Chapter 3 - Wildlife Toxicity Assessment for 2,4,6-Trinitrotoluene (TNT)

Abstract

Trinitrotoluene (2,4,6-trintrotoluene, TNT) is an extensively used explosive, which has been detected in soil and water at military sites and at munitions manufacturing and training operations. TNT contamination may be hazardous to animal health. The toxicity data of TNT on wildlife were evaluated using the benchmark dose procedure on sensitive adverse effects described for mammals and birds. Adjustments to the no observed adverse effect (NOAEL) and lowest observed adverse effect (LOAEL) values were used to derive toxicity reference values (TRVs) for amphibians and reptiles. The TRVlow and TRVhigh of 0.2 and 0.3mg/kg/day, respectively, for mammals were derived using body mass changes in dogs as a result of oral TNT exposure. The TRVlow and TRVhigh of 60 and 90mg/kg/day were calculated for birds based upon changes in plasma hemoglobin concentration related to dose. The TRVhigh and TRVlow of 40 and 4mg/kg soil were determined for amphibians using the LOAEL and NOAEL values reported for microcosm exposures conducted in red-backed salamanders with a low level of confidence. Plasma hemoglobin content was modeled in Western Fence Lizards where TRVhigh and TRVlow for reptiles were derived using benchmark dose of 19 and 14mg/kg/day, respectively, with a low level of confidence. Together, these values provide the tools to enable risk assessors to screen for adverse effects of TNT in terrestrial environments.