Child?s Development and Respiratory System Toxicity

Humans grow slower than many other species.A lot of growth and weight gain happen during childhood, and specifically during the first two years of age.Humans reach 70% of their adulthood height at the age of six.Growth accelerates during certain periods of childhood known as growth spurts.These growth spurts happen six times through childhood which are; neonatal, infantile, early childhood, middle childhood, late childhood, and pubertal period [1].Yet, growth during each of these growth peaks varies remarkably among individuals, mainly due to the integrative and mixed influence of cultural, behavioral, nutritional, genetic, and environmental factors.General body growth (i.e.weight and height) differs from internal organs growth.Human organs grow at different rates because cell divisions in these organs vary in time and pattern.While the liver and kidneys grow fast throughout childhood, the brain has shown minimal weight increase from childhood to adulthood.Growth of adipose tissues and muscles in childhood is not as fast as it is in teenage and adult years.The Lungs grow and gain weight faster than the kidneys, but slower than the liver [2,3]. Metabolism and Maturity of Metabolic ProcessesThe metabolic abilities in children are different than those in adults.The metabolic differences make them less susceptible to environmental AbstractContrary to the old saying, children are not small adults.Children are different from adults in their response to environmental stressors because of their special body composition, which continuously changes as they grow.Children's development at each stage of their life needs special consideration, especially that harmful exposures might impact their normal development, and increases their susceptibility to diseases later in life.This paper reviews children's biological characteristics, and their normal developmental changes that make them more susceptible to environmental exposures.The paper will also discuss ways in which this normal development is influenced by environmental toxicants especially early life exposures, as well as the possibility of disease development.In this review, asthma is used as an example of a respiratory disease influenced by environmental toxicants, and methods of risk assessment used to predict such a disease are discussed.