Recent advances in research on cyclic volatile methylsiloxanes in sediment, soil and biosolid: a review

Three cyclic volatile methylsiloxanes (cVMS) were widely used in various processes of production and industrials and frequently added to consumer products. cVMS are continuously released into the environment, causing increasing environmental and human exposing risks. cVMS were investigated in air, water, biogas, soil, sediment, biosolid and organism. Many scholars focused on the occurrence, behaviours, fate and effects of cVMS in environmental matrices all over the world. However, few studies paid attention to the environmental behaviour of cVMS in the solid phase. We assessed their environmental behaviour and fate in soil, biosolid and sediment. High concentrations of cVMS were detected in biosolids. Volatilisation, adsorption and degradation were the major environmental behaviours for cVMS in the solid phase. Although some aquatic organisms showed an appropriate level of bioaccumulation and bioconcentration, there were no obvious evidence of trophic biomagnification in aquatic food webs for octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). In addition, cVMS in the environment have not impacted for natural organisms because the concentrations in soil and sediment have not exceeded the maximum no-observed-effect-concentration threshold. Finally, regarding the major environmental behaviour in soil and sediment, suggestions for further study are proposed.