COLORADO HOUSE OKS BILL SETTING LIMIT ON POT IN DRIVER'S SYSTEM

The state House of Representatives gave final approval Wednesday to a bill
that would set a limit on how much marijuana drivers could have in
their systems before they are considered too high to drive.

But statistics from the state health department called into question
how many stoned drivers the limit would actually snare.

Last year, for instance, the department analyzed 1,510 blood samples
from drivers police suspected of driving under the influence of drugs,
according to data provided by department officials. Only 29 percent of
those samples came back with enough THC, the psychoactive component of
marijuana, to be above the limit lawmakers are considering. The rest
came back with less or no THC. Some of those samples may have tested
positive for another drug.

"It's not going to catch everybody," Thomas Raynes, the executive
director of the Colorado District Attorneys' Council, said of the
proposed limit. "But we think it's a reasonable starting point." The
council supports the bill.

Where to set the THC limit has been the most hotly contested issue
surrounding House Bill 1261. The House approved the limit at 5
nanograms of THC per milliliter of blood. But lawmakers earlier this
week sparred over whether the limit should be lower or higher.

THC levels typically spike to many times greater than 5 nanograms
immediately after use before falling. But, because THC amounts
fluctuate in the body less predictably than those of alcohol, it is
difficult to say how much a particular marijuana user can consume or
how long he or she must wait to stay below 5 nanograms.

Bill advocates say some research suggests drivers may be impaired with
THC levels of 2 nanograms or less.

Opponents say some marijuana users - especially those who have
developed high tolerances, such as medical-marijuana patients - may be
perfectly sober at levels above 5 nanograms.

The health department is one of three labs in the state certified to
conduct blood-sample drug analyses. In 2009, it tested 793 samples
from drivers police suspected of drugged driving. That jumped to 1,635
samples received last year, of which 125 have yet to be tested.

The department is facing such a backlog that none of the 1,176 samples
submitted so far this year have been tested.

Raynes said the increase in the number of samples from suspected
drugged drivers was one reason law enforcement officials wanted to set
a THC limit, which makes a drugged driving conviction almost automatic
for people who test above it. "We thought that we needed to get in
front of this," he said.

Blood samples are only taken from people police say they have good
reason to suspect of driving stoned. Raynes said drivers who test
below the level can still be charged with drugged driving, but
prosecutors must take extra measures to prove impairment.

Lauren Davis, a medical-marijuana attorney who is critical of the
proposal, said setting a limit will probably make it less likely that
someone testing below the limit would be prosecuted. But she said the
health department's numbers still point out that officials have little
concept of how much THC levels relate to bad driving.

"The real issue is 'Was their driving impaired?' " Davis said. "Not
'Do they have 5 nanograms in their blood?' That's a lot of people
getting stuck with needles for not a lot of results."

The health department numbers mirror findings from a Swedish study
published in 2008. The study looked at blood samples from suspected
drugged drivers over a 10-year period and concluded as many as 90
percent of the people with THC in their blood would not break a
5-nanogram limit.