The only book I found called “Urban Jungle” is about gardening!?
In making sure I got the term “sheeny man” spelled right I did a search. One of the first things that came up was that he was used as a threat to the kids - sort of like the “boogy man”.
Upton Sinclair. First part was a good story. Last part was a slog to get through. They were cutting ice blocks to sell in the cities from the settlement ponds outside the factories. Gross.