This study provides a comprehensive analysis of volatile organic compound (VOC) emissions in the context of 3D printing, a rapidly advancing technology that is transforming manufacturing processes. As the adoption of 3D printing grows, concerns regarding its potential impact on indoor air quality have emerged. This research addresses these concerns by investigating the risks associated with VOC emissions and proposing effective mitigation strategies. Using a robust methodology, filament and resin-based 3D printers were employed alongside VOC sampling equipment (Tenax tubes and personal pumps) to assess emissions. A detailed analysis of 49 VOCs revealed variable concentrations across different printing materials, with ethyl acetate being the dominant compound in resin printing and decanal in filament printing. While individual VOC levels were below 1% of occupational exposure limits, total VOC concentrations frequently exceeded the recommended indoor threshold of 200 µg/m³, particularly in resin-based processes. This raises concerns about the combined effects of multiple VOCs, some of which are known carcinogens. These findings underscore the need for further investigation into the cumulative health impacts of prolonged exposure to multiple VOCs. The study also emphasises the importance of accounting for both facility-specific conditions and material emissions to fully understand the environmental and health consequences of 3D printing. Preventative measures, such as enclosing 3D printers and equipping them with extraction systems, are recommended to safeguard user health.

The generation of CO₂ is an important element in assessing the environmental impact generated in a tunnel construction project, making this knowledge very useful for evaluating different alternatives. In this study, an analysis of the carbon footprint has been carried out, including the main elements during the construction phase of a tunnel employing a tunnel boring machine (TBM). The research proposes several options for an easy and quick calculation of CO₂ generation in a design phase. Its determination can be crucial for decision-making before and during the execution of any tunnel in the near future. The estimation models have been validated based on real case studies, defining the carbon footprint of each construction element. The proposed procedure can apply to any tunnel. However, it should be noted that it is an approximate analysis, and the limitations described in each section should be considered. The main CO₂ generator found in the construction process is the lining element; the percentage varies between 50% in tunnels with smaller diameters (4–5 m) and 75% for tunnels with larger diameters (9–10 m), followed by the auxiliary elements, 16%, and the operation of the tunnel boring machine itself, 11.2%, while the other parts remain in a range between 1.3 and 5.7%. This knowledge makes it possible to define the aspects on which efforts should be focussed to reduce the carbon footprint of the tunnel construction process.

Fused deposition modelling, or 3D printing, is an additive manufacturing technique that is quickly gaining popularity because of its ability to produce usable parts with several geometries. It provides multiple advantages in everyday life. However, the emerging risks of using 3D printers at home is an issue that needs to be addressed. It is estimated that a person spends, on average, 80-90% of their time inside a building, up to 60% of that time is at home. Therefore it is essential to control the pollutants in the indoor environment. This paper evaluated the Volatile Organic Compounds (VOCs) and nanoparticle emissions during 3D printing with the most common Poly-Lactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) materials. Real-time aerosol monitors were used to characterise particulate emission, and laboratory analysis was used to check the VOCs levels. During printing, an increase of VOCs and nanoparticles was observed. This increase was more significant during printing with ABS filaments than during printing with PLA filaments. The nanoparticles size emitted for the ABS filament was smaller than the particles emitted for the PLA filament. A carcinogen substance like benzene was found during printing. The pollutants levels observed may cause health problems, and it is recommended that printing be avoided without engineering controls in place, e.g. a good ventilation and extraction system.

The project SUBproducts4LIFE is a research project financed by the European Union within the framework of the LIFE programme which proposes to demonstrate innovative circular economy concepts by the reuse of industrial subproducts/waste (coal ash and gypsum from coal power plants, blast furnace slag and steelmaking slag from steel factories) for the remediation at a real scale of contaminated soils and brownfield areas related to Hg mining. The area it is developing includes the waste dumps and demolition waste of the metallurgical plant of the abandoned mercury mine La Soterraña in Asturias, Northern Spain. Before this restoration research project takes place, this paper aims to evaluate airborne mercury and arsenic levels in land strongly contaminated with arsenic and mercury. The goal is to evaluate the air quality and compare it with international literature under reference levels. The study sampled gaseous mercury with a high-resolution direct reading device (LUMEX RA-915) and arsenic and mercury particulates with an IOM sampler, Casella personal pump, analyzed in the laboratory, to ensure the Health and Safety of workers, visitors and pedestrians walking near the mine and near the villages. The study concludes that As and Hg levels in the air are below 1 μg/m³ for the general public and villages near the mine. For works in the rubble area in the mine, it is recommended that workers use personal protective equipment and control measures are used to keep arsenic and mercury levels as low as technically possible. Article Highlights: Gaseous Hg and airborne Hg and As particulates are measured in a strongly contaminated mercury mining and metallurgy site. High concentration of gaseous Hg is present in the strongly contaminated soils; therefore protective measures must be adopted for workers. Apart from an area with demolition rubble of a metallurgical plant, airborne Hg-As contamination is not harmful to workers or the general public.

The air quality in a hospital’s underground car park is a concern because diesel fumes from cars impact upon vulnerable people attending medical consultations. This research aims to quantify the potential health risk associated with a particular hospital car park. Particulate matter was evaluated in the area with direct reading devices for particle numbers and mass concentrations (CPC 3007, EEPS 3090, Trolex Air XD, Nanozen, and Grimm 1109). Elemental and total carbon concentrations were measured following the NIOSH 5040 method, while volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) were measured through laboratory analysis and Scanning Electron Microscopy and Energy Dispersive using X-Ray Analysis SEM-EDX microscopy. The nanoparticle levels reached over 80,000 nanoparticles/cm³ (double the German Institut für Arbeitsschutz (IFA) benchmark levels). Diesel particulate matter levels measured as elemental carbon were around 35% of the occupational limit, and from the 49 VOCs analyzed only 13 were detected in quantities below the 0.1% of the occupational limit, while levels of the 13 PAHs analyzed, were below the laboratory limit of quantification. The study concludes that particulate matter in the underground car park can easily exceed nanoparticles benchmark levels and could be harmful, mainly to vulnerable people. It is therefore recommended that they use the outdoor car park or minimize their time in the underground one.