The health burden of environmental exposures, including ambient air pollution and climate-change-related health impacts, is not equally distributed between or within regions and countries. These inequalities are currently receiving increased attention in environmental research as well as enhanced appreciation in environmental policy, where calls for environmental equity are more frequently heard. The World Health Organization (WHO) 2006 Global Update of the Air Quality Guidelines attempted to address the global-scale inequalities in exposures to air pollution and the burden of diseases due to air pollution. The guidelines stop short, however, of addressing explicitly the inequalities in exposure and adverse health effects within countries and urban areas due to differential distribution of sources of air pollution such as motor vehicles and local industry, and differences in susceptibility to the adverse health effects attributed to air pollution. These inequalities, may, however, be addressed in local air quality and land use management decisions. Locally, community-based participatory research can play an important role in documenting potential inequities and fostering corrective action. Research on environmental inequities will also benefit from current efforts to (1) better understand social determinants of health and (2) apply research evidence to reduce health disparities. Similarly, future research and policy action will benefit from stronger linkages between equity concerns related to health consequences of both air pollution exposure and climate change, since combustion products are important contributors to both of these environmental problems.