The Army is replacing traditional munitions with insensitive munitions (IM) resistant to accidental detonation. The aquatic toxicity of 1-methyl-3-nitroguanidine (MeNQ), which is being assessed for potential use in IM formulations, remains largely untested. The present study fills a number of critical data gaps for MeNQ aquatic toxicity by evaluating effects across two vertebrate and five invertebrate species. Specifically, responses in larval Pimephales promelas, Rana pipiens tadpoles, Chironomus dilutus, Lumbriculus variegatus, Hydra littoralis, Hyalella azteca, and Daphnia pulex were assessed in MeNQ exposures across various acute, subchronic, and chronic bioassays. Overall, survival was unaffected in most of the MeNQ exposures where significant lethal effects were only observed in D. pulex, H. littoralis, and C. dilutus and only at concentrations ≥ 2186 mg/L. Significant sublethal effects on growth were observed for C. dilutus at 903 mg/L and H. azteca at 1098 mg/L in 10-d assays. Significantly decreased reproduction was observed at 2775 mg/L for H. azteca in a chronic 35-d assay and at 174 mg/L for D. pulex in the 11-d three-brood assay representing a sublethal effect one order of magnitude more sensitive than the effective lethal concentration for D. pulex (2987 mg/L). Degradation of MeNQ in ultraviolet light (UV) greatly increased toxicity to D. pulex. Specifically, exposure to a MeNQ solution that was completely UV-degraded prior to D. pulex exposures resulted in an 11-d LC50 of 6.1 mg/L and a 50% reduction in reproduction at 3.125 mg/L, based on the original MeNQ parent-compound concentrations.

陆军正在用能够抵抗意外爆炸的不敏感弹药（IM）代替传统弹药。1-甲基-3-硝基胍（MeNQ）的水生毒性在IM制剂中可能被评估，目前尚未得到测试。本研究通过评估两种脊椎动物和五种无脊椎动物物种的影响，填补了MeNQ水生毒性的许多关键数据空白。具体而言，在幼虫反应黑头软口鲦，蛙蚊蝌蚪，摇蚊dilutus，蚓，水润沙参，Hyalella阿兹特克和蚤状溞在各种急性，亚慢性和慢性生物测定法中的MeNQ暴露量中进行了评估。总体而言，生存未受影响大部分MeNQ曝光其中显著致死作用中只观察到的D.蚤，水鬼蕉，和C. dilutus，只有在浓度≥2186毫克/升。未观察到对生长显著亚致死效应为C. dilutus在903 mg / L和H.阿兹特克在1098 mg / L的在10-d的测定。在慢性35天试验中，对于阿兹台克血吸虫，在2775 mg / L时观察到繁殖的显着降低，对于D. pulex在174 mg / L时观察到繁殖的降低。在11天的三血统试验中，代表亚致死作用的灵敏度比杜氏石。的有效致死浓度（2987 mg / L）高一个数量级。MeNQ在紫外光（UV）中的降解大大增加了对杜氏石。的毒性。具体而言，基于原始MeNQ母体，在暴露于D. pulex之前完全暴露于紫外线的MeNQ溶液中，导致11天LC50值为6.1 mg / L，在3.125 mg / L时繁殖减少了50％。化合物浓度。