knowledge about waste streams can lead to deductions about proprietary processes), because different sectors are not familiar enough with each others' operations to know what opportunities are available, and because materials derived from waste streams are often considered inferior to virgin material.
Finally, the current regulatory structure can also prevent the linking of industries or industrial processes for more efficient use of waste materials (or recycled material). Some current regulations thwart rather than facilitate recovery and use of waste. As a result regulations often increase rather than decrease the amount of waste produced. Pfahl (in this volume) provides an example of how the ecologically beneficial recycling of lead dross would have been halted had a U.S. Environmental Protection Agency ruling labeling solder dross as hazardous waste been maintained. Recycling would have ceased because most of the secondary smelters involved in recycling lead from solder dross were not licensed to handle a material defined as hazardous waste under the Resource Conservation and Recovery Act, although it is not clear that any real hazard would have been posed by their handling of the dross. This type of problem arises not because anybody intended the outcome. Rather, the current media-specific environmental regulatory system focuses on the disposal and treatment of waste, not on minimizing waste. Thus, it can discourage attempts to reuse waste rather than provide incentives to do so.
Impediments to implementing environmentally preferable alternatives, however, are not restricted to environmental laws and regulations. For instance, antitrust laws, especially in the United States, can hinder industry cooperation that would be critical to developing comprehensive product and material recycling systems (Anderson, in this volume); inappropriate standards and specifications by large customers, such as the federal government, can also stifle the diffusion of environmentally preferable technologies (Morehouse, in this volume); and consumer protection laws that classify "remanufactured" products as "used" (secondhand) discourage product-life extension activities such as refurbishment and component reuse.
A broader, systems-based approach to industrial activity thus begins to illustrate the deficiencies in current understanding of industrial ecologies and the consequences and effects of changing production and consumption processes. It also exposes the impact of fiscal and regulatory policies in shaping the structure and operation of industrial ecosystems. There is clearly a need to better understand current industrial ecosystems and to tap points of leverage within them to improve the environmental performance of these systems.
Several papers in this volume refer to sustainable development. Sustainable development represents the quest for an economy that exists in equilibrium with the earth's resources and its natural ecosystems. Sustainable development brings environmental quality and economic growth into harmony, not conflict. It is a concept that recognizes that economic activities and environmental considerations need to be integrated for humanity's long-term well-being. Sustainable develop-