Difficult ethical and political issues confront the application of scientific and technological solutions for preventing pollution from occurring. Often the questions embodying proposed solutions to known problems are ambiguous; and no singular solution can exist for all locations. Yet the common organizing principle for all solutions to environmental problems must be scientific, because only sound science can provide a rational understanding that decision-makers can use universally. The NATO Advanced Research Workshop (ARW) on Tools and Methods for Pollution Prevention (October 12-14, 1998,...