It's not human action that would worry me, it's nature. Freezing cycles could easily erode a pool in a few decades and make micro-cracks that fester unnoticed for years. Rust is an ever present issue for re-inforced concrete and is the cause of countless civil engineering disasters.
Practical Engineering on Youtube is a great overview of the issues we humans have with water: https://www.youtube.com/user/gradyhillhouse/playlists
Of interest here are these videos:
https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKf...
https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKf...
https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKf...