title: Toxicity and bioconcentration evaluation of RDX and HMX using sheepshead minnows in water exposures.
abstract: Lethal effects of the explosives RDX and HMX were assessed using ten-day water exposures to juvenile sheepshead minnows (Cyprinodon variegatus). For RDX, maximum mortality occurred during the first two days of exposure with a 10-d median lethal concentration (LC50) of 9.9 mg L(-1). The RDX 10-d median lethal residue (LR50) was 9.6 mg kg(-1) (34.9 μmol kg(-1)) wet weight (ww), the first RDX critical body residue reported for fish. Previous investigations reported that RDX body residues in marine amphipods up to 96 μmol kg(-1) ww and in marine mussels up to 86 μmol kg(-1) ww failed to result in significant mortality. The highest HMX concentration tested, corresponding to its apparent solubility limit in seawater (2.0 mg L(-1)), and the associated mean body residue (3 mg kg(-1) or 14 μmol kg(-1) ww) resulted in no significant mortality for exposed minnows. The mean 10-d bioconcentration factors for RDX (0.6-0.9 L kg(-1)) and HMX (0.3-1.6 L kg(-1)) were typically lower than 1, reflecting the low bioaccumulative potential for these compounds.
authors.affiliation: U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, USA. guilherme.lotufo@usace.army.mil
authors.forename: Guilherme R
authors.initials: GR
authors.lastname: Lotufo
authors.forename: Alfreda B
authors.initials: AB
authors.lastname: Gibson
authors.forename: J Leslie
authors.initials: JL
authors.lastname: Yoo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001392:Azocines / Q000493:pharmacokinetics / Q000633:toxicity; D001822:Body Burden; D053834:Explosive Agents / Q000493:pharmacokinetics / Q000633:toxicity*; D007695:Killifishes / Q000378:metabolism*; D007928:Lethal Dose 50; D014227:Triazines / Q000493:pharmacokinetics / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D001392:Azocines; D053834:Explosive Agents; D014227:Triazines; D014874:Water Pollutants, Chemical; C007950:octogen; C009160:cyclonite