[en] The United States has produced this report as part of the preparations for the United Nations Conference on Environment and Development (UNCED) to be held in Brazil in June 1992. It summarizes this nation's efforts to protect and enhance the quality of the human environment in concert with its efforts to provide economic well-being during the two decades since the United Nations Conference on the Human Environment was held in Stockholm. The information presented in this report is primarily and deliberately retrospective. It is an attempt to portray the many human, economic and natural resources of the United States, to describe resource use and the principal national laws and programs established to protect these resources, and to analyze key issues on the agenda of UNCED. This analysis is presented in terms of past and present conditions and trends, measures of progress made in responding to the key issues, and a summary of government activities, underway or pending, to address ongoing or newly emerging national environmental and resource management problems