PFAS (Per- and Polyfluoroalkyl substances) are synthetic contaminants that are persistent and pervasive. Exposure to PFAS can cause toxic effects in wildlife, but little is known about how it affects egg-laying species. To address this gap and provide better ecosystem health metrics, we collected 26 freshwater turtles from three different waterways, each with different levels of PFAS contamination. The turtles were tested for PFAS and analysed using omics-based approaches, which assess chemical contamination impacts through proteomics, lipidomics, and metabolomics.
Tests revealed that the turtles taken from the PFAS-impacted site had serum PFAS concentrations ten times greater than those taken from the control site, while those from the reference site had no measurable PFAS. Additionally, the distribution of PFAS within tissues showed a high bioaccumulative effect of perfluorooctanesulfonic acid (PFOS) in the liver and ovary tissues compared to serum values. Specific biochemical profiles of serum, tissues, eggs, and hatchlings showed that the impacted turtles exposed to elevated PFAS had an enhanced purine metabolism, glycerophosphocholines, and an elevated innate immune response, suggesting inflammation, metabolic preservation, and rerouting of central carbon metabolites. Lipid transport and binding activities were negatively correlated. Purine metabolism metabolites were significantly elevated in the PFAS-impacted eggs, while yolks were depleted in lipids tied to growth and development. This resulted in emerged hatchlings at both the impact (17 out of 44 hatchlings) and control sites (23 out of 71 hatchlings) showing atypical intergular scales, while only 2 out of 34 hatchlings from the reference site demonstrated this feature. This study highlights the impacts of PFAS exposure on wildlife and provides data-driven ecosystem management for informed decision-making for regulators.