Chronic toxicity of 2,4,6‐trinitrotoluene to a marine polychaete and an estuarine amphipod

Abstract

The chronic toxicity of sediment‐associated 2,4,6‐trinitrotoluene (TNT) to the marine polychaete Neanthes arenaceodentata and the estuarine amphipod Leptocheirus plumulosus was evaluated. Test organisms were exposed to sediments spiked with radiolabeled TNT for 28 d, after which time the endpoints of mortality, growth, and reproduction (L. plumulosus only) were assayed and compared against the TNT tissue concentrations as well as the TNT sediment concentrations. Survival was significantly reduced at a tissue concentration of 61 μg TNT/g wet wt tissue in N. arenaceodentata and at 6.3 μg TNT/g wet wt tissue in L. plumulosus. The growth end point demonstrated an apparent hormesis effect in both N. arenaceodentata and L. plumulosus with enhancement (significant for N. arenaceodentata) occurring at the lower TNT concentrations. Growth was significantly reduced at the highest TNT exposure of 10.0 μg TNT/g wet wt tissue in L. plumulosus. Reproduction was significantly reduced at a tissue concentration of 6.3 μg TNT/g wet wt tissue in L. plumulosus. The results of this study demonstrate that both N. arenaceodentata and L. plumulosus are sensitive to the presence of sediment‐associated TNT and that more information is needed about the toxicity of TNT to benthic fauna to facilitate risk assessment and management of TNT‐contaminated sites.

Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: II. Organism and population-level endpoints

“…A possible explanation is the phenomenon called hormesis, which can be identified as a growth enhancement induced by exposure to low doses of contaminant (Stebbing, 1997). This type of biological response has been already detected in G. locusta exposed to sediments spiked with copper (Correia et al, 2001) and has been increasingly reported in ecotoxicological studies, as for example sediment toxicity assessments with amphipods (Green et al, 1999) and other invertebrates (Martinez-Madrid, Rodriguez, Perez-Iglesias, & Navarro, 1999).…”

“…Toxicity was expressed by the lower survival, particularly males, and a biased sex ratio, more evident in sediment D. These severe toxic effects were not apparent in growth of surviving animals. However, caution must be taken interpreting growth data from chronic tests when there were significant reductions in survival (Green, Moore, & Farrar, 1999;Ingersoll et al, 1998;Sibley, Benott, & Ankley, 1997). One main concern is that growth may have been affected by reduction of organism density on the course of the test.…”

First observations of histopathological effects of 2,4,6-trinitrotoluene (TNT) in gills of European eel Anguilla anguilla (Linnaeus, 1758)

“…Despite its fast elimination, mutagenic properties and noxious effects of TNT, such as reduced survival, growth and reproduction, have been documented in several aquatic organisms (Smock et al 1976;Johnson et al 2000;Green et al 1999;Talmage et al 1999). However, few studies have considered the physiological mechanisms behind these effects in fish species.…”

A comparison of acute and chronic toxicity methods for marine sediments

“…However, others (Anderson et al, 1998;Bridges et al, 1997;Green et al, 1999) have reported reductions in N. arenaceodentata endpoints, more often expressed for growth than survival, in exposures to contaminated sediments. The 20-d method is documented in a routine testing program (DMMP).…”