or take into account degree of impairment, sometimes in a two-tier system. Legal limits may be set low, at the limit of detection, or higher to take effects into consideration. For example, while the project set a detection limit of 1 ng/ml in whole blood for THC in the roadside surveys, it was found that 2 ng/ml THC in whole blood (3.8 ng/ml THC in serum) seems to cause impairment equivalent to 0.5 g/l BAC. Such equivalents could not be calculated for other drugs.
"Any threshold discussion should address the question if the DRUID approach to determine risk threshold as equivalents to 0.5g/L alcohol is feasible. From a scientific point of view it can only be justified to accept the same risk for all psychoactive substances (including alcohol). From a political point of view the determination of risk thresholds as equivalents to 0.5g/L alcohol might be questionable, because a BAC of 0.5g/L is not a legal limit in all European countries.
Thresholds for Serum THC Level Compared With Blood Alcohol Content
"Drug per se laws are not quite analogous to the alcohol impaired-driving per se laws now in effect in every State make it illegal to operate a motor vehicle with a blood alcohol concentration (BAC) of .08 grams per deciliter or greater. Alcohol-impaired driving per se laws are based on evidence that all drivers are impaired at .08 BAC. Drug per se laws are more analogous to zero-tolerance laws that make it illegal to drive with certain drugs in the system."
Marijuana and Driving - More Data Needed: "The decreased speed during the simulated drive could be interpreted as an attempt to compensate for perceived cognitive impairment, Alternatively, marijuana may not have affected decision making and judgment and the reduction in speed would improve safety margins, While the clinical significance of a 3% to 5% decrease in speed may be questioned, previous research suggests such a decrease will result in approximately a 7% decrease in all injuries and a 15% decrease in fatalities (Nilsson 1981), Use of an alternate task design in which subjects are r
Cannabis and Driving Impairment: "The present study's subtle finding of decreased speed under the influence of acute marijuana is generally consistent with the literature, which has found that marijuana's effects on driving can be subtle.