URINE SCREENING TESTS UNSAFE

Sir:

THE case for urine screening tests for illicit drug driving,
(Chronicle Town edition March 16): although well intentioned, is
fundamentally flawed as drug-screening tests are unsafe.

Unlike the breathalyser which tests can accurately detect alcohol
impairment, drug tests fail on their own terms:

Their greatest shortcoming is their inability to determine impairment
at the time the test was taken.

Therefore, any standard levels of presumptive impairment become
meaningless in practical application.

The possible variations involved in drug screening tests render the
task of the general acceptance of a presumptive level of impairment
for cannabis practically impossible.

A positive drug test standing alone, is not precise enough to supply
the formal proof needed for prosecutions, such as driving under the
influence of drugs.

Don Barnard Legalise Cannabis Alliance http://www.lca-uk.org