May 13,1998

By Bob Engisch

(Ed. note: The move to test drivers for cannabis is a two edged sword for everyone. While cannabis is far less impairing than alcohol, no one wants seriously impaired drivers on the road. However, unless some realistic relationship is established between levels of "intoxication" and actual impairment, then the devices will be endlessly challenged in court and/or used by police to harass selected groups. When the legal basis for their use is finally established, the facts about marijuana’s impairment of driving will be established with results not to the liking of prohibitionists. Of course, you won’t hear about it in the prohibitionist media.)

MOTORISTS MAY FACE DOPE TESTS

AUSTRALIA’S cannabis smoking motorists could soon face the same sort of random breath testing as drinking drivers.

Further down the track, users of amphetamines - and even heroin and crack - could be caught in the same roadside police net.

A breath test unit to screen drivers for cannabis has been developed to prototype stage by doctors Ron Parsons and Zenon Mejglo, research chemists at the University of Tasmania in Hobart.

Dr Parsons has been working on the project for about 20 years and was joined by Dr Mejglo in 1992.

"I think we have proved that we can now detect cannabis in the breath," Dr Parsons said.

"At present the police only have one instrument, the breathalyser for alcohol. People smoke cannabis and blow nothing on the breathalyser. The police know their driving ability is impaired, but they can’t do anything about it.

"If the police had this, another breath analysis instrument, to say drivers had been smoking cannabis, then that’s a different kettle of fish. They’ve got them then and they have to have a blood test because breath analysis is only a screening test."

Dr Parsons said police in Tasmania could already order an immediate blood test if they suspected a driver was under the influence of drugs. Blood tests must be performed within two hours after smoking cannabis to be effective.

Dr Parsons said he was concerned about moves in Tasmania to "go soft" on cannabis. "If you go soft on cannabis the police have no check on people driving under its influence. And they will do it - they’re doing it now."

Dr Parsons said he could see breath analysis for cannabis becoming part of standard random breath testing.

The heart of the cannabis breath test device is a sensor disc, the exact chemical composition of which is a secret shared only by Drs Parsons and Mejglo. When an affected driver blows into a mouthpiece chemicals detecting cannabis turn the sensor disc red.

Light hits the disc, is reflected and measured by a photo diode. With any colour in it, the disc will show proportionately less light and provide a reading.

Dr Parsons said the device now represented a prototype, which a manufacturing company could look at and turn into a workable unit.

He said progress had been hampered by lack of research funds, particularly in view of cutbacks in Federal Government research funding.

"If we had received funding we would have had the device out on the streets by now."

He said he believed it should now be possible to take a saliva swab from drivers who had breath tested positive to cannabis to test for other drugs, including amphetamines, heroin, or ecstasy.