Dictyostelium discoideum developmental cycle (DDDC) assay: A tool for Hg toxicity assessment and soil health screening

► Solid-phase and monolayer DDDC assay variants evidence Hg toxicity in soil. ► Solid-phase DDDC assay is feasible, easy to conduct and toxicologically reliable. ► It provides ecologically relevant (population fitness) critical toxicity values. ► It constitutes a useful biotool for soil toxicity testing and soil health screening.