Potentially Toxic Elements (PTEs) Bioaccumulation in Fish from the Aries River, Romania: Screening-Level Human Health Risk Assessment

Background: The Arieș River basin in Romania is historically mining-impacted, and data on metal accumulation in its fish and the associated risk to consumers are scarce. Aims: This study investigated elemental accumulation in fish from the Arieș River and evaluated the potential health risks associated with fish consumption. Methods: A total of 40 fish representing five species were collected by angling between June and September 2025, after the legal fishing prohibition period. Eight tissues per fish (muscle, gills, liver, skin, bones, scales, eyes, and caudal fin) were analyzed by inductively coupled plasma–mass spectrometry (ICP-MS). Contamination and exposure were evaluated using the pollution index (PI), metal contamination index (MCI), estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) for non-carcinogenic risk, and carcinogenic risk and total carcinogenic risk (TCR) for carcinogenic risk. Species and tissue patterns were examined by multivariate analysis, including linear discriminant analysis (LDA). Results: Multivariate statistical analysis revealed distinct species- and tissue-related patterns in elemental composition. LDA differentiated species with an initial classification accuracy of 82.5% and a leave-one-out cross-validated accuracy of 72.5%, with Cr, Mn, Pb, Sr, and Ni having the highest contribution. Tissue discrimination was lower (approximately 60%), with Sr, Zn, and Cu as main discrimination variable. THQ values for individual elements and HI were below 1, indicating no appreciable non-carcinogenic risk under the assumed exposure conditions. The highest CR values were associated with Ni (nase muscle, 2.26 × 10−6) and As (nase skin, 6.28 × 10−7). TCR ranged from 3.16 × 10−7 to 3.37 × 10−6 and remained below 1 × 10−4, within the acceptable range. Conclusions: Elemental contamination in fish from the Arieș River was generally low, and species and tissue type influenced elemental composition and dietary relevance. Continued monitoring is advised, with seasonal sampling, inorganic arsenic speciation, and attention to species such as nase when assessing consumption risk.