Occurrence levels of perfluoroalkyl carboxylic acids (PFCA) and perfluoroalkyl sulfonic acids (PFSA) in European perch (Perca fluviatilis) samples collected from inland waters in Latvia: Component profiles, spatial distribution and dietary exposure to consumers

This study was performed to evaluate the occurrence of perfluorinated substances (PFAS) in European perch (Perca fluviatilis) samples from Latvian freshwater bodies. Twenty-nine samples of perch tissue homogenates were analyzed on the content of PFAS representing different sampling sites to cover all territory of Latvia evenly. The total PFAS concentrations (∑_PFAS) ranged from 0.27 to 3.50 ng g⁻¹ (mean 1.03 ng g⁻¹ and median 0.78 ng g⁻¹, respectively), while total priority four PFAS (∑_4PFAS) concentration was in the range from 0.20 to 3.09 ng g⁻¹ (mean 0.72 ng g⁻¹ and median 0.49 ng g⁻¹, respectively). The most prominent PFAS representative was perfluoroctanesulfonic acid (PFOS), presented in all samples at concentrations from 0.18 to 3.04 ng g⁻¹ and constituting ∼ 60% of the total selected PFAS fraction. Observed concentrations of ∑_4PFAS were significantly lower than established maximum levels (MLs), reaching maximum contamination up to 7% of respective ML. Calculated dietary intake figures do not exceed the safety threshold constituting from 5 to 7.5% of EFSA tolerable weekly intake (TWI) of 4.4 ng kg⁻¹ bw. wk⁻¹, however, a significantly higher intake of up to 45% of TWI could be obtained if maximum ∑_4PFAS concentrations are used in calculations. Analysis of the spatial distribution of PFAS concentrations across various sampling sites suggests multiple contamination sources impacting Latvian freshwater bodies. While observed concentrations generally appear lower compared to data from heavily industrialized regions, the possibility of localized areas within Latvia exhibiting elevated PFAS levels cannot be excluded.