Single and combined effects of metal-based fungicides on Eisenia andrei in different scenarios of climatic change

Abstract

Abstract This study evaluated the ecotoxicity of metal-based fungicides under the current scenarios of global climatic change (20°C and 25°C) in single and binary mixtures of copper oxychloride (CuOx) [200, 500 and 1000 mg/kg] and mancozeb (MnZn) [44, 850 and 1250 mg/kg]. Endpoints assessed included mortality, growth, avoidance behaviour, and reproduction utilising standardised protocols (ISO and OECD). Mortality in the exposure groups only exceeded 10% in the CuOx1000 and CuOx1000 + MnZn1250 mg/kg groups in all temperature-moisture combinations. However, the mortality rate exceeded 10% only in the treatment with CuOx500 + MnZn850 mg/kg at 20°C30%. Relative growth rates in the CuOx and MnZn treatment groups decreased with increasing concentrations. In both CuOx and MnZn treatment concentrations at 20°C30% and 25°C50% conditions, avoidance response behaviour was greater than 80% throughout the exposure, except in CuOx200 mg/kg, MnZn44 mg/kg and CuOx200 + MnZn44 mg/kg. The reproduction of exposed earthworms in all treatment groups was concentration-dependent and influenced by varying temperatures and soil moisture conditions. No juveniles or cocoons were produced in the CuOx1000 mg/kg treatment at 25°C30%, indicating that copper oxychloride may be more toxic than mancozeb, especially in drought conditions. This study found that different temperatures and soil moisture levels altered the ecotoxicity of CuOx and MnZn. It can be concluded that climate change is likely to significantly impact the outcomes of metal ecotoxicity to earthworms and their ecological activities.