To Örebro University

Background: Poly- and perfluoroalkyl substances (PFAS) are persistent pollutants affecting wildlife and biodiversity. Perfluorooctane sulfonic acid (PFOS) and one of its short-chain substitutes, perfluorobutane sulfonic acid (PFBS), are widely found in environmental components, especially in water. PFOS has been highlighted as causing deleterious effects on various organisms while PFBS adversity is suspected but requires further investigation. In this study, zebrafish embryos were exposed from 2 h post-fertilization to 28 days post-fertilization to two different concentrations (0.2 mu g/L and 2 mu g/L) of PFOS or PFBS. We then investigated the impacts of these early exposures later in life on adult fish fitness, growth, morphology, behaviour, and liver lipidomic profiles.

Results: PFOS exposure significantly reduced egg production, and both PFOS and PFBS altered growth patterns, organ development, and anxiety-like behaviour. Lipidomic analyses revealed persistent shifts in liver lipid composition that correspond to these phenotypic changes.

Conclusions: Taken together, our findings indicate that early-life exposure to low levels of PFOS and PFBS leads to long-term, sex-specific impairments in zebrafish physiology and behaviour, with disruptions in lipid metabolism emerging as a potential underlying mechanism.