Mice are used for inhalation and skin studies because they're cheap, we know their genome, they have a short lifespan for whole lifecycle observation and they're ideal for mapping to human respiratory and skin responses.
The migration from mouse models to human understanding is long and complex, and although it's a meme, "in mice" is a good shortcut for saying "This is a good start, but it's not ready to extrapolate into conclusions against the impact to human beings".