For some people, living in an affluent area can actually be a health hazard. This is the provocative conclusion of a study of the death records of more than 8,000 people living in four major US cities. The ill effects of being poor or living in economically disadvantaged areas have been demonstrated before, but it is unusual to consider that poor people living in richer areas may be no better off. Marilyn Winkleby, a researcher at Stanford University in California, decided to look into this and was surprised to find that the death rates in four Californian cities were actually highest for poor people living in the richest neighbourhoods. Her study offers two possible explanations: Poorer people living in rich areas may have to pay proportionally more for housing, intensifying the effect of poverty; alternatively, their health may suffer from the stress caused by continually being reminded that they are at the bottom of the pile. Another researcher, Richard Wilkinson, from the University of Nottingham in the UK, also suspects that stress is largely to blame. He reviewed more than 150 studies and concluded that health is generally poorer when differences in income are larger.