Toxicity of trinitrotoluene to sheepshead minnows in water exposures

Lethal effects of trinitrotoluene (TNT) to juvenile sheepshead minnows (JSHM) (Cyprinodon variegatus) were assessed in ten-day water exposures. Ten-day median lethal concentrations (LC50s) were 2.3 and 2.5 mg L−1, the 10-d median lethal residue value (LR50) was 26.1 μmol kg−1 wet weight (ww), and bioconcentration factors (BCFs) ranged from 0.7 to 2.4 L kg−1. The lethal effects of TNT and its transformation products 2-aminodinitrotoluene (2-ADNT), 2,4-diaminonitrotoluene (2,4-DANT) and trinitrobenzene (TNB) to JSHM were compared in 5-d static-renewal exposures. Nitroreduction decreased the toxicity of TNT to SHM, as the 5-d LC50 for 2-ADNT was 8.6 mg L−1 and the lowest lethal concentration of 2,4-DANT was 50.3 mg L−1. TNB (5-d LC50=1.2 mg L−1) was more toxic than TNT to SHM. The 5-d LR50s were 4.3 mg kg−1 ww (20.4 μmol kg−1) for SumTNT (TNT exposure) and 54.2 mg kg−1 ww (275.3 μmol kg−1) for 2-ADNT and significant mortality occurred at 47.4 mg kg−1 ww (283.6 μmol kg−1). The range of BCF values was from 1.8 to 2.4, 5.6 to 8.0, and 0.6 to 0.9 L kg−1 for TNT, 2-ADNT, and 2,4-DANT, respectively.