The authors concluded that blood THC concentrations of 8.2 ng/mL and 13.1 ng/mL correspond to deficits from alcohol of 0.05% and 0.08% respectively. This is much higher than the proposed limits of 2 to 5 ng/ml THC in whole blood for a summary offence and over 5 ng/ml for an indictable offence.
What is a high level of Delta 9 THC in blood?
The presence of Δ9-THC in blood at levels above 1 ng/mL is generally an indication of recent cannabis consumption for occasional users.
Is THC detectable in blood plasma?
THC and 11-OH-THC were quantified in all whole-blood and plasma samples for at least 2 h; after this time, detection rates decreased, with 10% detection in whole blood and 30% detection in plasma 22 h after smoking.
How long does Delta 9 THC stay in your blood?
Studies involving humans indicate that 80%-90% of the total dose of delta-9-THC is excreted within 5 days–approximately 20% in urine and 65% in feces (1). Plasma concentrations of delta-9-THC peak by the time a smoked dose is completed and usually fall to approximately 2 ng/ml within 4-6 hours.
What is the GC/MS value for THC carboxy?
Carboxy-THC- by GC/MS <3.0 ng/mL The presence of tetrahydrocannabinol carboxylic acid (THC-COOH), a major metabolite of delta-9-tetrahydrocannabinol, in urine at concentrations greater than 15.0 ng/mL is a strong indicator that the patient has used marijuana.
What is a high level of THC in urine?
Levels greater than 500.0 ng/mL suggest chronic and recent use. Chronic use causes accumulation of THC and THC-COOH in adipose tissue such that it is excreted into the urine for as long as 30 to 60 days from the time chronic use is halted.
How long does THC stay in the body?
This is why the THC level in blood drops by 90% within the first hour after smoking, even though the metabolic half-life of THC is estimated to be about four days. 3 Because of the high fat content in the brain, THC remains in the brain long after it can no longer be detected in the blood.
How is THC metabolized in the human body?
After consumption, either by inhalation or ingestion, the drug is metabolized to a variety of inactive chemicals, one of them being delta-9-tetrahydrocannabinol carboxylic acid. The immunoassay used to screen for tetrahydrocannabinol (THC) is designed to cross-react with THC carboxylic acid.
