re: Safe to eat catfish caught in the Mississippi River at BR south of Exxon?

Mercury and PCB's are the most concerning but if you look at a list of the highest level of those you will not see catfish there. The larger fish (I.e. tuna) are of greater concern due to bioaccumulation. Basically, the larger fish eat smaller fish and contaminates become concentrated in the larger fish. Also, while pesticides are concerning, the mississippi river simply has a tremendous volume of flow and dilutes whatever contaminates there may be. Here is a list LINK