THE POISON GARDEN website      Arum maculatum berries on a Cannabis leaf 

Search thepoisongarden.co.uk:

This free script provided by JavaScript Kit

Pontifications on Poison

Being some ramblings on events associated with poisonous plants.

Wednesday 6th June 2012

Earlier this week, I wrote about the problem of Chinese whispers in scientific papers. That is the difference between what the media says, what the press release says, what the abstract says and what the paper itself says.

Today, I came across another similar situation but with the added complication of the ‘paper’ not really being that, i.e. it is a non-peer reviewed report that looks like a paper, plus internal inconsistency about what it has to say and a difference, in some instances, between the document's claims and what the references used to support that claim say.

You may have seen the news reports; headlines like ‘One Joint 'Same Cancer Risk As 20 Cigarettes'’1 or ‘Cannabis users warned they face higher lung cancer risk’2 announced the publication of a report from the British Lung Foundation (BLF) reviewing the risks of smoking Cannabis sativa, marijuana, and detailing the results of a survey into people’s understanding of those risks.

Let’s follow the whispers backwards. The Yorkshire Post says;

in fact (emphasis added) the risk of developing lung cancer is 20 times greater from a cannabis joint than a legal tobacco cigarette.’

And Sky News uses the same words with;

‘in fact the risk of developing lung cancer is 20 times greater from a cannabis joint.’

The shift from possible to certain is clear from the press release from the British Lung Foundation3 which begins;

‘Risk of developing lung cancer is up to (emphasis added) twenty times greater in a cannabis cigarette than in a tobacco cigarette’

And goes on to quote Dame Helena Shovelton, BLF Chief Executive, saying;

‘each cannabis cigarette [young people] smoke could (emphasis added) increase their chances of developing lung cancer by as much as an entire packet of 20 tobacco cigarettes.’

There’s nothing unusual about that sort of escalation by the media. There’s a belief that the public can’t understand nuance so everything has to be reported as absolutes.

The report itself, however, begins by acknowledging that;

‘We know far less about the effects of cannabis smoke than the impact of tobacco smoke.’4

But, after saying that it says in the conclusions;

There are established links (emphasis added) between cannabis smoking and:
• chronic coughing;
• wheezing;
• sputum (phlegm) production;
• tuberculosis;
• legionnaires’ disease;
• aspergillosis;
• acute bronchitis;
• airway obstruction;
• pneumothorax, and
• lung cancer’

I want to look at three of those ‘adverse effects’; legionnaires’ disease, aspergillosis and tuberculosis (TB).

The report states that;

‘One study shows that cannabis smokers are at increased risk of developing legionnaires’ disease.’

One study is never really enough to be able to claim an ‘established link’ unless it is a really large well-conducted study. The study cited by the BLF, however, is a case report on three cases of legionnaires disease5 that relies heavily on the fact that two of the patients were younger than the normal age for contracting this infection to make the connection between their cannabis use and their disease.

In the case of aspergillosis, the ‘established link’ is based on one case study concerning a patient recovering from a bone marrow transplant to treat leukemia6, hardly typical of the mass of cannabis users. Plus the paper finds that the cannabis the man was using was contaminated with mould meaning there is no ‘established link’ with cannabis produced under controlled conditions.

The report gives four references for TB resulting from cannabis use. All four are case studies and all four are related to unusual circumstances of cannabis use.

In Queensland, 57 people were reactors to tuberculin skin tests. 45 of them had shared the same water pipe for smoking cannabis but the paper concludes (in spite of its title ‘A cluster of tuberculosis associated with use of a marijuana water pipe’);

‘the most important risk factor for acquiring TB infection in this cluster was close household contact with a case’7

In Baltimore, an outbreak of TB occurred in a community of gay men, predominantly HIV positive, living communally and using cannabis.8 The abstract makes no suggestion that this last was the dominant factor.

Another of the cited accounts deals with the practice of ‘shotgunning’ that is transferring exhaled cannabis smoke from person to person.9 Obviously, this practice is a good means of spreading infection with or without the presence of cannabis in the exhalations.

‘Hotboxing’ refers to smoking cannabis in a confined space, typically a car, so that exhaled smoke can be re-inhaled by anyone in the group. It is a means of ensuring the maximum use is made of the available marijuana.

A recently published biography of Barack Obama says that ‘hotboxing’ was his preferred method of using marijuana in his student days.11 The president hasn’t denied his student drug use but says he now realises it was wrong. That’s fine; many people regret things they have done in the past.

It would be helpful, however, if Obama would acknowledge that his luck in not being caught undertaking criminal acts means that he was able to go on to become president but, under his presidency, there are young people whose futures are being blighted because they haven’t been so lucky and are saddled with a criminal conviction for marijuana offences.

A case study from Seattle found that ‘hotboxing’ involving a group that included at least one TB carrier had caused the infection to be passed on.10

I’m really not sure I understand the motivation of the BLF. The report makes it quite clear that;

‘Although cannabis is the world’s most widely used illicit drug, there has been surprisingly little research into its effects on respiratory health.’

And then takes that ‘surprisingly little research’ and makes statements about the effects of cannabis smoking that simply cannot be supported by what evidence there is.

There is also the usual thing about cannabis being stronger these days. This the report believes means that;

‘the conclusions of many previous studies investigating the long-term effects of smoking cannabis may not be applicable to current cannabis smokers’

Yet of its 86 references 23 refer to papers that are over twenty years old.

It also includes a section on mental health and cardiovascular issues related to cannabis. This has no place in a report that is supposed to be about lung diseases and destroys any possibility of it being seen as an impartial assessment.

We know that smoking is harmful and it would be foolish to suggest that smoking cannabis, especially if done with tobacco, will not also be harmful but overstating what little evidence there is will not make people respond.

Much better to just say that there are almost certainly risks but that more research should be done to protect public health. It occurred to me that cannabis smokers might, when smoking tobacco, draw more on their cigarettes than a tobacco only smoker. I asked on Twitter if anyone knew if such research had been done but it seems not. I'm grateful to @AlexStevensKent and @TransformDrugs for the information they provided.

The truth is that prohibition, which is supposed to protect people from the harm of drugs (but doesn't), also prevents researchers from making better assessments of what those harms might be.

References

1.One Joint 'Same Cancer Risk As 20 Cigarettes' Sky News 4th June 2012
2.Cannabis users warned they face higher lung cancer risk Yorkshire Post 3rd June 2012
3.New report reveals dangerous lack of public understanding of the health risks of cannabis British Lung Foundation 6th June 2012
4.The impact of cannabis on your lungs British Lung Foundation 1st June 2012
5.Legionnaires Disease in Cannabis Smokers 10.1378/chest.10-0410 CHEST October 2010 vol. 138 no. 4 989-991
6.Fatal Aspergillosis Associated with Smoking Contaminated Marijuana, in A Marrow Transplant Recipient DOI 10.1378/chest.94.2.432 Chest 1988;94;432-433
7.A cluster of tuberculosis associated with use of a marijuana water pipe Munckhof, Konstantinos, Wamsley, Mortlock & Gilpin INT J TUBERC LUNG DIS 7(9):860–865
8.A multi-state outbreak of tuberculosis among members of a highly mobile social network: implications for tuberculosis elimination. Sterling, Thompson, Stanley, McElroy, Madison, Moore, Ridzon, Harrington, Bishai, Chaisson & Bur Int J Tuberc Lung Dis. 2000 Nov;4(11):1066-73.
9.“Shotgunning” as an illicit drug smoking practice Perlman, Perkins, Paone, Kochems, Salomon, Friedmann & Des Jarlais Journal of Substance Abuse Treatment - January 1997 (Vol. 14, Issue 1, Pages 3-9)
10.Tuberculosis Outbreak in Marijuana Users, Seattle, Washington, 2004 Oeltmann Oren, Haddad, Lake, Harrington, Ijaz, & Narita
11.Thanking his drug dealer in his yearbook and inventing the best ways to inhale: Book lifts lid on 'Barry' Obama's marijuana-smoking school days Daily Mail 25th May 2012

 

Follow @thepoisongarden on Twitter

Full Entries

2016

Tuesday 25th October 2016 Saturday 20th August 2016 Sunday 6th March 2016 Wednesday 3rd February 2016

2015

Saturday 28th November 2015 Friday 27th November 2015 Monday 17th August 2015 Wednesday 15th July 2015 Friday 26th June 2015 Thursday 25th June 2015 Thursday 30th April 2015 Wednesday 29th April 2015 Wednesday 11th March 2015 Tuesday 3rd March 2015 Saturday 28th February 2015 Sunday 22nd February 2015

November 2014

Monday 24th November 2014 Saturday 8th November 2014

October 2014

September 2014

Wednesday 24th September 2014 Monday 1st September 2014

August 2014

Tuesday 26th August 2014 Saturday 16th August 2014 Tuesday 5th August 2014 Friday 1st August 2014

July 2014

Sunday 27th July 2014 Wednesday 23rd July 2014 Sunday 13th July 2014 Sunday 6th July 2014 Tuesday 1st July 2014

June 2014

Wednesday 25th June 2014 Tuesday 24th June 2014 Sunday 22nd June 2014 Monday 9th June 2014 Wednesday 4th June 2014

May 2014

Monday 26th May 2014 Sunday 18th May 2014 Wednesday 14th May 2014

April 2014

Sunday 13th April 2014 Saturday 5th April 2014 Thursday 3rd April 2014 Tuesday 1st April 2014

March 2014

Monday 31st March 2014 Tuesday 25th March 2014 Friday 21st March 2014 Monday 17th March 2014 Sunday 16th March 2014 Tuesday 11th March 2014 Thursday 6th March 2014 Wednesday 5th March 2014 Saturday 1st March 2014

February 2014

Thursday 27th February 2014 Monday 24th February 2014 Wednesday 19th February 2014 Monday 17th February 2014 Thursday 13th February 2014 Monday 4th February 2014 Monday 3rd February 2014 Saturday 1st February 2014

January 2014

Thursday 28th January 2014 Thursday 23rd January 2014 Friday 17th January 2014 Wednesday 15th January 2014 Monday 13th January 2014 Thursday 9th January 2014 Tuesday 7th January 2014 Wednesday 1st January 2014

December 2013

Monday 23rd December 2013 Friday 20th December 2013 Tuesday 17th December 2013 Friday 14th December 2013 Thursday 12th December 2013 Sunday 8th December 2013 Wednesday 4th December 2013 Sunday 1st December 2013

November 2013

Friday 29th November 2013 Wednesday 27th November 2013 Tuesday 26th November 2013 Friday 22nd November 2013 Monday 18th November 2013 Friday 15th November 2013 Thursday 14th November 2013 Sunday 10th November 2013 Thursday 7th November 2013 Wednesday 6th November 2013 Friday 1st November 2013

October 2013

Thursday 31st October 2013 Sunday 27th October 2013 Wednesday 23rd October 2013 Monday 21st October 2013 Friday 18th October 2013 Friday 11th October 2013 Wednesday 9th October 2013 Tuesday 8th October 2013 Monday 7th October 2013 Tuesday 1st October 2013

September 2013

Monday 30th September 2013 Saturday 28th September 2013 Friday 27th September 2013 Monday 23rd September 2013 Sunday 15th September 2013 Monday 9th September 2013 Sunday 8th September 2013 Tuesday 3rd September 2013 Sunday 1st September 2013

August 2013

Tuesday 27th August 2013 Sunday 25th August 2013 Monday 19th August 2013 Friday 16th August 2013 Tuesday 13th August 2013 Friday 9th August 2013 Friday 2nd August 2013 Thursday 1st August 2013

July 2013

Saturday 27th July 2013 Sunday 21st July 2013 Wednesday 17th July 2013 Monday 15th July 2013 Saturday 13th July 2013 Friday 12th July 2013 Thursday 11th July 2013 Wednesday 10th July 2013 Tuesday 9th July 2013 Saturday 6th July 2013

June 2013

Friday 28th June 2013 Tuesday 25th June 2013 Friday 21st June 2013 Thursday 20th June 2013 Wednesday 19th June 2013 Saturday 15th June 2013 Sunday 9th June 2013 Saturday 8th June 2013 Saturday 1st June 2013

May 2013April 2013 March 2013 February 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 blog June 2012 blog May 2012 blog April 2012 blog March 2012 blog February 2012 blog January 2012 blog December 2011 blog November 2011 blog October 2011 blog September 2011 blog August 2011 blog July 2011 blog June 2011 blog


IMPORTANT NOTE

The POISON GARDEN website is not connected with Alnwick Garden Enterprises Ltd and/or The Alnwick Garden Trust.