Effects of perfluorooctanoic acid and perfluorooctane sulfonate on acute toxicity, superoxide dismutase, and cellulase activity in the earthworm Eisenia fetida

Abstract

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the two best-known perfluorinated chemicals and have received much attention due to their ubiquity in the environment. In the present study, we evaluated the effects of PFOS and PFOA on acute toxicity, superoxide dismutase (SOD), and cellulase activities in Eisenia fetida. The results of acute toxicity testing using a filter paper contact test and a natural field soil test showed that PFOA and PFOS exhibited acute toxicity in earthworms, and the toxic effect of PFOS was greater than that of PFOA. The results also showed that avoidance behavior is a more sensitive and easy operation biomarker than acute toxicity and will give us information for early diagnosis of soil pollution, well before the lethal effect becomes apparent. Subchronic exposure to PFOA or PFOS resulted in changes in SOD and cellulase activities in E. fetida, and SOD activity was more sensitive than cellulase activity during early exposure. Based on these findings, we suggest that avoidance behavior and SOD activity in earthworms are suitable biomarkers for evaluating the toxicity of PFOA- and PFOS-contaminated soils. These results indicate that exposure to PFOA and PFOS has a potential impact on soil animals and their environment.

Comparative Toxicological Effects of Perfluorooctane Sulfonate and Its Alternative 6:2 Chlorinated Polyfluorinated Ether Sulfonate on Earthworms

“…The LC50 is a widely used parameter to indicate the toxicity of contaminants to earthworms. The 14‐day LC50 value for PFOS calculated in the present study was comparable to that reported by Xu et al (2011; LC50 = 1.91 mmol/kg) and slightly higher than the value reported by Yuan et al (2017; LC50 = 0.96 mmol/kg). These differences may be due to the properties of the soil used.…”

Antioxidant defense system responses, lysosomal membrane stability and DNA damage in earthworms (Eisenia fetida) exposed to perfluorooctanoic acid: an integrated biomarker approach to evaluating toxicity

“…Based on the results of acute toxicity tests of PFOA to earthworms 30,37 and our pre-experiments, six different concentrations of 0, 10, 20, 40, 80 and 120 mg kg À1 soil (dry weight) were used in this study. The 80 mg kg À1 was considered as 1/10 of 14d-LC 50 for PFOA (about 800 mg kg À1 for earthworm E. fetida in soil).…”

“… 28,29 The oxidative stress biomarkers, including antioxidant enzymes, non-enzymatic antioxidants and lipid peroxidation level are frequently applied to explore the toxicity mechanism of many perfluoroalkyl substances (PFASs). Yuan et al 30 evaluated the effects of perfluorooctane sulfonate (PFOS) and PFOA on superoxide dismutase (SOD) in the earthworm E. fetida at sublethal concentrations and found that SOD activity was sensitive to evaluate the toxicity of PFOS- and PFOA-contaminated soils. Zhao et al 31 also assessed the potential toxicity of PFOA to the earthworm E. fetida by measuring the responses of SOD, catalase (CAT), glutathione S-transferase (GST) and lipid peroxidation (LPO) after exposure to 0, 5, 10, 20, and 40 mg kg −1 PFOA in soils for 7, 14, 21, and 28 days.…”

Acute Toxicity and Ecotoxicological Risk Assessment of Three Volatile Pesticide Additives on the Earthworm—Eisenia fetida

“…A few studies showed that avoidance response of earthworms could indicate lower AT concentrations than other traditional endpoints, such as mortality, biomass gain/loss, and even reproduction [ 41 , 42 ]. Nonetheless, the results of this study showed that the AT values of E. fetida to the toluene, xylene, trichloroethylene, and ternary mixture were higher than the 48 h-LC 50 value in the acute toxicity test.…”