What are the clearance levels for soil contaminant concentrations in areas where children play?

The determination of clearance levels for soil contaminant concentrations in areas where children play is critical for ensuring the safety and health of children. The correct answer of 400 PPM (parts per million) represents the threshold that has been established by various regulatory guidelines to minimize the risk of lead exposure in environments frequented by children.

This 400 PPM criterion is particularly significant because it is aligned with the recognized standards for lead in residential soil. It reflects an effort to balance the need for safe play areas with the reality that some level of contamination may be present due to historical practices, urban environments, or other factors. The focus on children is especially acute, as they are more susceptible to the harmful effects of lead exposure due to their developing bodies and behaviors, such as hand-to-mouth activity.

In contrast, the other values are above the safety threshold established for children's play areas. Higher concentrations of lead in soil, such as 1,200 PPM or 2,000 PPM, would pose a significant health risk and are not considered acceptable for places where children play. The presence of such elevated levels would demand intervention strategies, including remediation, to protect children's health and wellbeing.