> exposure is exposure Because damage to DNA adds up, and that's what causes cancer, right? Turns out, DNA is constantly being repaired, because it constantly

> exposure is exposure Because damage to DNA adds up, and that's what causes cancer, right? Turns out, DNA is constantly being repaired, because it constantly suffers chemical insults, mostly from reactive oxygen species. A carcinogen is dangerous once it overwhelms these repair mechanisms, and for that, it clearly makes a difference whether you take a single large dose or many small ones.