INTERPRET POT DATA WITH CAUTION, UN SAYS

The results of the United Nations 2007 World Drug Report, showing
Canada leading the industrialized world in marijuana consumption, need
to be interpreted with caution, to the UN body that did the drug study
says.

For one thing, only 104 of 192 countries asked to participate in the
study did so. Second, the reliability of the reporting data from those
104 countries wasn't uniformly reliable.

It's not easy to measure drug use objectively. The UN study relied on
self-reporting surveys, which can't always be trusted.

The only drug for which truly objective consumption data can be
obtained is cocaine, the result of new testing technology that allows
for the examining municipal waste water.

According to this process, scientists look for evidence of a chemical
called benzoylecgonine. Since this chemical does not come from any
other source than the organic processing of cocaine, it is considered
a reliable indicator of cocaine consumption.

According to the World Drug Report's appendix on methodology, "the
assumption is that cocaine that has been consumed is eventually
leaving the human body and - in developed areas - (that) most of this
will land in waste-water systems in the form of benzoylecgonine."

"It's a very credible testing mechanism," said Jurgen Rehm, senior
scientist with the Toronto-based Centre for Addiction and Mental health.

So, who, by this measure, is the cocaine king of the world, or at
least the industrialized world?

Waste-water tests that started in Italy in 2005 and later conducted
elsewhere found benzoylecgonine concentrations in New York City's
waste water far higher than in any other single city in the world. The
different concentrations were translated into estimated lines of
cocaine consumed per 1,000 people age 15 to 64.

By that measure, New York registered 134 lines per 1,000 people. Next
were Mirana de Ebro, in Spain (97 lines), and Washington, D.C. (56).

There were no Canadian cities in the Top 25 list.