Nature Deficit Disorder was coined as a term just over 10 years ago. It was the first time someone had done a study on just how not being out in nature was detrimental to our children.
It it now universally acknowledged and recognised that spending a lot of time outdoors – there is no upper limit really – has a positive effect on mental, physical and spiritual health.
Here is a recent news item on this. The clip is not playable but the article does describe the issue well.