What impact do food preservatives have on breast cancer occurrence?

We don't know, but at the turn of the century, arsenic and mercury were typical food preservatives. They worked! But they also created other problems. There is no free lunch. So it may be that some of today's food preservatives are problematic, but that may change. After all, we've learned not to use arsenic and mercury in our foods and are no longer poisoning people with those chemicals.