I read the book over a year ago, as part of preparation for a library discussion forum, and then bought it as a gift for someone later in the year. I do not remember that it had vulgar language. It is wonderfully creative book that brings together many different aspects of life in the city.
I think it would be inappropriate for a a child of 8 years old. Its not vulgar per se but does include a lot of unsavory characters and depictions of situations that could be disturbing to a young child. What age is appropriate/ Partially depends on what life experiences they have had but I would say at least mid teens
There's some profanity, and there are references to sex, but I don't remember either one being heavy enough to distract my attention from the story. I think it's a good book, and I hope a few f-bombs don't stop you, but to each their own.