Ecological risk assessment for perfluorohexanesulfonic acid (PFHxS) in soil using species sensitivity distribution (SSD) approach

• Published in: Journal of hazardous materials Vol. 439; p. 129667
• Main Authors: Liu, Yanju, Bahar, Md Mezbaul, Samarasinghe, S.V.A. Chamila, Qi, Fangjie, Carles, Sandra, Richmond, William R., Dong, Zhaomin, Naidu, Ravi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.10.2022
• Subjects: EC10/NOEC; EC30; Ecological toxicity; Perfluorohexanesulfonic acid (PFHxS); Species Sensitivity Distribution (SSD); Species Sensitivity Distribution (SSD); Perfluorohexanesulfonic acid (PFHxS); EC30; EC10/NOEC; Ecological toxicity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.129667

Perfluorohexanesulfonic acid (PFHxS) is one of the persistent organic pollutants that has been recommended to be listed in Annex A of the Stockholm Convention. It has gained increasing attention in recent years due to its toxic effects. The guideline values of PFHxS are commonly associated with PFOS in various countries and regulatory agencies. In this study, multispecies bioassays were conducted to determine the ecological toxic effects of PFHxS, including plants, soil invertebrates, and soil microorganisms, which indicated the EC10/NOEC values ranged from 2.9 to 250 mg/kg. Where possible, logistic models were used to calculate the EC30 values for various endpoints. The species sensitivity distributions were employed to estimate the ecological investigation levels for PFHxS contamination in soils using toxicity results from literature and this study. The calculation using EC10/NOEC values from both literature and this study indicated a most conservative HC5 as 1.0 mg/kg (hazardous concentration for 5 % of the species being impacted). However, utilisation of EC30 values derived from this study resulted in a much higher HC5 for PFHxS in contaminated soils (13.0 mg/kg) which is at the higher end of the existing guideline values for PFOS for protecting ecological systems. The results obtained in this study can be useful in risk assessment processes to minimize any uncertainty using combined values with PFOS. [Display omitted] •Different toxic effects were observed for soil organisms exposed to PFHxS.•SSD approach was used to calculate the HC5 for PFHxS contamination in soils.•Using EC10/NOEC from literature and this study results the most conservative HC5.•Using EC30 obtained in this study leads to HC5 at the higher end of existing PFOS guideline values.