Perfluorotetradecanoic acid (PFTeDA), a long-chain PFAS, is commonly detected in aquatic environments, yet its toxicological effects remain poorly understood. Mytilus trossulus were exposed for seven days to two levels of PFTeDA, 3 and 30 ng/L. In order to assess PFTeDA toxicity towards a model species, selected physiological and biochemical biomarkers were evaluated in the digestive, respiratory and gonadal tissues. We demonstrate that already environmentally relevant levels of PFTeDA induce histopathological changes in M. trossulus, including gill oedema, digestive gland atrophy, and gonadal stimulation. These effects may impair respiration, nutrient assimilation, and reproduction, ultimately affecting individual health and population dynamics. Our findings also indicate that PFTeDA induces a mild oxidative stress response, as substantial changes in the enzymatic activities were not observed. The results highlight the role of concentration, exposure duration, and species-specific physiology in shaping oxidative outcomes. Given the ecological role of M. trossulus as a bioindicator and filter feeder, our findings add to the growing evidence of PFTeDA environmental effects.

Per- and polyfluoroalkyl substances (PFAS) are a group of thousands of highly persistent anthropogenic chemicals widely used in many industries. Therefore, they are, ubiquitously present in various types of environments. Despite their omnipresence, ecotoxicological studies of most PFAS are scarce, and those available often assess the effects of long chain PFAS. In this study, we present the results of an exposure experiment in which wild aquatic amphipod Gammarus spp. was exposed to the short chain perfluorinated substance perfluorobutanoic acid (PFBA) at very low and environmentally relevant concentrations of 0, 10 and 100 ng/L. The exposure lasted for 12 days, and food intake and non-reproductive behavior were analyzed. Exposure to 10 and 100 ng/L PFBA resulted in a lower consumption of food during exposure but no effect on behavior was found. 

Per-and polyfluoroalkyl substances (PFAS) is a collective name for approximately 4700 synthetic chemicals ubiquitous in the aquatic environment worldwide. They are used in a wide array of products and are found in living organisms around the world. Some PFAS have been associated with cancer, developmental toxicity, endocrine disruption, and other health effects. Only a fraction of PFAS are currently monitored and regulated and the presence and effects on aquatic organisms of many PFAS are largely unknown. The aim of this study is to investigate the health effects of environmentally relevant concentrations of PFAS on aquatic organisms at different consumer trophic levels through a systematic review and meta-analysis. The main result shows that PFAS in concentrations up to 13.5 μg/L have adverse effects on body size variables for secondary consumers. However, no significant effects on liver or gonad somatic indices and neither on fecundity were found. In addition, the results show that there are large research gaps for PFAS effects on different organisms in aquatic environments at environmentally relevant concentrations. Most studies have been performed on secondary consumers and there is a substantial lack of studies on other consumers in aquatic ecosystems.