The corrosion inhibitors vary but are usually phosphates or silicates and they also adjust pH and the level of carbonates (mostly for buffering). For example, when fluoride is added to drinking water, it is often in the form of fluorosilicates with the silicate portion being a corrosion inhibitor. The amount of these substances is small and does not have evidence of causing cancer. Believe me, the people analyzing water systems are pretty particular about what they put in which is why they use multiple steps of sanitation to minimize chlorine disinfection by-products.

It's also relatively simple to use a decent charcoal-based water filter to eliminate the chlorine or monochloramine as well as other substances from the water. We use one at home, mostly because my wife can't stand the taste of the water otherwise (she's got very sensitive taste). Personally, I don't like the taste of water even if it's distilled (which has no taste), but then I'm weird.

Richard