SCRAM: A scoring and ranking system for persistent, bioaccumulative, and toxic substances for the North American Great Lakes.

The Scoring and Ranking Assessment Model (SCRAM) was developed to serve as an analytical tool in chemical scoring and ranking of Great Lakes contaminants. The model provides an initial screening evaluation, based on minimal amount of data, of large numbers of chemicals to identify those chemicals that have the greatest potential to cause adverse effects. The SCRAM model is different from most screening systems in that it assesses uncertainty. The SCRAM model was used to score a list of contaminants existing or potentially present in the Great Lakes. Data on environmental fate properties, such as persistence and bioaccumulation potential and toxicity were compiled on selected chemicals. Uncertainty scores were also assigned based on incompleteness of the database. A score was calculated for each chemical and given a relative rank based on its persistence, bioaccumulation, toxicity, and uncertainty. The relative rankings of chemicals can be used as a decision-making tool to determine which chemicals need immediate research or monitoring based on their SCRAM score and the chemical’s use and environmental loading.