Effects of TNT leakage from dumped ammunition on fish and invertebrates in static brackish water systems.

The objective of the present study was to study the release and effect of TNT from dumped ammunition. Cleaved artillery shells were placed in static brackish water systems for 5 months, and another 12 months with 5 cm sediment burial. The toxicity was determined in bioassays with crustaceans (Nitocra spinipes and Hyalella azteca) and/or European flounder (Platichtys flesus). The water phase was analysed for TNT using colorimetric method and GC-MS. This study showed a rapid release of TNT to acutely toxic concentrations when the cleaved ammuniton was not covered with sediment under static conditions, but that the release was effectively inhibited by sediment burial of the artillery shells. Hence, at least in a short-term perspective, acute adverse effects of sediment-buried ammunition on aquatic organisms should be greatly reduced.

TNT leakage through sediment to water and toxicity to Nitocra spinipes.

The fate and effects of 2,4,6-trinitrotoluene (TNT) at marine ammunition dumping sites are essentially unknown. The objective of this study was to examine the release from solid TNT to seawater when covered by sediment of two different types (sandy and fine-grained) and thickness (0, 1, 2, and 4 cm), under different temperatures (5, 10, and 20 degrees C), and light conditions (ambient daylight and darkness) in the laboratory. The water column was analysed for TNT and some of its common transformation products, and toxicity to the copepod Nitocra spinipes after 1, 2, 4, 8, 19, and 32 weeks. Leakage of TNT to seawater and the toxicity to N. spinipes was significantly reduced by sediment burial, especially in fine-grained sediment. Hence, this study suggests that adverse effects of TNT in dumped ammunition on aquatic organisms should be delayed/reduced at low temperature and when TNT is covered sediment, especially with fine-grained sediment.

Fate and effects of 2,4,6-trinitrotoluene (TNT) from dumped ammunition in a field study with fish and invertebrates.

2,4,6-Trinitrotoluene (TNT) is the major explosive ingredient in ammunition dumped into lakes and sea after World War II. The aim of the present field study was to study the fate and effect of TNT and its degradation products from dumped ammunition. Artillery shells were cleaved longitudinally to expose TNT and placed in open boxes filled with sediment, and then placed at the sea bottom. Sediment samples were taken in each box at the start and after 3, 9, 13, 20, 24, 33, and 36 months, and the sediments were tested for toxicity with bioassays using Nitocra spinipes (96 h), Hyalella azteca (96 h), and Daphnia magna (24 and 48 h). The result from the bioassays showed no impact of dumped ammunition on the survival of H. azteca and mobility of D. magna. Bioassays with N. spinipes showed significant differences in toxicity between control boxes and boxes with shells after 9 months and thereafter. The mean mortality (+/- SD) of N. spinipes in boxes with shells was 63 +/- 22%, and the mortality in control boxes was 23 +/- 17%. No continuous increase in sediment toxicity over time was found. After 3 years, cages with European flounder (Platichtys flesus) and blue mussels (Mytilus edulis) were attached to the boxes. The fish were examined for biochemical and physiological effects 8 weeks later. Exposure to ammunition, which had rested on the sea bottom 3 years, caused no significant effects on body indices, hematological variables, and detoxification and antioxidant enzymes activities in the flounder. The sediment, bile, and blood plasma of exposed fish, and hepatopancreas of exposed mussels, contained no detectable levels of TNT and its metabolites. Only minor disappearance of TNT from the shells could be detected by visual inspection on site (by scuba divers). This study suggests that the survival of sensitive benthic organisms, e.g., N. spinipes, might be negatively affected at an ammunition dumping site.

Tentative biomarkers for 2,4,6-trinitrotoluene (TNT) in fish (Oncorhynchus mykiss).

2,4,6-Trinitrotoluene (TNT) is the major explosive in ammunition dumped into lakes and the sea after World War II. To identify useful biomarkers of TNT-exposure for forthcoming fish monitoring studies at ammunition dumping sites, rainbow trout (Oncorhynchus mykiss) were intraperitoneal (i.p.) injected with TNT in peanut oil at doses of 0, 100, 200 or 400 mg TNT/kg body weight and sampled 72 h later. The study covered blood parameters, and hepatic antioxidant and detoxifying enzymes. Fish treated with TNT had an increased glutathione S-transferase (GST) activity and glutathione reductase (GR) activity, and a decreased percentage of oxidised glutathione (%GSSG) compared to the control group. In addition to increased methemoglobin, the increased glutathione and glutathione dependent enzyme activities indicate that TNT oxidises macromolecules and activates antioxidant defence systems which may be useful as general biomarkers of TNT-exposure. The fish bile was analysed for TNT and its metabolites by gas chromatography-mass spectrometry (GC-MS), and the toxicity of the bile was determined with the cladoceran Ceriodaphnia dubia. A dose-dependent increase in TNT, 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) was found in the hydrolysed bile of the TNT-treated fish. These results indicate that the fish are able to detoxify and excrete TNT and suggest that the detection of TNT, 2-ADNT and 4-ADNT in bile may be suitable as a direct marker of exposure to TNT.