Driving and marijuana: A deadly mix

Driving and marijuana: A deadly mix

	Published : Sat, 03 Dec 2005 01:35 By : Andrew Stead Print this Story

New research advises people not to drive after consuming marijuana as it is associated with a two-fold risk of a fatal car crash. This is true even for minute quantities of the drug, the study published in the latest issue of the British Medical Journal says.

Researchers at the French National Institute for Transport and Safety Research arrived at these conclusions after studying data involving 10,748 drivers who had a fatal car crash between 2001 and 2003. All these drivers were tested for alcohol consumption as well as for drugs.

It emerged that nearly 7 percent of these drivers were under the influence of pot while, 21.4 percent were drunk. About 3 percent of drivers were under the influence of a combination of alcohol and drugs. The data clearly shows that marijuana was not as lethal as alcohol, but researchers say that using pot, even in minute quantities was associated with double the risk of a fatal car crash.

The study also found that men were more likely to drive under the influence of drugs or alcohol and most of them tested positive for alcohol and drugs. This was true for younger people as well as those who drove mopeds and motorcycles. The active ingredient responsible for all the effects of marijuana is a chemical called delta-tetrahydrocannabinol (THC).

The researchers found that as the concentration of this chemical rose in the blood, so did the chance of being involved in a lethal accident. Drivers who had 1 nanogram/milliliter of THC in their blood had an 89 percent chance of being involved in accidents, while those who had 5ng/ml of THC had a 206 percent chance of succumbing in an accident.

"Driving under the influence of cannabis increases the risk of involvement in a crash," said Bernard Laumon, the lead author of the study. "The risk of responsibility for fatal traffic crashes while driving under the influence of cannabis has a significant dose effect that shows a causal relationship between cannabis and crashes."