Any ceramic media has the potential to release aluminum (the main metal people have documented via ICP tests) but IMO it’s not a huge issue. Aluminum definitely has the potential to be toxic, but for every person who has seen increased levels, there’s at least another who has not seen elevated levels. Many people who have seen increased aluminum even admit that their tanks are healthy and thriving, but it is something to note and keep an eye on.
I used bio balls the entire time my 80g was set up (2 years) and had no problems with coral growth, coloration, etc, though I did not ever so an ICP test and cannot say for sure where my aluminum levels were. My advice would be, if you’re going to use ceramic media, just don’t go crazy with it. No need to fill your entire sump or dump multiple boxes of bio media in your tank.