Why are Children Especially Vulnerable to the Health Effects of Environmental Hazards?

Children are much more vulnerable to environmental health hazards than adults. This is because they have different behaviors than adults that make them more likely to come into contact with hazards. Their still growing bodies also respond differently to some hazards. Here are some examples of how their behaviors and unique physiology make children more vulnerable:  

• From birth, children breathe more air, drink more water, and eat more food relative to their body weight than adults. For example, when a child and an adult each eat the same sized piece of fruit, the child is eating a greater amount of that fruit because their body is smaller in comparison. If that fruit is contaminated with a pesticide or other contaminant, the child is also eating more of that contaminant.  
• Children also absorb more contaminants— after a meal, an adult will absorb 20% of ingested lead, whereas a toddler absorbs as much as 50%. Similarly with children’s skin, their smaller bodies mean that they absorb more of a contaminant even when exposed to the same amount as an adult. Many contaminants can cross the placenta or into breastmilk, resulting in unique pathways of exposure during vulnerable periods of early development.  
• Children depend on adults to ensure a safe environment. Children’s immune systems are still developing, which also makes them more vulnerable to environmental hazards. Early exposure to carcinogens (substances that can cause cancer such as tobacco smoke) may increase the risk of cancer in later life.