| Abstract
| - Four approaches for predicting the risk of chemicals tohumans and fish under different scenarios were comparedto investigate whether it is appropriate to simplify riskevaluations in situations where an individual is makingenvironmentally conscious manufacturing decisionsor interpreting toxics release inventory (TRI) data: (1) therelative risk method, that compares only a chemical'srelative toxicity; (2) the toxicity persistence method, thatconsiders a chemical's relative toxicity and persistence; (3)the partitioning, persistence toxicity method, that considersa chemical's equilibrium partitioning to air, land, water,and sediment, persistence in each medium, and its relativetoxicity; and (4) the detailed chemical fate and toxicitymethod, that considers the chemical's relative toxicity, andrealistic attenuation mechanisms such as advection,mass transfer and reaction in air, land, water, and sediment.In all four methods, the magnitude of the risk wasestimated by comparing the risk of the chemical's releaseto that of a reference chemical. Three comparativescenarios were selected to evaluate the four approachesfor making pollution prevention decisions: (1) evaluationof nine dry cleaning solvents, (2) evaluation of four reactionpathways to produce glycerine, and (3) comparison ofrisks for the chemical manufacturing and petroleum industry.In all three situations, it was concluded that ignoring orsimplifying exposure calculations is not appropriate, exceptin cases where either the toxicity was very great orwhen comparing chemicals with similar fate. When thetoxicity is low to moderate and comparable for chemicals,the chemicals' fate influences the results; therefore, werecommend using a detailed chemical fate and toxicity methodbecause the fate of chemicals in the environment isassessed with consideration of more realistic attenuationmechanisms than the other three methods. In addition,our study shows that evaluating the risk associated withindustrial release of chemicals (e.g., the toxics releaseinventory) may be misleading if only mass emissions areconsidered.
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