In September 2006, the US Environmental Protection Agency and the US Centers for Disease Control (CDC) co-organized a symposium on "Air Pollution Exposure and Health." The main objective of this symposium was to identify opportunities for improving the use of exposure and health information in future studies of air pollution health effects. This paper deals with the health information needs of such studies. We begin with a selected review of different types of health data and how they were used in previous epidemiologic studies of health effects of ambient particulate matter (PM). We then examine the current and emerging information needs of the environmental health community, dealing with PM and other air pollutants of health concern. We conclude that the past use of routinely collected health data proved to be essential for activities to protect public health, including the identification and evaluation of health hazards by air pollution research, setting standards for criteria pollutants, surveillance of health outcomes to identify incidence trends, and the more recent CDC environmental public health tracking program. Unfortunately, access to vital statistics records that have informed such pivotal research has recently been curtailed sharply, threatening the continuation of the type of research necessary to support future standard setting and research on emerging exposure and health problems (e.g. asthma, multiple sclerosis, diabetes, and others), as well as our ability to evaluate the efficacy of regulatory and other prevention activities. A comprehensive devoted effort, perhaps new legislation, will be needed to address the standardization, centralization, and sharing of data sets, as well as to harmonize the interpretation of confidentiality and privacy protections across jurisdictions. These actions, combined with assuring researchers and public health practitioners appropriate access to data for evaluation of environmental risks, will be essential for the achievement of our environmental health protection goals.