A significant amount of dangerous air pollution New Yorkers breathe incomes from the buildings we live and work in. About 9000 big apartment and commercial buildings in Manhattan, Brooklyn, Queens, and the Bronx, boilers burn a dirty fuel to heat their units. This type of oil—referred to as “residual” because it is essentially the leftovers from the petroleum distillation process—releases soot and toxic chemicals into the air. Over time, inhaling the fumes can lead to cardiovascular disease, asthma, and even early death. “Residual Risks” analyses the health, environmental, and economic benefits of switching away from this dirty fuel to cleaner alternatives like natural gas.