MarijuanaNews.com : Full Text of British Lung Foundation Report Including Misleading Press Release.

Posted November 15,
2002
(MarijuanaNews
note: The following is the press release from the BLF. It misrepresents their
study which misrepresents the data. The full text follows and at the end there
is a link to a separate page with the footnotes.)

BLF LAUNCHES MAJOR REPORT ON CANNABIS

A shocking new report released today shows that smoking pure cannabis is
just as harmful to
lungs as tobacco.

Three cannabis joints a day cause the same damage to the lining of the
airways as 20 cigarettes.

The BLF’s Cannabis - A Smoking Gun? report also shows that, when cannabis
and tobacco are smoked together, the effects are dramatically worsened.

Evidence
shows that tar from cannabis cigarettes contains 50 per
cent more carcinogens (cancer-producing agents) than tobacco.

(MarijuanaNews note: Maybe. They use a 1975 report for the benzpyrenes and
benzanthracenes levels. It is odd that there is not better data on both tobacco
and cannabis smoke. There is controversy about both.

The other citations are
not for original data but rather citations of the 1975 study.

In
Marijuana Myths, Marijuana Facts Zimmer
and Morgan cite a 1991 study by R. G. Harvey (Polycyclic Aromatic Hydrocarbons,
Chemistry and Carcinogenicity, Cambridge Press) that found more of both
benzpyrenes and benzanthracenes in tobacco smoke.

Inasmuch as cannabis
can be smoked as all female flowers, or as a mixture of leaves and flowers, or
as pure resin (hashish) there would seem to be a need for a more complete
analysis. Inasmuch as there is such a variety of formulas for cigarettes it
would seem that there is a need for a much wider range of sampling. Also, there
is much controversy over the accuracy of the testing of tobacco smoke.

Consider this from the
Royal
College of Physicians:
“The addictive properties of nicotine also mean that simplistic machine
measurements of tar and nicotine yields from cigarettes do not reflect real tar
and nicotine exposure to smokers. Smokers adjust the way they smoke in order to
self-administer a satisfactory dose of nicotine - a process known as
‘compensation’. In response to reduced nicotine concentration in smoke, a smoker
can adjust nicotine intake back to a satisfactory level by smoking more
intensely, holding smoke in the lungs for longer, smoking more of the cigarette,
or by blocking ventilation holes in the filter. Cigarette testing machines do
not adjust their inhalation profile in response to changes in nicotine. This
criticism of cigarette testing is not a minor point; it completely undermines
the approach currently used both for regulation of tar and for consumer
labelling.”)

Cannabis ‘Not safer than
tobacco’

BLF Chairman Dr Mark Britton
said: “These statistics will come as a surprise to many people, especially those
who choose to smoke cannabis rather than tobacco in the belief it is ’safer’ for
them.

“It is vital that people are
fully aware of the dangers so they can make an educated decision and know the
damage they may be causing. Our report is not about the moral rights and wrongs
of cannabis, but simply making sure everyone is completely clear about the
respiratory health risks involved.”

A survey carried out earlier
this year showed that 79 per cent of children believed that cannabis was ’safe’.
Only two per cent understood correctly that there are health risks associated
with smoking the drug¹.

A Smoking Gun? also shows that the health dangers of cannabis have
substantially increased since the 1960s, due to increased amounts of THC in the
cannabis consumed today. As a result longitudinal studies from 40 years ago
cannot be taken as accurate.
(MarijuanaNews note: This is
one of the great flaws in this report. In fact, that claim is an indication that
they are simply following the Prohibitionist party line.

There is no data
on THC levels from the 1960s and cannabis in the UK has been consumed largely in
the form of resin, or hashish, as the report itself acknowledges, making this
line misleading and irrelevant.)

BLF Chief Executive Dame Helena
Shovelton said: “Puff and inhalation volume with cannabis is up to four times
higher than with tobacco - in other words you inhale deeper and hold your breath
with the smoke for longer before exhaling. This results in more poisonous carbon
monoxide and tar entering into the lungs.”

The BLF recommends that
the
Government implements a public health education campaign on the health risks
of cannabis.
There
should be more research into cannabis and the lungs, and its potential link
with the development of chronic lung disease.

Reclassification of cannabis and the impact on
the perceptions of children in the UK, Susan Kaplin,
Life Education Centres, August
2002.

(MarijuanaNews
note: I was not able to find that particular study, but it is unfortunate that
HRH Prince Charles is a patron of this group. They seem to specialize in
prohibitionist propaganda.

See

LIFE EDUCATION CENTRES CONCERNED ABOUT RECENT REPORTS ON RE-CLASSIFICATION OF CANNABIS

and

CHILDREN CONFUSED ABOUT CANNABIS

They actually argue
that medical cannabis and not arresting adults for possession “sends the wrong
message” to children that cannabis is harmless. If that were true it would
simply prove that drug education in the UK is a fraud, which thanks to
organizations like the BLF, it often is.)
See
If The Best Two Word
Explanation for Cannabis Prohibition Is “Bad Journalism,” The Best 3 Word
Explanation Is “Quack, Quack, Quack.” — Wholesale Malpractice In UK As Lambeth
Experiment Spreads.
and
Crime Declined Sharply
London Area With De Facto Decrim. The Narks Caught In Yet Another Lie. Surprise!
Surprise!

Full text of BLF
report:

A SMOKING GUN UK?
From
http://www.lunguk.org/news/a_smoking_gun.pdf

Cannabis is the most widely consumed illegal drug in the UK. Recent media
coverage has focused on the public and political debate around issues such as
reclassification of cannabis and how the police should deal with those who sell
or are found to be in possession of varying amounts of the substance.

What has been consistently missing from the public debate on the safety or
otherwise of cannabis as compared to other illegal drugs is the impact of
smoking cannabis on respiratory health and the possible link with
nicotine addiction in the form of tobacco smoking.

This report sets out to identify existing scientific and medical research on
cannabis smoking and respiratory health. It identifies what conclusions it is
possible to draw from the
existing evidence and highlights gaps in our knowledge which require further
research.

The aim of this report
is to ensure that those taking part in the debate on cannabis and those engaged
in promoting health education to our young people have the fullest possible
information on the medical and scientific evidence of the impact of cannabis
smoking on respiratory health.

Many young people will
make decisions about whether they wish to use cannabis or not – regardless of
its legal status. We have a duty to ensure that they do so with full knowledge
of the risks associated with smoking cannabis.

SUMMARY OF FINDINGS AND
RECOMMENDATIONS

While there is a wealth
of research into the health impact of tobacco smoking, there is relatively
little on the effects of cannabis smoking.

Research investigating
whether the inhalation of cannabis smoke causes damage to the lungs and airways
focuses on whether this effect is independent of the effects of tobacco smoke or
not.

In general, the studies
indicate that there is an increased negative health impact on those who smoke
cannabis compared to those who do not smoke at all. When cannabis is smoked
together with tobacco then the effects are additive.

However, what is not
clear is whether it is the addition of the cannabis or the tobacco which is more
harmful or whether this is the result of the combined effects of equally harmful
substances.

Some key findings
emerge from the research:

•
The cannabis smoked today is much more potent that that smoked in the 1960s. The
average cannabis cigarette smoked in the 1960s contained about 10mg of
tetrahydrocanabinol (THC), the ingredient which accounts for the psychoactive
properties of cannabis, compared to 150mg of THC today. This means that
longitudinal studies carried out in the 1960s and 1970s may not be indicative of
the effects of cannabis cigarettes smoked today.
See

Potent Pot Myth Undermined
By Report From The Ultimate Authority. Cited By Swedish Prohibitionist Who Don’t
Seem To Understand. As Usual.

• Studies comparing the
clinical effects of habitual cannabis smokers versus non-smokers demonstrate a
significantly higher prevalence of chronic and acute respiratory symptoms such
as chronic cough and sputum production, wheeze and acute bronchitis episodes.

• 3-4 Cannabis
cigarettes a day are associated with the same evidence of acute and chronic
bronchitis and the same degree of damage to the bronchial mucosa as 20 or more
tobacco cigarettes a day.

Cannabis tends to be
smoked in a way which increases the puff volume by two-thirds and depth of
inhalation by one-third. There is an average fourfold longer breath-holding time
with cannabis than with tobacco. This means that there is a greater respiratory
burden of carbon monoxide and smoke particulates such as tar than when smoking a
similar quantity of tobacco.
(MarijuanaNews note: This is a clear example of the effects of the way that
cannabis is smoked under cannabis prohibition is attributed to cannabis itself.)

• Cannabis smoking is
likely
to weaken the immune system. Infections of the lung are due to a combination of
smoking-related damage to the cells lining the bronchial passage (the fine
hair-like projection on these cells filter out inhaled microorganisms) and
impairment of the principal immune cells in the small air sacs caused by
cannabis.
See

People With AIDS Benefit
From – Not Harmed by Medical Marijuana in Government Approved Test. Politically
Very Important – Medically Pointless.

• The evidence concerning a possible link between cannabis smoking and Chronic
Obstructive Pulmonary
Disease (COPD) has
not yet been conclusively established.
A number of studies indicate a causal relationship between the two whereas
others contradict these findings.

(MarijuanaNews note: Actually, as noted the leading researcher in the field has
concluded that cannabis smokers will not get emphysema and do not lose lung
function. However, you will have to go to footnote 50 to find that fact.)

• Research linking
cannabis smoking to the development of respiratory cancer exists although there
have also been conflicting findings. Not only does the tar in a cannabis
cigarette contain many of the same known carcinogens as tobacco smoke but the concentrations of these are up to 50% higher in the smoke
of a cannabis cigarette. It also deposits four times as much tar on the
respiratory tract as an
unfiltered cigarette of the same wieght. Smokers of cannabis and tobacco
have shown a greater increase in cellular abnormalities indicating a
cumulative effect of smoking both.

• The THC in cannabis
has been shown to have a short term bronchodilator effect. This has lead to
suggestions that THC may have therapeutic benefits in asthma. However, the
noxious gases, chronic airway irritation or malignancy after long term use
associated with smoking would seem likely to negate these benefits

THE EFFECT OF CANNABIS
SMOKING ON RESPIRATORY HEALTH

1. SCOPE OF THIS REPORT
AND BACKGROUND

This report surveys the
current medical and scientific research into the direct effects of smoking
cannabis – both alone and in combination with tobacco – on the smoker’s
respiratory health. The report is divided into two parts the first part outlines
the constituents of cannabis, the amount of cannabis smoked and the dynamics of
smoking cannabis compared with tobacco. The second part surveys the findings of
the existing published research into the biological effects on respiratory

health of cannabis which is smoked, both in the short-term and long-term. Full
references to the individual publications are included at the end of the report.

Prevalence of cannabis
smoking in UK

Cannabis is the most
widely consumed illegal drug in the UK by gross weight (it is estimated that
486,224kg were consumed in 1998 – this is roughly the weight of 7,000 people put
together)1. It is often smoked together with tobacco although it
can also be ingested in the form of ‘hash cookies’ or taken as cannabis
oil.
(MarijuanaNews note: The UK has the highest level of cannabis in the EU despite
having some of the harshest laws. It is unlikely that something that has been
used so widely for so long would have any hidden dangers that would be revealed
by a review of old studies.)
See
New Dutch Study on “Licit
and illicit drug use in the Netherlands” Shows Why International Anti-Dutch
Prohibitionist Propaganda Campaign Is Vital to Drug Warriors. How Ideology
Works.

Constituents of
cannabis

The smoke of the same
quantity of cannabis and tobacco smoke contains the same constituents and
quantities of chemicals known to be toxic to respiratory
tissue as tobacco smoke, apart from nicotine(2,3.) This includes carbon
monoxide, bronchial irritants, tumour initiators, tumour promoters and
cancer-producing agents(4).
Tar from cannabis
cigarettes contains up to 50% higher concentrations of the carcinogens benzanthracenes and benzpyrenes
than tobacco smoke (6,7, 8.)

There are three main
species of cannabis, Cannabis sativa, Cannabis indica and Cannabis ruderalis.
The plant is also known as hemp.
As a drug of abuse
it is either taken in the form of herbal cannabis
(marijuana) which consists of the
dried leaves and female flower heads or as cannabis resin (hashish) which
is the resin secreted by the leaves and flower heads and may be compressed into
blocks.

Cannabis contains over
400 compounds including 60 different cannabinoids (plant derivatives unique to
cannabis) the most abundant of which is tetrahydrocanabinol (THC). This accounts
for the psychoactive properties of cannabis. It is highly soluble in fats and
rapidly absorbed in the respiratory and gastrointestinal tract lining. The
intoxicating effects depend on the way in which cannabis is taken – blood
concentrations after oral ingestion are only about 25-30% to those obtained

when cannabis is smoked(9.) About 50% of the THC in a cigarette of herbal
cannabis is inhaled in the mainstream smoke, nearly all of which is absorbed
through the lungs, rapidly entering the bloodstream and reaching the brain
within minutes.

A
greater amount of tar is inhaled from the cannabis cigarette butt rather than
its tip. There is also a higher concentration of carbon monoxide and THC in the
smoke from the butt end.
The effect of the carbon monoxide is to produce high concentrations of
carboxyhaemoglobin in the blood (10,) which interferes with the transport of
oxygen around the body. This is likely to be due to decreased filtration of
insoluble particles and differential burn rates.
The clinical implication
of this is that smoking cannabis cigarettes down to the butt is more harmful
than smoking a similar quantity of cannabis cigarettes to a longer butt length.
(MarijuanaNews note: This is an important point for smokers, but it is also an
artifact of cannabis prohibition.)

Other cannabinoids
which interact with THC although are not actually psychoactive in themselves are
cannabidiol and cannabinol. The amounts and proportions of the various
cannabinoids in each plant vary from strain to strain, and can be adjusted by
breeding.

Amount of Cannabis
smoked

THC is present in
varying concentrations in the stalks, leaves, flowers and seeds of the plant as
well as the resin secreted by the female plant. This has an impact on the
potency of different cannabis preparations. Furthermore, sophisticated
cultivation has increased the potency of cannabis products over the last 20
years. Whereas the
average cannabis cigarette of the 1960s and 1970s contained about 10mg of THC
today it may contain up to 150mg of THC, or 300mg if laced with hashish oil

(MarijuanaNews note: That is nonsense, but the reference to hash oil is
puzzling. There is nothing new about it and putting it on a joint or mixed
cannabis/tobacco cigarette would have had the same effect 30 years ago. In fact,
it did.)

This means that the
modern cannabis smoker may be exposed to greater doses
of THC than in the
1960s and 1970s(12, 13), which in turn means that studies investigating the
longterm effects of smoking cannabis have to be interpreted
cautiously.
(MarijuanaNews note: That is the whole purpose of that part of the party line.
Of course, later studies do not find the harm that was predicted – as their own
citations show.)

Cannabis and tobacco

Cannabis resin, the most commonly used form of cannabis in the United Kingdom,
is often smoked mixed with tobacco.

(MarijuanaNews note: This makes
the references to cannabis potency irrelevant but they don’t notice.)

Although this can
confound research on the respiratory effects of smoking pure cannabis, the
well-documented consequences of smoking tobacco need therefore also be
considered in the evaluation of the effects of cannabis smoking on respiratory
health.

It has been calculated
that smoking 3-4 cannabis cigarettes a day is associated with the same evidence
of acute and chronic bronchitis and the same degree of damage to the bronchial
mucosa as 20 or more tobacco cigarettes a day(14, 15.)

Dynamics of smoking
cannabis vs tobacco

Significant differences have been noted in the dynamics of smoking cannabis
and tobacco including an approximately two-thirds larger puff volume, a
one-third greater depth of inhalation and a fourfold longer breath-holding time
with cannabis than with
tobacco(16).
This means that there is a greater respiratory burden of carbon monoxide and
smoke particles than when smoking a similar quantity of tobacco. Similarly with
tar, it has been estimated that smoking a cannabis cigarette results in a
fourfold greater amount of tar inhaled and retention in the respiratory tract or
one-third more tar than smoking a tobacco cigarette(17)
(due to the longer
breath holding time for cannabis and differences in filtering characteristics of
the two types of cigarette).
(MarijuanaNews note: This is an artifact of prohibition not something intrinsic
to cannabis. No mention of vaporizers.)

2. EFFECTS OF SMOKING CANNABIS ON RESPIRATORY HEALTH

The British Medical Association estimates that smoking a cannabis cigarette
containing only herbal cannabis leads to an approximately fivefold increase in
blood carboxyhaemoglobin concentration (which is formed by carbon monoxide
reacting with the oxygen
carrying particle haemoglobin in red blood cells, thereby reducing the transport
of oxygen.)

Within minutes of
smoking cannabis significant decreases in airway resistance and increases in
specific airway conductance have been observed in healthy individuals, which
persist for at least one hour(19). This is caused by THC which has subsequently
been investigated for its possible therapeutic use in diseases such as asthma
(see below).

From a clinical
perspective, the main effects of smoking cannabis on the lungs are pulmonary
infections and respiratory cancer.

Immune responses

Several studies
indicate that smoking cannabis has a negative effect on the immune system. THC
has been shown to decrease the function of several white blood cells (T cells,
natural killer cells and macrophages) that help protect the lungs against
micro-organisms(20). Alveolar macrophages in particular are important in
regulating lung immunity and their central location in the lung’s air sacs means
that they are exposed to very large amounts of cannabis smoke.

Twice as many alveolar
macrophages as normal have been found to be produced in the lungs of cannabis
smokers and three times as many in cannabis & tobacco smokers(21). These
macrophages have been found to be considerably larger and contain more ingested
particles than is the case in non-smokers(22). They are also functionally
impaired in that they are less likely to kill tumour target cells(23) and a
variety of common fungal organisms and bacteria such as Candida albicans
and Candida pseudotropicalis(can cause thrush), Legionella pneumophila(26)
can cause
pneumonia) and Staphylococcus aureus(27)
(can cause food poisoning).

Macrophagal ability to
produce a variety of chemicals that play a key role in the immune response to
infection and malignancy has also shown to be impaired(28)

A decreased immune
function may explain why there appears to be an association between cannabis use
and opportunistic bacterial and fungal pneumonias in patients with cancer(29)
and transplant(30, 31) patients as well as those with
human immunodeficiency virus (HIV) infection(32).

Inflammation

Visual inspection of
the central airway of cannabis smokers has shown increased redness, swelling and
mucous secretion by comparison to non-smokers(33.) Smoking tobacco in
conjunction with cannabis appears to have an additive effect(34,35.) An increase
in the number and size of small blood vessels and replacement of the normal
ciliated surface lining cells (with hair-like projections) by mucus-secreting
cells have also been observed.

This may explain why
cannabis smokers tend to suffer from chronic cough and phlegm as there may not
be sufficient ciliated cells to remove the mucus from the airways.

Chronic Obstructive
Pulmonary Disease, COPD

COPD is an umbrella term for conditions such as emphysema and chronic
bronchitis. The evidence that COPD is mostly smoking related is already well
established. Currently more than 32,000 people die from COPD every year in the
UK.

(MarijuanaNews note: As we shall see in footnote 50 cannabis does not appear to
cause COPD. The media never read the footnotes.)

EFFECTS ON RESPIRATORY
HEALTH

There is a lot of
evidence that the long-term effects of habitual cannabis smoking include a
significantly higher prevalence of chronic and acute respiratory symptoms such
as chronic cough, chronic sputum production, wheeze and acute bronchitis
episodes(36, 37, 38, 39) by comparison to non-smokers. There is evidence of a
cumulative effect of smoking cannabis and tobacco in two studies(40, 41)
although not in another(42.)

Some studies indicate
that young cannabis smokers may be at risk of developing obstructive airway
disease in later life(43, 44). This is supported by animal studies in which
dogs(45), monkeys(46) and rats(47, 48) have been exposed to varying doses of
cannabis for 12-30 months and suffered damage to the smaller airway which
is a major site of injury in tobacco-related COPD as well as acute and chronic
pneumonia. However, other studies contradict a causal relationship between
smoking cannabis and COPD(49,50, 51). Regular cannabis smoking has been associated with emphysema in some
studies(52, 53) but not so in others(54, 55) . These studies are, however
non-conclusive as they did not distinguish between smoking only cannabis and
smoking cannabis together with tobacco.

They also only involved
a relatively small number of participants. A further study involving
rats exposed to
increasing doses of cannabis for 6 months did not display any evidence of
emphysema although this was the case in rats exposed to tobacco smoke(56.)

Further research in
this area is necessary to provide more conclusive results.
(MarijuanaNews note: In other words, there is no proof of their desired
conclusion and much evidence that it is false, but they want more research while
they pretend that what they claim is a fact.)

Respiratory cancer

More people die of lung
cancer in the UK than from any other cancer – more than 34,000 people die every
year in the UK.

As already mentioned, the tar from a cannabis cigarette contains many of the
same (and even higher concentrations of) carcinogenic compounds found in
cigarette smoke and deposits four times as much tar on the respiratory tract in
comparison to an unfiltered cigarette of the same weight. This amplifies the
exposure of cannabis smokers
to particles that are known to be involved in the development of lung cancer.

There are a number of
case studies (over 75) reporting cancers of the aero-digestive tract in young
adults with a history of cannabis use (57, 58, 59, 60, 61, 62, 63) which are
rare in adults under the age of 60 although the exact cause of these cancers is

not clearly identifiable as many of the cases also used alcohol and tobacco.
A retrospective
study undertaken in the United States(64) did not find a link between smoking
cannabis and tobacco-related cancers but it has been suggested that the time
span investigated may not have been sufficient to study the long-term
effects(65).
There is clearly a need for more epidemiological research in this area.

As it is, the development of cancer is a multistep process comprised of
sequential alterations in genomic DNA (the genetic material contained in cells)
which are promoted and/ or interact with environmental and genetic factors. It
is thereforeoften not clear
what the exact cause of a particular cancer may be.

Research suggests that cannabis might contribute to cancer by manipulating
the genetic makeup of cells. For lung cells to transform into cancerous cells, a
specific combination of genes that regulate cell growth must be activated (in
the case of oncogenes) and/ or mutate (in the case of tumour suppressor genes).
THC has been shown to increase the production of a chemical particle (CYP1A1)
that is responsible for causing benzpyrene (a constituent of cannabis smoke) to
promote alterations in one
of the most common tumour suppressor genes, p53 thereby facilitating the
development of respiratory cancer(66,
67). The gene p53 is thought to play a role in 75% of all lung cancers(68) and
has been found to be expressed
in 11% of individuals who smoke cannabis and tobacco(69).
Other studies looking at the effect of tar in cannabis smoke on animals(70, 71,
72) also indicate a correlation between cannabis and respiratory cancer.

An increase in cellular
abnormalities has also been observed in cannabis smokers by comparison to
non-smokers(73, 74). Abnormalities include an increase in the production of
mucus producing cells (goblet cells) and reserve cells, transformation
of ciliated cells into cells that resemble skin (squamous metaplasia), an
accumulation of inflammatory cells and abnormalities in the cell nuclei. Nuclear
alterations and squamous metaplasia have been described as precursors to the
development of lung cancer in tobacco smokers(75).

In addition, smokers of
cannabis and tobacco have shown a greater increase in cellular abnormalities
indicating an additive effect.

Oral soft tissues

The effects of tobacco
smoking on oral soft tissues have been well documented but there is little data
available on the effects of cannabis smoking. However, there are some case
reports that heavy cannabis use is associated with cancer of the tongue (76,
77), larynx(78) and lung(79).

Other lung conditions

There have been
isolated reports of spontaneous pneumothorax (breaches of the lungs causing gas
in the lung cavity leading to compression of the lungs) and pneumomediastinum
(breaches of the lungs causing gas in the cavities of the respiratory tract)
associated temporally with the use of cannabis(80, 81, 82) which are
thought to be caused by
deep inhalation of cannabis smoke to enhance absorption of THC and hence the intoxication caused by it(83).
Deep inhalation coupled with direct pulmonary toxicity from components in
cannabis in susceptible smokers has also been implicated with the formation of
large lung bullae
(watery blisters) in the upper respiratory area(84).

Contamination of cannabis

There has been a report
of chronic cannabis smoking leading to necrotizing pulmonary granulomata (these
are changes in the lungs at cellular level which may prevent the lungs from
working as they should) (85) as a result of possible fungal contamination of
cannabis.
(MarijuanaNews note: Again, this is a result of cannabis prohibition. After all,
contraband is much more likely to be contaminated than a legal product.)

Health care utilization
by cannabis smokers

This has been assessed
in an epidemiological study in which cannabis smokers who had never smoked
tobacco were compared with non-smokers(86).
Frequent cannabis smokers
showed a slight increase in outpatient visits for respiratory and
other
illnesses compared with non-smokers as well as a small increased risk of
hospitalization.

(MarijuanaNews note: Only a slight increase? That hardly supports the idea that
cannabis is as dangerous as tobacco. Where are the bodies?)

Potential therapeutic
benefits

The bronchodilator
effects of THC in cannabis have also been found in the case of asthmatics with
mild to moderate airway obstruction although not to the same extent as in
healthy people(87). This has led to suggestions that THC might
have therapeutic benefits in asthma. However, the noxious gases, chronic
airway irritation or malignancy after long-term use associated with smoking
would seem likely to negate these benefits over the long term. Oral intake of
THC has also shown to cause unwanted side-effects such as central nervous system
intoxication and an excessive increase in heart rate(88,
89). Furthermore, tolerance to the bronchodilator effects of THC has been demonstrated after several weeks of
use(90).
(MarijuanaNews note: It is especially appalling that the BLF ignores
vaporization in this context.)

RECOMMENDATIONS

From a clinical perspective the main effects of smoking cannabis on the lungs
are increased risk of pulmonary infections and respiratory cancers. Benzpyrene,
a known constituent of the tar of cannabis cigarettes has been shown to promote alterations in one of the most common tumour suppressor genes, p53, hence
facilitating the development of respiratory cancer. Gene p53 is thought to play
a role in 75% of all lung cancers.

The British Lung
Foundation recommends a public health education campaign aimed at young people
to ensure that they are fully aware of the increased risk of pulmonary
infections and respiratory cancers associated with cannabis smoking.

The increased potency
of the cannabis smoked today compared to the cannabis smoked twenty/thirty years
ago suggests that earlier studies may underestimate the effects of cannabis
smoking.
(MarijuanaNews note: Yeah, lie to the kids in a new campaign. That will further
undermine the credibility of any “drug education.” No one should believe
anything that these people say. They are proven liars catering to the police
state propagandists.)

In addition the lack of conclusive evidence concerning the link between cannabis
smoking and Chronic Obstructive Pulmonary Disease (COPD) underlines the need for
further research.

The British Lung
Foundation recommends that further research is undertaken to take
into account the
increased potency of today’s cannabis
and to establish what link
(if any)
there is between COPD and cannabis smoking.

See
Footnotes to British
Lung Foundation Report Plus NORML’s Comments.