How can pollution affect children's health differently than adults?
Pollution often has a greater effect on children compared to adults because children experience a greater concentration of the pollutant because they have a smaller body size and are still developing.
If an adult and a child both consume an identical amount of an identical contaminant, the child is going to be at a greater risk purely because the child is smaller. Thus, the child experiences the contaminant at a greater concentration.
Below, the same number of yellow dots can be found in both containers, but the container on the left is smaller in size and more concentrated.
Children are also growing and developing. They may absorb certain contaminants more easily, they may come into contact with certain contaminants at a different rate than adults, they may metabolize certain chemicals differently. To read more, see this summary.
For example, indoor air pollution puts children at greater risk of acute respiratory infections whereas their mothers are at risk for chronic bronchitis and chronic obstructive pulmonary disease (read report here).
Fetuses are especially at risk. Certain environmental exposures can cause birth defects, premature birth, or termination of the pregnancy. TIME has a good review article here.
To read the Environmental Protection Agency's framework for risk assessment specifically in regards to children, click here.