A strategy for assessing environmental fate and exposure of chemicals

by MacLeod, Matthew John

.4 Strategy for Assessing Environmental Fate and Exposure of Chernicals blatthew John b1acLtiod .A systematic six-stage strategy for assessing environmental fate and human exposure to coniaminants is dcveloped and illustrated for a suite of 77 chemicals. The assessrnent stratrgp relies on mass balance models of chernical fate to describe chernical partitioning and migration in evaluative. regional. and local scale cnvironments. A novel multiple pathway hurnan exposure mode! that yields a metric for deducing maximum tolerable environmental concentrations is presented. An ~pproach to quanti@ing unccnainty in complrx models is devcloped and applied to regional and local scaic mass balance models. Predictions of the modéls are generally in agreement with availabie monitoring data. and overall fate assessments are consistent with recent detailed contaminant specific studies carried out under the Canadian Environmental Protection Act. A rok for comprehrnsive screening-level assessments of this type in formulating rational management stratrçies for chernicais is suggested.