<p>The persistence and accumulation of dioxins (PCDDs), furans (PCDFs) and dioxin-like polychlorinated biphenyl (dl-PCBs) continue to raise public health concerns. 480 serum samples from adults (18–65 years old) living in a Mediterranean Region of Spain were collected. All 29 congeners analysed were detected, with detection frequencies ranging from 3% (123789-HxCDF) to 100% (PCB-118, PCB-105, PCB-167, PCB-157, PCB-156, and PCB-189). Eight PCB congeners showed median concentrations exceeding 100 pg g⁻¹, with congener’s concentrations ranging from 0.13 pg g⁻¹ (PCB-81) to 15886.2 pg g⁻¹ (PCB-118). The congeners that contributed most, in terms of toxic equivalents (TEQ), were 12378-PCDD among PCDD/Fs and PCB-126 among dl-PCBs. The median total concentration of PCDD/Fs and dl-PCBs, expressed in TEQ, was 8.9 pg TEQ g⁻¹. In the worst-case scenario, expressed as percentile 95 (p95), obtained concentration was 19.7 pg TEQ g⁻¹. Overall, the total range of the sum oscillated from 2.8 pg TEQ g⁻¹ to 28.3 pg TEQ g⁻¹. As expected, a significant relationship was found between participants’ age and the overall score. Two main age groups were identified in the present study: 18–40 years and 41–65 years. Additionally, statistically significant effects were observed for smoking status, home location, gender, body mass index (BMI) and dietary consumption were revealed. A health risk assessment for PCDD, PCDF and dl-PCBs was carried out. Hazard index (HI) values for both the median and p95 were below the concerned level (HI &lt; 1). However, 3% of the total analysed samples exhibited HI exceeding 1, suggesting potential risk in a small subset of the population.</p> Graphical Abstract <p></p>