Why does my hair turn green from the swimming pool?

If you are a blonde like me and enjoy laps in a swimming pool, you may have noticed your hair acquires a green tint after frequent swims in chlorinated water.

This happens to both bleached and natural blondes. In fact, the green tinge happens to everyone, but it's less visible on dark hair and those whose hair isn't damaged by chemical treatments such as bleaching.

But what exactly causes this green discolo