Search Results (1,071)

This paper proposes a complete solution, implementing a low-cost, energy-independent, network-connected, and scalable environmental air parameter monitoring system. It features a remote sensing module which provides environmental data to a cloud-based server and a software application for real-time and historical data processing, standardized air quality indices computations, and a comprehensive visualization of environmental parameters evolutions. A fully operational prototype was built around a low-cost micro-controller connected to low-cost air parameter sensors and a GSM modem, powered by a stand-alone renewable energy-based power supply. The associated software platform has been developed by using Microsoft Power Platform technologies. The collected data is transmitted from sensors to a remote server via the GSM modem using custom-built JSON structures. From there, data is extracted and forwarded to a database accessible to users through a dedicated application. The overall accuracy of the air quality monitoring system has been thoroughly validated both in controlled indoor environment and against a trusted outdoor air quality reference station. The proposed air parameters monitoring solution paves the way for future research actions, such as the classification of polluted sites or prediction of air parameter variations in the site of interest. Full article

Indoor air quality (IAQ) is a critical determinant of respiratory health and plays an essential role in asthma management. Exposure to indoor pollutants such as particulate matter (PM_2.5), volatile organic compounds (VOCs), and biological allergens can exacerbate asthma symptoms. This pilot quasi-experimental, one-group pretest–posttest study evaluated the combined effect of high-efficiency particulate air (HEPA) purifiers and tailored asthma education on the IAQ and asthma outcomes of 30 adults diagnosed with asthma. Indoor PM_2.5, total VOCs (tVOC), temperature, and relative humidity were monitored using low-cost air quality monitors across three home locations for 30 days, and participants completed baseline and follow-up assessments of asthma control (ACQ) and quality of life (AQLQ). The intervention reduced PM_2.5 concentrations from 21.32 µg/m³ to 18.19 µg/m³ (p < 0.001), while tVOC levels increased slightly from 237.05 ppb to 251.81 ppb (p = 0.02). The median ACQ scores improved from 1.17 to 0.50 (p < 0.001), the proportion of participants with well-controlled asthma (ACQ ≤ 0.75) rose from 30% to 66.7%, and the median AQLQ scores increased from 5.75 to 6.30 (p < 0.001). Participants in the intervention experienced significantly improved asthma control, quality of life, and indoor PM_2.5 levels, which underscores the significance of integrating environmental and educational strategies in adult asthma management. Full article

Low-concentration trichloroethylene (TCE) and tetrachloroethylene (PCE) indoors pose a significant threat to human health due to their potent carcinogenic properties. However, existing research has predominantly focused on high-concentration scenarios in industrial settings, offering limited guidance for indoor air purification. This study investigated the adsorption mechanisms and performance regulation of coconut shell activated carbon for TCE/PCE through experimental analysis, molecular simulations, and dynamic modeling. Experimental results demonstrated that PCE, characterized by its non-polar nature and high boiling point, exhibited a substantially higher adsorption capacity than TCE. Increased humidity induced competitive adsorption between water molecules and pollutants, reducing the adsorption capacity of PCE by approximately 30%. Molecular simulations validated that water molecules occupied the active sites of oxygen-containing functional groups and pores, impeding the diffusion of TCE/PCE, while the non-polar surface of activated carbon preferentially adsorbs PCE. A dynamic prediction model developed in this study accurately forecasted breakthrough curves under varying pollutant concentrations, temperatures, humidities, and air velocities and quantified the service life of activated carbon. Response surface methodology revealed that controlling inlet concentrations (TCE < 7 ppb, PCE < 30 ppb), air velocity (<1 m/s), humidity (<50%), and temperature (<25 °C) can extend the service life of activated carbon to 3–5 months. Full article

Indoor exposure to particulate matter (PM_2.5 and PM₁₀) remains a significant public health problem, especially in high-traffic areas, where outdoor pollution, building characteristics, and user activity jointly influence indoor air quality. This study aims to synthesise and compare the effectiveness of key technical solutions to reduce indoor PM concentrations in different types of buildings. A comprehensive review and comparative analysis of published experimental and field studies were conducted, covering residential, educational, office, medical, sports, and heritage buildings. The interventions evaluated included mechanical ventilation and filtration systems, portable HEPA air cleaners, integrated building envelope solutions, airflow optimisation strategies, and selected auxiliary technologies. Reported performance metrics such as baseline indoor and outdoor PM concentrations, air exchange rate (ACH), filter class, clean air delivery rate (CADR), and percentage reduction were systematically analysed. The results indicate that mechanical filtration, particularly high-efficiency HVAC (Heating Ventilation and Air-Conditioning) systems and HEPA filters, provide the most reliable and repeatable reductions in PM_2.5 and PM₁₀, especially under controlled airflow and recirculation conditions. Integrated approaches that combine airtight building envelopes, mechanical ventilation, and local air purification achieved the highest overall effectiveness. The findings confirm that successful PM mitigation requires context-specific multicomponent strategies tailored to building type, outdoor pollution load, occupancy, and ventilation design. Full article

Silver tarnishing in museum environments depends on multiple, interacting factors that are not often studied in situ. With the aim of addressing the problem in real-world scenarios, this study presents a one-year assessment at the National Archaeological Museum of Spain, in Madrid, a museum that houses a significant collection of silver objects. Pure Ag coupons were placed in four display cases—two designs with different airtightness—and in an adjacent gallery. Tarnishing was quantified by colorimetry, gravimetry, and galvanostatic reduction, and analyzed in relation to environmental parameters (T/RH) and gaseous pollutants (H₂S, SO₂, HF, HCl, formic and acetic acids), measured with passive samplers. Coupons showed different degrees of tarnish, with annual corrosion rates ranging from IC1 (very low) to IC2 (low), without a straightforward relation to hydrogen sulfide concentrations. Electrochemical profiles and XPS on representative coupons identified Ag₂S as the dominant product, with AgCl and minor Ag₂SO₄ in the coupons exposed outside the airtight cases, indicating different contributions inside and outside the cases. Findings highlight that sulfide concentration is not the sole driver; case airtightness, internal materials, cleaning products used on adjacent areas, and, possibly, other aspects influence silver tarnishing. Full article

Indoor air quality (IAQ) in high-rise residential buildings is an increasing concern, especially in hot and humid climates where prolonged indoor exposure elevates health risks. This study evaluates the performance of Fresh Air Handling Units (FAHUs) using two complementary approaches: (1) real-time sensor data to quantify IAQ conditions and (2) occupant survey responses to capture perceived comfort and pollution indicators. The results show that floor level did not predict satisfaction, even though AQI data revealed clear differences between flats, suggesting perceptions are driven more by sensory cues than by actual pollutant levels. Longer weekday exposure emerged as a stronger predictor of dissatisfaction. These gaps between perceived and measured IAQ highlight the need for improved ventilation scheduling and greater occupant awareness. FAHUs were found to be inefficient, consuming 21–26% of total building energy while lacking pollutant-specific monitoring capabilities. To address these issues, the study recommends the integration of IoT-enabled sensors for real-time pollutant detection, enhanced facade sealing to minimize external infiltration, and the upgrade of filtration systems with HEPA filters and UV purification. Additionally, AI-driven predictive maintenance and automated ventilation optimization through Building Management Systems (BMS) are suggested. These findings offer valuable insights for improving IAQ management in high-rise buildings, with future research focusing on AI-based predictive modeling for dynamic air quality control. Full article

Intelligent ventilation is positioned as a key axis for reconciling energy efficiency and indoor air quality (IAQ) in residential and non-residential buildings. This review synthesizes 51 recent publications covering control strategies (DCV, MPC, reinforcement learning), IoT architectures and sensor validation, energy recovery (HRV/ERV, anti-frost strategies, low-loss exchangers, PCM-air), active envelope solutions (thermochromic windows) and passive solutions (EAHE), as well as evaluation methodologies (uncertainty, LCA, LCC, digital twin) and smart readiness indicator (SRI) frameworks. Evidence shows ventilation energy savings of up to 60% without degrading IAQ when control is well-designed, but also possible overconsumption when poorly parameterized or contextualized. Performance uncertainty is strongly influenced by occupant emissions and pollutant sources (bioeffluents, formaldehyde, PM2.5). The integration of predictive control, scalable IoT networks, and robust energy recovery, together with life-cycle evaluation and uncertainty analysis, enables more reliable IAQ-energy balances. Gaps are identified in VOC exposure under DCV, robustness to sensor failures, generalization of ML/RL models, and standardization of ventilation effectiveness metrics in natural/mixed modes. Full article

Occupant interactions with built environments significantly influence indoor airflow patterns. Among these interactions, door openings are common, which affect airflow fields and contribute to the dispersion of airborne contaminants. The wakes originating from alterations in airflow patterns contribute to the transport of pollutants and must be carefully considered for system design in critical environments to avoid cross-contamination of susceptible bodies (e.g., patients, precision manufacturing, etc.). Therefore, knowledge about the movement patterns of these wakes is crucial in the context of indoor air quality. In this study, a series of experiments were conducted in a controlled chamber under two different schemes of a swing door opening and three different flow regimes to study the turbulent vortices produced from door openings and their spatiotemporal propagation. Additionally, an enhanced event-based modeling (EBM) approach was employed to develop a data-driven prediction of the transient indoor air patterns resulting from door-opening activities. The results suggest a significant effect of a door opening on indoor airflow fields. The velocity fields demonstrate that consecutive openings under different ventilation conditions have a prolonged impact on the propagation of door-opening-induced wakes farther into the test chamber. The quantification of the change in kinetic energy from the door opening also shows that the level of ventilation governs the flow patterns resulting from human-induced perturbation of the steady-state flow fields. The EBM approach effectively approximated the airflow patterns and demonstrated its potential to predict transient airflow disturbances caused by door operations. Full article

Accurate environmental monitoring in outdoor and indoor settings is critical for exposure assessment in environmental and public health research. Conventional methods, predominantly relying on high-end instruments or laboratory analyses, face limitations in real-world applications due to their high cost and inflexibility. Recent advances in low-cost sensor technologies have enabled more adaptable monitoring. This study systematically reviews research utilizing low-cost sensors for environmental monitoring in real-world settings across China. A literature search was performed using the Web of Science database, resulting in the inclusion of 43 eligible studies out of 31,003 initially identified records. These studies primarily investigated air pollution (17 studies), noise (14), light (7), and water pollution (5). Results reveal that air and noise pollution were the most extensively examined factors. Nevertheless, the reviewed studies exhibited notable shortcomings, including limited geographical/thematic coverage, inadequate reliability validation, small sample sizes (typically under 100 participants), and short durations (often under one month). This review discusses these challenges and suggests future research directions. By synthesizing current practices and identifying gaps, this work offers valuable insights to guide the design of future sensor-based environmental monitoring projects and inform the selection of suitable sensors. Full article

Ensuring good air quality in indoor environments of historical and artistic significance is essential not only for protecting valuable artworks but also for safeguarding human health. While many studies in this field tend to focus on the preservation of cultural heritage, fewer have addressed the impact on visitors and worshippers. Yet, places such as museums, galleries, churches, and other religious sites attract large numbers of people, making indoor air quality a key factor for their well-being. This study focused on evaluating air quality within the Santuario della Beata Vergine dei Miracoli in Saronno, Italy, a religious site that welcomes large numbers of visitors and worshippers each year. A detailed analysis of particulate matter was conducted, including chemical characterization by ICP-MS for metals, ion chromatography for water-soluble ions, and thermal–optical analysis for the carbonaceous fraction, as well as assessments of size distribution and radiometric properties. The results indicated overall good air quality conditions: concentrations of heavy metals were below levels of concern (<35 ng m⁻³), and gross alpha, beta, and ¹³⁷Cs activity concentrations remained below the minimum detectable thresholds. Hence, no significant health risks were identified. Full article

Indoor Air Quality (IAQ) is a major public health concern, as prolonged exposure to indoor environments can significantly affect users’ well-being. In this context, the research proposes a sampling protocol, developed in compliance with ISO 16000 principles, for the assessment of key chemical and physical parameters influencing air quality in inpatient rooms. These spaces host fragile users, while also requiring adequate protection for healthcare staff. Referring to the scope of the paper, the study outlines a comprehensive methodology for monitoring selected volatile organic compounds (VOCs) and microclimatic factors—temperature and relative humidity—using passive samplers and/or active sensors. The protocol also integrates outdoor measurements to better understand the contribution of internal emission sources. Monitoring activities are scheduled over one year, with regular sampling campaigns (at least one week per month) to analyze seasonal variations and long-term trends. The flexible structure of the protocol allows it to be adapted to different research objectives and types of healthcare facilities. Overall, the proposed approach provides a replicable framework for assessing IAQ in healthcare settings and identifying the main factors affecting indoor environmental performance. This supports improvements in both environmental quality and health protection within healing spaces. Full article

Coniferous species are known for their ability to purify air from particulate matter (PM), yet particulates accumulated during cultivation, transport, and outdoor storage may be transferred indoors. This study assesses the particulate load, subsequent retention, and further accumulation/release of PM by commercially available Christmas trees—Norway spruce (Picea abies (L.) H. Karst.) and Caucasian fir (Abies nordmanniana (Steven) Spach). Trees were examined in two commercial forms and maintained in six typical households (three with cut and potted P. abies, three with cut and potted A. nordmanianna) for 30 days. Measurements at four intervals included concentration dynamics of total PM, PM size fractions, as well as surface vs. in-wax PM ratios and epicuticular waxes on needles. Results showed that potted trees carried substantially higher initial PM loads than cut trees, with P. abies exceeding 200 µg·cm⁻², likely due to differences in production and handling. Potted P. abies and cut A. nordmanniana retained large PM fractions more effectively than cut P. abies. In contrast, the fine PM fraction, the most health-relevant, was best accumulated by cut P. abies. Wax-bound PM shares increased time in potted trees and decreased in the cut. Overall, the findings suggest that choosing a Christmas tree is not only an aesthetic preference but a decision with measurable implications for winter indoor air quality. Full article

Accurate prediction of urban air quality during fire events is frequently limited by the lack of experimentally validated source terms. Current pollution dispersion models often rely on idealized input parameters that fail to capture the complex thermal and chemical dynamics of real-world indoor fires. Addressing this gap, this study presents an experiment which reproduces an office-type fire using a wooden crib with a calibrated thermal load, enabling accurate determination of the HRR through the mass loss rate method. Temperature evolution was monitored with 27 thermocouples positioned across five vertical planes, while toxic gas concentrations were measured near the upper boundary of the exterior opening. The experimental data were used to calibrate and validate the numerical model, with HRR representing the primary parameter and temperature and toxic gas concentrations serving secondary validation metrics. Quantitative comparison showed good agreement between the experimental and simulated trends, with acceptable prediction errors and consistent reproduction of the dominant physical mechanisms governing fire development, ventilation-driven flow, and pollutant accumulation. Overall, the combined experimental–numerical approach provides a validated framework for future simulations on larger and more complex geometries, ensuring reliable input parameters for urban-scale fire scenarios. Full article

In recent decades, significant efforts have been devoted to constructing energy-efficient buildings, providing comfortable indoor environments. However, measures such as enhanced airtightness, while reducing infiltration through the building envelope, might consequently reduce natural ventilation. This reduction is a critical concern because natural ventilation is an essential factor in controlling indoor air quality (IAQ), and its diminution could therefore worsen IAQ. Sick building syndrome has emerged as a term used to describe health hazards linked to the time spent indoors but with no particular cause. Since people spend most of their time indoors, the demand for continuous and real-time IAQ management to reduce human exposure to pollutants has increased considerably. In this context, low-cost sensors (LCS) for IAQ monitoring have become popular, driven by recent technological advancements and increased awareness regarding indoor air pollution and its negative health impacts. Although LCS do not meet the performance requirements of reference and regulatory equipment, they provide informative measurements, offering high-resolution monitoring, emission source identification, exposure mitigation, real-time IAQ assessment, and energy efficiency management. This perspective article proposes a general model for LCS systems (and subsystems) implementation and presents a prospective analysis of their strengths and limitations for IAQ management, reviews the literature regarding sensor system technologies, and offers design recommendations. It provides valuable insights for researchers and practitioners in the field of IAQ and discusses future trends. Full article

The conservation of cultural heritage is highly influenced by environmental factors, including chemical and biological air quality and microclimatic conditions. Understanding their combined effects is essential for developing preventive conservation strategies. This study focuses on the indoor air quality in the King’s Apartment in the Royal Palace of Turin (Italy), a historic building lacking air-conditioning systems, where a multidisciplinary approach was applied to assess the conservation environment. Continuous monitoring of Total Volatile Organic Compounds (TVOC), particulate matter (PM_2.5 and PM₁₀), temperature and relative humidity was performed between March 2024 and July 2025 using portable sensors; aerobiological analyses were carried out through active and passive sampling, while volatile compounds were identified via SPME-GC/MS. Pollutants and biological monitoring revealed fluctuations influenced by microclimatic variations and spatial position. Notably, results showed that one room exhibited the highest levels of concern across all monitoring activities, representing the most vulnerable environment. The use of a multidisciplinary approach enabled a comprehensive understanding of the environmental conditions affecting the King’s Apartment, highlighting the relevance of collaboration in heritage science to guide evidence-based preventive conservation strategies. Full article