To estimate the health damages associated with air pollution in developing countries,
policy makers are often forced to extrapolate results from studies conducted in industrialized
countries. These extrapolations, however, may be inappropriate for two reasons. First, it is not
clear that the relationships found between pollution and health at the relatively low levels of
pollution experienced in industrialized countries hold for the extremely high pollution levels
witnessed in developing countries. Levels of particulate matter, for instance, are often three to
four times higher in developing countries than in industrialized ones. Second, in developing
countries, people die at younger ages and from different causes than in industrialized countries,
implying that extrapolations of the impacts of air pollution on mortality may be especially
misleading