Evaluation of Human and Ecological Risks Associated with Remedial Wood Preservatives

摘要

A risk assessment was sponsored by Osmose Utilities Services, Inc., and conducted by O'Brien & Gere (OBG) to evaluate potential ecological and human health impacts, if any, related to the application of six (6) supplemental or remedial wood preservatives to in-service utility poles. The Osmose preservative technologies evaluated included a preservative paste, MP500-EXT; a dry preservative bandage, Pole Wrap CB; an internal liquid preservative, Hollow Heart CB; and three (3) internal fumigant formulations, WoodFume, MITC-FUME, and EZ-FUME.For this risk analysis, OBG researchers utilized a ground water transport computer model to generate "worst case" estimates of preservative release in stormwater and groundwater at a 15-meter (50 ft) distance downgradient from the pole. Risk to human receptors was determined by comparing the modeled surface water concentrations of active ingredients to USEPA Regional Screening Levels (RSLs) for tap water. Risk to aquatic receptors from individual constituents was determined by comparing the modeled surface water concentrations to the USEPA's ECOTOX and BTAG freshwater screening benchmarks.Predicted potable well concentrations of active ingredients from the six (6) remedial preservative formulations were found to be below the respective RSLs established by the USEPA for tap water. Similarly, the predicted surface water concentrations for all active ingredients were below the established USEPA ECOTOX and BTAG benchmarks for aquatic receptors. Based on the results of this risk assessment, it is concluded that supplemental utility pole treatments of MP500-EXT, Pole Wrap CB, Hollow Heart CB,MITC-FUME, WoodFume, and EZ-FUME provide minimal risk to the environment and human health when properly applied.