SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes - Part I. Structure of the scoring and ranking system

Hundreds of chemical contaminants have been identified in the Great Lakes S ystem of North America. Depending on the agency or organization, various su bset lists of these contaminants have been identified as chemicals of poten tial concern. However, there is no agreement on the method that should be u sed to make management decisions. Except for consensus on approximately 40 chemicals that most North American agencies agree can cause deleterious eff ects if released into the environment, no agreement has been reached regard ing the priority that contaminants should receive for further action. That leaves hundreds of chemicals that have been, are being, or potentially coul d be released into the environment that have nor been evaluated yet. A prof ile for potential chemicals of concern is generally thought to include pers istence in the environment, potential to bioaccumulate, and ability to caus e toxic effects at environmentally relevant concentrations. Except for the International Joint Commission's definition of persistence (> 8 weeks resid ence time in air, water, soil or sediment), there is little concurrence abo ut what defines these characteristics. For instance, the State of Michigan currently has no established definitions or profiles of persistent, bioaccu mulative, toxic substances. Furthermore, there is no standard process to ra nk chemicals relative to these characteristics. The Chemical Scoring and Ra nking Assessment Model (SCRAM) has been developed to provide a process to r ank-order chemicals based on these characteristics. The SCRAM system was de veloped primarily for use in the Great Lakes region of North America and pa rticularly in Michigan, bur it is not site-specific. Use of this system may assist in pollution prevention activities and other future chemical contro l efforts, allowing attention to be focused first on those chemicals likely to present the greatest hazard.