> For a substance that needs to be ingested in high doses for an average human (even a small child) over an extended period of time, what's the harm of having a

> For a substance that needs to be ingested in high doses for an average human (even a small child) over an extended period of time, what's the harm of having a contaminated park? You have relatively infrequent exposure, and you likely don't eat / drink from the area Based on my experiences with how our children behave when they're playing in parks, I much prefer the thought of parks not being contaminated! Small kids typically come home from parks dirty. Heck, small kids come away from pretty much anything dirty :)