Kids are different: developmental variability in toxicology

doi:10.1016/0300-483X(96)03389-6

Toxicology

Volume 111, Issues 1–3, 17 July 1996, Pages 15-20

https://doi.org/10.1016/0300-483X(96)03389-6 Get rights and content

Abstract

Data on the impact of many environmental compounds to human health is often lacking, particularly when considering the risk to the unborn and developing child. The stage of development of the individual at the time of exposure to a toxicant has not always been considered. For example, a higher percentage of ingested lead is absorbed from the gastrointestinal tract of infants than adults. Renal elimination also follows a developmental pattern, being very limited during the newborn period, increasing during infancy and childhood, and declining gradually after puberty. Genetic polymorphisms in metabolic enzyme activity add another dimension of variability. Depending on the particular chemical, this may serve as a protective factor or increase susceptibility to toxic effects (e.g. epoxide hydrolase and fetal hydantoin syndrome). Children also have distinctive behaviors and target organ susceptibilities that warrant special consideration. The consequences of developmental changes are well-known in medical practice, and many drug doses are modified based on age, liver, and renal function, and other factors that may influence pharmacokinetic behavior of drugs. There is a sizable body of such information available, in part, in the pediatric and clinical pharmacology and toxicology literature. The concept of the significance of developmental stage is becoming increasingly important in toxicological risk assessment as well.

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Table 1 illustrates different aspects of toxic substance exposure as described by Sexton et al. (1995). Again, the focus on children or childhood is highlighted in this paper because of their potential vulnerabilities (Bruckner, 2000; Graeter and Mortensen, 1996; Makri et al., 2004; Schwenk et al., 2003; Walker, 2005). “Although there is no single ‘correct’ set of age groups, adopting a common convention for defining age groups will enable scientists to better understand differences in exposure and risk across life stages and the factors that may account for such differences, such as nutritional status, prevalence of certain diseases, ethnic/cultural norms regarding activity or behavior patterns, population genetic characteristics, meteorological conditions, geography, and social stress” (Firestone, 2010).
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Kids are different: developmental variability in toxicology

Abstract

J. Pediatr.

Biochem. Pharmacol.

Fundam. Appl. Toxicol.

Toxicol. Appl. Pharmacol.

Mutat. Res.

Blood

Mercury exposure from interior latex paint

N. Engl. J. Med.

Methylmercury poisoning in Iraq

Science

Prenatal prediction of risk of the fetal hydantoin syndrome

N. Engl. J. Med.

Abnormal neuronal migration, deranged cerebral cortical organization, and diffuse white matter astrocytosis of human fetal brain: a major effect of methylmercury poisoning in utero

J. Neuropathol. Exp. Neurol