The Second U.S.-Dutch International Symposium on Aerosols was one of many cooperative activities in environmental protection called for in a Memorandum of Understanding signed in 1980 between the U.S. and the Netherlands. The symposium focused on a wide range of topics concerning air pollution: air quality, welfare effects, health effects, control technologies, and policy and management strategies. Approximately 300 people from The Netherlands, Canada, Germany, Belgium, The United Kingdom, Japan, Korea, Sweden, India, and the United States attended the symposium. Participants included governmental regulatory officials, research scientists, air pollution control experts, industrial representatives, members of environmental conservation groups, media representatives, and graduate students from several nations. Because of the nature of environmental problems (which are transnational or even global) and the important role that a cooperative effort such as this plays toward development of rational approaches to environmental protection, the governments of the United States and The Netherlands renewed the Memorandum of Understanding in June 1985 for another five years.