Indoor air最新文献

Background: Exposure to pollutants such as particulate matter (PM) disrupts homeostasis. The effect of PM on autophagy, as an essential factor of homeostasis, has been confirmed in several studies, but there is no comprehensive and detailed review of the mechanism involved. In this systematic review, we aim to investigate the mechanism involved in PM-induced autophagy of humans, animals, and cell lines.

Method: PubMed, Google Scholar, and Web of Science were searched using MESH terms related to PM and autophagy. Eligibility criteria were experimental studies in which PM was exposed and autophagy markers were assessed. Microtubule-associated protein 1A/1B-light chain 3-II (LC3-II), Beclin 1, and Sequestosome 1 (p62) are three important markers in the autophagy assay.

Result: Initially, 5842 articles were identified, of which 94 studies focused on the role of PMs in autophagy. Given the differences in exposure, we classified studies according to their type, “in vivo” or “in vitro.” A review of various studies has shown that, regardless of the exposure method, short-term exposure to PMs induced autophagy in almost all studies. In contrast, long-term exposure and pathological conditions can inhibit autophagy or block the flow of autophagy.

Conclusion: In living organisms, from unicellular organisms to large animals, autophagy supports cellular homeostasis under various conditions, such as exposure to pollutants. Chronic exposure to components such as PM or diseases can affect homeostasis by inducing nonphysiological conditions such as inflammation, excessive ROS production, and ultimately inhibition of autophagy.

In managing the urban subsurface environment contaminated by chlorinated solvents, various criteria, including environmental quality standards and human health risks, should be considered as the basis for decision-making. Vapor intrusion, particularly in urban environments, can serve as a major pathway for human exposure to soil or groundwater contamination, leading to indoor air pollution and posing potential health risks. In this study, the vapor intrusion risk posed by chlorinated solvents was assessed at levels meeting the environmental quality standards in South Korea. The results indicated that the vapor intrusion risks exceeded the acceptable risk criteria by approximately two to four orders of magnitude. Despite variations in site conditions, the health risk remained a significant concern. The case studies demonstrated that health risks exceeding the acceptable risk criteria can occur at contaminated sites that do not exceed environmental quality standards. They also highlighted that contaminated site management decisions can vary depending on the applied criteria. This study focused on vapor intrusion; additional pathways may further increase the risk. The risk criteria appear more stringent than environmental quality standards. It is necessary to revise the environmental quality standards for chlorinated solvent contamination, especially concerning urban subsurface pollution, or to apply site-specific criteria. This underscores the need for a cautious and conservative approach in managing urban contaminated sites and suggests that vapor intrusion risk assessment can serve as an effective tool in environmental risk management.

In indoor offices, it is often difficult to ensure high air quality and thermal comfort. Common problems are low relative humidity and the need for cooling. Previous research has shown that indoor greening can contribute to keeping the relative humidity and temperature at an appropriate level. In order to quantify the contribution of transpiration to evapotranspiration of vertical greening systems, various tropical ornamental plants were characterized in this study with regard to their transpiration rate and stomatal conductance under different indoor climatic parameters. Light intensity (PAR) showed a positive and air temperature a negative correlation with transpiration rate and stomatal conductance, while the dependence on relative humidity and soil moisture was not significant. Furthermore, two vertical greening systems with Philodendron hederaceum ‘Brasil’ were investigated in a parallel room set-up, where one room contained the greening system and the other room served as a reference. The vertical greening systems showed an evapotranspiration rate in the range of 55 to almost 100 g m⁻² h⁻¹, which increased the relative humidity from 20%–40% in the reference room to 40%–60% during the 3-week measurements in March 2023. This improved the comfort in the rooms.

Background: Indoor air quality (IAQ) is regarded as a significant factor influencing older adults’ health, and opening windows for ventilation can help improve IAQ. This study revealed the relationship between indoor ventilation frequency (IVF) and instrumental activities of daily living (IADL) in Chinese older adults for the first time.

Methods: Data were obtained from cross-sectional data published in the 2017–2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS) database. A multifactor logistic regression model was used to analyze the association between IVF and IADL in Chinese people aged 65 and above, which was observed in different subgroups. Further propensity score matching (PSM) and three sensitivity analyses enhanced the robustness of the results.

Results: After adjusting for all covariates, moderate and high IVF was associated with 33.8% (OR = 0.662, 95% CI: 0.507–0.864) and 42.6% (OR = 0.574, 95% CI: 0.444–0.742) reduction in the risk of having an IADL disability, compared to the low one, respectively. Among the results, significant associations were found only between IVF in summer and winter and older adults’ risk of IADL disability. Subgroup analyses showed that the association between IVF and IADL was specific in different subgroup populations. The results of the interaction analyses indicated that drinking significantly modified the relationship between IVF and IADL disability (p for interaction < 0.05).

Conclusion: In this nationally representative sample analysis, a higher window opening frequency for indoor ventilation was statistically significantly associated with a decrease in IADL disability among Chinese older adults. These results provide an essential basis for relevant policy development and new health intervention strategies to lower older adults’ risk of disability.

Air pollution negatively impacts human health, with pollutants such as PM_2.5 linked to increased mortality, respiratory infections, lung disease, heart disease, and stroke. Recent trends, such as increased building airtightness and changes in occupant behavior during the COVID-19 pandemic, highlight the need for greater attention to indoor air quality (IAQ). Mechanical ventilation (MV) systems are commonly used to improve IAQ and occupant comfort, especially in airtight homes, yet their effectiveness in humid winter conditions remains underexplored. This study examined the impact of MV, specifically positive pressure ventilation (PPV) systems, on IAQ in eight single-family homes in northern New Zealand. Data were collected over 12 weeks in winter, with 6 weeks of monitoring before and after PPV installation. Additionally, the study period overlapped with varying COVID-19 lockdown levels, enabling an assessment of how increased occupancy influenced IAQ. The findings show that PPV system installation resulted in reductions over the winter period of 68% for particulate matter (PM) concentrations (both PM_2.5 and PM₁₀) and 9% in relative humidity (RH), with no significant changes in temperature. PM_2.5 concentrations increased by an average of 56% during the COVID lockdown, potentially resulting from increased occupancy levels.

Elementary school students, as primary users of classrooms, are directly affected by the lighting environment, which influences their visual comfort and cognitive performance. This study investigates the changes in cognitive performance under five classroom illumination levels to optimize lighting conditions. Cognitive performance was assessed by combining physiological measurements with a novel index: the ratio of correctness to reaction time. The results show gender-specific sensitivity to lighting, with female students being more responsive than males. By integrating subjective questionnaires and objective physiological indicators, the study identified an optimal desktop illuminance range of 600–800 lx for maximizing cognitive performance. These findings provide a practical approach for determining optimal classroom lighting based on both cognitive and physiological data.

Indoor levels of total volatile organic compounds (TVOCs) can influence students’ learning and productivity by affecting cognitive performance. To investigate whether TVOC affects cognitive performance in schools, especially in newly constructed or renovated buildings within the first 3 months, a single-blind experiment was conducted in a climate chamber. Then, 33 university students were exposed to three moderate TVOC concentrations: below 100, 1000, and 2000 μg/m³, all emitted by solvent-based paint. Ventilation (30 m³/h), temperature (22°C), relative humidity (50%), lighting, and noise levels were maintained at constant values for all exposure conditions. Cognitive performance was measured through reaction speed and accuracy using a computer-based test battery that included 10 randomized tasks; all participants completed the test three times. Participants’ perceptions of the environment were investigated through pretest and posttest questionnaires. The results indicate no statistically significant differences in reaction speed or accuracy were observed between exposure to medium–low (1000) and low (100 μg/m³) TVOC levels. Exposure to a medium–high level of TVOC (2000 μg/m³) significantly reduced task accuracy by 4.9% compared to the low level (100 μg/m³). No statistically significant effect on reaction speed was observed. Participants’ perceptions of air quality were rated significantly worse at both the 1000 and 2000 μg/m³ TVOC exposure levels compared to the low level. Overall, no significant differences in cognitive performance were observed between the medium–low and low TVOC exposure levels. Both accuracy in memory tasks and well-being were negatively affected when comparing the medium–high level to the low level of TVOC. These findings highlight the critical need for monitoring and controlling TVOC levels during the early stages of construction and renovation to improve indoor air quality. Future studies could investigate a broader range of VOC sources and incorporate additional strategy-based cognitive tasks.

Background: Recent studies have shown that indoor air pollutants (IAPs) affect air quality and cause respiratory issues, particularly allergic rhinitis (AR). This study investigated the association between exposure to IAPs and AR risks and symptoms.

Methods: We gathered data from 1864 individuals who responded to the 2022 Korea National Health and Nutrition Examination Survey, after excluding 116 individuals with missing data from the indoor air quality survey. Participants were categorized into AR and non-AR groups based on the history of AR. IAPs included particulate matter, carbon dioxide, formaldehyde, volatile organic compounds, benzene, toluene, ethylbenzene, xylene, styrene, and environmental tobacco smoke. Logistic regression determined the risk of AR according to a single IAP exposure level. Negative binomial regression was used to investigate the association between AR-related symptoms and number of highly exposed IAPs.

Results: The prevalence of AR was 6%. Exposure to several IAPs was higher in the AR group. The association between individual IAP and AR risk was not significant after adjusting for covariates. The odds ratios for the diagnosis, duration, and severity of AR increased with increasing numbers of exposure to high levels of IAPs.

Conclusions: There was no significant association with AR for each pollutant as a single exposure. However, the risk of AR-related symptoms significantly increased with the number of exposure to high levels of IAPs. These findings provide valuable insights for interventions to improve indoor air quality to mitigate the prevalence and severity of AR.

Indoor air quality (IAQ) plays a crucial role in safeguarding the health of both patients and healthcare workers in hospital environments. Accurate IAQ analysis and prediction are vital for optimizing ventilation, filtration, and other control measures to maintain a safe indoor atmosphere. This study investigates IAQ in hospital spaces by utilizing long-term data from internet of things (IoT) sensors installed in general wards and negative pressure isolation wards. Given the significant influence of outdoor air, IAQ requires continuous monitoring across different seasons and extended periods. In this study, IAQ was measured over nearly a year, capturing seasonal variations and long-term trends. Clustering algorithms were applied to identify complex patterns and detect anomalies in key IAQ parameters, including temperature, CO₂ concentration, and particulate matter 2.5 μm (PM_2.5). These clustering results were then integrated into a long short-term memory (LSTM) model to enhance IAQ prediction for subsequent time steps. The findings indicate that incorporating clustering results as input variables substantially improves IAQ prediction accuracy. Notably, the root mean squared error for PM_2.5 prediction decreased from 8.51 to 3.99 when clustering results were included. This study underscores the potential of leveraging IoT sensors and machine learning techniques for real-time IAQ monitoring and forecasting in hospital settings. These insights can support the development of effective control strategies to maintain a healthy and comfortable indoor environment for both patients and healthcare workers.

Background: Exposure to house dust endotoxins is known to cause diseases across various organ systems; however, their effect on mortality remains unclear.

Objective: This study is aimed at investigating the association between house dust endotoxins and mortality in US adults.

Methods: National Health and Nutrition Examination Survey data from 2005 to 2006 were used in this study. Participants were linked to mortality data from the date of the survey through December 31, 2019. A multivariate Cox regression analysis was used to determine the association between house dust endotoxins and mortality. All analyses were performed in the overall population and across different sensitization statuses.

Results: This cohort study included 3171 adults aged 20 years or older (weighted median age (P25–P75): 45 (32–58) years; 49.2% male). Among them, 1287 participants were sensitized to inhalant allergens. During a median follow-up of 13.8 years, 672 deaths occurred. In participants sensitized to inhalant allergens, house dust endotoxins were significantly associated with all-cause mortality. The hazard ratio (HR) comparing the highest and lowest tertiles of house dust endotoxin levels was 1.98 (95% confidence interval (CI): 1.32–2.97) for all-cause mortality. An association was observed between endotoxin concentration and cardiovascular disease mortality when analyzed as a continuous variable (HR: 1.29, 95% CI: 1.01–1.56). In nonsensitized participants, no significant association was found between house dust endotoxins and mortality.

Conclusion: Exposure to house dust endotoxins was associated with all-cause mortality in adults sensitized to inhalant allergens.