TNT, RDX, and HMX Decrease Earthworm (Eisenia andrei) Life-Cycle Responses in a Spiked Natural Forest Soil

Abstract

Sublethal and chronic toxicities of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) on earthworm Eisenia andrei in a sandy forest soil were assessed. Various reproduction parameters of fecundity (total and hatched number of cocoons, number of juveniles, and their biomass) were significantly decreased by TNT (> or = 58.8 +/- 5.1 mg/kg dry soil), RDX (> or = 46.7 +/- 2.6 mg/kg), and HMX (> or = 15.6 +/- 4.6 mg/kg). These effects occurred at much lower concentrations than those reported earlier using artificial soil preparations. Growth of adults was significantly decreased in the TNT-spiked natural soils at 136.2 +/- 25.6 mg/kg dry soil, the highest concentration having no significant mortality. In contrast, survival and growth were not significantly reduced at relatively high measured concentrations of RDX (167.3 mg/kg) and HMX (711.0 mg/kg). Although TNT, RDX, and HMX share a common life-cycle response ( i.e., decreased juvenile counts), a number of differences related to other reproduction parameters (e.g., productivity of cocoons) was observed. These results indicate that the tested explosives do not support a common mechanism of toxicity, at least in the earthworm, probably due to differences in their physical-chemical properties as well as metabolites formed during exposure.

Effects, transfer, and fate of RDX from aged soil in plants and worms

“…Concentrations of 500 mg RDX kg À1 spiked on artificial soil reduced earthworm (Eisenia fetida) biomass, but by less than 20% (Phillips et al, 1993). A concentration of 711 mg spiked HMX kg À1 soil did not significantly reduce E. Andrei biomass (Robidoux et al, 2002b).…”

“…was reported not to affect survival of worms (Robidoux et al, 2002b). RDX, MNX and TNX were recovered in the worm tissues.…”

Role of soil interstitial water in the accumulation of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine in the earthworm Eisenia andrei

“…The toxicity of RDX to earthworms has been well documented [6][7][8][9][10][11][12]. Although RDX was not lethal to soil invertebrates such as adult enchytraeids up to approximately 20,000 mg/kg [13], adverse sublethal effects at lower concentrations have been reported.…”

“…Although RDX was not lethal to soil invertebrates such as adult enchytraeids up to approximately 20,000 mg/kg [13], adverse sublethal effects at lower concentrations have been reported. For example, exposure to RDX in soil can decrease juvenile production in Eisenia andrei [7,8], Enchytraeus albidus [14], and Enchytraeus crypticus [13], with the lowest-observed effect concentration values ranging from 15 to 3,715 mg/kg , depending on the test species.…”

Acute Toxicity of Bismuth to the Earthworm <i>Eisenia andrei</i>

“…The soil was collected from a site located in a non-contaminated area. This soil is representative of soil from Canadian range training area and similar soils were used in earlier toxicological studies to consider higher bioavailability of compounds [22][23][24]. After collection, soil was sieved (2 mm) to remove rocks, roots, and other large particles, then subjected to a battery of preliminary toxicity tests (i.e.…”