Long-Term Environmental and Human Health Impacts of Hazardous Waste Incineration: A Case Study in Catalonia, Spain

This comprehensive review synthesizes findings from studies conducted over more than two decades to assess environmental and human health impacts near Spain's first hazardous waste incinerator (HWI) located in Constantí (Tarragona, Catalonia). Through integrated analysis of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and metals across soil, vegetation, human tissues, and dietary matrices, the studies have shown: (1) PCDD/F concentrations decreased by 75-96% in biological samples and dietary intake over 20 years, aligning with global emission reductions rather than HWI operations; (2) metal trajectories showed arsenic intermittently exceeding carcinogenic thresholds in soils (1.1 × 10-4 risk index) and chromium accumulating in autopsy tissues (+16% in kidney), although without HWI-specific spatial gradients; (3) systemic biomarkers revealed policy-driven declines—blood lead dropped by 70% post-EU regulations, while mercury became undetectable in tissues post-2010. Health risk assessments confirmed that PCDD/F intake (0.122 pg WHO-TEQ/kg/day) remained below WHO thresholds, with no attributable cancer risks for metals except legacy arsenic. The studies included in the program of surveillance show that PCDD/Fs and metals emissions by the HWI have meant a rather low contribution to population exposure to metals and PCDD/Fs compared to dietary and historical sources. However, residual risks warrant attention. This mainly concerns chromium speciation and arsenic in soils, as well as the effects on vulnerable subpopulations and the synergistic effects among toxicants. Epidemiological studies are also required.