Task Group G, Effects on Materials and Cultural Resources, is part of the Interagency Task Force on Acid Precipitation that was established by the Acid Precipitation Act of 1980. There are currently eleven agencies participating in the Materials Effects Task Group. The National Park Service, U.S. Geological Survey, and the Environmental Protection Agency are the only participating agencies that receive funding from the Task Force. In planning the Materials Effects Research Program the Task Group has two basic objectives: (1) To develop the methodology and data bases for assessing material related benefits of acidic deposition control policies, and (2) To provide guidelines for protection or restoring individual structures especially historical and cultural sites.