Toxicity and bioaccumulation of the fluorosurfactant cCO in the earthworm Eisenia foetida (Savigny, 1826).

Cyclic CO (cCO, CAS number 1190931-27-1) is a perfluoralkyl ether PFAS used as a polymerization aid in the synthesis of fluoropolymers and produced in Italy since 2011 as substitute of PFOA. To date, available ecotoxicological information on cCO is related to regulatory requirements and limited to data on aquatic organisms, while the information on the effects for terrestrial organisms is completely lacking. This work reports the first ecotoxicological data of cCO on terrestrial invertebrates: short- and long-term toxicity of cCO on Eisenia foetida (Savigny, 1826), exposed to spiked soil under laboratory conditions, was investigated evaluating the earthworm survival and growth (observed after 7, 14 and 28 days of exposure), and reproduction (observed after an exposure period of 56 days). Furthermore, also bioaccumulation was investigated (28 days of exposure); overall results are discussed in comparison with literature data available for legacy PFAS. cCO did not cause significant mortality on earthworms, for any of the tested concentrations and exposure periods (NOEC: > 1390 mg/kg d.w.), while the reproduction (measured as juveniles production) appears to be a more sensitive endpoint (EC50: 10.4 mg/kg d.w., EC10: 0.8 mg/kg d.w.). The observed adverse effects occur at levels significantly higher than realistic soil concentrations and cCO appears to be less toxic than PFOA and PFOS. As for bioaccumulation, the results indicate a negligible bioaccumulation potential of cCO, whose Biota-Soil Bioaccumulation Factors (BSAF) are significantly lower than all other considered PFAS.