The Affected thrive in polluted conditions, comfortable only when breathing smog. Many of them enjoy squalor for squalor's sake.
Affected Foremen are especially charismatic Affected leaders who are able to unite vast numbers of lesser Affected, and convince them to work together for the greater good. The motivate their followers to run grime factories which function exclusively to pump smog into the London air. This, of course, makes surface conditions even less bearable for the Trueborn, making grime factories a prime target for Trueborn campaigns to retake the surface.
Meanwhile, Affected beggars love to inhabit decrepit surroundings, and seek poverty above all else. The Affected Beggar King embraces the philosophy that "Poverty is the only true luxury," and routinely throws away everything he can, earning the title "The poorest man in the world."
The Affected are, of course, known for their acute madness.