COVID-19 hospital indoor environments and how it helped patients' recovery and staff's work: a case study in South Korea.

The indoor environment has been recognized as a crucial factor that can influence health and wellbeing of occupants. This is particularly true in hospital settings, where various environmental attributes can significantly affect patients' recovery and staff members' productivity. The present study aimed to investigate how occupants in hospitals perceived indoor environment, focusing specifically on COVID-19 hospitals across Republic of Korea. The study recruited two groups of participants: patients (n = 100) who had been hospitalized in COVID-19 hospitals and staff members (n = 103) who worked in COVID-19 hospitals. The data collected from the participants were analyzed using multiple regression models to determine which environmental attributes significantly affected their perception of the indoor environment. The study revealed that satisfaction with indoor acoustic environment and odor were significant predictors for how patients perceived the indoor environment as helpful for their recovery from COVID-19. On the other hand, odor was also the significant factor affecting staff members' perceived helpfulness for work. The results suggested that different environmental attributes can have a significant impact on the perception of the indoor environment, depending on the characteristics of occupancy. The study's findings provided insights into the certain environmental factors that COVID-19 hospitals can prioritize. These insights can help policymakers and hospital administrators to develop strategies to create hospital environments that meet the needs of both groups. The study also suggested that further research is needed to investigate additional factors affecting occupants' perception of the indoor environment in hospital settings.

Relationship between indoor noise perception and remote work during the COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has had a major influence on working patterns worldwide, given the various lockdown periods and the shift to remote working. As people's noise perception is known to be closely linked with their work performance and job satisfaction, investigating the noise perception in indoor spaces, especially in situations where people work from home, is crucial; however, studies on this aspect are limited. Thus, here, this study aimed to investigate the relationship between indoor noise perception and remote work during the pandemic. The study assessed how people who worked from home perceived indoor noise, and how it related with their work performance and job satisfaction. A social survey was conducted with respondents who worked from home during the pandemic in South Korea. A total of 1,093 valid responses were used for data analysis. Structural equation modeling was used as a multivariate data analysis method to simultaneously estimate multiple and interrelated relationships. The results showed that indoor noise disturbance significantly affected annoyance and work performance. Annoyance with indoor noise affected job satisfaction. Job satisfaction was found to have a significant impact on work performance, particularly on two dimensions of the work performance that are crucial for achieving organizations' goals. Moreover, one dimension of the work performance had a significant impact on annoyance. The study proposed that reducing negative perception of indoor noise and improvement of job satisfaction can lead to the maximization of one's work performance when working from home.

Time-Dependent Serial Changes of Antigen-Presenting Cell Subsets in the Ocular Surface Are Distinct between Corneal Sterile Inflammation and Allosensitization in a Murine Model.

The kinetics of antigen-presenting cells (APCs) vary depending on their resident tissues and the manner of immunization. We investigated the long-term changes in mature APC and T-cell subsets over 4 weeks in the ocular surface in murine models of corneal quiescent or potent sterile inflammation, and allosensitization using partial (PT), syngeneic (Syn), and allogeneic (Allo) corneal transplantation. In PT, CD11bintCD11chiMHCIIhiCD86hi cells increased until 4 weeks with an increase in IFNγhi T cells. In Syn, both CD11bintCD11chiMHCIIhiCD86hi and CD11bhiCD11chiMHCIIhiCD86hi APC subsets increased until 4 weeks with a brief increase in CD69hi T cells at 2 weeks. In Allo, CD11bintCD11chiMHCIIhiCD86hi and CD11bhiCD11chiMHCIIhiCD86hi APC subsets increased until 4 weeks, and an early increase in CD69hi T cells was observed at 2 weeks followed by a late increase in IFNγhi T cells at 4 weeks. The frequency of the IFNγhi T cell subset was positively correlated with the frequency of the CD11bintCD11chiMHCIIhiCD86hi subset, indicating the existence of APC-T cell interaction in the ocular surface. Together, the results indicate that allosensitization in mature APCs leads to T-cell activation in the ocular surface, whereas sterile inflammation merely induces a brief and non-specific T-cell activation in the ocular surface.

Inter-floor noise classification using convolutional neural network.

In apartment houses, noise between floors can disturb pleasant living environments and cause disputes between neighbors. As a means of resolving disputes caused by inter-floor noise, noises are recorded for 24 hours in a household to verify whether the inter-floor noise exceeded the legal standards. If the noise exceeds the legal standards, the recorded sound is listened to, and it is checked whether the noise comes from neighboring households. When done manually, this process requires time and is costly, and there is a problem of whether the listener's judgments of the sound source are consistent. This study aims to classify inter-floor noise according to noise sources by using a convolutional neural network model. A total of 1,515 sound sources of data recorded for 24 h from three households were annotated, and 40 4s audio clips of six noise sources, including "Footsteps," "Dragging furniture," "Hammering," "Instant impact (dropping a heavy item)," "Vacuum cleaner," and "Public announcement system" were identified. Moreover, datasets of 16 classes using ESC50's urban sound category audio were used to distinguish the inter-floor noise heard indoors from the external noise. Although DenseNet, ResNet, Inception, and EfficientNet are models that use images as their domains, they showed an accuracy of 91.43-95.27% when classifying the inter-floor noise dataset. Among the reviewed models, ResNet showed an accuracy of 95.27±2.30% as well as a highest performance level in the F1 score, precision, and recall metrics. Additionally, ResNet showed the shortest inference time. This paper concludes by suggesting that the present findings can be extended in future research for monitoring acoustic elements of indoor soundscape.

Animal and Plant Protein Intake and Body Mass Index and Waist Circumference in a Korean Elderly Population.

Controversy exists on whether animal and plant proteins influence obesity differently. The purpose of this study was to evaluate the association between total, animal, and plant protein intake with the body mass index (BMI), waist circumference (WC), and renal function in the Korean elderly. Study participants included Korean adults aged 60 years or older from the Korean National Health and Nutrition Examination Survey in 2013⁻2014. Height, weight, and waist circumference were measured and the body mass index was calculated. One-day 24-hour recall data were used to estimate daily total, animal, and plant protein intake. Glomerular filtration rate (GFR) was calculated by using the Modification of Diet in Renal Disease (MDRD) equation. General linear modellings were used to assess the relationships between protein intake, BMI and WC. The mean age was 69.2 ± 0.2 years and 44.2% were male. The total daily protein intake was 1.1 ± 0.02 g/kg/day and 0.9 ± 0.02 g/kg/day for males and females, respectively. Only one third of protein intake was from animal sources. In males, BMI (regression coefficient (95% CI); −1.30 (−1.55, −1.06), p < 0.001; −0.29 (−0.52, −0.05), p = 0.016; −1.30 (−1.8, −1.02), p < 0.001, respectively) and WC (−3.87 (−4.58, −3.16), p < 0.001; −0.90 (−1.58, −0.22), p = 0.010; −3.88 (−4.68, −3.08), p < 0.001, respectively) decreased as daily intake of plant protein (g/kg/day), animal protein (g/kg/day) and total protein (g/kg/day) increased. Similar associations were shown in Korean females. GFR was not associated with protein intake regardless of protein source in both sexes. In Korean adults aged 60 years or older, the protein intake was associated with a favorable obesity index without decrease in renal function. The effect was similar in both males and females, with both animal and plant proteins.

The Mediating Role of Parental Support in the Relationship between Life Stress and Suicidal Ideation among Middle School Students.

BACKGROUND: Youth suicide is increasingly being recognized as a major social problem in South Korea. In this study, we aimed to explore the effects of parental support on the relationship between life stress and suicidal ideation among middle-school students. METHODS: This study analyzed data from a cross-sectional study on mental health conducted by the South Korea National Youth Policy Institute between May and July of 2013. Questionnaire responses from 3,007 middle-school students regarding stress factors, thoughts of suicide during the past year, and parental support were analyzed in terms of 3 subscale elements: emotional, academic, and financial support. RESULTS: Among the participants, 234 male students (7.8%) and 476 female students (15.8%) reported experiencing suicidal ideation in the past year. Life stress significantly influenced suicidal ideation (P<0.001), and parental support and all of the subscale elements had a significant influence on decreasing suicidal ideation. As shown in model 1, life stress increased suicidal ideation (adjusted odds ratio [aOR], 1.318; P<0.001), and, in model 2, the effect of life stress on suicidal ideation decreased with parental support (aOR, 1.238; P<0.001). CONCLUSION: Parental support was independently related to a decrease in suicidal ideation, and life stress was independently related to an increase in suicidal ideation. Parental support buffered the relationship between life stress and suicidal ideation.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity and Metabolic Syndrome among Korean Children and Adolescents: Korea National Health and Nutrition Examination Survey, 2010-2014.

The aims of this study were to assess the diagnostic value of the weight-to-height ratio (WHtR) for the detection of obesity and metabolic syndrome (MS) in Korean children and adolescents, and to determine the advantages of WHtR as a population-based screening tool in comparison with other obesity indicators, such as body mass index (BMI) and waist circumference (WC). We performed a cross-sectional analysis of data from 3057 children and adolescents (1625 boys, 1332 girls) aged 10-19 years who were included in the fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2012) up to the second year of the sixth KNHANES (2013-2014). Receiver operation characteristic (ROC) curves were generated to determine the optimal cutoff value and accuracy of WHtR for predicting individual obesity indicators or more than two non-WC components of MS. The area under the ROC curve (AUC) is a measure of the diagnostic power of a test. A perfect test will have an AUC of 1.0, and an AUC equal to 0.5 means that the test performs no better than chance. The optimal WHtR cutoff for the evaluation of general obesity and central obesity was 0.50 in boys and 0.47-0.48 in girls, and the AUC was 0.9. Regarding the assessment of each MS risk factor, the optimal WHtR cutoff was 0.43-0.50 in boys and 0.43-0.49 in girls, and these cutoffs were statistically significant only for the detection of high triglyceride and low High-density lipoprotein (HDL) cholesterol levels. When a pairwise comparison of the AUCs was conducted between WHtR and BMI/WC percentiles to quantify the differences in power for MS screening, the WHtR AUC values (boys, 0.691; girls, 0.684) were higher than those of other indices; however, these differences were not statistically significant (boys, p = 0.467; girls, p = 0.51). The WHtR cutoff value was 0.44 (sensitivity, 67.7%; specificity, 64.6%) for boys and 0.43 (sensitivity, 66.4%; specificity, 66.9%) for girls. There was no significant difference between the diagnostic power of WHtR and that of BMI/WC when screening for MS. Although the use of WHtR was not superior, WHtR is still useful as a screening tool for metabolic problems related to obesity because of its convenience.

Is Health Literacy Associated With Depressive Symptoms Among Korean Adults? Implications for Mental Health Nursing.

OBJECTIVE: This study investigated whether health literacy is associated with depressive symptoms among Korean adults, when adjusting for relevant risk factors for depression. METHODS: Data were collected from a sample of 585 community-dwelling Korean adults living in Seoul and Kwangju, South Korea, using a quota sampling strategy. A cross-sectional, multivariate regression analysis was used to investigate the association between health literacy and depressive symptoms. RESULTS: When controlled for covariates, a lower level of health literacy was significantly associated with a higher level of depressive symptoms. CONCLUSION: Health literacy may play an important role in preventing and treating depression. Future research is needed to determine if improving health literacy, through health promotion interventions, can enhance community-dwelling Korean adults' understanding of depressive symptoms and relevant treatment options.

Having a usual source of care and its associated factors in Korean adults: a cross-sectional study of the 2012 Korea Health Panel Survey.

BACKGROUND: Usual source of care (USC) is one of the hallmarks of primary care. We aimed to examine the status of having a USC and its patient-related sociodemographic factors among Korean adults. METHODS: Data were obtained from the 2012 Korea Health Panel survey. Panel participants were selected for the study who were aged 18 years or older and who replied to questionnaire items on having a USC (n = 11,935). RESULTS: Of the participants, 21.5% had a usual place and 13.9% had a usual physician. Reasons for not having a USC were seldom being ill (66.1%), the preference to visit multiple medical institutions (27.9%), and others. The private community clinic was the most common type of usual place (57.0%). In patient-reported attributes of care provided by a usual physician, the percentages of positive responses for comprehensiveness and coordination were 67.2% and 34.5%, respectively. By institution type, primary care clinics showed the lowest percentage (32.8%) of positive responses for coordination. Adjusted odds ratios of having a usual physician were 3.77 (95% confidence interval, CI: 3.75-3.79) for those aged 65 years or older (vs. aged 18-34 years), 1.31 (CI: 1.30-1.31) for females (vs. males), 0.72 (CI: 0.72-0.73) for unmarried people (vs. married), 1.16 (CI: 1.16-1.16) for college graduates or higher (vs. elementary school graduate or less), 0.64 for the fifth quintile (vs. the first quintile) by household income, 1.53 (CI: 1.52-1.54) for Medical Aid (vs. employee health insurance) for type of health insurance, and 4.09 (CI: 4.08-4.10) for presence (vs. absence) of a chronic diseases. CONCLUSIONS: The proportion of Korean adults who have a USC is extremely low, the most influential factor of having a USC is having a chronic disease or not, and Korean patients experience much poorer health care coordination than do patients in other industrialized countries. The findings of this study will give insight to researchers and policy makers regarding the potential facilitators of and barriers to promoting having a USC in the general Korean public.

Inflammatory masses on boy's scalp.

The fact that our 8-year-old patient's brother and sister also complained of similar papules helped us make the diagnosis.

Association between cigarette smoking history and mortality in 36,446 health examinees in Korea.

BACKGROUND: It is well known that smoking is a preventable factor for all-cause mortality; however, it is still questionable how many years after smoking cessation that people will have reduced risk for mortality, in particular in those with a high interest in their own health. We aimed to examine the association between time since quitting smoking and total mortality among past-smokers relative to current smokers. MATERIALS AND METHODS: We enrolled 36,446 health examinees that voluntarily taken with diverse health check-up packages of high cost burden in 1995-2003 and followed them till death by 2004. The history of cigarette smoking consumption was collected using a self-administrative questionnaire at the first visit time. Mortality risk by smoking cessation years was analyzed using Cox's proportional hazard model. RESULTS: Compared to non-smokers, male smokers over 15 pack-years had higher risk for total mortality (HR=1.49, 95%CI 1.02-2.18). The mortality risk in female smokers with same pack-years was more pronounced than that in male smokers (HR=2.83, 95%CI 1.17-7.04) despite a small number of cases. Compared to current smokers, a decrease of total mortality was observed among those who ceased smoking, and inverse dose-response was found with years after cessation: RR 0.98 (95%CI, 0.64-1.41) (<2 yrs), 0.60 (95%CI, 0.43-0.83) (3-9 yrs), and 0.58 (95%CI, 0.43-0.79) (≥10 yrs). CONCLUSIONS: A reduced risk of total mortality was observed after 3 years of smoking cessation. Our findings suggest that at least 3 years of smoking cessation may contribute to reduce premature mortality among Asian men.

Miller Fisher syndrome related to Orientia tsutsugamushi infection.

Miller Fisher syndrome is typically associated with a preceding infection, especially with Campylobacter jejuni. We describe a patient with Miller Fisher syndrome following Orientia tsutsugamushi infection, which to our knowledge has not been previously reported.

The cutoff value of waist circumference for predicting metabolic risks in pre- and post-menopausal korean women: analysis of 2010 korean national health and nutrition examination survey data.

BACKGROUND: With metabolic syndrome (MS) being a major risk factor for cardiovascular disease, and central obesity being a major predisposing factor for MS, intensive research is currently being performed on cutoff values according to race and sex. Menopause is an especially significant factor in designating cutoff values for female central obesity, as menopause brings sudden bodily changes that induce central obesity and increased prevalence of MS. Therefore this study aimed to investigate the cutoff values for the obesity index and its validity in predicting the criteria for MS in Korean women according to menstrual status. METHODS: The study focused on 3,103 women 20 years of age or older participating in the 2007 Korea National Health and Nutrition Examination Survey. Definitions of non-adipose components of MS were defined by the International Diabetes Federation, and menstrual status was judged on the basis of survey results. The sensitivity, specificity, and positive and negative predictive values of the central obesity index (body mass index [BMI], waist circumference [WC], waist-to-height ratio [WHtR]) according to menstrual status for two or more non-adipose components of MS were calculated based on the Youden index. RESULTS: Area under the curve (AUC) values predicting the presence of two or more metabolic risk factors were higher in pre-menopausal women, with AUC values for BMI, WC, and WHtR being, in pre- and post-menopausal women, 23.1 kg/m(2) vs. 23.9 kg/m(2), 76.1 cm vs. 82.5 cm, and 0.49 vs. 0.53, respectively. The WC cut off (76 cm) for pre-menopausal women was found to be more sensitive and more effective at screening for MS risks than the cutoff value given by the Korea Society for the Study of Obesity. CONCLUSION: The central obesity index showed better predictability for MS risk in pre-menopausal women. Because the central obesity index cutoff values are lower in pre-menopausal women, the possibility of metabolic risk can be considered for pre-menopausal women with WC lower than 85 cm. Assessment and control of other risks are needed accordingly for preventing the development of MS.

Higher quality primary care is associated with good self-rated health status.

OBJECTIVE: To ascertain the association between primary care quality and self-rated health status. METHODS: A cross-sectional study using the Korean primary care assessment tool (K-PCAT). The K-PCAT is a validated tool based on the definition of primary care in Korea, consisting of 5 domains and 21 items providing a total primary care quality score. Data were collected from patients of family physicians working at nine private clinics as their usual source of care. The main outcome measure was self-rated health status. RESULTS: Data were analyzed for 531 study participants. Bivariate analysis of socio-demographic variables of patients, who participated in this study as primary care quality assessors, revealed that those with high self-ratings of health tended to have higher household incomes and more frequent exercise. Those with high self-ratings of health had higher total primary care scores than those with low self-ratings of health, as determined through bivariate analysis (P < 0.01). After being adjusted for age, sex, the number of diseases being treated, education years, household income, smoking status, alcohol intake and the frequency of regular exercise, the total primary care score was found to be positively associated with good health. CONCLUSIONS: Primary care quality, as assessed by the K-PCAT, was positively associated with good self-rated health status.

New diagnostic criteria for obesity and overweight in Korean children and adolescents using 2007 Korean National Growth Charts.

The diagnostic criteria (KCDC Criteria) to define obesity and overweight of Korean children and adolescents were newly presented in the 2007 Korean National Growth Charts. The KCDC Criteria were criticized for several problems caused by upward shift of body mass index (BMI) percentile curves of the growth charts. This study was conducted to establish new diagnostic criteria (New Criteria) for obesity and overweight in Korean children and adolescents that would be less affected by a change of BMI distribution in the reference population of the Growth Charts. The BMI values for ages 2-18 years corresponding to Asia-Pacific adult BMI cutoffs of obesity (25.0 kg/m(2)) and overweight (23.0 kg/m(2)) were calculated with L, M and S values presented in the 2007 Korean National Growth Charts. Additionally, we examined the frequencies of obesity and overweight among children and adolescents who participated in the 2005 National Growth Survey based on both New Criteria and KCDC Criteria. The Z-scores corresponding to BMIs of 25 and 23 kg/m(2) at 18-years-of-age were 0.99 and 0.41 in boys, and 1.34 and 0.71 in girls, respectively. The BMI values corresponding to these Z-scores from age 2 to 18 years were determined as new BMI cutoffs for obesity and overweight. The frequencies of obesity and overweight estimated by New Criteria were greater by 2 times in boys and 1.5 times in girls than those by KCDC Criteria. We suggest that New Criteria could be a good alternative that can resolve problems caused by upward shift of BMI percentile curves of the 2007 Korean National Growth Charts.

Socioeconomic Indicators Associated with Initiation and Cessation of Smoking among Women in Seoul.

BACKGROUND: While smoking prevalence in Korean men has been decreasing, it is increasing in Korean women. Little is known about women's smoking inequalities in Korea. This study was conducted to investigate the association of socioeconomic indicators with the initiation and cessation of smoking among Korean women. METHODS: This was a cross-sectional study on 9,089 women aged 25-64 years from the 2008 Seoul Community Health Survey. The data on smoking and socioeconomic status were obtained through face-to-face interviews. Smoking initiation rate was defined as the proportion of the individuals who had started smoking at least one cigarette among all subjects. Smoking cessation rate was calculated by dividing the number of individuals who had quit smoking by the number of ever smokers. Education level, total family income and occupation were investigated as socioeconomic indicators. RESULTS: Education level was significantly associated with both initiation and cessation of smoking. Lower educated women had a higher likelihood of smoking initiation (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.17 to 2.51) but lower likelihood of smoking cessation (OR, 0.38; 95% CI, 0.22 to 0.66) than higher educated women. Smoking initiation rate was higher in manual workers (OR, 1.65; 95% CI, 1.20 to 2.27) than in non-manual workers. However, there were no significant differences of both initiation and cessation of smoking according to total household income. CONCLUSION: This study shows that there are smoking inequalities among Korean women. It is thought that education level and occupation are important determinants of women's smoking status.

Distribution of abdominal visceral and subcutaneous adipose tissue and metabolic syndrome in a Korean population.

OBJECTIVE: This study aimed to assess the correlation between abdominal subcutaneous adipose tissue (SAT) and metabolic syndrome (MetS) in Korean adults after adjusting for the effects of visceral adipose tissue (VAT). RESEARCH DESIGN AND METHODS: The SAT/VAT ratio (SVR) was calculated using abdominal computed tomography in 2,655 subjects. We used regression analyses to assess whether the SVR predicted MetS. RESULTS: For both sexes, the prevalence of elevated triglycerides, reduced HDL, and elevated fasting glucose significantly decreased with increasing quintiles of SVR (P for trend < 0.05). The prevalence and odds ratios of MetS significantly decreased as the SVR increased (men: odds ratio 0.5 [95% CI 0.3-0.7]; women: 0.2 [0.1-0.5] for comparisons of lowest vs. highest quintile; P for trend < 0.05). CONCLUSIONS: After adjustment for VAT, abdominal SAT was inversely correlated with the occurrence of MetS.

Alcohol consumption and higher incidence of impaired fasting glucose or type 2 diabetes in obese Korean men.

It is inconclusive whether moderate alcohol consumption reduces the diabetes risk. We observed the development of impaired fasting glucose or type 2 diabetes according to the amount of alcohol intake and body mass index. The annual health evaluation data of 2,500 male workers from 2002 to 2006 were reviewed retrospectively deleting personal identification code. The information contained sex, age, medical history, smoking status, alcohol consumption, participating regular exercise, anthropometric, and biochemistry measurement. Impaired fasting glucose or diabetes was determined when fasting plasma glucose was > or =100mg/dL. Thousand seven hundred seven subjects were eligible after excluding medical history of diabetes or fasting glucose > or =100mg/dL at baseline. The relative risks of its development in group of taking 1-14, 15-29, and > or =30.0g ethanol were 0.842 (95% confidence interval [CI], 0.603-1.176), 1.068 (95% CI, 0.736-1.551), and 1.019 (95% CI, 0.662-1.568) within normal weight group, 1.164 (95% CI, 0.795-1.705), 1.421 (95% CI, 0.947-2.133), and 1.604 (95% CI, 1.031-2.495) within overweight group, and 1.498 (95% CI, 1.042-2.153), 1.634 (95% CI, 1.091-2.447), and 1.563 (95% CI, 1.019-2.396) within obese group each after adjusting age, family history of diabetes, smoking, exercise, serum fasting glucose, aspartate aminotransferase, and gamma-glutamyltransferase with nondrinkers as a reference group. Not only high alcohol consumption but also moderate drinking was related with higher incidence of impaired fasting glucose or diabetes in obese Korean men.

Differential oxidative stress response in young children and the elderly following exposure to PM(2.5).

OBJECTIVES: The mechanism of the adverse health effects of ambient particulate matter on humans has not been well-investigated despite many epidemiologic association studies. Measurement of personal exposure to particulate pollutants and relevant biological effect markers are necessary in order to investigate the mechanism of adverse health effects, particularly in fragile populations considered to be more susceptible to the effects of pollutants. METHODS: We measured personal exposure to PM(2.5) and examined oxidative stress using urinary malondialdehyde three times in 51 preschoolers and 38 elderly subjects. A linear mixed-effects model was used to estimate PM(2.5) effects on urinary MDA levels. RESULTS: Average personal exposure of the children and elderly to PM(2.5) was 80.5 +/- 29.9 and 20.7 +/- 12.7 mug/m(3), respectively. Mean urinary MDA level in the children and the elderly was 3.6 +/- 1.9 and 4.0 +/- 1.6 mumol/g creatinine. For elderly subjects the PM(2.5) level was significantly associated with urinary MDA after adjusting for age, sex, BMI, passive smoking, day-care facility site, alcohol consumption, cigarette smoking, and medical history (heart disease, hypertension and bronchial asthma). However, there was no significant relationship for children. CONCLUSIONS: The elderly were more susceptible than young children to oxidative stress as a result of ambient exposure to PM(2.5). Identification of oxidative stress induced by PM(2.5) explains the mechanism of adverse health effects such as cardiovascular or respiratory diseases, particularly in the elderly.