A Review of Field Measurement Studies on Thermal Comfort, Indoor Air Quality and Virus Risk

Chlorinated paraffins in multimedia during residential interior finishing: Occurrences, behavior, and health risk

Though with bioaccumulation and toxicity, chlorinated paraffins (CPs) are still high produced and widely utilized in various daily necessities for extender plasticization and flame retardation. CPs can be released during the reprocessing processes of finishing materials and distributed in multi-environmental media. Herein, concentrations and compositions of CPs in four representative media including interior finishing materials, PM10, total suspended particulate (TSP), and dust samples collected from eight interior finishing stages were studied. Unexpectedly, CP concentrations in ceramic tiles was found to be high with a mean value of 7.02 × 103 μg g-1, which could be attributed to the presence of CPs in the protective wax coated on ceramic tiles surfaces. Furthermore, the pollution characteristics of short-chain and medium-chain CPs (SCCPs and MCCPs) in those samples were inconsistent. According to the investigation regarding Kdust-TSP and [Formula: see text] , the occurrence and distribution of CPs in indoor atmospheric particles (PM10 and TSP) and dust were highly affected by reprocessing processes (cutting, hot melting, etc.) compared to that in the finishing materials. Moreover, dermal contact was the primary pathway of CP exposure for the occupational population (interior construction workers) for most interior finishing stages, and the interior finishing process is the prime CP exposure period for the occupational groups. As suggested by our assessment, though hardly posing an immediate health risk, CPs exposure still presents unneglected adverse health effects, which calls for adequate personal protections during interior finishing, especially in developing countries.

Dwelling in times of COVID-19: An analysis on habitability and environmental factors of Spanish housing

In the wake of the SARS-CoV-2 pandemic, promoted by the World Health Organization (WHO), governments urged people to stay at home. For this reason, practically all human activity took place inside the houses. The research question established if housing quality responded to people’s needs in the context of confinement. Specifically, the purpose was to taxonomize the dwelling stock occupied by confined households during the first COVID-19 wave in Spain, as well as to deepen in features and subjective perceptions on Indoor Environmental Quality (IEQ). As an exploratory study, an online questionnaire was disseminated in the Spring of 2020, obtaining 1,673 valid responses. A descriptive statistical analysis included sociodemographic, territorial and housing variables, related to indoor environmental quality, the availability of outdoor spaces, and the prospects for changes in. Also, a logistic regression stablished multivariate relations for the dependent variable “general dwelling satisfaction”. The results associated urban habitat, tenancy regime, higher incomes, and fewer cohabitants, with worse perceived IEQ, and lack of own outdoor space. Same variables showed relations with people’s desire for domestic changes. In conclusion, it is remarkable the determining role of housing design for dwellers’ satisfaction, especially in uncertain times like COVID-19 pandemic. This not only conditioned the different ways of inhabiting and occupying dwellings, but also the people’s capacity to face lockdown. The built environment, the habitat, and households’ circumstances also influenced. The latter did on people's perception of their experience, and how they lived and expressed it. Additionally, resilient building design and renovation opportunities were identified.

Data-Driven Prediction of COVID-19 Daily New Cases through a Hybrid Approach of Machine Learning Unsupervised and Deep Learning

Air pollution is associated with respiratory diseases and the transmission of infectious diseases. In this context, the association between meteorological factors and poor air quality possibly contributes to the transmission of COVID-19. Therefore, analyzing historical data of particulate matter (PM2.5, and PM10) and meteorological factors in indoor and outdoor environments to discover patterns that allow predicting future confirmed cases of COVID-19 is a challenge within a long pandemic. In this study, a hybrid approach based on machine learning and deep learning is proposed to predict confirmed cases of COVID-19. On the one hand, a clustering algorithm based on K-means allows the discovery of behavior patterns by forming groups with high cohesion. On the other hand, multivariate linear regression is implemented through a long short-term memory (LSTM) neural network, building a reliable predictive model in the training stage. The LSTM prediction model is evaluated through error metrics, achieving the highest performance and accuracy in predicting confirmed cases of COVID-19, using data of PM2.5 and PM10 concentrations and meteorological factors of the outdoor environment. The predictive model obtains a root-mean-square error (RMSE) of 0.0897, mean absolute error (MAE) of 0.0837, and mean absolute percentage error (MAPE) of 0.4229 in the testing stage. When using a dataset of PM2.5, PM10, and meteorological parameters collected inside 20 households from 27 May to 13 October 2021, the highest performance is obtained with an RMSE of 0.0892, MAE of 0.0592, and MAPE of 0.2061 in the testing stage. Moreover, in the validation stage, the predictive model obtains a very acceptable performance with values between 0.4152 and 3.9084 for RMSE, and a MAPE of less than 4.1%, using three different datasets with indoor environment values.

Study on the Influence of Fresh Air System of Range Hood on Kitchen Air Quality

In this paper, a combination of simulation and testing is used to quantitatively analyze the influence of a fresh air system of indoor range hood on kitchen air quality. The evaluation criteria of kitchen air quality are established based on the air age and air exchange efficiency. The results show that, when the fresh air system is switched to on from off, the indoor mean air age is reduced to 94.7 s from 468.6 s, and the air exchange efficiency is improved to 82.4% from 16.7%. The air quality is upgraded to fresh from moderate pollution. The presented simulation analysis process can provide a guideline for in-depth study of the kitchen air quality and quantitatively assess the kitchen fresh air system.

Assessment of indoor and outdoor air quality in primary schools of Cyprus during the COVID–19 pandemic measures in May–July 2021

Combined pollutant effects from indoor and outdoor sources on children's health, while being at school have not been holistically tackled. The aim of the School Temperature and Environmental Pollutants Study (STEPS) was to perform a school population representative assessment of indoor air quality (IAQ) in primary schools of densely and intermediate populated areas of Cyprus (n = 42). The study took place during May–July 2021 when a school-specific COVID-19 protocol was in place. Questionnaire-based characteristics of schools/classrooms were collected along with 24/48-h long IAQ monitoring of air temperature, relative humidity (RH), particulate matter (PM), carbon dioxide (CO₂) and volatile organic compounds (VOCs), using low-cost sensors. Mixed effect models assessed the IAQ determinants during school hours. Indoor PM, temperature, RH and VOCs increased with progressing school periods in the day, while indoor CO₂ decreased. Indoor RH and CO₂ were negatively associated with % open windows, while indoor PM_2.5 was positively associated. Most of school time (85%), indoor air temperature exceeded the recommended upper limit (27 °C), while a third of indoor PM_2.5 (24-h) measurements exceeded 15 μg/m³. The interplay of clean indoor air with adequate ventilation and adaptation to heat stress in schools is important and its comprehensive characterization requires holistic methodological approaches and tools.

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A primary school population representative study of indoor air quality was conducted in Cyprus during May-July 2021.

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Natural ventilation measures, like open windows and doors during class hours, helped in maintaining adequate ventilation.

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The study took place during the summer period with indoor air temperature being above the recommended value most of school time.

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A third of the 24-hour indoor PM_2.5 measurements exceeded the WHO recommended value.