Co-exposure of butyl benzyl phthalate and TiO2 nanomaterials (anatase) in Metaphire guillelmi: Gut health implications by transcriptomics

Abstract

During the COVID-19 pandemic, an abundance of plastic face masks has been consumed and disposed of in the environment. In addition, substantial amounts of plastic mulch film have been used in intensive agriculture with low recovery. Butyl benzyl phthalate (BBP) and TiO₂ nanomaterials (nTiO₂) are widely applied in plastic products, leading to the inevitable release of BBP and nTiO₂ into the soil system. However, the impact of co-exposure of BBP and nTiO₂ at low concentrations on earthworms remains understudied. In the present study, transcriptomics was applied to reveal the effects of individual BBP and nTiO₂ exposures at a concentration of 1 mg kg^-1, along with the combined exposure of BBP and nTiO₂ (1 mg kg^-1 BBP + 1 mg kg^-1 nTiO₂ (anatase)) on Metaphire guillelmi. The result showed that BBP and nTiO₂ exposures have the potential to induce neurodegeneration through glutamate accumulation, tau protein, and oxidative stress in the endoplasmic reticulum and mitochondria, as well as metabolism dysfunction. The present study contributes to our understanding of the toxic mechanisms of emerging contaminants at environmentally relevant levels and prompts consideration of the management of BBP and nTiO₂ within the soil ecosystems.

Keywords: BBP; Earthworm; Engineered nanomaterials; Titanium dioxide; Transcriptome.