Abstract：In order to investigate the toxic effects and safety concentrations of potassium peroxymonosulphate compound tablets to leech Whitmania pigra and snail Radix plicatula, the leeches weighing (1.440±0.217) g and snails weighing (0.048±0.011) g were put into 80-mesh silk mesh bags, tied tightly, and disposed in 4.89 L round transparent plastic boxes exposed to potassium persulfate complex tablets with concentrations of 0 (control group), 8.00, 12.13, 18.38, 27.86, 42.22 and 64.00 mg/L and 10.00, 15.85, 25.12, 39.81, 63.10, 80.00 mg/L, respectively, in acute toxicity tests at the temperature of 26.0—28.0 ℃ using the static poisoning method. The body surface tissue of the test animals challenged with potassium persulfate complex tablets was histologically observed, and the effects of potassium peroxymonosulphate compound tablets on their growth were carried out at the maximal tolerance dose, the safe concentration and the 96 h median lethal concentration of 10%. The results showed that the wrinkles of the back skin and even death were observed in the leeches exposed to potassium peroxymonosulphate compound at dose of ≥12.13 mg/L, with 24—96 h median lethal concentration of 22.25—30.55 mg/L and safe concentration of 5.59 mg/L. The poisoning and even death were found in the snails exposed to potassium peroxymonosulphate compound at a dose of ≥15.85 mg/L, with the 24—96 h median lethal concentration of 35.32—54.70 mg/L and safe concentration of 4.96 mg/L. Observation of tissue sections showed that potassium peroxymonosulphate compound tablets led to necrosis of columnar epithelial cells, partial loss of the mucus layer, increase in mucus secreting cells, and decrease in contents on the back surface of the leeches, resulting in the disappearance of the mucus layer on the surface, disordered morphology of microvilli at the edges of epithelial cells, and an increase in mucus secreting cells in the snails. There was not effect on the growth of the test animals at potassium peroxymonosulphate compound tablets concentrations below the safe concentration. The findings indicate that the potassium peroxymonosulphate compound tablets can be safely used for disinfection of cultural water of W. pigra at concentration of ≤4.96 mg/L.
2025, Vol. 44 
