EXTRA-HIGH CANNABIS THEORY GOES UP IN SMOKE
The effective strength of cannabis consumed in Britain has remained stable
for the past 30 years, according to a European Union study published today.
The research says there is no evidence for claims that most cannabis
consumed in Britain and the rest of Europe is now 10 times or more stronger
than it was in the 70s.
The US drugs "tsar" John Walters and toxicologist John Henry of St Mary's
hospital in Paddington, west London, are among those who have warned that
the cannabis available now bears little resemblance to that on the market
30 years ago, with serious health dangers for regular users.
The EU study says that the strength of the active ingredient - THC - has
remained unchanged at about 6% for most of the cannabis smoked in Britain.
It says the amount of cannabis put in the typical British joint has also
remained constant for 20 years at about 200mg for marijuana and 150mg for
The results are based on analysis by the Forensic Science Service of
cannabis seized by the police between 1995 and 2002. The study acknowledges
that there has been an unknown increase in home-grown cannabis, which can
be two to three times more potent, but says that more than 70% of the
market is taken by the "traditional" imported Moroccan cannabis resin.
Imported resin typically has a strength of 6% THC against 30% in the
"skunk" and other super-strong strains that Professor Henry and others have
warned against. Sinsemilla, the unpollinated plant which produces a
powerful strain, has doubled in potency since 1995, but only from 6% to 12%.
The research, published by the European monitoring centre for drugs and
drug addiction, is the first European review of the potency of cannabis.
"There has been much speculation on the strength of cannabis available
today, but little in the way of hard evidence," said its director, Georges
Estievenart. He said the concerns that had been raised were worrying as
cannabis was the most commonly used illicit drug in the EU, with many
countries reporting that more than 20% of people had used it at some time
in their lives.
The study was complicated by the fact that not only do different types of
cannabis such as resin or hash have different strengths, but potency also
depends on the individual plant and on how and where it was grown.
The vintage can also have an impact on its strength with THC breaking down
at a rate of 17% a year if it is kept at room temperature.
The report shows that the effective potency of cannabis in nearly all EU
countries, including Britain, has remained at about 6%-8% THC in the last
30 years, with the only exception being the Netherlands, where by two years
ago the strength of the average cannabis consumed had reached 16%.
This is mainly due to the increasing availability of intensively produced
home-grown cannabis in Holland.
The EU report says that while herbal cannabis is most common in the
Netherlands, Austria, Belgium and the Czech Republic, Britain remains in a
group with Germany, Ireland and Portugal where the market is still
dominated by imported cannabis resin mainly from Morocco.
The authors say that they are concerned about the growth of higher potency
intensively cultivated home-grown cannabis appearing in Europe. The report
concludes it is possible that regular use of such higher potency cannabis
could lead to health problems such as panic attacks and minor psychological
problems, but as yet this kind of cannabis remains relatively rare.