Age

Children under the age of one year have the highest rates of fatal poisoning (see Figure 6.2), particularly those in low-income and middle-income countries. Generally, mortality rates are highest in infants and decrease with age until 14 years. After that, there is an increase again, almost everywhere, in children 15 years of age and older. In many settings, this increase may be due to substance use, or to unintentional or undetermined drug overdoses (7). In some places, the increase may be as a result of entry into the workplace, with its increased exposure to risks.

FIGURE 6.2

Fatal poisoning rates per 100 000 children by age and sex, World, 2004. Source: WHO (2008), Global Burden of Disease: 2004 update.

Gender

Boys have higher rates than girls in all regions of the world except the low-income and middle-income countries of the Western Pacific region (see Table 6.1). The poisoning rate for boys in the WHO African region is 5 per 100 000 population, while for girls in the high-income countries of the Eastern Mediterranean and Western Pacific regions the rate is as low as 0.1 per 100 000 population.

TABLE 6.1

Mortality rates due to poisoning per 100 000 children by sex, country income level and WHO region, 2004.

Medicines

Medicinal drugs are the leading cause of non-fatal poisoning in children in middle-income and high-income countries.

• A hospital-based study from United Arab Emirates found that 55% of childhood poisonings were due to medicines. Analgesics, non-steroidal anti-inflammatory drugs and antihistamines were the most commonly ingested drugs in children in the 1–5-year age group (21).
• A study from Turkey reported that accidental ingestion of drugs was most common (57.7%) in children aged between 1 and 5 years and that the most frequent offending agent was analgesics (33).
• In the United States, in 2003, some 570 000 pharmaceutical exposures were reported in children less than 6 years old (34). This figure represented 23.8% of all poisoning reports, with analgesics accounting for almost 100 000 cases. Additionally, more than 50 000 children under the age of 5 years were treated in emergency rooms for an unintentional exposure to medicinal drugs. Prescription medicines were more commonly implicated than over-the-counter drugs (34).
• In England and Wales, during the period 1968–2000, medications accounted for 12.8% of unintentional poisoning deaths in children aged less than 10 years (23).

Organic fuels and solvents

Ingestion of hydrocarbon fuel used for cooking, heating or lighting is a common cause of childhood poisoning in low-income countries (25–29). Paraffin oil is the leading cause of childhood poisonings in many countries, where it may account for up to 16% of all paediatric poisonings, mainly in children aged between 1 and 3 years (2, 16, 30, 31, 35–38).

Organic solvents (such as paint remover, glue and acetone), as well as diethylene glycol (a component of antifreeze), have also been implicated in mass unintentional poisonings of children through contaminated medicines or toiletries. In 1998, 109 children in Haiti fell ill after consuming paracetamol (known as acetaminophen in the United States) contaminated with diethylene glycol, and 85 of them died (39). In similar incidents in Bangladesh, India, Nigeria and Panama, children were poisoned as a result of poorly regulated manufacturing processes (39).

In addition to the unintentional ingestion of organic fuels and solvents, intentional inhalation of volatile substances (such as “glue sniffing”) by adolescents can result in sudden cardiac death, since inhaled hydrocarbons are about 140 times more toxic than when ingested (40).

Pesticides

Children living in agricultural communities are at risk of acute pesticide poisoning. In the Central American region, in 2000, about 12% of all acute pesticide poisoning occurred in children less than 15 years of age, with an incidence rate of 5.7 per 100 000 population (41). In poor communities, where there is often little separation between work and the home, children may be exposed to pesticide residues present in work clothes, in the air from spraying and in household dust (42). In Nicaragua, children living near cotton farms have been found to suffer poisoning from organophosphates (43).

Some of the factors contributing to fatal food poisonings are the inappropriate use and storage of pesticides; the handling of food, while or after working, without proper washing of hands; and the unsafe disposal or reuse of pesticide containers. An example was the food contaminated with thallium, a rodent poison, that was eaten by children in the Peruvian Andes in 1999, causing 24 deaths (44).

In addition to these types of indirect exposure to pesticides, there are direct exposures. A study in China found that children had been exposed directly to rodenticides used in and around the home (45). The International Labour Organization estimates that there are approximately 250 million working children between the ages of 5 and 14 years and that some 40% of these are exposed to toxic substances in the rural areas of developing countries (42).

Household chemicals

Chemicals around the house to which children may have access contribute significantly to unintentional poisonings in childhood. In the United States in 2004, among children less than 6 years of age, there were over 120 000 exposures to household cleaning agents, such as ammonia, bleach and laundry detergents (11). While most exposures to cleaning agents result in mild poisoning, bleach, dishwasher detergents and ammonia can lead to severe tissue damage. These agents are found in most households in developed countries. Several other studies have confirmed the existence of similar household agents in childhood exposures to toxic substances (3, 21, 22, 46).

Carbon monoxide

In the United States, some 1600 children under 5 years of age are treated in emergency departments each year and 10 die as a result of unintentional non-fire-related exposure to carbon monoxide. This type of poisoning among children most commonly occurs from furnaces, motor vehicles, stoves, gas pipes and generators (47). In low-income countries, indoor cooking fires in homes with poor ventilation can lead to carbon monoxide being produced as a result of incomplete combustion. This in turn can result in respiratory disease in children – from long-term exposure, rather than acute toxicity (32, 33, 48).

Other substances

Inorganic substances – including arsenic and the heavy metals lead, copper and mercury – are also responsible for some childhood poisonings. The majority of poisonings due to heavy metals and other inorganic substances are the result of chronic exposure and are therefore excluded from this discussion. In rare instances, though, acute exposure to these agents can result in poisonings. As an example, acute lead encephalopathy with an 11% rate of mortality was reported in Oman, after a lead-containing local medication was given by parents to young infants (49).

Plant toxin poisoning – involving plants such as ackee, oleander, datura and cassava – is less frequently reported. Such poisoning can cause morbidity. Death from ingesting plant toxins, though, is rare. Two exceptions are the tragedy in Haiti in 2001, in which 65 children died after eating unripe ackee fruit (50); and the consumption of C. occidentalis beans, the cause of recurrent outbreaks of encephalopathy among young children in western Uttar Pradesh, India (51).

Animal envenomations (poisoning from bites or stings) from snakes (see Box 6.1), scorpions and spiders are a relatively common form of child poisoning in certain areas of the world. These include parts of Asia, the Pacific and South America, and the desert areas of North Africa, West Asia and North America. Envenomations, for instance, in Saudi Arabia account for as much as 30% of all poisonings among children aged 6–12 years (22, 52, 53).

BOX 6.1

Snakebites. Snakebite is an eminently treatable, but neglected, injury affecting predominantly tropical developing countries. As is also the case with dog bites, recent improvements in injury coding and surveillance, including community surveys in low-income (more...)

Age

Age has a strong association with poisoning as it determines the behaviour, size and physiology of the child, thus influencing types of exposure and outcome (69). Infants and small children are closer to the ground than older children and tend to put their hands and small objects into their mouths. As a result they are at increased risk of exposure to toxins found at low levels or in the soil or dust – such as rodenticides. Many studies have confirmed that poisoning rates increase dramatically at around 2 years of age, as young children become more mobile and have increased access to toxins (16). Young children are particularly susceptible to the unintentional ingestion of poisons, especially liquid ones (70). The risk of poisoning among young children is exacerbated by their size and physiological development. Most substances increase in toxicity as the dose increases relative to body mass. Some toxins are eliminated by enzyme systems in the body that develop as the child grows older.

In adolescents, where poisoning can be caused by alcohol misuse or the use of other recreational drugs, fatality rates are higher than in younger children (71).

Gender

Boys appear to be at consistently higher risk of poisoning than girls (4, 36, 72). With specific regard to poisoning from the ingestion of paraffin, though, some studies have shown no difference between boys and girls, while others have shown a preponderance among boys (25, 28, 37). The discrepancy in these findings may be explained by gender differences in socialization between different countries. In some cultures, girls are expected not to engage in outdoor activities or to adopt risk-taking behaviours (27).

Poverty

Socioeconomic status is strongly associated with injury and deaths from poisoning, not only between countries but also within countries (73). Studies from the United Kingdom show that the risk of dying from poisoning among children from poor backgrounds is more than three times higher than the risk for children in affluent areas (74). One study in Greece, however, showed no association between social and demographic factors and child poisonings (75). Nonetheless, socioeconomic status may well be the strongest risk factor for poisonings in children as it affects exposure, is itself associated with several other risk factors (such as physical underdevelopment in children) and is linked to poor outcomes of injury.

In developing countries, socioeconomic status is a strong predictor for household fuel consumption, itself linked to an increased exposure to paraffin. At the same time, poverty drives children into work that is usually poorly paid but with high risks of injury. Poor people tend to live with inadequate sanitary facilities – for washing, and sewerage and waste disposal – and limited storage space to keep harmful substances away from children. Poor dwellings are more likely to be close to areas sprayed with pesticides or to toxic dumps, or to draw their water from contaminated sources. Poverty and malnutrition can also place children at risk of poisoning by forcing them to consume unsafe but cheaply obtained foods – such as undercooked cassava or unripe ackee fruit, both of which are toxic.

The ability to withstand toxic effects depends, among other factors, on the nutritional and health status of the child. Children living in poverty are generally inadequately nourished and therefore more vulnerable to poisons than their healthier counterparts. In addition, conditions of poverty frequently prevent people from accessing health care.

Characteristics of the agent

The more concentrated or more potent the toxic agent, the greater the risk of severe morbidity and mortality. Chemical analyses of seven samples of paraffin from South African refineries found significant differences in their levels of toxicity (76).

The nature of the substance is also important. There is a higher incidence of injury associated with liquid agents than with solid compounds (69). Households with children are more likely to have liquid medications. Liquid preparations are easier to swallow than powdered preparations, such as dishwasher detergents or tablets, because they do not stick to the mucosa of the mouth. Nor do they usually produce a burning sensation (which powdered preparations do) which would limit the amount consumed. Unfortunately, powdered chemicals are now being produced with an anti-caking agent, which increases the ease of flow of the powdered chemical, but which also makes ingestion easier.

The physical appearance of a toxic substance plays a large part in its attractiveness to children, while its chemical composition determines its effect. Features such as size, colour and texture may attract or deter a child from handling and ingesting a substance. Studies show that liquids rather than solids, clear liquids rather than dark coloured ones, and small solids rather than large solids have more appeal to young children and are therefore more likely to be ingested by them (77). Bright colours in solid medications may also make them more attractive to children.

Storage and access

The most obvious risk factor for ingestion of a substance is its presence in the domestic environment, within reach of the child. Dispensing substances – such as paraffin and medications – in unlabelled or incorrectly labelled containers without child-resistant closures also increases the risk of poisoning (14, 26). Paraffin oil is frequently stored in bottles or other containers meant for cold drinks, milk or fruit juice, which children associate with beverages (36, 66, 78). In some places, tablets are poured into unsealed envelopes or ziplock bags, and liquids into nondistinctive, poorly labelled containers. Children may also drink from containers, such as cups, which have previously been used for refilling heating or lighting appliances (79). White pesticide powders improperly stored close to food substances can be mistaken for flour, starch or milk, and have led to poisonings of entire families (80).

Even when dangerous products are stored in distinctive containers with visual warning labels – such as images of “skull and crossbones” – young children are unlikely to recognize the significance of these signs (81). Some studies have found carelessness, overcrowding or limited space to be the cause of incorrect storage (14, 36). Research in Australia has shown that many products leading to child poisoning incidents were recently purchased or else not kept in their usual place of storage (80, 82). Medicine and bathroom cabinets, and kitchen cupboards and drawers appeared to be the safest storage places, while handbags, refrigerators, shelves and bathroom ledges were the least safe (83). Even safe packaging cannot compensate for unsafe storage.

In developed countries, many products are required by law to be distributed in child-resistant packaging (84). This usually involves either a bottle with a child-resistant closure or a blister pack. Child-resistant closures make it more difficult for a child to open a container because they require a series of complex actions – such as squeezing and turning, or pushing downwards and turning. The standard for the testing of child-resistant closures adopted in most countries requires that at least 85% of children aged from 42 to 51 months must be unable to open the container within five minutes, and at least 80% must fail to open the container following a non-verbal demonstration (85).

No closure, though, is perfect. In the child testing, up to 20% of children aged between 42 and 51 months may be able to overcome the child-resistant closure. Many parents are unaware that young children may indeed be able to access the contents of child-resistant packaging. Child-resistant closures should therefore never take the place of good supervision (24).

Season and climate

There are significant seasonal variations in the incidence of poisoning cases for different poisoning agents. Summer is the time of greatest risk for the ingestion of paraffin, medications and organophosphates and for bites from scorpions and snakes (25, 36). Several explanations have been put forward. Children on their summer holidays are more likely to be outdoors or to be left at home unattended or in the care of an older child or elderly relative (65, 86, 87). Children may also consume more fluids because of the warmer weather. Around national or religious holidays, parents or siblings may be less alert to hazards or children may exhibit more attention-seeking behaviour (88).

Although the incidence of poisoning is higher during the summer months, a few types of poisoning are more common in winter or during cold weather. These include carbon monoxide poisoning – from heating appliances – and poisoning through ingesting cough or cold medicines, as these are often considered harmless and left unattended (89).

Socioeconomic environment

Several case–control studies in low-income and middle-income countries have highlighted social and demographic risk factors in the poisoning of children. These factors include the presence of young parents, residential mobility and limited adult supervision (65, 90, 91). Although parents and caregivers may have been present at the time of the poisoning incident, studies confirm they were usually engaged in household duties or attending to personal needs. In a significant proportion of cases, poisoning occurred when a child was left in the care of another child or with a grandparent (65, 87, 91, 92).

Poor living conditions, local beliefs and customs and ignorance of the dangers of chemicals are other risk factors associated with acute poisoning (14). Previous poisoning may also be a risk factor (72).

The socioeconomic environment has an effect on the exposure to the risks of poisoning as well as on outcomes. The absence in many countries of policies, standards or laws governing the manufacture, labelling, distribution, storage and disposal of toxic substances place children at risk of poisoning. Poor quality control in the manufacture of medicines exposes children to toxic contaminants in these products. The unregulated packaging and distribution of medicines and other potentially toxic substances in sachets and containers that are not child-resistant increases the ease with which children can gain access to them. The uncontrolled storage and dumping of pesticides near homes and in water supplies expose children, especially those from poorer households, to toxins.

The toxicity of agents is also influenced by the political environment. In the United Kingdom during the 1970s, a significant proportion of child poisonings were attributed to medicines, such as aspirin, barbiturates and safapryn, a drug that was a dangerous combination of paracetamol and aspirin (23). Aspirin is no longer prescribed for children and barbiturates have been replaced by less toxic agents such as benzodiazepines. In addition, the chemical industry now produces less toxic pesticides. Economic forces, though, are responsible for the continuing use in developing countries of outdated agents, both pharmaceutical and non-pharmaceutical, that often carry high risks.

Reduction of toxicity

Removing a poisonous substance effectively may not always be possible. An alternative approach is to lower the level of the toxicity of the offending agent or to neutralize it in some way. One way of doing this is to reduce the concentration of the active ingredient. In Saint Lucia, a policy of selling acetic acid only in diluted form led to a fall in the rate of childhood poisonings. Previously, concentrated vinegar had been easily available, and had been responsible for several poisoning deaths (93). Another example of lowering toxicity is the reformulation of methylated spirits as principally ethyl alcohol, rather than the more toxic methanol.

In a similar way, less toxic pesticides may be used to prevent cases of acute pesticide poisoning (32). However, safer pesticides are generally more expensive, so that financial incentives or subsidies are probably needed if they are to be used in poorer countries. Introducing organic pesticide management or an integrated vector management system (94) will also lead to a fall in the number of cases of acute pesticide poisoning. To operate such systems, though, requires scientific expertise (41).

Reducing the toxic effects of ingestible poisons by adding an antidote to the substance has also been attempted, but has not been proved to be effective. In the United Kingdom, paracetamol was manufactured with added methionine, an antidote to paracetamol overdose (95). This product, though, was withdrawn because it was more expensive than the paracetamol-only formulations that remained on the market. In addition, the use of oral methionine was questioned, as the substance was associated with allergic reactions.

Safer packaging and storage

The success in reducing unintentional child poisoning through safer packaging and storage over the past three decades has relied on:

–

education of parents and caregivers – about the risks and how to protect against them;

–

legislation – to prevent unsuitable containers (such as are normally used to store food or drinks) being used to store harmful substances; and to make packaging around harmful substances resistant to tampering by children.

In South Africa, paraffin oil is used for heat for cooking and is frequently stored in bottles previously used for storing beverages. A successful programme to tackle this dangerous practice involved the free distribution of containers with child-resistant closures (see Box 6.2). As a result, the annual incidence of poisoning fell, over a period of 14 months, from 104 per 100 000 to 54 per 100 000 (80).

BOX 6.2

Change the packaging, save a life. Some 40 000 to 60 000 children in South Africa ingest paraffin oil each year, and suffer consequent poisoning. Between 170 and 500 of those admitted to hospital with paraffin poisoning do not survive. This figure, though, (more...)

In affluent countries, medicines stored in the home are more likely to be implicated in childhood poisoning than they are in poorer countries. In many places, tablets or capsules are emptied into cheap containers such as paper or plastic envelopes. In developed countries, commercially packaged medicines are sold in a variety of preparations and strengths – in standard screw-capped or clip-capped bottles, in bottles with child-resistant closures and in blister packs. To avoid errors of dosage, particularly among elderly people, some medications are dispensed in special boxes where multiple morning, lunchtime and evening doses are stored together.

Child-resistant packaging is one of the best-documented successes in preventing the unintentional poisoning of children (96). In England and Wales, unintentional poisoning deaths of children aged under the age of 10 years fell steadily from 151 per 100 000 in 1968 to 23 per 100 000 in 2000 (23). Similarly, in the United States, the annual rate of unintentional ingestion of 15 regulated substances in children younger than 5 years fell from 5.7 per 1000 in 1973 to 3.4 per 1000 children in 1978 – with nearly 200 000 unintentional ingestions prevented during that period (97). Both these reductions were largely as a result of the introduction of child-resistant packaging.

Safe storage of poisons in the home requires a secure location where a child cannot overcome barriers of locks or height. Although children will devise complex strategies to get hold of medicines, doing so takes time. The main reason, therefore, for storing poisons out of reach of children is that this is a delaying strategy – as indeed is child-resistant packaging.

Child-resistant packaging has been proved effective for medications, fuels, household chemicals and pesticides. The cost to manufacturers and distributors may be an obstacle, but this is likely to be outweighed by the large savings from treating children who have been unintentionally poisoned. The costs to households may be offset by government subsidies, such as the free distribution of such containers (91). Child-resistant packaging should be used on all drugs sold over the counter, to help prevent children consuming these potentially lethal products (98).

Reducing an agent’s attractiveness

One study has shown that the appropriate design of packaging can be an effective means of reducing the attractiveness for children of harmful substances (99). Other studies, on the ingestion by children of paraf n, have recommended that containers be made of darkened material in which the contents are invisible (25). The reason for this is that, since paraf n may be easily mistaken for water, a non-transparent, dark container is less likely to be associated with a drinkable liquid than a transparent, light-coloured container. Another suggestion is to modify the taste and colour of paraf n as well as modifying the containers in which it is stored (27). In Australia, changing the colour of paraffin to blue led to a decrease in the incidence of paraffin ingestion (101).

The addition of bitter agents is another method of stopping children from consuming significant quantities of harmful substances. Studies have shown that this approach may be useful, though it is possibly more appropriate for household products of mild to moderate toxicity rather than for pharmaceutical products (102, 103).

Labelling containers with warning stickers showed no deterrent effect on children at risk aged under 6 years (81, 104). The possible effectiveness of warning labels depends very heavily on their being understood by all, and assumes some degree of literacy. It has even been suggested that in some cases, warning labels may attract children (81).

Removing toxic agents

The most effective way to prevent children coming into contact with a poison is to remove the poison itself. An example of this is the Manchineel tree. The fruit of this tree looks like an edible green apple but the fruit, bark and sap are all toxic. Poisonings from the Manchineel tree, especially among children, used to be common in the Caribbean, despite warning signs and educational campaigns. Eventually, the trees were removed by the authorities from the beach areas where they were prevalent and replaced by coco plum trees, with a consequent fall in the number of poisoning cases.

Alternatively, toxic agents may be replaced by other substances with a lower toxicity. As examples, the following highly toxic substances have been largely replaced in many places by less toxic substances having a similar intended effect (23):

–

barbiturates (a class of sedative-hypnotic drugs) by benzodiazepines;

–

cresol (a preservative) by chlorocresol;

–

aspirin by paracetamol;

–

toxic anti-inflammatory drugs with less toxic non-steroidal anti-inflammatory drugs.

Sometimes the change from toxic to less toxic substances occurs as a side effect of economic development. The incidence of paraffin ingestion, for instance, has been found to fall when countries move from using individual fuel sources, such as bottled paraffin, to safer alternatives such as electricity and natural gas supplied by public utilities (32).

Child-resistant packaging

Standards and policies for child-resistant packaging currently only exist in a handful of high-income countries, such as Australia, Canada, New Zealand, the United States and the European Union. The absence of laws (or their lack of enforcement) and policies on manufacturing, storing, distributing and disposing of hazardous products has led to deaths of children as a result of contaminated medicines and toothpaste. In the Bhopal catastrophe, methyl isocyanate – a poisonous gas, heavier than air, that is used in the production of pesticides – was released into the atmosphere. In the absence of a strong local legislative framework, international standards and laws need to play a role in regulating global companies, currently often able to operate with lower levels of care than in their country of origin.

In 1970, the United States introduced child-resistant packaging in its Poisons Prevention Packaging Act. With rates of compliance among manufacturers of between 60% and 75%, the incidence of unintentional ingestion of baby aspirin was reduced by 45%–55% and of regular aspirin by 40%–45% in children less than 5 years old (105). Poisoning deaths among children under 5 years of age, resulting from the ingestion of substances regulated by the 1970 law, declined from 450 in 1962 to 216 in 1972 and 33 in 2005 (106).

The European Union has laws (107) mandating the storage of toxic substances in child-resistant containers that are:

–

clearly and appropriately labelled;

–

in places that are not within reach of children or near to foodstuff;

–

labelled in such a way that the substances in question cannot be mistaken for food.

This clearly places the onus for protecting children from toxic substances on households as well as on manufacturers and distributors. These laws may account for the low rates of child poisoning seen in much of Europe.

Blister packs

Blister packs (non-reclosable packaging) for medicines in tablet or capsule form are increasingly being used for dispensing. Soon after they were introduced such packs were considered to be child-resistant, because of the time it takes to remove each individual tablet or capsule and led to some reductions in child poisoning (108). However, as the use of blister packs has increased, it has become clear from poison centre data that young children can access medications from such packs. While removing and swallowing the tablets from a single strip of a blister pack may be less likely to be harmful than having access to a full bottle of the comparable liquid form, for many medicines even a few tablets can be a toxic or even a lethal dose for a young child. One advantage of blister packaging is that parents may better recall how many tablets had been used before the child swallowed some – thus being able to calculate the maximum number that may have been ingested. The disadvantage of blister packs is their transportability. Studies have shown that children often remove medications from handbags, particularly those belonging to the grandmother (109). This has prompted the development of a European standard for child-resistant blister packs, using a child test panel similar to the one for the reclosable child-resistant packaging standard.

Acute management of poisoning

Box 6.3 outlines the general principles governing the management of all cases of acute poisoning (48, 117).

BOX 6.3

Managing acute poisoning: the general principles. Remove the child from the source of exposure and decontaminate the child, as described below, if the poison has been inhaled or absorbed through the skin or mucous membranes. Contaminated clothing, including (more...)

Early and accurate diagnosis and management of poisoning decrease the risk of morbidity and mortality. It is therefore vital that caregivers seek help from a poison centre or a professional health-care worker. An assessment, including the previous history, should be made if possible, though this may be dif cult with children. It is important to keep the airway clear, the breathing regular and the circulation flowing.

The agent is likely to be known, but the dosage may have to be estimated. Treatment should be based on the greatest exposure that could have occurred. There are many sophisticated tests and procedures, but their effectiveness has in some cases been questioned. Some of these tests may in any case not be possible to perform in most developing countries.

Poison control centres

Poison control centres provide advice to individuals and health-care institutions. They direct first aid where appropriate, and refer more severe poisonings to a health care facility. Poison control centres are responsible for less severe outcomes in cases of poisoning. They also eliminate much unnecessary contact with more expensive health-care services (118). They were initially set up in high-income countries and have since been established in many low-income and middle-income countries (see Box 6.4).

BOX 6.4

The National Poisons Information Centre in Sri Lanka. In Sri Lanka in 2005, poisoning accounted for almost 90 000 hospital admissions and 1785 deaths. Around a third of these cases were in children under the age of 18 years. The first poison control centre (more...)

There are problems, though, in establishing poison control centres in less developed countries. Often, the need for such centres is not properly appreciated. There is likely to be a shortage of adequately trained staff, and poor clinical and laboratory toxicology services for further management of cases (119). In addition, the effectiveness of poison control centres depends on good telephone communications, which may in some places be limited, though this obstacle is likely to be overcome by the increasing use of mobile telephones (120).

It is estimated that for every dollar spent on a poison control centre contact there is a saving of nearly eight dollars, as more than 70% of cases are resolved over the telephone (118). If these centres did not exist, an estimated 600 000 additional possible poisoning cases would receive treatment at a health-care facility each year, at an added cost of US$ 545 million.