Algal growth stimulation and toxicity in response to exposure to the new insensitive military high-nitrogen energetic triaminoguanidinium-1-methyl-5-nitriminotetrazolate.
Triaminoguanidinium-1-methyl-5-nitriminotetrazolate (TAG-MNT) is a nitrogen-rich energetic compound being developed as a potential component of insensitive munition formulations. The purpose of the present study was to assess the toxicity of TAG-MNT to the green alga Pseudokirchneriella subcapitata as well as to determine whether the high N content of TAG-MNT could result in increased algal growth in aquatic systems and potentially contribute to eutrophication using a 96-h algal growth bioassay in N-limited test media. Results were compared with algal exposures to current-use energetics 2,4,6-trinitrotoluene (TNT) and royal demolition explosive (RDX). The TNT exposure resulted in a lowest-observed-adverse-effect concentration (LOAEC) for algal growth of 1.72 mg/L and a 50% inhibition concentration (IC50) and 95% confidence limits of 0.972 mg/L (0.955, 0.973). The RDX algal growth LOAEC was 0.10 mg/L, and the RDX IC50 was 0.635 (0.416, 0.875). Neither TNT nor RDX exposure resulted in stimulation of algal growth. In repeated testing, TAG-MNT exposure resulted in LOAECs of 0.55 and 5.20 mg/L. Stimulation of algal growth was observed at 0.06 mg/L at a mean increase of 163.2% (± 71.7) relative to the control in TAG-MNT test A and at the 0.005 mg/L treatment at a mean increase of 174.3% (± 59.9) in TAG-MNT test B. The authors' results indicate the potential for high-N energetics to significantly stimulate algal growth at low concentrations in N-limited systems.
U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, Mississippi, USA.
Jacob K
JK
Stanley
James M
JM
Biedenbach
Amber L
AL
Russell
Anthony J
AJ
Bednar
D000460:Chlorophyta / Q000187:drug effects* / Q000502:physiology; D006146:Guanidines / Q000633:toxicity*; D014303:Trinitrotoluene / Q000633:toxicity
D006146:Guanidines; C000588787:triaminoguanidinium-1-methyl-5-nitriminotetrazolate; D014303:Trinitrotoluene
Algae; Energetic compounds; Growth; Stimulation; Triaminoguanidinium-1-methyl-5-nitriminotetrazolate