Microplastics (MP) are ubiquitous in all parts of the ecosystem and have recently been proven to impact the toxicity of other environmental pollutants significantly. Most of the existing studies were conducted with aquatic organisms and focused on the effect of MPs on metal toxicity. Moreover, aged MPs, which are more environmental relevant structures of MPs, are rarely investigated in terms of toxicity. Oxygen-containing groups formed by aging increase MPs' charge, hydrophilicity, and polarity, affecting MP-organic pollutant binding. Hence, the impacts of MPs and aged MPs on the toxicity of organic emerging pollutants on soil organisms are lacking in the literature. This study aims to investigate the toxic effect of selected emerging organic pollutants on soil organism E. crypticus, in the presence of polypropene (PP) MPs and aged PP MPs. Selected emerging contaminants were diclofenac, ciprofloxacin, EE2, diuron, terbutryn, anthracene, diphenyl ether and diethyl hexyl phthalate. Toxicity was investigated for the reproduction end point, and NOEC and EC50 values were reported. PP and aged PP were added to the sets at a 5mg/kg concentration. It was found that microplastics alone did not show any effect on the reproduction of E. crypticus at this concentration, but they significantly increased the toxicity of organic pollutants. The individual NOEC value for microplastics and pollutants was 12.5mg/kg. In the presence of microplastics and aged microplastics, the pollutants were shown to have a significant effect at this concentration. The EC50 values of pollutants also decreased in the presence of MPs. Although the existing concentrations of the emerging contaminants in the soil is much lower than 12.5 mg/kg, the presence of PP and aged PP should be considered for the environmental risk management of organic emerging contaminants in the soil due to their potential to alter the reproduction toxicity.
Impact of microplastics and aged microplastics on the toxicity of emerging contaminants in the soil
.