Ecotoxicological evaluation of boron, arsenic, iodine and selenium on reproduction, mortality and avoidance of folsomia candida (Collembolan)

Abstract

Soil plays a significant role in the ecosystem. Soil pollutants have increased largely from a wide range of sources in the last decades. Trace elements accumulated in soil because of anthropogenic activities (e.g. industry, agricultural production, and health products) may pose a potential risk to environmental safety. Therefore, it is necessary to evaluate the ecotoxicological effects of trace elements on soil model animals. To evaluate the ecotoxicological impacts of four trace elements (As, B, Se, and I), the 28-days long tests based on the OECD guideline 232 had been executed with Folsomia candida (Collembola). The chosen trace elements were mixed with OECD artificial soil in the following concentrations [mg/kg]: 0, 0.0023, 0.0069, 0.0205, 0.0617, 0.185, 0.555, 1.66, and 5 for selenium; 0, 0.5, 7.5, 11.25, 16.875, 25.312, 37.969, and 56.953 for iodine; 0, 0.0002, 0.001, 0.005, 0.025, 0.125, 0.625, 3.125, and 15.625 for boron; 0, 0.01, 0.03, 0.1, 0.3, 0.9, 2.7, 8.1, and 24.3 for arsenic. Meanwhile, 48-hours sublethal test (avoidance tests) had been carried out with Folsomia candida. Survival, reproduction, and avoidance behavior of F. candida were regarded as endpoints with the main ecotoxicological values (NOEC, LOEC, EC50, and LC50). The four trace elements all showed toxic effects on F. candida in different degrees and they had similar toxicity on the survival of F. candida, while boron showed higher toxicity on reproduction than the others. The survival of F. candida was more sensitive than reproduction to each element. Avoidance behaviour of F. candida was the most sensitive to boron, followed by arsenic and iodine, and finally selenium. In this study, boron and arsenic appeared to be potential risks in the natural fields.

Soil plays a significant role in the ecosystem. Soil pollutants have increased largely from a wide range of sources in the last decades. Trace elements accumulated in soil because of anthropogenic activities (e.g. industry, agricultural production, and health products) may pose a potential risk to environmental safety. Therefore, it is necessary to evaluate the ecotoxicological effects of trace elements on soil model animals. To evaluate the ecotoxicological impacts of four trace elements (As, B, Se, and I), the 28-days long tests based on the OECD guideline 232 had been executed with Folsomia candida (Collembola). The chosen trace elements were mixed with OECD artificial soil in the following concentrations [mg/kg]: 0, 0.0023, 0.0069, 0.0205, 0.0617, 0.185, 0.555, 1.66, and 5 for selenium; 0, 0.5, 7.5, 11.25, 16.875, 25.312, 37.969, and 56.953 for iodine; 0, 0.0002, 0.001, 0.005, 0.025, 0.125, 0.625, 3.125, and 15.625 for boron; 0, 0.01, 0.03, 0.1, 0.3, 0.9, 2.7, 8.1, and 24.3 for arsenic. Meanwhile, 48-hours sublethal test (avoidance tests) had been carried out with Folsomia candida. Survival, reproduction, and avoidance behavior of F. candida were regarded as endpoints with the main ecotoxicological values (NOEC, LOEC, EC50, and LC50). The four trace elements all showed toxic effects on F. candida in different degrees and they had similar toxicity on the survival of F. candida, while boron showed higher toxicity on reproduction than the others. The survival of F. candida was more sensitive than reproduction to each element. Avoidance behaviour of F. candida was the most sensitive to boron, followed by arsenic and iodine, and finally selenium. In this study, boron and arsenic appeared to be potential risks in the natural fields.