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The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database.We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process.The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the "casting" process of the "manufacture of basic precious and non-ferrous metals" industry was 53.29 μg/mWe evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

Background: Particulate matter of less than 2.5 micrometers (PM2.5) is associated with various adverse health outcomes. Limited evidence exists however regarding the effects of the individual constituents of indoor PM2.5 and whether their concentrations are affected by the environment or lifestyle. We here investigated the associations between these individual constituents and respiratory outcomes, the living environment, and daily life behaviors in patients with chronic obstructive pulmonary disease (COPD). Methods: This was a prospective panel study involving COPD patients recruited from three hospitals in the Republic of Korea. Detailed questionnaires on living environments and lifestyle practices were completed by the participants. Associations between indoor PM2.5 constituents and respiratory outcomes, living environments, and daily life behaviors were then analyzed. Correlation analyses were conducted using a Spearman’s rank-order or Pearson’s correlation. Results: A total of 89 stable COPD cases were included. Their mean age was 68.1 years and 84 (94.4%) were men. The median indoor PM2.5 concentration was 11.3 μg/m3. Titanium was significantly associated with small airway resistance. Higher concentrations of aluminum, bromine, and silicone correlated with more frequent exacerbations. Regarding the living environment, the copper concentrations were negatively correlated with the distance from a road and with the floor level of residence. A higher manganese concentration was associated with greater traffic volume. An increased ventilation time was associated with lower concentrations of copper and silicone, whereas the air purifier operation time on a day with a heavy dust level was negatively correlated with barium and titanium concentrations. Iron and manganese were negatively correlated with a frequency of cleaning the kitchen ventilator. Conclusion: PM2.5 comprises various chemical constituents, each showing different relationships with clinical parameters in patients with COPD. Such constituents may be affected by environmental factors or lifestyles and should be considered as part of individualized intervention strategies through further studies.

Background In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

Health damage from humidifier disinfectants is an unprecedented environmental health disaster. Humidifier disinfectants were used broadly in Korea from 1994 to 2011. Most studies have focused on respiratory problems because of the exposure route and primary respiratory symptoms. This overlooks the previous research results that humidifier disinfectants could move to extrapulmonary organs and induce toxic effects. Thus, the objective of this study was to examine toxic hepatitis cases developed after inhaling humidifier disinfectant. We focused on the indications of toxic hepatitis in two pediatric cases and one female adult case. All patients were exposed to humidifier disinfectants in a residential space. These disinfectants all contained polyhexamethylene guanidine (PHMG). Rapid increases in blood hepatic enzyme levels were seen. Two patients were discharged after treatment. Death occurred in one patient who was diagnosed with fulminant hepatitis of unknown cause. This human case series study supports prior knowledge that hepatotoxicity can occur by inhaling humidifier disinfectant.

Objective To prevent occupational cancers, carcinogen exposure surveillance systems have been developed in many countries. This study aimed to develop a carcinogen exposure database specific to South Korea. Methods Twenty known human carcinogens were selected for this study. The International Standard Classification of Industry was used for a classification scheme of industries. Three nationwide occupational exposure databases, the Work Environment Measurement Database, the Special Health Examination Database, and the Work Environment Condition Survey, were used to calculate reference exposure prevalence estimates by carcinogen and industry. Then, 37 professional industrial hygienists with at least 19 years of field experience provided their own exposure prevalence estimates, after reviewing the abovementioned reference estimates derived from three data sources. The median value of the experts’ estimates was used as the final exposure prevalence. Finally, the number of exposed workers was computed by multiplying the final exposure prevalence by the number of workers extracted from the 2010 national census data by carcinogen and industry. Results The exposure prevalence and the number of exposed workers were calculated according to 20 carcinogen and 228 minor industrial groups, assuming year 2010 circumstances. The largest population was exposed to welding fumes (326 822 workers), followed by ultraviolet radiation (238 937 workers), ionizing radiation (168 712 workers), and mineral oil mist (146 798 workers). Conclusions Our results provide critical data on carcinogen exposure for the prevention of occupational cancers.

Many studies have been conducted on presenteeism and absenteeism, but the relationship between presenteeism and absenteeism is unclear. This study was undertaken to investigate the effect of presenteeism on future absenteeism.This study was conducted on non-white collar workers that underwent general health examinations in 2014 and 2015. We asked subjects to fill out a questionnaire about their experiences of presenteeism for the past one year in 2014. In 2015, it was checked whether the same subjects had any experience of absence from work due to injury or disease during the past year. The χA total of 12,572 workers were included in the study. For workers who experienced presenteeism, the OR for injury absence was 2.705 (95% confidence interval [CI]: 2.044-3.581), and the OR for disease absence was 4.906 (95% CI: 3.996-6.024) after adjusting for sociodemographic and occupational confounding factors. For men that experienced presenteeism, the OR for injury absence was 3.035 (95% CI: 2.258-4.081), and the OR for disease absence was 5.508 (95% CI: 4.340-6.989). For women that experienced presenteeism, the OR for injury absence was 1.322 (95% CI: 0.577-3.028), which was not significant, and the OR for disease absence was 3.629 (95% CI: 2.405-5.475).This study suggests that presenteeism can influence future absenteeism. The effect of presenteeism may depend on cause of absence. Men who experienced presenteeism showed greater effects on injury and disease absence than women. For women, experience of presenteeism had a significant effect on disease absence but not on injury absence.

Exposure to particulate matter (PM) has been known to develop asthma in children and the oxidative stress-related mechanisms are suggested. For the development of asthma, not only the exposure dose but also the critical window and the risk modifying factors should be evaluated.We investigated whether prenatal exposure to PM10 increases the risk of childhood asthma and evaluated the modifying factors, such as gender and reactive oxidative stress-related gene.A general population-based birth cohort, the Panel Study of Korean Children (PSKC), including 1572 mother-baby dyads was analyzed. Children were defined to have asthma at age 7 when a parent reported physician-diagnosed asthma. Exposure to PM10 during pregnancy was estimated by land-use regression models based on national monitoring system. TaqMan method was used for genotyping nuclear factor, erythroid 2-related factor, NRF2 (rs6726395). A logistic Bayesian distributed lag interaction model (BDLIM) was used to evaluate the associations between prenatal PM10 exposure and childhood asthma by gender and NRF2.Exposure to PM10 during pregnancy was associated with the development of asthma (aOR 1.03, 95% CI 1.001.06). Stratifying by gender and NRF2 genotype, exposure to PM10 during 26-28 weeks gestation increased the risk of childhood asthma, especially in boys with NRF2 GG genotype.A critical window for PM10 exposure on the development of childhood asthma was during 26-28 weeks of gestation, and this was modified by gender and NRF2 genotype.

Background Pediatric allergic diseases are a major public health concern, and previous studies have suggested that exposure to traffic-related air pollution (TRAP) exposure is a risk factor. These studies have typically assessed TRAP exposure using traffic measures, such as distance to major roads, or by modeling air pollutant concentrations; however inconsistent associations with pediatric allergic diseases have often been found. Using road proximity and density, we previously found an association between TRAP and atopic eczema among approximately 15,000 children living in Seoul, Korea, heavily populated and highly polluted city in which traffic is a major emission source. We aimed to conduct a parallel analysis using modeled air pollution concentrations and thus examine the consistency of the association. Specifically, we examined the associations of individual-level annual-average concentrations of NO2, PM10, and PM2.5 with symptoms and diagnoses of three pediatric allergic diseases including asthma, allergic rhinitis, and atopic eczema. Methods The study population included 14,614 children from the Seoul Atopy Friendly School Project Survey in Seoul, Korea, in 2010. To assess individual exposures to TRAP among these children, we predicted annual-average concentrations of NO2, PM10, and PM2.5 at the children’s home addresses in 2010 using universal kriging and land use regression models along with regulatory air quality monitoring data and geographic characteristics. Then, we estimated odds ratios (ORs) of the three allergic diseases for interquartile increases in air pollution concentrations after adjusting for individual risk factors in mixed effects logistic regression. Results Symptoms and diagnoses of atopic eczema symptoms showed an association with NO2 (OR = 1.07, 95% confidence interval = 1.02–1.13; 1.08, 1.03–1.14) and PM10 (1.06, 1.01–1.12; 1.07, 1.01–1.13). ORs of PM2.5 were positive but not statistically significant (1.01, 0.95–1.07; 1.04, 0.98–1.10). No association was found between asthma and allergic rhinitis, although PM2.5 showed a marginal association with allergic rhinitis. Conclusions Our consistent findings regarding the association between TRAP and the prevalence of atopic eczema using traffic measures and surrogate air pollutants suggested the effect of TRAP on children’s health. Follow-up studies should elucidate the causal link, to support subsequent policy considerations and minimize adverse health effects in children.

The recent global pandemic of the novel coronavirus disease 2019 (COVID-19) is affecting the entire population of Nepal, and the outcome of the epidemic varies from place to place. A district-level analysis was conducted to identify socio-demographic risk factors that drive the large variations in COVID-19 mortality and related health outcomes, as of 22 January 2021. Data on COVID-19 extracted from relevant reports and websites of the Ministry of Health and Population of Nepal, and the National Population and Housing Census and the Nepal Demographic and Health Survey were the main data sources for the district-level socio-demographic characteristics. We calculated the COVID-19 incidence, recovered cases, and deaths per 100,000 population, then estimated the associations with the risk factors using regression models. COVID-19 outcomes were positively associated with population density. A higher incidence of COVID-19 was associated with districts with a higher percentage of overcrowded households and without access to handwashing facilities. Adult literacy rate was negatively associated with the COVID-19 incidence. Increased mortality was significantly associated with a higher obesity prevalence in women and a higher smoking prevalence in men. Access to health care facilities reduced mortality. Population density was the most important driver behind the large variations in COVID-19 outcomes. This study identifies critical risk factors of COVID-19 outcomes, including population density, crowding, education, and hand hygiene, and these factors should be considered to address inequities in the burden of COVID-19 across districts.

Introduction By substituting the general ‘susceptibility factor’ concept for the conventional ‘gene’ concept in the case-only approach for gene-environment interaction, the case-only approach can also be used in environmental epidemiology. Under the independence between the susceptibility factor and environmental exposure, the case-only approach can provide a more precise estimate of an interaction effect. Methods Two analysis examples of the case-only approach in environmental epidemiology are provided using the 2015–2016 and 2017–2018 US National Health and Nutritional Examination Survey (NHANES): (i) the negative interaction effect between blood chromium level and glycohemoglobin level on albuminuria and (ii) the positive interaction effect between blood cobalt level and old age on albuminuria. The second part of the methods (theoretical backgrounds) summarized the logic and equations provided in previous studies about the case-only approach. Results (i) When a 1 μg/L difference of both blood chromium level (mcg/L) and a 1% difference in blood glycohemoglobin level coincide, the multiplicative interaction contrast ratio (ICRc/nc) was 0.72 (95% CI 0.35–1.60), with no statistical significance. However, when only the cases were analyzed, the case-only ICR (ICRCO) was 0.59 (95% CI 0.28–0.95), with a statistical significance (a negative interaction effect). (ii) When a 1 μg/L difference of both blood cobalt levels and a 1-year difference in age coincide, the multiplicative interaction contrast ratio (ICRc/nc) was 1.13 (95% CI 0.99–1.37), with no statistical significance. However, when only the cases were analyzed, the case-only ICR (ICRCO) was 1.21 (95% CI 1.06–1.51), with a statistical significance (a positive interaction effect). Discussion The discussion suggested the theoretical background and previous literature about the possible protective interaction effect between blood chromium levels and blood glycohemoglobin levels on the incidence of albuminuria and the possible aggravating interaction effect between blood cobalt levels and increasing ages on the incidence of albuminuria. If the independence assumption between a susceptibility factor and environmental exposure in a study with cases and non-cases is kept, the case-only approach can provide a more precise interaction effect estimate than conventional approaches with both cases and non-cases.

Background The prevalence of atopic dermatitis (AD) is increasing worldwide. Prenatal particulate matter with an aerodynamic diameter

Some survivors of humidifier disinfectants (HDs) complain of chronic, inexplicable fatigue, and post-exertional malaise (PEM). Two-day cardiopulmonary exercise tests (CPETs) performed 24 hours apart (2-day CPET protocol) are increasingly employed to evaluate PEM and related disabilities among individuals with chronic fatigue syndrome (CFS). The purpose of this study was to assess the reproducibility of CPET variables in individuals who had been exposed to HD and to show that 2-day CPET is an objective means of differentiating between fatigue conditions in people with CFS symptoms who have been exposed to HDs. Twenty-nine HD survivors with CFS symptoms were enrolled in this study. To document and assess PEM in CFS, a 2-day CPET was conducted to measure baseline functional capacity (CPET1) and provoke PEM. Twenty-four hours later, a second CPET assessed changes in related variables, focusing on PEM effects on functional capacity. This CPET also measured changes in energy production and physiological function, objectively documenting PEM effects. In the 2-day CPET, the peak oxygen consumption (VO2peak), VO2 at ventilatory threshold (VO2@VT), time to reach VO2peak, and time to reach VO2@VT were significantly decreased (p

Background: Air pollution is associated with perceived stress in the general population, but its influence on maternal perceived stress during pregnancy has not been investigated.We aimed to investigate the relationship between air pollution and non-specific perceived stress among pregnant women.Methods: Our analysis included2162 pregnant women who had participated in the cohort for childhood origin of asthma and allergic disease study between 2008 and 2015. Maternal exposures to particulate matter with an aerodynamic diameter < 2.5 µm (PM2.5) and < 10 µm (PM10), as well as to nitrogen dioxide (NO2) and ozone (O3) for each trimesterand the entire pregnancy were determined using land-use regression models. Maternal perceived stress during the third trimester was assessed using the 14-item Perceived Stress Scale (PSS): scores ranged from 0-56 with higher scores indicating increased stress. Linear regression models were applied to estimate associations between PSS scores and each air pollutant, after adjusting for socio-demographic and behavioral covariates.Results: In single-pollutant models,after adjustment, an IQR increase in the whole pregnancy exposure to PM2.5 and PM10 and O3 in the third trimester was related to 0.37 (95% confidence interval [CI]: 0.01, 0.74) and 0.55 (95% CI: 0.12, 0.98) and 0.29 (95% CI: 0.05, 0.52) points increase in the PSS score, respectively.This association was more evident in women with child-bearing age and lower levelofeducation, and the association of PM10was stronger in thespring season.In multi-pollutant models, exposures to PM10 and O3 were associated with higher perceived stress. Conclusion:Our findings suggest that pregnancy exposure to PM2.5, PM10and O3 is positively associated with maternal PSS score during the third trimester.

Background The relationship between smoking status or second-hand smoking and occupational injuries has been the subject of considerable study, but few have studied the relationship between nicotine dependence and occupational injuries. The objective of this study was to investigate the relationship between nicotine dependence and occupational injury among employees at a range of Korean companies. Methods Initially, the personal and occupational characteristics and nicotine dependences of workers were measured, and 12 months later a survey was used to determine whether subjects had experienced any occupational injury. This study was conducted in several workplaces on 6,893 male workers in manufacturing and service industries that received health screening at Inha University Hospital in Incheon. Results The adjusted odds ratios (ORs) of occupational injury in the low, moderate, and high nicotine dependence groups were 1.38 (95% confidence interval [CI]: 1.04-1.84), 1.52 (95% CI: 1.10-2.10), and 1.71 (95% CI: 0.92-3.19), respectively. For smokers only, adjusted ORs tended to increase linearly (p for trend < 0.05). When only smokers were included, analysis of continuous FTND (Fagerstrom Test of Nicotine Dependence) scores showed that adjusted OR increased by 1.10 (95% CI: 1.03-1.19) per FTND point. After stratifying the data by working type and working hours per week, the non-shift work group maintained this relationship (OR: 1.13, 95% CI: 1.04-1.24) and OR was higher in the group that works more than 60 hours per week with FTND score as a continuous variable (OR: 1.24, 95% CI: 1.07-1.44). Conclusions The study shows nicotine dependency might affect occupational injury. From a short-term perspective, addressing worker's nicotine dependence by giving an adequate break time or smoking area might reduce work-related injuries.

Background Air pollution is associated with depressive and anxiety symptoms in the general population. However, this relationship among pregnant women remains largely unknown. Objective To evaluate the association between pregnancy air pollution exposure and maternal depressive and anxiety symptoms during the third trimester assessed using the Center for Epidemiologic Studies-Depression and State-Trait Anxiety Inventory scales, respectively. Methods We analyzed 1481 pregnant women from a cohort study in Seoul. Maternal exposure to particulate matter with an aerodynamic diameter Results In single-pollutant models, an IQR increase in PM2.5, PM10, and NO2 during the second trimester was associated with an increased risk of depressive symptoms (PM2.5 RR = 1.15, 95% CI: 1.04, 1.27; PM10 RR = 1.13, 95% CI: 1.04, 1.23; NO2 RR = 1.15, 95% CI: 1.03, 1.29) after adjusting for relevant covariates. Similarly, an IQR increase in O3 during the third trimester was associated with an increased risk of depressive symptoms (RR = 1.09, 95% CI: 1.01, 1.18), while the IQR increase in O3 during the first trimester was associated with a decreased risk (RR = 0.89, 95% CI: 0.82, 0.96). Exposure to PM2.5, PM10, and NO2 during the second trimester was significantly associated with anxiety symptoms. The associations with PM2.5 and O3 in single-and multi-pollutant models were consistent. Conclusions Our findings indicate that increased levels of particulate matter, NO2, and O3 during pregnancy may elevate the risk of depression or anxiety in pregnant women.

Background The effect of exposure to particulate matter (PM) on human health is a global public health concern. To develop an effective strategy to reduce PM exposure, we performed detailed questionnaire surveys regarding the type of lifestyle required to avoid PM exposure in patients with chronic obstructive pulmonary disease (COPD). We correlated the data with real-time PM concentration during the winter season. Methods We enrolled 104 patients with COPD aged 40 years or older. Detailed questionnaire surveys were conducted among participants, and internet of things-based sensors were installed at their homes to measure the indoor PM2.5 concentration, which was continuously monitored between December 2019 and February 2020. The associations among PM2.5 concentration, patients' lifestyles, and the impact of both concentration and lifestyle on COPD exacerbation were analyzed. Results Mean outdoor PM2.5 concentration was higher than mean indoor PM2.5 concentration during the study period (21.28 ± 5.09 μg/m3 vs. 12.75 ± 7.64 μg/m3), with a mean difference of 8.53 ± 7.99 μg/m3. Among the various social factors and practices that aim to avoid exposure to PM, six practices and economic statuses were confirmed to reduce indoor PM2.5 concentration compared to outdoor concentration; Contrarily, these practices created a significant difference between the outdoor and indoor PM2.5 concentrations. The six practice items that showed a significant difference were 1) checking air quality forecast (the difference: −13.31 ± 1.35 μg/m3, p = 0.013), 2) indoor air filter operated (−15.43 ± 1.32 μg/m3, p Conclusion Lifestyle and economic levels can affect the indoor PM2.5 concentration, which may impact COPD exacerbation.

Background The aim of this study is to investigate the relationship between fatigue and occupational injury. Methods This study was conducted at a university hospital in 2014 and 2015. In 2014, the fatigue severity scale (FSS) was used to evaluate workers' fatigue levels. Later, when the same workers were examined in 2015, a questionnaire survey was conducted to determine whether they had experienced absences or treatment for work-related accidents. The χ2 test was used to analyse the relationship between demographic characteristics, fatigue levels, and occupational injuries. After controlling for confounders, a logistic regression analysis was performed to calculate the odds ratios (ORs). Results In 2014, 19,218 workers were screened during health examination and their fatigue level were evaluated using FSS questionnaires. in 2015, workers' occupational injury was evaluated. In result, men in the moderate- and high-fatigue groups, after adjusting for age, smoking and drinking habits, chronic diseases, and occupational factors such as size of company industrial classification and type of work (shift or non-shift), adjusted ORs for hospital treatment due to occupational injury were 1.76 (95% confidence interval [CI]: 1.39–2.24) and 2.61 (95% CI:1.68–4.06), respectively. Among men in the medium- and high-fatigue groups, the adjusted ORs for absence due to occupational injury were 2.06 (95% CI: 1.52–2.80) and 3.65 (95% CI: 2.20–6.05), respectively. No significant association was observed between fatigue and occupational injury in women. Conclusions Male workers with high fatigue levels have a higher risk of experiencing work injuries. This study suggests that active intervention be considered to prevent injuries in workers with high scores on workplace fatigue evaluation scales.

Background: An association between maternal exposure to air pollution and the birth weight distribution has been reported, but the extent to which this relationship varies according to socioeconomic status (SES) is unknown. This study examined the relationship using the data from a Korean birth cohort. Methods: Data for singleton births in Seoul from 2007 to 2017 (n = 1739) were analyzed. Maternal exposures to particulate matter with an aerodynamic diameter

Background Most of the studies that have examined the association between the sub-factors of occupational stress and depressive symptoms have used cross-sectional data. However, our study has longitudinally measured the occupational stress and depressive symptoms of Korean workers of a semiconductor manufacturing company across six years to intending to investigate the associations between the sub-factors of occupational stress and depressive symptoms using longitudinal data. Methods Data collected from the workers of a semiconductor manufacturing company. Out of 1,013 recruited workers, 405 (40.0%) completed the survey questionnaires at 3 and 6-year follow-ups. Occupational stress was measured using a shorter version of the Korean Occupational Stress Scale (KOSS), whereas depressive symptoms were assessed using the Korean version of the Center for Epidemiological Studies-Depressive Symptoms Scale (CES-D). The data of male and female participants independently analyzed. Longitudinal associations were analyzed using panel data analysis with fixed effects. Results In panel data analysis with fixed effects, job insecurity (B = 0.048, p-value = 0.004) was associated with depressive symptoms among male workers. In female workers, inadequate social support (B = 0.080, p-value < 0.001), job insecurity (B = 0.039, p-value = 0.004), lack of reward (B = 0.059, p-value = 0.004) and discomfort in occupational climate (B = 0.074, p-value < 0.001) were associated with depressive symptoms among female workers. Conclusions Temporal changes in the sub-factors of occupational stress were associated with changes in depressive symptoms within the same period. There was a gender difference in occupational stress sub-factors related to depressive symptoms.

Additional file 3: Table S2. Odds ratios and 95% confidence intervals of symptoms and doctor-diagnoses of three allergic diseases for interquartile increases in individual-level annual average concentrations of NO2, PM10, and PM2.5 (6.46 ppm, 3.80 μg/m3, and 3.63 μg/m3, respectively) in 14,614 children of the Seoul Atopy Friendly School Project Survey in Seoul, Korea, for 2010.

Background Individual particulate respirator use may offer protection against exposure to particulate matter < 2.5 µm in diameter (PM2.5). Among elderly Korean women, we explored individual particulate respirator use and cardiopulmonary function. Methods Recruited in Seoul, Korea, 21 elderly, non-smoking women wore particulate respirators for six consecutive days (exlcuding time spent eating, sleeping, and bathing). We measured resting blood pressure before, during, and after respirator use and recorded systolic and diastolic blood pressure, mean arterial blood pressure, pulse pressure, and lung function. We also measured 12-hour ambulatory blood pressure at the end of the 6-day long experiment and control periods. Additionally, we examined physiological stress (heart rate variability and urinary 8-hydroxy-2′-deoxyguanosine) while wearing the particulate respirators. Person- and exposure-level covariates were also considered in the model. Results After the 6-day period of respirator use, resting blood pressure was reduced by 5.3 mmHg for systolic blood pressure (P = 0.013), 2.9 mmHg for mean arterial blood pressure (P = 0.079), and 3.6 mmHg for pulse pressure (P = 0.024). However, particulate respirator use was associated with changes in physiological stress markers. A parasympathetic activity marker (high frequency) significantly decreased by 24.0% (P = 0.029), whereas a sympathetic activity marker (ratio of low-to-high frequency) increased by 50.3% (P = 0.045). An oxidative stress marker, 8-hydroxy-2′-deoxyguanosine, increased by 3.4 ng/mg creatinine (P = 0.021) during the experimental period compared with that during the control period. Lung function indices indicated that wearing particulate respirators was protective; however, statistical significance was not confirmed. Conclusion Individual particulate respirator use may prevent PM2.5-induced blood-pressure elevation among elderly Korean women. However, the effects of particulate respirator use, including physiological stress marker elevation, should also be considered. Trial Registration Clinical Research Information Service Identifier: KCT0003526, Graphical Abstract

This study investigated whether the association between household air pollution (HAP) and nutritional status (stunting, underweight, or wasting) among children differ by caste/ethnicity. Child anthropometry data for 9,914 children aged 0–59 months were analyzed linearly as Z scores and as dichotomous categories. Exposure to HAP was significantly associated with a decrease in child height-for-age and child weight-for-age, as well as with stunting and underweight. Children in low caste (Dalits) had higher prevalence of stunting (odds ratio [OR] = 1.21; 95% confidence intervals [CI] = 1.01, 1.44), underweight (OR = 1.47; 95% CI = 1.24, 1.75), and wasting (OR = 1.53; 95% CI = 1.21, 1.92) than those children in upper caste group. This association was modestly attenuated with adjustment for HAP. Exposure to HAP partly explained the caste-ethnic difference in undernutrition among children in Nepal.

Background The global labor market is moving towards increasing job instability. Relatively few studies have examined the relationship between precarious employment and subjective well-being using quantitative scales. We evaluated the association between wage workers' employment status and their subjective well-being through the Cantril ladder scale using Korean Welfare Panel Survey data (KOWEPS). Methods This study used KOWEPS data. A total of 4,423 wage workers were divided into permanently employed workers, temporarily employed workers and daily employed workers. The relationship between precarious employment and subjective well-being was analyzed by multiple linear regression adjusted for potential confounding factors. Results The more unstable the employment status, the lower the subjective well-being, which can be expressed by the Cantril ladder scale. The mean score of both temporarily employed and daily employed workers were statistically significantly lower (B = -0.454, p < 0.001; B = -0.994, p < 0.001, respectively) than permanently employed workers. This appeared to be the same when occupational and sociodemographic factors were adjusted (B = -0.153, p = 0.002 for temporarily employed, B = -0.610, p < 0.001 for daily employed). Conclusions The more unstable the employment status, the lower the subjective well-being score according to the Cantril ladder scale.

Introduction: Chronic obstructive pulmonary disease (COPD) is commonly affected by particulate matter (PM) exposure. In this study, we aimed to evaluate whether behavioral interventions to reduce PM exposure improve clinical outcomes in patients with COPD. Methods: A multicenter randomized controlled trial will be conducted involving 120 participants recruited from 3 hospitals in the capital region of the Republic of Korea. Patients aged 40 to 80 years with a diagnosis of COPD and a forced expiratory volume at 1 s

Prenatal particulate matter