Analysis of bacterial biodiversity and ecological risk evaluation of organophosphorus in Lianhuan Lake

PLOS One | https://doi.org/10.1371/journal.pone.0332712 September 26, 2025 13 / 20 3.6 Organophosphorus ecological safety analysis 3.6.1 Analysis of the organophosphorus content. The results of the organic phosphorus gas analysis (Fig 5 and Table 7) of the water bodies and sediments of the Lianhuan Lake showed that A total of ten organophosphates are detected, Thionazin (0.010 μg/L), Ethoprophos (0.013 μg/L in N1, 0.028 μg/L in N3), Suprofos (0.161 μg/L in N1, 0.075 μg/L in N3), EPN (0.246 μg/L), Coumaphos (0.101 μg/L), O,O,O-Triethylphosphorothioate (0.008 μg/L), Mevinphos (0.015 μg/L), Naled (0.021 μg/L), Z-Tetrachlorvinphos (0.043 μg/L) and Prothiophos (0.019 μg/L). Organophosphorus compounds in N1 included thionazin, ethoprophos, sulprofos, EPN and coumaphos, with a concentration of 0.010, 0.013, 0.161, 0.246 and 0.101 μg/L, respectively. Thionazin was an organophosphorus pesticide that was mainly used to control pests on crops. Ethoprophos was a broad-spectrum agent for controlling nematodes and underground pests. Sulprofos killed microorganisms and insects in water and was often used as an insecticide and fungicide. EPN was widely applied in controlling various pests, and it could also slow down the burning rate. Coumaphos was a non-endogenous insecticide, particularly effective against Diptera pests, and was also used to control ectoparasites, with remarkable effect on skin flies. Organophosphorus compounds in N3 included ethoprophos and sulprofos, with concentrations of

0.028 and 0.075 μg/L, respectively. Organophosphorus compounds in W4 included O,O,O-Triethylphosphorothioate, mevinphos, naled, Z-Tetrachlorvinphos and prothiophos, with concentrations of 0.008, 0.015, 0.021, 0.053 and 0.019 μg/L, respectively. O,O,O-Triethylphosphorothioate was mainly used as an insecticide and could effectively control various pests. Mevinphos was an organophosphorus insecticide that inhibited acetylcholinesterase and had broad-spectrum insecticidal action, commonly used against chewing and sucking insects and leaf mites. Naled was an organophosphorus insecticide produced by the reaction of dichlorvos with bromine; it had a wide activity spectrum, including contact, stomach toxicity and fumigation. Z-Tetrachlorvinphos was a highly effective and low-toxic organophosphorus insecticide; it was highly effective against Lepidoptera, Diptera and various Coleoptera pests, but had low toxicity to warm-blooded animals. Prothiophos was frequently utilized in agricultural fields and orchards for managing and preventing pests and diseases. Furthermore, it could be used in both residential and industrial settings for insecticidal and antiseptic purposes Organophosphorus compounds in N3 included ethoprophos and sulprofos, with concentrations of 0.028 and 0.075 μg/L, respectively. Organophosphorus compounds in W4 included O,O,O-Triethylphosphorothioate, mevinphos, naled, Z-Tetrachlorvinphos and prothiophos, with concentrations of 0.008, 0.015, 0.021, 0.053 and 0.019 μg/L, respectively.

O,O,O-Triethylphosphorothioate was mainly used as an insecticide and could effectively control various pests. Mevinphos was an organophosphorus insecticide that inhibited acetylcholinesterase and had broad-spectrum insecticidal action, commonly used against chewing and sucking insects and leaf mites. Naled was an organophosphorus insecticide produced by the reaction of dichlorvos with bromine; it had a wide activity spectrum, including contact, stomach toxicity and fumigation. Z-Tetrachlorvinphos was a highly effective and low-toxic organophosphorus insecticide; it was highly effective against Lepidoptera, Diptera and various Coleoptera pests, but had low toxicity to warm-blooded animals. Prothiophos was frequently utilized in agricultural fields and orchards for managing and preventing pests and diseases. Furthermore, it could be used in both residential and industrial settings for insecticidal and antiseptic purposes. Approximately 362,000 acres of agricultural land were located around Lianhuan Lake, of which 237,000 acres were planted to corn; 87,000 acres to rice, 33,000 acres to soybeans, and 3,000 acres to potatoes. As a result of extensive agricultural activity, pesticides (especially organophosphate pesticides) were heavily used to control pests and diseases. These pesticides entered the lake through surface runoff, irrigation drainage, and rainfall washout, resulting in increased concentrations of organophosphorus compounds in the water column. 3.6.2 ECOSAR. The results of the ECOSAR evaluation of the toxicity of organophosphorus to aquatic plants, fish

and invertebrates (Fig 6) indicated that in acute and chronic toxicity assessments, nine organophosphorus compounds— Thionazin, Ethoprophos, Suprofos, EPN, Coumaphos, O,O,O-Triethylphosphorothioate, Mevinphos, Naled, and Prothiophos—were found to present different levels of risk to fish, Daphnia and algae. Suprofos, Coumaphos and Prothiophos were highly toxic to Daphnia, and Suprofos and Prothiophos were highly toxic to fish. In acute toxicity