Iason Verginelli

This review presents a process-based decision-making framework for chlorinated vapor intrusion (CVI) mitigation. CVI mitigation refers to the set of engineered strategies aimed at interrupting, attenuating or transforming vapor fluxes before they reach indoor environments. Existing literature and technical guidelines typically classify mitigation strategies according to technological configuration (active versus passive), rather than physical and chemical processes governing vapor transport and attenuation, which may lead to suboptimal design choices and reduced system resilience. To address this limitation, this framework proposes a process-based classification of CVI mitigation strategies based on the dominant mechanisms controlling vapor migration in subsurface. Five mechanistic categories are identified: driving-force control through pressure manipulation, dilution via air exchange, diffusive flux control through physical barriers, density-driven attenuation in permeable sub-slab layers, and in situ transformation based on sorption or degradation. By explicitly linking mitigation technologies to transport and transformation processes, the proposed framework provides a structured basis for mechanism-oriented selection, integrating performance, longevity, climate resilience, and lifecycle energy demand. In addition to established mitigation approaches, such as sub-slab depressurization, this work highlights emerging passive strategies, including high permeable granular layers and horizontal reactive or adsorbing barriers, as potential low-energy alternatives for durable management. Overall, the proposed framework supports site-specific, sustainability-oriented decision-making on CVI mitigation.

At the European Union level, approximately 60–70% of soil is in unhealthy or degraded conditions. One of the soil threats is the legacy of industrial pollution, as historic industrial pollutants discharged into the ground continue to pose risks to both the environment and human health. As part of the legislative measures adopted in the late 90 s, Human Health Risk Assessment (HHRA) was introduced as a standardized method for evaluating risks associated with contaminated sites. To support the quantification of these risks, various software tool models were developed. This study reviews 12 HHRA tools for contaminated sites developed across different countries. First, an overview of national legislative frameworks concerning contaminated sites, with a particular focus on the use of HHRA as a decision-making tool, is provided. Subsequently, the study compares and discusses the methodologies adopted by each tool, the exposure pathways and receptors considered, the integrated contaminant databases, and additional features provided by the models. The comparison highlights the diversity of functionalities offered by the different tools, reflecting a lack of harmonization among national regulations regarding contaminated site management. Beyond the need for a harmonized approach at the EU level, potential future developments include the design of more user-friendly interfaces capable of expanding exposure scenarios, updating contaminant lists (including emerging pollutants such as PFAS), integrating uncertainty analysis, incorporating Geographic Information System (GIS)-based visualizations, and integrating artificial intelligence (AI)/machine learning (ML).

In line with circular economy principles and the reduction of primary material exploitation, waste-to-energy (WtE) by-products such as bottom ash (BA) are increasingly being used as raw materials in cement and ceramics manufacturing. However, it is critical to verify that the final product presents not only adequate technical properties but also that it does not pose negative impacts to the environment and human health during its use. This study investigates the environmental compatibility of the use of ceramic porcelain stoneware tiles manufactured with BA as partial replacement of traditional raw materials, with a particular focus on the leaching behavior of the tiles during their use, and also after crushing to simulate their characteristics at their end of life. To evaluate the latter aspect, compliance leaching tests were performed on crushed samples and compared with Italian End-of-Waste (EoW) thresholds for the use of construction and demolition waste as recycled aggregates. Whereas, to assess the environmental compatibility of the tiles during the utilization phase, a methodology based on the application of monolithic leaching tests to intact tiles, and the evaluation of the results through multi-scenario human health risk assessment and the analysis of the main mechanisms governing leaching at different stages, was employed. The results of the study indicate that the analyzed BA-based tiles showed no significant increase in the release of potential contaminants compared to traditional formulations and fully complied with End-of-Waste criteria. The results of the monolith tests used as input for site-specific risk assessment, simulating worst-case scenarios involving the potential contamination of the groundwater, indicated negligible risks to human health for both types of tiles, even considering very conservative assumptions. As for differences in the release mechanisms, tiles containing BA exhibited a shift toward depletion-controlled leaching and some differences in early element release compared to the ones with a traditional formulation.