Reproductive toxicity of nitroaromatics to the cricket, Acheta domesticus.

The effect of TNT (2,4,6-trinitrotoluene) and its metabolites, 2,4-dinitrotoluene (2,4-DNT), 2-amino-4,6-dinitrotoluene (2A-DNT), and 4-amino-2,6-dinitrotoluene (4A-DNT) on cricket (Acheta domesticus) reproduction was evaluated. We previously used crickets to assess the toxicity of a nitramine explosive (RDX) and its metabolites. It is common to find that while much information on the environmental impact of the parent compound is available in the literature, such is often not the case for the degradation metabolites of the parent compound. In some instances, these metabolites are as toxic (or more so) as the parent compound and we hypothesized that this might be the case for TNT. The presence of TNT and its metabolites in sand (10 microg/g) did not adversely affect cricket egg production, but adversely affected hatching of cricket eggs as compared to controls. However, there were no differences in hatching success among TNT and metabolite treatment groups. Hatching success of cricket eggs in soil or following topical exposure decreased as concentrations of TNT and its metabolites increased. The relative toxicity of TNT and its metabolites in soil generally followed the trend of TNT<2A-DNT<4A-DNT<2,4-DNT. In addition, toxicity appeared to be higher in sand than in sandy loam soil or in the topical exposure test. After 45 days of exposure in sandy loam soil, the EC(20) (20% effect concentration), EC(50) (50% effect concentration), and EC(95) (95% effect concentration) were 14, 116, and 10,837 microg/g for TNT: 1.7, 32, and 16,711 microg/g for 2A-DNT: 1.9, 9, and 296 microg/g for 4A-DNT: and 0.4, 5.7, and 1437 microg/g for 2,4-DNT. Overall, results suggest that parent TNT and metabolites are toxic to cricket eggs at relatively high concentrations and these toxic effects are manifested as a decrease in hatching success.

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites on cricket (Acheta domesticus) survival and reproductive success.

The effect of two major hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), on cricket (Acheta domesticus) survival and reproduction was studied. RDX metabolites did not have adverse effects on cricket survival, growth, and egg production. However, MNX and TNX did affect egg hatching. MNX and TNX were more toxic in spiked-sand than in topical tests. TNX was more toxic to egg than MNX. Developmental stage and exposure time affected hatching. After 30 days exposure to MNX or TNX, the EC20, EC50, and EC95 were 47, 128, and 247 microg/g for TNX, and 65, 140, and 253 microg/g for MNX in topical tests. The ECs for 20, 50, and 95 were 21, 52, and 99 microg/g for MNX, and 12, 48, and 97 microg/g for TNX in sand. No gross abnormalities in cricket nypmhs were observed in all experiments indicating that neither TNX or MNX is teratogenic in this assay.