Well here's an extra data point: It's definitely true of Montreal. The poor live in the north and east ends whereas the rich live in the "West Island" (the west

Well here's an extra data point: It's definitely true of Montreal. The poor live in the north and east ends whereas the rich live in the "West Island" (the west side of the island where all the suburbs are) and Westmount (which is roughly the west/southwest side of Mount Royal). Most of the majorly polluting industry is just off the east side of downtown Montreal.