2. What makes children and elderly people more likely to swallow such products?
- 2.1 What makes children more likely to swallow such products?
- 2.2 Why might some elderly people swallow such products?
2.1 What makes children more likely to swallow such products?
The SCCS opinion states:
7. CONSUMER RELATED FACTORS FOR CPRF AND CAP INTAKE
There is no universally agreed age range for what constitutes childhood. Article 1 of the United Nations Convention on the Rights of the Child defines “children” as persons up to the age of 18. However, in many reports of the United Nations (UN) and the World Health Organization (WHO), the term “children” refers to persons up to the age of 14 years (e.g. UN 2010, WHO 2010b). The term “infant” refers to children between the ages of 1 month and 12 months (Berk 2009, WHO 2010c); however, other definitions vary between birth and 3 years of age. The term “toddler” refers to children who are learning to walk, so it is typically used for children aged 1 to 2 years (Berk 2009), but sometimes also up to 3 years. As children less than 6 years old are more frequently involved in accidental poisoning than older children, special attention will be paid to this category in the following section. Children less than 6 months old are not considered in this opinion because it is unlikely that they will be able to reach CPRF/CAP by themselves.
7.1.1. Child physiology
It is generally known that in organisms of different sizes, physiological functions such as basal metabolic rates correlate much better with the body surface area rather than with the body weight. This is also reflected by drug dosing; paediatric therapy usually requires higher doses (per kilogram body weight), compared to therapy of adults. In concordance, susceptibility towards xenobiotics is not generally higher in children compared to adults. However, differences in kinetics of distinct xenobiotics in children of a specific age, especially very young age groups, may well have the consequence that external exposures identical to those of adults lead to increased response due to higher ‘‘internal’’ doses (Renwick et al. 2000).
Numerous studies have been investigating the activity of xenobiotic metabolising enzymes in different age groups. There are considerable species and inter-individual differences (Schwenk et al. 2003).
In general, the most prominent differences in toxicokinetics are found in children less than 1 year old and especially in the first few days and weeks of life (Scheuplein et al. 2002). By the age of 2 years, most of the biochemical and physiological parameters that affect toxicokinetics have reached maturation, although differences still exist. Thus, it seems reasonable to be extra cautious in the risk assessment of children as an exposed group as there are differences between children and adults in toxicokinetics (especially babies in their first months) and toxicodynamics (especially at different stages of development), which may render children more susceptible to the toxic effects of a substance.
Particular attention should be paid to the effects on the nervous, reproductive, endocrine and immune systems, and also on the metabolic pathways, all of which in part develop new functional properties during childhood (Falk-Filipsson et al. 2007).
7.1.2. Children’s behaviour
The present opinion focuses on children between 6 months and 6 years of age, as this is the group of children for which ingestions of cosmetics and liquid household products appear to be most likely.
Age has a strong association with accidental ingestion and poisoning, as with children’s injuries in general (Hillier and Morrongiello 1998). Children under the age of 1 year have the highest rates of fatal poisonings, but non-fatal poisonings appear to be more common between 1 and 4 years of age. The risk of poisonings increases particularly at around 2 years of age, as young children become more mobile and have increased access to toxins (WHO 2008a). It is instructive to look at some general developmental milestones of children up to 6 years of age (see Table 3
, Annex III).
Young children are particularly susceptible to accidental ingestion, especially liquids, because they are very inquisitive, put most items in their mouths (e.g. hand-to-mouth activity) and are unaware of consequences. The quantities involved are often small (a mouthful/sip). The volume of a swallow is 4.5 ml for a child aged between 18 months and 3 years, and in an adult it is 15 ml (Jones and Work 1961; cited in Mofenson et al. 1984). A toddler’s mouthful is approximately 9.0 ml (Ratnapalan et. al. 2003).
Children who are hungry or thirsty are more likely to accidentally ingest products within their reach than children who are not. The very fact that they want something to eat or drink increases the likelihood that they will ingest something that smells good to them (Whitford et al. 2001).
7.1.3. Children’s environment and parental supervision
Reduced observation and supervision of children may increase the risk of exposure and subsequent accidental poisoning e.g. during holiday periods, festivals and other events (Amitai et al. 2000, WHO 2008a). A good example is when meals are being prepared. It is common for children to have free run of the house as adults focus their attention on preparing a meal (Whitford et al. 2001). The most significant injuries reported following ingestions of poisons by children seem to occur as a result of them drinking from opened containers within their reach. There are still many cases which are related to storing corrosive solutions in unlabelled containers or more seriously, routine drinking bottles which other adults unknowingly give to their children (Riffat and Cheng 2009, WHO 2008a).
In an American study that made in-home observations of safety hazards related to burns, poisoning and falls, maternal supervisory style, rated on dimensions of protectiveness, was an important correlate of all types of household hazards (Glik et al. 1993). In this study, risk perceptions of the mothers had little influence on home hazards. In another study, maternal perceptions of risk variables interacted with maternal safety behaviour (Dal Santo et al. 2004). A recent study on parental perceptions of injury risks shows that parents underestimated scenarios with high injury/death rates and overestimated scenarios with low injury /death rates (Morrongiello et al. 2009, Will et al. 2009).
However, direct evidence linking supervision to child injury is scarce and more research is needed to assess the independent contribution of this factor (independent, for instance, from socio-economic status) to injury risk (Morrongiello 2005).
7.1.4. Socio-economic and related factors
The variable most frequently correlated with poisonings is socio-economic status (SES). SES is a strong predictor of observed home hazards (Glik et al. 1993), unsafe childcare practices (Hapgood et al. 2000), fatal unintentional injuries, and to a lesser extent, of nonfatal injuries (Cubbin and Smith 2002). In particular, unemployment and homes needing repair appear to be risk factors for unintentional injuries at home (Dal Santo et al. 2004, Glik et al. 1993, WHO 2008a).
There are many variables related to SES, for instance, maternal social support, stress and coping (Dal Santo et al. 2004). Stress in the home in this context is defined as regular changes in lifestyle demanding social re-adjustment (Eriksson et al. 1979, Shaw 1977). More recent studies also confirmed that risk factors for accidental poisoning in children may include child behaviour but also stress at home, size, education and income of the family, absence of the parents, and the accessibility of the poisonous products (Eriksson et al. 2008, Katrivanou et al. 2004, Soori 2001).
Although SES is the best studied predictor of different injury risks, even affluent families do not undertake safety practices all the time, and most of the variation in the number of safety practices, for instance, is not explained by SES (Hapgood et al. 2000). Thus, further research is needed.
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and/or having child- appealing properties, (2011), 7.1 Children, Children, pp. 14-16
2.2 Why might some elderly people swallow such products?
The SCCS opinion states:
7.2. Elderly people
There is no universally agreed age range for what constitutes “elderly”. Most developed countries, however, use the chronological age of 60 or 65 years, roughly equivalent to retirement ages, as a definition of “elderly” or an “older person” (WHO 2010a). The WHO uses 60+ years to refer to older persons (e.g. WHO 2007, WHO 2008b). For the purpose of this opinion, the elderly are considered as persons aged 75 years and above.
7.2.1. Physiology of elderly people
At ages of 75 and above, a proportion of the population may show signs of aging, such as physical and mental deterioration. This is due to a combination of factors including physical and mental disease, under-/malnutrition and relative deprivation superimposed on the various physiological changes that occur with age alone. This latter group is at special risk of adverse effects of drugs, chemicals and the environment.
The elderly are exposed and respond to xenobiotic chemicals differently than younger people in a number of important aspects. These differences are wide ranging and include physiological, pathological and environmental factors (Crome 2003).
Principal differences occurring during aging are listed below (adapted from Crome 2003) (see also Table 4
, Annex III):
- Decline in a wide range of physiological systems characterised by a reduction of functional reserve.
- Different environmental experiences, both current and across the life-span.
- Increased prevalence of sub-clinical and clinical disease (degenerative, malignant and infectious).
- Increased use of medication and "special foods" for medical purposes.
- Increased risk of adverse response to medication.
- Different expectations (brought up before the age of consumerism).
- Relative social, economic and cultural deprivation.
In adulthood, increasing age is accompanied by a progressive decline in the function of most physiological systems (Elmadfa and Meyer 2008, Young 1997). Almost all human physiological systems show evidence of deterioration in structure and/or function with age. In most cases, this is of little importance except when the body is placed under stress. For example, the same degree of chest infection is more likely to precipitate an episode of cardiac failure in an older person than in someone who is younger. Following such an event, recovery may be slower than in a younger person and there may also be permanent disability (Crome 2003).
7.2.2. Behaviour patterns of the elderly influencing safety
Poisoning is a significant problem in the elderly. However, most of the research on poisonings in elderly people is focused on the accidental intake of medication (Hahn et al. 2006, Klein-Schwartz and Oderda 1991). Research on the possible causes for accidental ingestions and poisonings in the elderly is scarce, but the following factors are likely to play a role:
- Frequently, the olfactory and gustatory perception is reduced. More than half of people between 65 and 80 years of age show major olfactory impairment. This increases to more than three-quarters in those over 80 years old (Doty et al. 1984).
- Impaired vision is also likely to decrease the ability of distinguishing between acceptable (edible, drinkable) and unacceptable products. The legibility of printed warnings therefore becomes especially important for older adults with impaired vision (Parsons et al. 1999).
- Older people are aware of hazards in the home and of safety information on products. However, they often report usability problems when using household products. In a focus group study with 45 older adults between 61 and 84 years of age, 55% of respondents reported motor difficulties in handling products, 42% reported memory difficulties, 40% perceptual difficulties, and 29% difficulties with symbol comprehension and text comprehension (Mayhorn et al. 2004).
- Older adults often have problems understanding product warning information, especially when product-specific knowledge cannot be used and memory demands are high (Hancock et al. 2005). In general, short-term memory capacity decreases as age increases, so warnings should be kept as brief and direct as possible (Parsons et al. 1999).
- Unlike young children, elderly people are often left by themselves for extended periods and they are not under constant observation, as a rule.
- Elderly people may not call for help immediately, or they may keep silent about what has happened, for reasons of shame or uncertainty.
- If elderly people are disoriented (e.g. due to illnesses or medications), they often lack the ability of distinguishing between acceptable and unacceptable products, even if their senses have been preserved (Klein-Schwartz and Oderda 1991).
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and/or having child- appealing properties, (2011), 7.2 Elderly People, pp. 16-17