Any thoughts/opinions about swimming pools?

I would like to take my son to help him get used to the water,
I have not been near a pool in about 4 years ,I took him as a baby and swam alot before my pregnancy and during.
But a few years ago my copper levels were high and I was advised by nutritionist that the pools had copper in the water.
Also what about the chlorine in the water?

Apart from taking him to the pool,I can wait untill the summer
and take him to the sea, the atlantic on the west of Ireland