Liquid crystal monomers in soil: Developing priority list based on the proposed soil health indicators

Liquid crystal monomers (LCMs) are emerging pollutants that have attracted attention recently due to their unique chemical properties and wide applications. However, in-depth research on LCMs' potential risks to soil health remains blank. Therefore, 107 LCMs and nine soil health characterization proteins/enzymes were selected as research objects in this study. A grading evaluation system for soil health toxicological effect indicators under LCMs exposure was constructed from five dimensions (i.e., soil animals, soil plants, soil microorganisms, soil carbon, nitrogen and phosphorus cycles, and human health) by molecular docking and molecular dynamics simulation methods. Priority control lists for soil health toxicological effects under LCMs exposure were developed based on the proposed evaluation system, with rationality verified through non-bonded interaction, 2D-QSAR and Meta-analysis. Results showed that 32, 56 and 19 LCMs presented unacceptable, potential, and acceptable soil health risks, respectively. The oxidative damage of LCMs to plant leaves, the toxicity to earthworm growth and development, and its effects on key enzymes of the soil nitrogen cycle were suggested to be the priority-attention indicators. This is the first study that provides theoretical support for revealing the toxicological effects of LCM exposure on soil health and relevant pollution control strategies.