Indoor air最新文献

Radon, a naturally occurring radioactive gas, can pose significant health risks when it accumulates indoors. Despite the potential dangers, developing policy countries such as Ghana lack both legislation and a national average for radon levels in homes and workplaces. In contrast, Italy has implemented the European Directive EURATOM/59 through D.Lgs 101, establishing clear guidelines for radon monitoring and mitigation. This paper examines the differences in knowledge and awareness of radon gas risks between Italy and Ghana through a propensity score matched analysis of a survey. It is aimed at describing the current state of knowledge about radon, assessing awareness levels, and discussing the importance of addressing radon risks in Italy and Ghana. Key results after matching showed that Ghanaians reported more frequently that their house was not at risk (74% vs. 54%, p = 0.037) but were more extremely worried than Italians (13% vs. 2%, p < 0.001), answering that radon health risks were completely unacceptable (38% vs. 23%, p < 0.001). Findings also revealed that the Ghanaian population demonstrates a higher level of trust in their authorities (28% vs. 16% in the overall cohort and 29% vs. 21% in student subcohorts Ghanaian vs. Italian, respectively). Results on the matched subcohorts of undergraduates confirm that Ghanaian students are significantly more worried than Italian students about radon risks (averagely worried or higher 58% vs. 28%, p = 0.013) and deem radon risk less acceptable (unacceptable or lower 70% vs. 60%, p = 0.046).

Upward migration of vapors from subsurface contamination into overlying buildings is known as vapor intrusion (VI) and can result in exposure of the building’s inhabitants to contaminants that can cause detrimental health effects. Multiple lines of evidence (MLEs), such as groundwater, soil, soil gas, and indoor air volatile organic compound (VOC) concentrations, are used to evaluate a building for VI and potential risk of occupant exposure. Background sources of contaminants contained within a building can result in a false positive determination of VI and installation of mitigation systems that are not needed. To avoid a false positive determination, some VI guidance documents recommend the prioritization of subslab soil gas (SSSG) concentrations over indoor air concentrations for determination of a VI issue. If the SSSG VOC concentrations are above a determined concentration, then VI is assumed to be possible; depending upon the concentration, immediate mitigation may be required. The major challenge to characterizing VI potential is the number of samples needed to confidently assess VI exposures due to the extreme variability in vapor concentrations across both time and space, and this study explores variability in SSSG and how many SSSG samples are needed. To address this issue, SSSG samples were collected between December 2020 and April 2022 from six commercial buildings in Fairbanks, Alaska, and between May 2019 and June 2021 from a large, compartmentalized warehouse at a coastal site in Virginia. Types of samples collected included indoor air; outdoor air; SSSG; soil gas; radon; differential pressure; indoor and outdoor temperature; heating, ventilation, and air conditioning (HVAC) parameters; and other environmental factors. To illustrate how these results can inform estimates of expected SSSG variability and thus the number of samples required to characterize variability, the temporal and spatial variabilities of the results observed at the test sites were used as a “similar population” to estimate necessary sample sizes for characterization of VI levels and to explore how temporal and spatial factors may influence estimates. The estimated SSSG sample requirement ranged from 1 to 80 samples and thus showed the substantial sensitivity of the systematic project planning equation to cases in which the action level and the average concentration are similar. We recommend that the estimated number of samples generated from the collected data for the buildings should only be used as a starting point for planning purposes. The number of SSSG samples to initially collect at a large building to characterize VI can be calculated, but the actual number should include adjustments for features of a building (e.g., past usage, separate foundations, and footers) and conditions at a site (e.g., proximity to source and depth to groundwater) that may alter the required number of SSSG samples.

High sleep quality is essential for people’s health. Numerous studies have investigated the relationship between indoor environmental quality and sleep quality, and the thermal environment, in particular, has been shown to have a significant effect on sleep quality. However, most of these studies measured the thermal environment of the bedroom for only short periods of time. Although seasonal variations and individual differences in sleep quality have been reported, most studies on the thermal environment and sleep quality have not adequately taken these factors into account. Therefore, the present study measured bedroom temperature and sleep quality objectively without intervention for 1 year and mathematically modeled the annual variation in bedroom temperature and sleep efficiency using a simplified sine function. This mathematical model was able to quantitatively characterize individual differences in the annual variation of bedroom temperature and sleep efficiency. The amplitude and phase of the sine function indicate the annual variation range of sleep efficiency and the degree to which sleep efficiency decreases in summer or winter. The mathematical model was also able to identify bedroom temperatures that optimize sleep efficiency. Analysis of each participant’s annual bedroom temperature and sleep efficiency revealed that sleep efficiency was high in the spring and fall when temperatures were moderate for all participants, while sleep efficiency decreased during the summer and winter and that there were individual differences in terms of whether sleep efficiency decreased more during the summer or winter. Furthermore, there were differences in the bedroom temperature that optimized sleep efficiency for each individual, and the vulnerability of sleep efficiency to fluctuations in bedroom temperature also differed for each individual. By utilizing the developed mathematical model, the bedroom temperature could be individually controlled to enhance sleep efficiency, thereby impacting health and performance.

Household air pollution from solid fuels (HAPSF) is a significant contributor to chronic obstructive pulmonary disease (COPD). Using the Global Burden of Disease (GBD) 2021, this study focuses on the burden of COPD caused by HAPSF in high-risk individuals aged ≥ 55 years, aimed at filling the research gap concerning exposure risk in the elderly population. From 1990 to 2021, the age standardized disability-adjusted life year (DALY) rate for COPD due to HAPSF declined across all five sociodemographic index (SDI) regions, with the most pronounced reduction in high SDI areas (AAPC: −14.5%). The age–period–cohort (APC) model revealed distinct trends: net drift showed a continuous decline in most regions except low SDI areas, where DALY rates increased significantly after age 75. In addition, the APC model also reveals sex and inequality issues: the risk ratio of men in the middle SDI region is always higher than that of women, whereas the risk of men in all other SDI regions is lower. Decomposition analysis revealed that epidemiological shifts—primarily reduced HAPSF exposure due to cleaner energy transitions, improved healthcare access, and public health interventions—were the key drivers of declining DALYs (316.35%), outweighing pressures from population growth and aging. Frontier analysis highlighted countries such as Samoa, Pakistan, and India as underperformers relative to their SDI levels, signaling an urgent need for targeted policies. Projections using the Nordpred model suggest a continued decline in DALYs from 2022 to 2044, underscoring the potential for sustained progress. This study provides key insights into reducing the global burden of COPD caused by HAPSF, emphasizing a comprehensive strategy to address socioeconomic and sex issues to achieve health equity.

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.