I grew up half a block from a freight train line, and you could hear it, but it wasn’t really an issue. Trains have gotten a lot louder in the US recently due to lack of rail maintenance. (Concretely, the transbay BART tube is screeches was above osha safety limits inside the car these days, but was quiet when new. The problem is that you need to grind rails to have a rounded top or they screech (and wear out train wheels), but BART doesn’t bother.

Anyway, noise pollution has a real impact on health, but so does particulate carbon and benzene from freeways. Before moving near a major road, find out what sort of PM 2.5 is typical, and check to see if everything is coated in black dust. If so, and you can afford some other place, move there instead.