This study investigated the characteristics of personal PM2.5 exposure among 109 participants residing in Seoul over a two-month period, from February 2024 to April 2024. The participants were categorized into four sub-populations, and personal exposure to PM2.5 was assessed using portable monitors, GPS, and time-activity diaries. To understand the time-activity patterns, the daily occupancy rate for different microenvironments was calculated. Additionally, daily PM2.5 exposure contribution and integrated exposure were quantified. A time series analysis was conducted to identify differences in time-activity patterns and PM2.5 exposure among the sub-populations. ANOVA analysis indicated statistically significant differences in PM2.5 concentrations across populations and microenvironments (p<0.05). However, post-hoc analysis revealed specific microenvironments within certain sub-populations where PM2.5 concentration differences were not significant (p>0.05). All sub-populations spent more than 90% of their time indoors, and the results for exposure contribution and integrated exposure indicated that the home, which had the highest occupancy rate, was the most significant contributor to PM2.5 exposure. This study is expected to serve as foundational data for future indoor air quality management and the development of personalized strategies for reducing PM2.5 exposure.

Recently, the importance of inflammation in carcinogenesis has been recognized and studied extensively. As a result, a clear correlation between inflammation and carcinogenesis has been well established in some types of cancers. Despite a high prevalence of chronic periodontitis, one of the most common inflammatory diseases in the general population, there are only a few reports on the role of chronic periodontitis in oral cancer progression. In this study, we aimed to investigate genetic changes in oral cancer cells induced by repetitive Porphryomonas gingivalis infections to mimic chronic periodontitis in a clinical setting. Cells of oral squamous cell carcinoma (OSCC), the most common type of oral cancer, and P. gingivalis 381 were used for the present study. ID1 and ID3 were mRNAs of higher expression in the P. gingivalis-infected group compared to the uninfected control. These mRNAs have been regarded as important modulators participating in cancer progression. Future studies will provide an insight into the roles of the molecules we identified in oral cancer progression. Outcomes from these studies will also shed light on the significance of chronic periodontitis induced by bacterial pathogen, such as P. gingivalis, in progression of oral cancer and relevant molecular mechanisms underlying altered cancer cell behaviors.

Cellular microenvironment is an essential issue for regulating epithelial characteristics through the alteration of intricate signaling pathways and intercellular communications in different cell types. Thus, microenvironment influences tumor initiation, progression, and metastasis. This study aimed to investigate the relationship between microenvironment and epithelial property in HPV16 E6/E7-immortalized human oral keratinocytes (IHOKs). To investigate characteristics of IHOK cultured in different media, two media were used, which included keratinocyte growth media (KGM), F-medium composed of 3:1 ratio of DMEM and F-12 (P media) supplemented with 10% FBS and 1% penicillin/streptomycin. Proliferative property and invasive and migratory activity were observed. As results, proliferating activities of IHOK in different culture condition were changed. Likewise, migratory and invasive activities were also different depending on media types. These results suggest that cellular microenvironment can affect modification of biological properties of epithelial cells.

Embryonic stem cell-preconditioned microenvironment is important for cancer cells properitities by change cell morphology and proliferation. This microenvironment induces cancer cell reprogramming and results in a change in cancer cell properties such as differentiation and migration. The cancer microenvironment affects cancer cell proliferation and growth. However, the mechanism has not been clarified yet. Using the ES-preconditioned 3-D microenvironment model, we provide evidence showing that the ES microenvironment inhibits proliferation and reduces oncogenic gene expression. But ES microenvironment has no effect on telomerase activity, cell viability, cellular senescence, and methylation on Oct4 promoter region. Furthermore, methylation of Nanog was increase on ES-preconditioned microenvironment and supports results that no difference on RNA expression levels. Taken together, these results demonstrated that in the ES-preconditioned 3-D microenvironment is a crucial role for cancer cell proliferation not senescence.

This study presents residential indoor and outdoor exposure concentrations distributions of volatile organic compounds (VOCs, benzene, toluene, xylene) and nitrogen dioxide (NO₂) in industrial area (case) and agricultural area (control) during 5 days. Concentrations of VOCs and NO₂ were measured with passive samplers in residential indoor and outdoor. Most of benzene, toluene and NO₂ mean concentrations in case area were higher than those in control area. Considering the indoor and outdoor ratios (I/O) were higher than 1, the residence might be have the sources of indoor air pollutants such as smoking and using of gas range. Residential indoor concentrations of benzene, toluene, and NO₂ with indoor smokers were higher than those and without indoor smokers. In conclusion, it is suggested that personal exposures to air pollutants might be affected by indoor sources as well as outdoor pollutants emitted from industrial complex, and indoor air quality and outdoor air quality should be simultaneously considered to reduce the personal exposure to air pollutants.

The information about time spent in microenvironments plays a critical role for an exposure assessment of the person concerned, considering the personal exposure relies on the characterization of activity patterns of the population at risk and human activities impact the timing, location, and level of personal pollutant exposure. The purposes of this paper were to present indoor time activity patterns of Korean from a population-based study and to determine individual factors of time spent in microenvironments. The population based study collected time activity pattern of about 32,000 Korean for two consecutive days. The mean times spent at home, other indoors, outdoors, and transportation in related to the whole sample of 19.025 people are 14.23hrs(59.3%), 6.80hrs(28.3%), 1.26hrs(5.2%), and 1.75hrs(7.3%) in weekday, respectively. Database provides information on how the proportion of persons in different locations changes by time of day in weekday. Here, we see that over 90% of respondents were in a residence from about 11 PM to 5 AM, and the largest proportions of respondents in offices, factories, schools and public buildings occur between 8 AM and 5 PM.