Chapter 1

A General Introduction to Poisons and Poisoning

POISONS ARE EVERYWHERE. THOUSANDS of people die every year from accidental poisoning caused by household products, wild plants, venomous creatures, occupational hazards and many more.

In a one-year period from 2005 to 2006, the United Kingdom’s National Poisons Information Service, which supplies specialist information and advice on the treatment of poisoning to doctors, received 90,000 telephone calls, of which almost 10,000 related to poisoning by household products alone.

All substances can be poisons, but the right dose distinguishes a poison from a remedy. So said the physician Paracelsus nearly 500 years ago. Even water can be a poison if you drink enough of it. But, by poison, we usually mean a substance that causes serious bodily harm or ultimately death from just a very small quantity.

Many of these poisonous substances have been abused throughout the years. For example, Dr Harold Shipman, a GP who killed at least 215 of his patients in the final decades of the twentieth century (more about him in Chapter 20), and other medical professionals took advantage of their special position and ease of access to poisonous medicines, using them deliberately to kill. Lesser mortals used whatever was available: rat poison such as the tasteless and odourless arsenic was frequently added to a variety of food and drinks without conjuring suspicion.

Many different foodstuffs have been used by murderers to hide poison, from scones and cakes to spaghetti Bolognese. Murderers are inventive, and where a stronger flavour is needed to mask the poison, such as with phosphorus, HP sauce and curry have also been used.

Poisoning may be deliberate like this, but it may also be unintentional. Of the thousands of cases of poisoning every year, the majority are accidental. The incidence of poisoning continues to rise annually, due to the increasing availability of potent medicines, the illicit use of so-called recreational drugs like ecstasy and an ever-growing number of toxic substances used in industry. Luckily, the number of antidotes is increasing as well: until recently there had been no antidote to cocaine overdoses, but in September 2008 scientists from Kentucky University in the USA announced that they had discovered one that they will develop. And more sophisticated medical treatments used today mean that, although incidences of poisoning are increasing, fewer of them result in fatalities.

Cleaning substances, painkillers, cosmetics and plants are the most common causes of accidental poisoning, and small children constitute the largest group of patients involved in these cases. Fortunately most of them survive because of prompt treatment. The majority of deaths from poisoning are of adults, and the largest number each year are caused by antidepressants, painkillers and street drugs.

Many examples of poisoning were first made known by their publication in medical journals. The British Medical Journal (BMJ) and The Lancet are probably the oldest and best known in Britain. In the United States, the New England Journal of Medicine and the Journal of the American Medical Association (JAMA) are considered the most prestigious. There are a great many medical journals published regularly throughout the world on every conceivable specialist topic, and, through these journals, cases and causes of poisoning are still frequently made known to the medical profession and the wider world.

Dr Thomas Neill Cream was a physician born in Glasgow who studied medicine at McGill University in Canada and graduated in 1876. He practised as a physician in Chicago, where he was also involved in murder, arson, abortion and blackmail. In 1881, he poisoned his mistress’ husband with strychnine. Showing rather odd behaviour for a murderer, he wrote to the district attorney suggesting that the body be exhumed. As a result he aroused suspicion and was arrested, tried and sentenced to life imprisonment.

His sentence was shortened and, upon release in 1891, he came to London, where for several months he preyed on prostitutes, giving them pills laced with strychnine. He managed to kill four of them. Being cross-eyed, he was somewhat noticeable in appearance, and so became known as the Cross-Eyed Lambeth Poisoner. As he had done in Chicago, he drew attention to himself and was soon arrested.

A prostitute who survived his attentions remembered the cross-eyed doctor well. After she came forward and identified him, he was charged with murder. A chemist told the court that Dr Cream had purchased Nux Vomica (which contains strychnine) and some gelatin capsules from his shop. A search of Dr Cream’s lodgings produced no less than seven bottles containing strychnine. The jury convicted him and he was hanged in November 1892.

What’s your poison?

Not surprisingly, along with the many naturally occurring poisons – animal, vegetable and mineral – there are many more man-made ones. All poisons are chemicals of one sort or another, and work in a wide variety of ways.

With the wide variety of poisons and poisoning techniques comes a wide spectrum of undesired effects. Many chemicals, while not toxic themselves, can be converted into toxic breakdown products – metabolites – by enzymes in the body. This is what happens with alcohol, a poison that occurs many times in this book, in both good and evil guises. The degree of poisoning of a person will depend on how fast the toxic metabolite is produced, compared to the speed with which the body can break it down into something less toxic, or excrete it.

In 1914 the French government banned the liqueur absinthe, claiming that it caused hallucinations and epilepsy. But this was not true. The ban was really an attempt to reduce the number of alcoholic poisonings and deaths, for the common good.

Absinthe is a highly alcoholic drink, containing some 68 per cent alcohol. It is made by infusing double-distilled spirit with wormwood flowers and other herbs. The wormwood plant contains a bitter alkaloid called thujone. The essential oils of aniseed, coriander, fennel, peppermint, hyssop, angelica and lemon balm are used to mask its bitter taste in the drink. The finished product, absinthe, is a pale green liqueur, which has traditionally been served by pouring iced water over a sugar cube placed in a perforated spoon, above a glass containing the absinthe. The alcohol and water mix results in the traditional cloudy drink.

While the alkaloid thujone certainly is a narcotic poison, the quantity to be found in absinthe is unlikely to cause any problem. The high alcohol content in absinthe was the real culprit in this particular case.

Exposure – it will get you either way

Poisoning can result from either acute or chronic exposure to a noxious substance. Acute exposure refers to when the poison is delivered as a large single dose. Chronic exposure is usually due to a low level of exposure over a prolonged period of time – anything from days to decades.

About 40 years ago mentholated cigarettes were very popular. These were manufactured and packaged in the same way as any other cigarette, except that the tissue and foil wrapping encasing the cigarettes within the carton were impregnated with menthol. Only a short period of storage time was needed for the menthol to suffuse the cigarettes.

A woman who smoked 80 mentholated cigarettes daily for three months developed insomnia, an unsteady gait, thick speech, a tremor of the hands, mental confusion, depression, vomiting and cramps in her legs. Her heart rate was found to be very slow, at only 44 beats per minute. All these symptoms rapidly disappeared when she smoked ordinary cigarettes, without menthol. Later a test dose of 65mg three times a day for seven days produced the same slow heart rate and evidence of toxicity. Now that’s a lesson learned the hard way.

Chronic exposure can result in a slow accumulation of a poison within the body, as has happened to workers in a number of industries in the past. For example, the lung disease silicosis can have a latency period of about ten years before the symptoms begin to show themselves. With asbestosis, this period may be as long as 25 years.

In recent years there has been a massive increase in the number of cases of skin cancer, not only due to chronic exposure to sunlight but also to chronic sunbed tanning in beauty parlours. Young ladies who try the acute approach to tanning in coin-operated booths usually end up on the news, having required hospital treatment for burns.

Ultra-violet or even visible radiation from sunlight acting on the skin, in conjunction with a number of drugs, can trigger photo-toxic and photo-allergic reactions. Contact with some plants can cause allergic reactions too – the sap of spurges, Euphorbias, can cause contact dermatitis if it gets on the skin, and is much worse if it happens while the skin is exposed to sunlight, often resulting in an acute condition requiring hospital treatment. For gardeners, this can have serious consequences as initial slight acute reactions can become serious and chronic, as we shall see in Chapters 8 and 9.

Poisoners of the deliberately murdering kind tend to match their motive with the type of poisoning. For example, those who are in a hurry to collect the life insurance of their victim prefer a massive one-off acute dose while others use the slow insidious method of chronic exposure, in the hopes that they are less likely to be discovered. In recent times, both techniques have been used and abused.

Dena Thompson was nicknamed the Black Widow because she chose lonely single men as her victims. She preyed on them physically, sexually and financially, tricking them out of a total of more than £500,000. It was in 1982 that she met her first husband, Lee Wyatt, whom she married two years later.

In 1990 she met and bigamously married Julian Webb. Only a few months later, she told him that she had cancer, a lie created to extort money from him. In 1994 she murdered him by mixing some tricyclic antidepressants and painkillers into a home-made curry for a quick kill, the spices in the curry masking the bitter taste of the drugs. When he died, she persuaded the police that he had committed suicide due to depression. However, her mother-in-law was suspicious and refused to allow her son’s body to be cremated, which would have destroyed any evidence. She insisted that he be buried, but no investigation was attempted for years.

Dena then rekindled an old friendship with a teacher and obtained money from him by using the cancer story once again.

In 1995 she was sent to prison for stealing money from the building society where she worked. At that trial, she tried to blame the theft on her original husband, Lee Wyatt. Upon her release from prison she had a relationship with a prison officer and then with an army officer. In 1997 Lee Wyatt finally divorced her, and she then set off to find another victim.

In 1999 Richard Thompson became her third husband and the cancer story was used yet again. She spent over £12,000 on his company credit card, emptied his savings account and then attempted to kill him. At a trial the following year, she was cleared of the attempted murder but found guilty of stealing the money from him as well as from two former boyfriends, and she was sent to prison yet again.

Julian Webb’s body was exhumed in 2001 and re-examined, largely as a result of his mother’s insistence over the years that he would never commit suicide. This belated forensic investigation proved that Webb had indeed been poisoned by curry. At a further trial, the Black Widow was sentenced to life imprisonment for murder, and she will serve at least 16 years in prison before her sentence is re-evaluated.

Different poisons tend to build up in specific parts of the body: for example, lead gets into the bones while insecticides prefer body fat. But the central nervous system is by far the most frequently affected by poisoning, followed by the circulation, the liver and the kidneys. Less frequently affected are the lungs and skin, and bones and muscles least of all. Forensic examination of a body can uncover poison in any of these places, as in the case of the Black Widow, Julian Webb and the killer curry.

In December 2007, Heather Mook, who had previously been convicted in 1981 for poisoning her seven-year-old daughter Theresa with antidepressants, was found guilty of trying to murder her husband using antidepressants and rat poison in his spaghetti Bolognese. She had cooked the poisoned pasta in an attempt to get away with the theft of £43,000 worth of life savings intended to pay for a nursing home for her husband’s mother.

Like the Black Widow, she too had tricked friends into handing over £20,000 by pretending she was being treated for cancer. At her trial, many other scams and deceptions came to light, together with a string of previous convictions, including a £5million luxury car and bogus hotel property scam. When the jury found her guilty, she was sent away for psychiatric reports before being jailed indefinitely, although she will be considered for parole after serving a minimum of five years in prison.

Going cold turkey

We all know that the morning after can be mildly unpleasant after a few glasses of wine, but a nightmare after a few bottles. If the body can break down toxins rapidly enough, then the ill effects of a poison will be minimal, as with the occasional glass of wine. But when the quantity of the noxious substance outweighs the speed of the body’s ability to break it down, as with binge drinking, an awful hangover is only the best-case scenario.

Exposure to a number of poisons taken together may sometimes change the speed of absorption, breakdown or excretion. The effect may be a simple additive one, where the total effect is equal to the sum of the effects from each substance on its own. But often there is a synergistic effect, where the total combined consequence is far greater. Such synergy is seen, for example, with alcohol and cocaine, which both affect the brain on their own but produce much more serious effects when taken together. Sometimes even the presence of a non-poisonous substance can increase the toxicity of a poison, an effect called potentiation, such as in Chapter 3, where a perfectly edible mushroom should not be eaten by beer drinkers.

The opposite effect, antagonism, is far more useful, as this is how an antidote works. Antidotes are used in the treatment of poisoning to interfere with or counteract the action of toxins. Drugs derived from opium, such as morphine, and synthetic drugs made from it, like heroin, are called opioids. Opioids all act at specific receptors in the body, particularly in the brain, to depress the central nervous system. The effects of an opioid overdose can be reversed within seconds by an intravenous injection of an opioid antagonist drug, such as naloxone, which is used to compete with the opioid drug at these receptors, thus rapidly reversing their effects – a sort of instantaneous cold turkey.

Everything in moderation

A controversial theory called hormesis suggests that low-dose stimulation by some poisons may lead to protection against their toxic effects. Dioxins are environmental poisons and carcinogens produced during the manufacture and incineration of plastics. But in minute doses in rats, these dioxins have been shown to reduce certain cancer rates. It has been known for centuries that very small doses of cyanide or strychnine act as tonics; indeed, many medicines in the past included them as ‘must-have’ ingredients.

Curiously, nuclear workers have been found to have lower rates of some cancers than the general population, perhaps due to their exposure to poisonous substances – in moderation – at work. In Cornwall, the radioactive gas radon, escaping from the underlying rock, can build up in houses that are not adequately ventilated. But this county’s rate of childhood leukaemia is lower than the national average. This controversial theory even appears to hold with certain plants, which have been found to flourish when given low doses of certain herbicides. As a result of this theory, some doctors suggest that a moderate intake of alcohol is healthier than none at all.

The effects of some poisons are reversible, so the effect of a moderate dose will wear off with time, as the body breaks down – that is, metabolises – the poison into less toxic substances, which can then be excreted. Fortunately this is the case with alcohol. With some toxins the body responds by way of rapid evacuation, as in the case of food poisoning, where vomiting and diarrhoea quickly remove the cause of the problem. Other poisons, like the heavy metals such as lead and mercury, tend to accumulate because our body has no use for them, and so it stores them away until eventually the quantity is so great that the poison starts to interfere with vital functions.

Unintended side effects

Poisoning produces a number of common and expected symptoms: abdominal pain and vomiting, progressing in more serious cases to delirium and loss of consciousness, and even slowing respiration and death. A host of other symptoms can also occur during this progression, some of which may be highly characteristic to the poisonous substance.

George Hersey lived and worked in South Weymouth, Massachusetts. This young widower became engaged to a young lady called Mary Tirrell. Unfortunately she died soon after the announcement of their engagement. Her parents, seeing the young man’s grief, offered George a home with them. He accepted and soon befriended their eldest daughter, Betsy. She was plain, unmarried and 25 years old. She always seemed somewhat low in spirits. In those days, she was likely to remain a spinster. Betsy began to look after George, mending his shirts and caring for his appearance. George did not work for a time, but he studied chemistry and, in particular, poisons, about which he could talk quite knowledgeably.

As the months went by, Betsy and George embarked on a secret love affair. But even so, Betsy’s depression continued. One day George went to Boston and bought some strychnine from a pharmacy, explaining that he wanted it to put down a dog. In early May 1860, he took Betsy out for a carriage ride and on returning home went straight to bed, complaining of a headache. Betsy sat with the family that evening, reading aloud from the newspaper, before she too retired.

Half an hour later she was thrashing about in bed, twitching, convulsing and screaming. Her back was arched and she was in terrible pain, symptoms suggestive of strychnine poisoning. George was sent to fetch the doctor, but Betsy was dead before he arrived. A post-mortem showed that Betsy was three months pregnant. The doctor thought that she had been poisoned. The coroner was notified and tissues from various parts of the body were removed for further analysis. Betsy’s parents, upon learning of the pregnancy, ordered George out of their house.

A search of the dead woman’s room produced a spoon with traces of jam. Subsequent analysis showed this to be strychnine-laced jam. George Hersey was arrested and put on trial. He pleaded not guilty but a Boston doctor appeared at the trial and testified that George had requested that he perform ‘an operation’ on a lady friend who was pregnant. The doctor had refused, of course, and had also refused to supply strychnine that was also requested.

The court decided that George had supplied Betsy with the poisoned laced jam, telling her that it would ‘help’ her out of her trouble, and she had taken it in the hopes of getting rid of her baby. The defence tried to suggest that Betsy had committed suicide because of her depression, but the jury found George guilty of murder, and he was sentenced to death. Before his execution, he admitted to causing Betsy’s death but denied killing his first wife and his fiancée Mary Tirrell, Betsy’s sister.

While some symptoms of poisoning are expected, others can creep up on us, sometimes even revealing seemingly harmless substances as poisonous. Medications prescribed by doctors can produce unwanted and even harmful effects, described as iatrogenic. This does not imply that there has been any lack of care by the doctor. Adverse, unwanted reactions may simply be a side effect of the medication, and may be unavoidable and mild. For example, the drowsiness caused by taking one of the older type of antihistamines is inevitable, as these older antihistamines cross the blood-brain barrier while the newer non-drowsy type do not, or do so to a far lesser extent. In recent years, this drowsiness side effect has been put to good use in over-the-counter remedies sold to treat insomnia.

We all know that you can have too much of a good thing, and sometimes iatrogenic illness can be caused by the interaction of several different types of well-intentioned medicines taken together. Every year, many elderly patients fall ill and are admitted to hospital due to interaction of their prescribed medicines – either with one another, or more likely with over-the-counter medicines or herbal remedies purchased by the patient, or their well-meaning relatives. This is not a new phenomenon: the physicians who treated King Charles II went overboard in their eagerness to cure their royal patient, and they killed him in the process.

It is widely believed that King Charles II was killed by the treatment he received from his physicians during his final illness. Charles II was born in 1630. His father, Charles I, was beheaded in 1649, and Charles II was forced to live in exile in Europe for nine years until the collapse of Cromwell’s regime, after which he was restored to the throne. He reigned from 1660 to 1685.

His final illness began with a sore foot when he retired to bed on Sunday 1st February 1685. By the next morning he appeared to be quite ill. The royal physician, Sir Edmund King, attended to the royal foot, but while a barber was preparing to shave the king, Charles II was struck with an apoplexy (now called a stroke). In an attempt to purge his leader of the illness, Sir Edmund immediately bled the king of 16 ounces of blood – the better part of a pint. He risked his own death with this act, as he should first have obtained the permission of the Privy Council.

By now, a dozen physicians were gathered about the king’s bed, all of them anxious to draw off the ‘toxic humours’ assailing their monarch. He was bled, he was purged, his head was shaved, and cantharides – Spanish Fly – plasters were applied to his scalp to cause blistering; plasters of spurge were also applied to his feet to induce yet more blisters. When they didn’t work, red-hot irons were applied to his skin. The large royal bedroom became very crowded, with 75 or more people now present: not only the physicians and their assistants, but also family members and many state officials.

The physicians worked on their monarch for five days, applying enemas of rock salt and syrup of buckthorn and an ‘orange infusion of metals in white wine’. The king was treated with white hellebore root, Peruvian bark (now better known as quinine), white vitriol in paeony water, a distillation of cowslip flowers, sal ammoniac, julep of black cherry water – in addition to even more bizarre medicaments such as oriental bezoar stone from the stomach of a goat and boiled spirits from a human skull. Nothing worked, but despite all this ‘treatment’, the king apologised to those about him: ‘I am sorry, gentlemen, for being such an unconscionable time a-dying.’ It seems hardly surprising that he then added, ‘I have suffered much more than you can imagine. ’

By the following Friday (6th February 1685), the king was totally exhausted. His body was raw and aching with the burns and inflammation caused by his treatment, so his physicians gave him heart tonics, but it was all to no avail and the king lapsed into a coma. He died at noon on the following day. The historian Thomas Babington Macaulay recounted at the time that the poor king was ‘tortured like an Indian at the stake’. In an extreme case of iatrogenic effects, the king was killed with kindness. Fortunately, today, doctors know far more about how medicines work and such polypharmacy is now much rarer – though not unknown.

So that’s poisoning in a nutshell, but this chapter only skims the surface. Read on to discover where poison comes from, how to treat poisoning, how to avoid it – and some of the people who didn’t.