I did a search a while back, on potassium bromate testing, and I remember finding approximately a dozen tests done in mostly academic settings. These were thorough projects with published papers. One test project found a connection with renal cancer in rats, with large amounts of bromate. I don't recall the amounts, but I think these tests usually use large amounts. The other tests could not find a connection.
I have decided that I will use bromated flour as I think the risk is no more than that which is naturally found in our environment, and I mean naturally found.
Mostly I use Con-Agra Occident unbleached. I bake my loaves at 350 for an hour, and they are done! I also use King Arthur Special, which is the same as their retail bread flour, and Sir Lancelot, which is their high-test bread flour, at 14 percent gluten. I blend these flours in different amounts depending on what I am making.
I think this culture is afraid of its own shadow. People are afraid of everything!
Eggs were bad for you and now they're good for you. The sun, the giver of life, will give you cancer. The exhaust from your car will give you cancer. The only way to get rid of all these risks is to die.