Effects of a Common Surfactant Sodium Lauryl Sulfate on Early Life Stages of Two Fish and One Amphibian Species

Sodium lauryl sulfate (SLS) is an anionic surfactant used as an emulsifying detergent in personal care products (PCPs). As a pseudo-persistent pollutant, it accumulates in aquatic ecosystems with consequent adverse effects on the whole ecosystem. Most of the studies about the toxicity of SLS on non-target species were conducted before 2010, and just a bunch of recent studies focus on this topic. Due to the COVID-19 pandemic, there has been a rise in the use of PCPs, thus increasing SLS release in aquatic environments. Therefore, the present study aims to assess the impact of SLS on non-target organisms Danio rerio, Cyprinus carpio, and Xenopus laevis, through embryotoxicity tests. Embryos were exposed to different concentrations of SLS (0.1, 0.5, 1, 5, 10, 15 mg/L) for 96 h and relevant toxicity endpoints (mortality, hatching rate, and malformations) were monitored each 24 h. Additionally, heart rates along with animal length were measured. The study highlights the high sensitivity of D. rerio and X. laevis when exposed to SLS concentrations comparable to the one detected in the environment. Specifically, relevant results have been observed in the endpoint of mortality (D. rerio showed 100% mortality in the highest concentrations), hatching and malformations in both animals. Heart rate measurements showed significant differences in C. carpio and D. rerio in all the concentrations tested. Graphical abstract