An increasing number of studies have shown that certain types of environmental toxicants can contribute to acute cardiovascular events and/or disease development. However, with exception of studies that deal with perhaps tobacco smoke exposure, there are few detailed studies that clearly define specific relationships between potential environmental cardiotoxicants and disease. In this regard, the present review discusses the growing body of epidemiological and experimental studies that investigate the effects of particulate matter (PM) and/or ozone (O3), two current types of air pollutants that are under investigation as factors in cardiovascular dysfunction and disease development. Several potential mechanistic pathways are suggested and reviewed, such as altered1 autonomic balance, systemic inflammation and increased oxidative/nitrosoxidative stress. © 2005 Elsevier Ltd. All rights reserved.