FORENSICS EXPERT EXPLAINS MARIJUANA TESTING MYTHS

When a student is caught in possession of marijuana, there is little
they can use as an excuse to get out of being arrested or slapped with
a hefty fine, according to Mahmoud ElSohly, a research professor at
the Research Institute of Pharmaceutical Sciences at the University of
Mississippi.

As part of the Forensic Science Seminar Series, ElSohly made his
presentation, "Marijuana in Forensics," to about 60 students and
members of the community in Pastore Chemical Laboratory Friday.
Referring to his latest research, ElSohly talked about the fact and
fiction of marijuana usage and why certain defenses for positive
marijuana testing don't hold up in court.

"When the tests come back positive for marijuana, some people say, 'I
went to a party and people were smoking pot,'" ElSohly said. "This
issue has been studied to death."

ElSohly said the party scene he described would be an example of
passive inhalation, something that could not cause a marijuana test to
show up positive. "There's no way you'd be up to the physical
guidelines," he said.

ElSohly said another excuse that wouldn't hold up in court would be
the "hemp seed" defense. Hemp seed and oil contain small amounts of
THC, or tetrahydrocannabinol, which are responsible for the
psychometer effects of marijuana.

According to ElSohly's research, hemp seed and oil can be found in 120
different products on the market today. Because the amount of THC is
significantly less, however, ElSohly said students that using hemp
products as an excuse for a positive drug test would be disappointed
in a police officer or an employer's reaction. Like passive
inhalation, there would not be enough THC in a sample after ingesting
hemp to meet the guidelines for "testing positive."

The latest problem has been the surfacing of medical marijuana, or
Marinol, which is the only medical marijuana treatment that has been
approved by the FDA.

"This will be positive on a drug test for marijuana," ElSohly said.
"Marinol is nothing but THC, and THC comes from marijuana."

Marinol can be prescribed for everything from arthritis to intense
muscle pain as an off label prescription, he said.

According to state law, individual caretakers or patients in Rhode
Island are allowed the equivalent of 2.5 ounces of usable marijuana
after being approved through an extensive screening process provided
by the state health department. Because of an increase in medical
marijuana laws and research, ElSohly's research team developed a way
to separate true medical marijuana users from arrested individuals who
were using it to get out of trouble.

Researchers found that a variation of THC called tetrahydrocannabivarin,
or THCV, is only found in human samples after one has smoked a
marijuana cigarette or ingested it in baked form.

"We had to show that THCV would not come out even if you smoked
Marinol," he said. "Marijuana cigarettes contain both THCV and THC.
With the others, there's nothing. We've been able to prove that THCV
is only excreted in human urine as a result of the ingestion of a
product containing THCV, which is not the result of smoking or orally
ingesting Marinol. This has become standard."

Currently, the most common types of drug testing for employers and
police include taking urine and blood samples. However, ElSohly said
that some places differ, and may use oral fluids or screen in
different ways.

"There can be physical deposits in the mouth if you smoke a marijuana
cigarette," he said, explaining the process of testing oral fluids.
"[If done this way], it requires very sophisticated testing.
Nevertheless, it's being used as an option."

ElSohly said there are pros and cons to each type of drug testing,
even blood tests. Though testing for marijuana through blood can be
good because blood provides a constant volume, when being pulled over
after smoking, sometimes time works against the test. "The problem is,
you hit somebody [while driving after smoking] and it's usually an
hour before ... It's not enough THC in the blood to be positive on a
drug test," he said.

One audience member asked ElSohly what would happen if the subject
doesn't give permission for testing at the given time.

"If you have to give permission for a subject, you've got a problem
there," ElSohly said.

ElSohly also talked about the effects marijuana has on subjects who
are driving. Though it is believed by some that getting high won't
impair individuals behind the wheel, ElSohly explained that the
physiological and cognitive effects can impair drivers.

"If you do a field sobriety test, you can see the effects," he said.
"You have the impairing effects of the drug - it's a motivational syndrome."

ElSohly said there are other dangerous effects of marijuana that don't
include getting behind the wheel after getting high.

"Marijuana cigarettes are twice as carcinogenic as a regular
cigarette," he said. "There are too many pharmacological things going
on there. When you bake it in a brownie, you avoid any problems with
the lungs. But you add to the problems when you get it from somewhere
else where it could be laced with pesticides or something. Especially
overdoing [marijuana] is a big problem."

If used for too long, he said, there could be consequences. "The thing
is, if you quit, the effects are reversible. If you quit before you
die, it'll be all right," he joked.

ElSohly has been conducting research at the University of Mississippi
since 1975. The university has conducted research on drug testing, the
increasing potency of marijuana and is now trying to find a way to
trace the origin of marijuana samples. ElSohly said that security of
the marijuana fields has not yet proved to be a problem.

"Marijuana is the most abused illicit drug in the world," he said.
"There are specific rules and regulations for growing it. We have
security guards 24 hours a day. We have cameras on the field. We even
have to keep an eye on the security guards."