Frequently Asked Questions
Why is that plant trying to kill me?
It isn’t. The idea that the plant has some reason for trying
to kill you is the result of the arrogance of the human species.
Until quite recently, the belief was that human beings are not only
the most advanced species in the world, they are the reason the
world exists. Different cultures have had different theories
about the creation of the world and life on earth but they all
assume that human beings are at the centre of the creator’s purpose.
From this viewpoint a plant which harms a human being must be doing
it deliberately and a lot of philosophical effort has been put,
historically, into trying to determine what the plant’s motivation
is.
Theophrastus Phillippus Aureolus Bombastus von Hohenheim
(1493-1541), who became known by the single name, Paracelsus, was a
Swiss. Depending on the view of his work taken, he is
described as a philosopher, aesthete and nutter.
Paracelsus was the first person to say that trying to determine why
a plant was trying to poison someone was the wrong approach.
Plants contain substances which they need for their life cycle and
some of those substances can cause harm to living creatures by
combining with a substance which is essential to the creature’s own
life cycle.
See also, How Can Birds Eat Poisonous Berries?
How Can Birds Eat Poisonous Berries?
Simple. It isn’t poisonous to them. See ‘Why is that
plant trying to kill me?’ for a detailed explanation of what we
actually mean when we call a plant poisonous.
If a creature doesn’t have a substance which will combine with the
‘poison’ in the plant, then that ‘poison’ will have no effect on
that creature.
Poisons, generally, work in one of two ways. They combine with
a substance which is essential to a creature’s life creating a third
substance which is excreted. It is the removal of the
essential substance which results in the harm. Or, the
substance created by the reaction of the ‘poison’ with the substance
in the creature is itself harmful to the creature.
The best example of the different effect a plant has on different
creatures is the Conium maculatum, poison hemlock. The
principal active ingredient in poison hemlock is called coniine.
For humans it can be a deadly poison working on the peripheral
nervous system. That is to say it numbs the extremities first, the
fingers and toes, and the numbness creeps into the body eventually
reaching the chest and paralysing the lungs. Death results
from asphyxiation but the mind remains unaffected so the victim is
aware of the creeping numbness bringing death to them.
Birds are completely unaffected by coniine. They actually do
nothing with the substance and, as a result, it builds up in the
flesh without causing them any ill effect. This means the
coniine is still available to poison a human being if they consume
the flesh of the bird. In a twenty year period in Italy, where
wild birds are often trapped or shot as they migrate south, there
were seventeen cases of hemlock poisoning resulting from the eating
of wild birds. Four resulted in death and, in one case, the bird
had been in a freezer for three months but the coniine was still
active.
How Many People Die Because of Poison Plants?
That depends on what is meant by ‘because of poison plants’.
If the question is how many die from accidental ingestion of plant
material, such as eating berries from a poisonous plant, then the
answer is very few indeed. There are two reasons for this low
mortality rate even though all these very dangerous plants are all
around us.
First, the majority of poisonous plants are emetic; eat a large
amount and you are likely to suffer violent vomiting which removes
the poison from the stomach before it has the chance to do a great
deal of harm. One example from the Alnwick Garden Poison Garden will
serve to illustrate the point.
A middle aged couple had visited an elderly aunt who had prepared a
meal for them. The aunt kept her fresh vegetables in a basket on a
shelf in her outer kitchen under a shelf housing spring bulbs
waiting to be planted. Unnoticed some daffodil bulbs had dropped
into the vegetables and the aunt had used them, instead of onions,
to prepare the meal.
The husband consumed a whole bulb and the wife half of a bulb.
Within ten minutes the husband suffered violent vomiting but felt
better immediately after. It was an hour later before the wife
was sick and she then suffered vomiting and diarrhoea for two days.
So, the husband benefited from the emetic effect of a large dose
whereas the wife suffered the symptoms normally described as
resulting from ingestion of spring bulbs.
The second important factor in keeping accidental deaths from plant
poisoning at such a low level is taste. The overwhelming
majority of poison plants are unpleasant to the taste. The
Solanum dulcamara, woody nightshade, has a very attractive red berry
but its taste is extremely bitter. Anyone picking a few from a
hedgerow would be unlikely to swallow much plant material as soon as
they experienced the bitter taste.
The bright orange berries of Arum maculatum, cuckoopint or lords and
ladies, have an acrid taste and, because the poison is in the form
of needle sharp oxalate crystals, the mouth and throat very soon
begin to tingle from the irritation caused. So, a child coming
across the plant in the woods and deciding to try the berries would
very soon find the taste unacceptable and not eat above a couple and
then, when the mouth or throat began to tingle from the irritation,
would rush to seek assistance allowing serious harm to be avoided.
In Europe as a whole, the number of deaths from ingestion of a
poisonous plant is so small that no separate statistics are
collected. In the USA, less than five people a year die as a
result of eating a poison plant.
Evidence that poison plants cause far less harm than might be expected can be found in 'Accidental poisoning deaths in British children 1958-77' published by the British Medical Journal. Neil C Fraser reports on a total of 598 poisoning deaths of children under 10 years of age. In the period covered only three deaths were attributed to plants. Even this low number is overstated since one death was due to fungi and in one of the other two 'the role of ingestion in the child's demise is doubtful'. Thus there may have been only one confirmed plant death, with 'hemlock' being the plant responsible, in twenty years. Fraser's analysis makes it clear that medication, household cleaning materials and cosmetics pose a much higher risk than poison plants.
So, the plants don’t cause many deaths?
Actually, they do, millions of deaths every year, in fact. But
not when they are in their natural state. The huge numbers of
deaths occur once we start to make products from the plants.
In Europe, over seven thousand people die from an overdose of heroin every
year and, around the world, over five million die from smoking
related diseases.
One key message of The Poison Garden website is that the plants aren’t
‘bad’. We make them harmful by the ways in which we use them.
I Have Children - Should I Clear my Garden Out?
As we become increasingly risk averse, people are more inclined
to think that they should try and remove all the poisonous plants
from their gardens. This ignores the fact that many poisonous plants
are found in the wild or on public land, like parks and street plant
displays, and that almost any plant can be harmful if you have
enough of it.
Sadly, this idea of clearing everything out is, often, put forward
in books on poison plants and, increasingly, on websites written by
people who don't know what they are talking about.
For a realistic view of the situation regarding plants and children,
I recommend
'Poisonous Plants: a guide for parents and childcare providers'
by Elizabeth Dauncey.
Is Cannabis Addictive?
No. It is important to distinguish between addiction and dependency.
An addictive substance is usually characterised by two things; a
need for increasing amounts in order to experience the same effects
and evidence of physical symptoms if the substance is suddenly
withdrawn. A third is sometimes included which is the creation
of a craving for the substance but, in effect, this is the beginning
of withdrawal symptoms.
Dependency is when there are psychological effects from the absence
of the substance. There are, undoubtedly, people who become
dependant on cannabis because they feel uncomfortable and stressed
if they do not have their usual supply of the substance but even
those who might be considered to be highly dependant are not
completely controlled by the substance in the way that an alcoholic
or heroin addict is.
Anyone who has ever known an alcoholic knows that they have to have
a drink whenever they crave it whether that is first thing in the
morning or during working hours. Cannabis does not create the
same irresistible need.
In its 2006 annual report, the United Nations Office on Drugs and
Crime (UNODC) says that ‘many daily users have rules around when and
where they will consume, generally restraining their use to leisure
time. Surveys of users in New Zealand show 95 per cent of smokers
polled said they never used
the substance at the workplace……A study of users in Amsterdam, where
the drug is widely tolerated, found that declining to consume at
work was the single most commonly followed ‘rule’ around
consumption, and that 27 per cent of their sample of experienced
users adhered to this rule, while a further 20 per cent abstained
from smoking during the day, and 15 per cent abstained during the
morning’.
People who are addicted don’t make the ‘rules’ about how to indulge
their addiction, the addiction does that for them.
Does Cannabis Lead to Other Drugs?
There are studies which show that a high proportion of addicted drug
users began by using cannabis and this is used to argue that
cannabis leads on to more harmful drugs. The problem with that
argument is that it may be an example of the principle of post hoc
ergo proptor hoc, a later event happened because of an earlier
event, whereas there is no evidence for a causal link. What we
cannot know is how many of those people would have become drug
addicts even if there were no such thing as cannabis.
The United Nations Office for Drugs and Crime puts forward another
view. In its 2006 World Drugs Report it quotes research which
‘concludes that associations between early cannabis use and later
drug use and abuse/dependence cannot solely be explained by common
predisposing genetic or shared environmental factors. [The research]
argue[s] that association may arise from the effects of the peer and
social context within which cannabis is used and obtained. In
particular, early access to and use of cannabis may reduce perceived
barriers against the use of other illegal drugs and provide access
to these drugs.’
In other words, because cannabis is illegal people who use it become
acquainted with a criminal world in which ‘harder’ drugs are also
available and lose their inhibitions about buying illegal
substances.
My own view is that telling lies about cannabis may be the mechanism
which makes it a ‘gateway’ drug. If young people are told that
cannabis is extremely harmful and that use will lead to idleness,
aggressiveness and mental health problems they are highly likely to
find their own experience of it to be markedly different. If
they are now told that heroin is an addictive substance which leads
to many deaths each year due to overdose, they may look at the
situation regarding cannabis where they were lied to about its
effects and assume that what is being said about heroin, or any of
the other ‘hard’ drugs, is also lies.
Are any of the poisons undetectable?
No, not today. Modern forensic science, if properly used, can
detect even the tiniest amount of any poison.
But that isn’t the question you wanted to ask.
Is it possible to get away with murder?
That’s more to the point. Because that is a very different
question. Given that these poisons can be detected even in the
smallest amounts, the way to get away with murder is to not have
anyone look for the poisons. In other words, if no-one
suspects murder took place, no-one will go looking for any poisons.
We pay much more attention to death than we used to so it is less
likely that unexpected deaths won’t get fully investigated but
investigation is by no means certain. Harold Shipman had a
twenty three year career of murdering patients with an overdose of
morphine but, for most of that time, no-one suspected murder was
taking place.
In the past, when death was less likely to be closely examined,
getting away with murder was much easier. Take, for example,
strychnine derived from the Strychnos nux-vomica plant. During
Victorian times it was a major component of rat poison and, with
inner city areas being rat infested, rat poison was easy to buy with
no questions asked. Strychnine has a bitter taste but, if you put it
in something expected to be bitter, you can disguise the taste.
As soon as your victim says ‘This tastes funny’ you’ve lost the
chance of murder not being suspected.
Strychnine is a stimulant, making the muscles contract
uncontrollably. Death is often the result of exhaustion but
the contractions also lead to the muscles pulling themselves away from
the bones allowing the body to contort into normally impossible
positions. These contortions and convulsions are called ‘tetanic’
because they look very like the death throws of tetanus, which was
endemic in Victorian slums.
So, strychnine was easily obtained and no-one would notice the
murderer had purchased it, the taste could be disguised so the
victim wouldn’t suspect anything and the death would be attributed
to tetanus.
Should we buy the Afghan Opium Poppies?
After reaching a figure of 193,000 hectares, in 2007, opium poppy cultivation in Afghanistan fell to 157,000 hectares in 2008 and 123,000 hectares in 2009. The UNODC 'Afghanistan Opium Survey - Winter Rapid Assessment 2010' believes that the area under cultivation will be roughly similar in 2010 but that climatic conditions could reduce the yield. The actual weight of opium produced will depend on climatic conditions but it is certain that Afghanistan will continue to provide over 90% of the world’s heroin supply which, incidentally, exceeds the world’s heroin demand by a large margin.
The substantial falls in poppy cultivation in recent years have more to do with higher prices for other crops, such as wheat, than enforcement action. Even UNODC gives crop pricing as the prime reason for fluctuations in the area under cultivation and notes that the recent falls in wheat prices could lead to an increase in poppy growth for 2011.
There have been suggestions that the ‘West’ should buy the poppy crop to prevent it being turned into heroin but that is not as simple as it seems.
There are large areas of Afghanistan which are suitable for poppy cultivation but are not, at present, used because the existing production is some 20-30% above demand. If poppy farmers are able to sell their crop to the UN or NATO, the demand becomes unlimited. If farmers are paid not to grow poppies then those who are presently not growing them may feel aggrieved that they are being punished for doing as there were asked. The figure quoted of $1 billion as the value to farmers of the poppy crop would not, therefore, be the cost of compensating farmers as many non-growers would need to be compensated.
But, $1 billion is only the value of the poppy crop to the farmers. The total value of heroin to the Afghan economy is nearer $2.5 billion because of the ‘added value’ of manufacture and distribution. Much of this extra $1.5 billion goes into the pockets of anti-government forces which get lumped together under the name the Taliban. If you compensate just the farmers then the Taliban will go looking for others to grow their poppies for them but if you pay off the whole industry then, in effect, you are paying the Taliban to kill NATO troops which, clearly, would be politically unacceptable.
