Hobbs Melissa S, Grippo Richard S, Farris Jerry L, Griffin Billy R, Harding Lora L
Harry K. Dupree-Stuttgart National Research Center, U.S. Department of Agriculture, Agriculture Research Service, P.O. Box 1050, Stuttgart, Arkansas 72160, USA.
Environ Toxicol Chem. 2006 Nov;25(11):3046-52. doi: 10.1897/05-453r2.1.
Potassium permanganate (KMnO4) is used worldwide in freshwater pond aquaculture for treatment and prevention of waterborne external parasitic, bacterial, and fungal diseases. Nevertheless, KMnO4 has not been approved by the U.S. Food and Drug Administration, and insufficient information exists to allow evaluation of the environmental risk of KMnO4 exposures. Limited data exist concerning KMnO4 toxicity to nontarget species in systems receiving aquaculture effluent from treated ponds. The goal of this research is to generate effects data for use in developing an ecological risk assessment of KMnO4. Toxicity tests were used to compare the relative sensitivities of five standard aquatic test species to KMnO4. Acute toxicity test results using synthetic moderately hard water show static 96-h mean median lethal concentration (LC50) values +/- standard deviation (SD) of 0.058 +/- 0.006 mg/L for Ceriodaphnia dubia, 0.053 +/- 0.009 mg/L for Daphnia magna, 2.13 +/- 0.07 mg/L for Pimephales promelas, 4.74 +/- 1.05 mg/L for Hyalella azteca, and 4.43 +/- 0.79 mg/L for Chironomus tentans. Most of these values are below the recommended KMnO4 treatment rate of at least 2.0 mg/L or 2.5 times the water's potassium permanganate demand (PPD; an estimation of the available reducing agents in the exposure water), suggesting significant environmental risk. However, repeating these laboratory tests using pond water resulted in significantly reduced toxicity, with static 96-h mean LC50 values (+/-SD) of 2.39 +/- 0.36 mg/L for C. dubia, 1.98 +/- 0.12 mg/L for D. magna, 11.22 +/- 1.07 mg/L for P. promelas, 13.55 +/- 2.24 mg/L for H. azteca, and 12.30 +/- 2.83 mg/L for C. tentans. The PPD of synthetic moderately hard water was 0.329 +/- 0.114 mg/L; however, pond water PPD was 5.357 +/- 0.967 mg/L. The effective disease-treating dose based on 2.5 times the PPD would thus be 0.823 and 13.392 mg KMnO4/L, respectively, exceeding the LC50 for most of these nontarget organisms, even in pond water, immediately after treatment.
高锰酸钾（KMnO₄）在全球淡水池塘水产养殖中用于治疗和预防水生外部寄生虫、细菌和真菌疾病。然而，KMnO₄尚未获得美国食品药品监督管理局的批准，并且缺乏足够信息来评估KMnO₄暴露的环境风险。关于KMnO₄对接收来自处理后池塘的水产养殖废水系统中非目标物种的毒性数据有限。本研究的目标是生成效应数据，用于开展KMnO₄的生态风险评估。毒性试验用于比较五种标准水生试验物种对KMnO₄的相对敏感性。使用合成中度硬水进行的急性毒性试验结果显示，对于角突网纹溞，静态96小时平均半数致死浓度（LC₅₀）值±标准差（SD）为0.058±0.006毫克/升；对于大型溞，为0.053±0.009毫克/升；对于黑头呆鱼，为2.13±0.07毫克/升；对于阿氏摇蚊，为4.74±1.05毫克/升；对于摇蚊幼虫，为4.43±0.79毫克/升。这些值大多低于建议的KMnO₄处理率至少2.0毫克/升或水的高锰酸钾需求量（PPD；暴露水中可用还原剂的估计值）的2.5倍，表明存在重大环境风险。然而，使用池塘水重复这些实验室试验导致毒性显著降低，角突网纹溞的静态96小时平均LC₅₀值（±SD）为2.39±0.36毫克/升，大型溞为1.98±0.12毫克/升，黑头呆鱼为11.22±1.07毫克/升，阿氏摇蚊为13.55±2.24毫克/升，摇蚊幼虫为12.30±2.83毫克/升。合成中度硬水的PPD为0.329±0.114毫克/升；然而，池塘水的PPD为5.357±0.967毫克/升。基于PPD的2.5倍的有效疾病治疗剂量因此分别为0.823和13.392毫克KMnO₄/升，即使在处理后的池塘水中，也超过了大多数这些非目标生物的LC₅₀。
