Atmospheric deposition of pollutants, including polycyclic aromatic hydrocarbons (PAH), is recognized as a significant contributor in many locations to water quality problems, including toxic contamination of the fish and shellfish living in the waters. PAH are a subset of a set of compounds known as polycyclic organic matter (POM), which are organic compounds primarily formed from the incomplete combustion of organic materials, such as coal and wood. Several PAH compounds have been classified as probable human carcinogens (ATSDR 1995). The U.S. Environmental Protection Agency (U.S. EPA) has been directed by the Clean Air Act to consider the contribution of atmospheric deposition to pollution in the Great Waters, which comprise the Great Lakes, Lake Champlain, Chesapeake Bay, and many of the estuaries of the coastal United States. POM are included in the group of pollutants of concern for the Great Waters. Background information on the sources, deposition, and environmental concentrations of the pollutants of concern is summarized in detail in a series of reports, the most recent of which is Deposition of Air Pollutants to the Great Waters Third Report to Congress (U.S. EPA 2000), hereafter referred to as the Third Report to Congress. U.S. EPA is no longer required to submit reports to Congress on deposition of air pollutants to the Great Waters. However, much new information related to environmental concentrations, deposition trends, and sources of PAH in the Great Waters has been published since the Third Report to Congress, and is compiled here. The recent research also is compared to findings described in the Third Report to Congress. Much of the information in this survey report relates to recent findings in temporal and spatial trends in both the Great Lakes and Chesapeake Bay regions. Other studies address the creation of new source profiles in different areas. For example, studies for Galveston Bay and the city of Miami have recently been completed, which detail sources of PAH to these regions. Highlights of long-term temporal and seasonal trends, findings and spatial trends in various locations, and sources and emissions from the newly published scientific literature are presented in the textbox in this section. References are provided at the end of this summary.