Integrative assessment of sediment quality in acidification scenarios associated with carbon capture and storage operations

Efforts to stem global change include the application of new technological developments that aim to reduce atmospheric carbon dioxide (CO2) through the capture and storage (CCS) of this greenhouse gas in stable geological structures. In this paper, we assess the potential risks related to the application of CCS technology and the acidification of aquatic ecosystems through CO2 enrichment. We use the multiple lines of evidence approach (LOEs) to characterize the effects of the acidification with contamination in aquatic sediments. We highlight and discuss the effects of acidification on the LOE: including contamination and mobility of contaminants in sediments, toxicity, macro-benthic community structure, in situ effects and bioaccumulation/biomagnification processes. We further assess the results of acidification on the toxicity of organic contaminants such us antibiotics or illicit drugs like free base form of cocaine (crack). The main goal of using the LOEs approach is to distinguish between adverse effects that are associated with contaminants and those related to acidification by enrichment of CO2 as a result of CCS technology. Previous assessments have not designed or conducted to incorporate an integrative point of view, nor have they employed a weight-of-evidence approach (WOE) in risk characterization and management of CCS operations and other situations related to acidification by enrichment of CO2 in the aquatic ecosystem. Based on the findings of this review, the WOE is capable to identify the effects of the acidification on the different LOEs used for sediment quality: contaminant mobility, the adverse effects in organism under laboratory, and field conditions, and the bioaccumulation/biomagnification of contaminants. The main strength in using WOE is the ability of this method to discriminate between LOE responses associated with contamination by different organic and inorganic substances from those related to CO2 acidification itself. The WOE will significantly improve the risk assessment in areas affected by potential leakages of CO2 during CCS operations.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author