Toxicity and bioaccumulation of reduced TNT metabolites in the earthworm Eisenia andrei exposed to amended forest soil.
Soils contaminated with 2,4,6-trinitrotoluene (TNT) and TNT primary reduction products have been found to be toxic to certain soil invertebrates, such as earthworms. The mechanism of toxicity of TNT and of its by-products is still not known. To ascertain if one of the TNT reduction products underlies TNT toxicity, we tested the toxicity and bioaccumulation of TNT reduction products. 2-Amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-diamino-6-nitrotoluene (2,4-DANT) and 2,6-diamino-4-nitrotoluene (2,6-DANT) were tested separately in adult earthworms (Eisenia andrei) following a 14-d exposure to amended sandy loam forest soil. TNT, 4-ADNT, and 2-ADNT were lethal to earthworms (14-d LC(50) were: 580, 531 and 1088 micromol kg(-1), or 132, 105 and 215 mgkg(-1) dry soil, respectively) and gave the following order of toxicity: 4-ADNT>TNT>2-ADNT. Exposure to 2,4-DANT and to 2,6-DANT caused no mortality at 600 micromol kg(-1) or 100 mgkg(-1) dry soil. We found that all four TNT reduction products accumulated in earthworm tissues and 2-ADNT reached the highest levels at 3.0+/-0.3 micromol g(-1) tissue. The 14-d bioaccumulation factors were 5.1, 6.4, 5.1 and 3.2 for 2-ADNT, 4-ADNT, 2,4-DANT and 2,6-DANT, respectively. Results also suggest that some TNT metabolites are at least as toxic as TNT and should be considered when evaluating the overall toxicity of TNT-contaminated soil to earthworms.
Lachance
Bernard
B
Applied Ecotoxicology Group, Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada H4P 2R2. bernard.lachance@cnrc-nrc.gc.ca
Renoux
Agnès Y
AY
Sarrazin
Manon
M
Hawari
Jalal
J
Sunahara
Geoffrey I
GI
D000704:Analysis of Variance; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism*; D010084:Oxidation-Reduction; D012989:Soil Pollutants / Q000493:pharmacokinetics / Q000633:toxicity*; D018675:Toxicity Tests; D014303:Trinitrotoluene / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics / Q000633:toxicity*
D012989:Soil Pollutants; D014303:Trinitrotoluene