Is tuna healthy or dangerous to eat?

Personally, I used to love tuna, especially fresh tuna. Living in Florida and Hawaii for years, it was easy to get caught that morning fish. But after some research on the subject, both the potential for chemical contamination and the effect of over fishing on the oceans have gotten me off seafood. Espeically the chem side. I am not worried about living longer, but I don’t want to go via a long battle with some chemically induced illness that simply not eating tuna could avoid. I like to think of it as a deal I have with the big ocean predators. I won’t eat their food and they don’t eat me.