Who has sustained psychological symptoms nine years after the Hebei Spirit oil spill?: The Health Effect Research on Hebei Spirit oil spill (HEROS) study.

This study evaluated risk factors for sustained psychological symptoms in affected residents, nine years after the Hebei Spirit oil spill in Korea in 2007. The participants included residents of high-exposure areas, living within 2 km from the contaminated coast (n = 2013), among the cohort of the Health Effect Research on Hebei Spirit oil spill study from 2009 to 2016. Symptoms for post-traumatic stress disorder (PTSD), depression, psychosocial distress, and anxiety, as well as sociodemographic information were assessed through questionnaire interviews. Trajectory analysis was conducted to identify the group with sustained symptoms over time and logistic regression analysis was performed to identify risk factors for sustained symptoms adjusted for covariates. A longer duration of clean-up work, lower household income, and presence of a chronic disease in all type of symptoms, and being female, younger age, and higher educational level in all symptoms but PTSD, showed a significant association with increased risk of sustained symptoms. The highest risk was found in the subgroup with a longer clean-up together with offshore and maritime occupations or lower income in PTSD, depression, and anxiety, compared with those with a shorter clean-up and other occupation or higher income. Increased risk of sustained PTSD in relation to a longer clean-up was limited to those with a lower educational level (p-interaction = 0.009). The results suggested that participating longer in clean-up work increased sustained psychological symptoms, synergistically with socioeconomic factors such as offshore and maritime occupations, lower household income, or economic losses related to educational level.

Impacts of ambient air pollution on glucose metabolism in Korean adults: a Korea National Health and Nutrition Examination Survey study.

BACKGROUND: Exposure to air pollution was reported to affect glucose metabolism, increasing the risk of diabetes mellitus. We conducted an epidemiological study on glucose metabolism and air pollution by exploring the levels of fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) with changes in ambient air quality, depending on the characteristics of the susceptible population. METHODS: We carried out a cross-sectional analysis of a nationally representative sample of 10,014 adults (4267 in male and 5747 in female) from the Korea National Health and Nutrition Examination Survey in 2012 and 2013 along with data from the Korean Air Quality Forecasting System. The analysis was performed using a generalized linear model stratified by sex, age, and presence of diabetes. We assessed the changes in FBG and HbA1c associated with exposures to particulate matter (PM10), fine particulate matter (PM2.5), and nitrogen dioxide (NO2) after controlling for confounders. RESULTS: There were 1110 participants with diabetes (557 in male and 553 in female). Overall, the FBG level increased by 7.83 mg/dL (95% confidence interval [CI]: 2.80-12.87) per interquartile range (IQR) increment of NO2, 5.32 mg/dL (95% CI: 1.22-9.41) per IQR increment of PM10 at a moving average of 0-6 days, and 4.69 mg/dL (95% CI: 0.48-8.91) per IQR increment of PM2.5 at a moving average of 0-5 days. HbA1c increased by 0.57% (95% CI: 0.04-1.09) per IQR increment of PM10 at a moving average of 0-60 days and 0.34% (95% CI: 0.04-0.63) per IQR increment of PM2.5 at a moving average of 0-75 days. The change in FBG and HbA1c increased more in the diabetic group, especially in males aged 65 years or more. There was a strong association between elevation in diabetes-related parameters and exposure to air pollution. CONCLUSIONS: Our study provides scientific evidence supporting that short- and mid-term exposure to air pollution is associated with changes in biological markers related to diabetes. This finding suggests that the impact of air pollution should be reflected in chronic disease management when establishing local health care policies.

An association between oil spill clean-up work and cardiovascular disease.

BACKGROUND: In December 2007, Taean, South Korea, experienced the largest oil spill in Korean history. After about 10 years of follow-up, we evaluated the long-term effect of the disaster on the cardiovascular health of residents and clean-up workers/volunteers. OBJECTIVE: We examined the relationship between the duration of oil clean-up work and the risk of incident angina and myocardial infarction (MI). METHODS: We used data from a prospective cohort study, the Health Effects Research of Oil Spill (HEROS); we included adult cohort members free from cardiovascular disease who completed at least the first two surveys (n = 1737). At baseline, members reported the number of days they participated in oil clean-up work; during the subsequent surveys, they reported newly diagnosed cases of angina or MI. We fitted a time-varying interval-censored proportional hazard model, controlling for age, sex, body mass index, smoking status, monthly household income, and distance from the affected seashore to residence. RESULTS: The risk of incident angina or MI was greater in those with more than 15 days' exposure; those with 15-59 days showed a hazard ratio (HR) of 1.34 (95% confidence interval [CI]: 0.87, 2.06) those with 60-179 days had an HR of 1.31 (0.95, 1.79), and those worked longest (180 or more days) showed the strongest association with a HR of 1.75 (95% CI: 1.17, 2.61). CONCLUSION: We found that a greater duration of clean-up work was associated with an increased risk of incident angina or MI.

Compliance of Antihypertensive Medication and Risk of Coronavirus Disease 2019: a Cohort Study Using Big Data from the Korean National Health Insurance Service.

BACKGROUND: There is a controversy whether it is safe to continue renin-angiotensin system blockers in patients with coronavirus disease 2019 (COVID-19). We analyzed big data to investigate whether angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers have any significant effect on the risk of COVID-19. Population-based cohort study was conducted based on the prescription data from nationwide health insurance records. METHODS: We investigated the 1,374,381 residents aged ≥ 40 years living in Daegu, the epicenter of the COVID-19 outbreak, between February and March 2020. Prescriptions of antihypertensive medication during the year before the outbreak were extracted from the National Health Insurance Service registry. Medications were categorized by types and stratified by the medication possession ratios (MPRs) of antihypertensive medications after controlling for the potential confounders. The risk of COVID-19 was estimated using a difference in difference analysis. RESULTS: Females, older individuals, low-income earners, and recently hospitalized patients had a higher risk of infection. Patients with higher MPRs of antihypertensive medications had a consistently lower risk of COVID-19 than those with lower MPRs of antihypertensive medications and non-users. Among patients who showed complete compliance, there was a significantly lower risk of COVID-19 for those prescribed angiotensin II receptor blockers (relative risk [RR], 0.751; 95% confidence interval [CI], 0.587-0.960) or calcium channel blockers (RR, 0.768; 95% CI, 0.601-0.980). CONCLUSION: Renin-angiotensin system blockers or other antihypertensive medications do not increase the risk of COVID-19. Patients should not stop antihypertensive medications, including renin-angiotensin system blockers, because of concerns of COVID-19.

Spectrum of susceptibility to air quality and weather in individual children with atopic dermatitis.

BACKGROUND: Exposure to air pollution aggravates symptoms of atopic dermatitis (AD) in children in the population studies. Variability in individual patient's response from individual susceptibility is needed to be explored. OBJECTIVE: This study aimed to investigate spectrum of individual variability in the associations between AD symptoms and air quality. METHODS: We enrolled 89 children aged 0-6 years with AD (22 890 person-days). Daily manifestation of symptoms was recorded for an average of 257 days (range 100-499). Both an individual analysis using logistic regression models and an overall analysis using a generalized estimating equation were performed. RESULTS: The odds ratios of an individual ranged 0.24-8.11 for particulate matter <10 µm in diameter (PM10 ), 0.09-101.92 for nitrogen oxide (NO2 ), 0.03-44.00 for ozone (O3 ), 0.11-58.30 for sulfur dioxide (SO2 ), 0.00-15.83 for carbon monoxide (CO), 0.00-39 446.94 for temperature, and 0.03-5.18 for relative humidity, demonstrating a wide individual variability. In the overall analysis, PM10 , NO2 , SO2 , and CO had a significantly positive association, whereas temperature and relative humidity were negatively associated with AD symptoms. Air pollution was responsible for aggravation of symptoms from 24.7% (O3 ) to 39.3% (SO2 ) of AD children. Overall, 71.9% of the AD children responded to at least one or more air pollution and weather variable. CONCLUSION: Responses of AD children to air pollution and weather variable were considerably variable among individuals. An individualized model would be useful to forecast and manage AD symptoms in patients.

Malaria Incidence of the Regions Adjacent to the Demilitarized Zone in the Democratic People's Republic of Korea, 2004-2016.

BACKGROUND: Vivax malaria reemerged in the Korean peninsula in 1990s beginning from the western border area and spread across both Koreas rapidly with its peak incidences reported on the early 2000s. There have been few reports on the malaria incidence in the Democratic People's Republic of Korea (North Korea) that provides detailed epidemiological features. The purpose of this study was to describe the time trends and spatial distribution of malaria in North Korea with comparison to those in South Korean regions across the border. METHODS: The incidence of malaria in each province of North Korea from 2004 to 2016 was estimated based on data from domestic and international health authorities. Consistency of the data was evaluated by calculating the ratio of malaria cases in each province to the total cases each year. We also compared the changes in malaria incidence over time in South and North Korea adjacent to the demilitarized zone. RESULTS: In North Korea, the incidence of malaria in the three provinces adjacent to the demilitarized zone was the highest (52.1-315.3 per 100,000), followed by Pyeonganbuk-do (14.7-113.5 per 100,000), where railways and road networks were connected to northern China. The incidence of malaria in each province of North Korea reported after 2011 was more consistent than when compared with previous annual data, and there was also a positive correlation between changes in incidence over time when compared with malaria incidence in South Korea (r = 0.855, r = 0.596). CONCLUSION: The malaria report of North Korea was relatively consistent in its spatiotemporal tendency since 2011, suggesting improvement of the quality of the surveillance data. The strong correlation between North and South Korean malaria incidence at regional level suggests that collaboration between both sides are essential for the successful elimination of malaria in the Korean peninsula.

Epidemiologic Trends and Seasonality of Scabies in South Korea, 2010-2017.

Scabies is a parasitic skin infection with intense itching. Scabies infection seriously impairs quality of life, while outbreaks in medical institutions cause financial losses. This study aimed to present the annual and seasonal trend of prevalence of scabies in the national population. Scabies cases were extracted from National Health Insurance Service database and its epidemiologic characteristics were assessed. To analyze the seasonality of scabies occurrence, temperature and humidity were included in the model as weather factors, and the per capita gross national income index was adjusted. The annual prevalence by age group was 0.56-0.69 per 1,000 persons until the age of 40 years and peaked at 3.0-4.1 per 1,000 persons in the age group over 80 years. The number of women diagnosed with scabies has been consistently higher compared to that of men since 2010. Mean number of cases diagnosed as scabies was lowest in spring, approximately 4,000 cases, when the average temperature was less than 5°C at 2 months prior, whereas more than 6,000 scabies cases occurred in autumn when temperatures exceeded 25°C at 2 months prior. This study presents the epidemiological characteristics and seasonality of all cases nationwide over 8 years and will help to establish control policies.

Increasing Number of Scarlet Fever Cases, South Korea, 2011-2016.

The increasing number of reported scarlet fever cases during 2011‒2016 in the National Notifiable Infectious Disease database in South Korea occurred because of increased overall reporting and expanded reporting criteria rather than because of increasing scarlet fever incidence. Further increases are anticipated because of other expansions in reporting requirements.

Burden of Disease Attributable to Inadequate Drinking Water, Sanitation, and Hygiene in Korea.

BACKGROUND: Diarrheal and intestinal infectious disease caused by inadequate drinking water, sanitation, and hygiene (WASH) is not only a great concern in developing countries but also a problem in low-income populations and rural areas in developed countries. In this study, we assessed the exposure to inadequate WASH in Korea and estimated the burden of disease attributable to inadequate WASH. METHODS: We used observational data on water supply, drinking water, sewage treatment rate, and hand washing to assess inadequate WASH conditions in Korea, and estimated the level of exposure in the entire population. The disease burden was estimated by applying the cause of death data from death registry and the morbidity data from the national health insurance to the population attributable fraction (PAF) for the disease caused by inappropriate WASH. RESULTS: In 2013, 1.4% of the population were exposed to inadequate drinking water, and 1.0% were living in areas where sewerage was not connected. The frequency of handwashing with soap after contact with excreta was 23.5%. The PAF due to inadequate WASH as a cluster of risk factors was 0.353 (95% confidence interval [CI], 0.275-0.417), among which over 90% were attributable to hand hygiene factors that were significantly worse than those in American and European high-income countries. CONCLUSION: The level of hand hygiene in Korea has yet to be improved to the extent that it shows a significant difference compared to other high-income countries. Therefore, improving the current situation in Korea requires a continuous hand washing campaign and a program aimed at all people. In addition, continuous policy intervention for improvement of sewage treatment facilities in rural areas is required, and water quality control monitoring should be continuously carried out.

Estimation of Cancer Incidence and Mortality Risks Attributed to Diagnostic Medical Radiation Exposure in Korea, 2013.

BACKGROUND: Radiation exposure from medical procedures has been rapidly increasing. We purposed to estimate the fraction of cancer incidence and mortality attributed to diagnostic medical radiation exposure in Korea. METHODS: Using information on diagnostic medical radiation exposure from various sources including national health examination (National Health Insurance Service), private health examination, and conscription health examination; the annual mean exposed organ dose (mGy) from all diagnostic medical radiation use, grouped by sex and 5-year age ranges up to 80 years, was calculated. Cancer incidence and mortality lifetime attributable risks (LARs) up to 85 years using estimated exposed organ doses and biological effects of ionizing radiation (BEIR) VII model (excess relative risk and excess absolute risk) were estimated. Using background cancer incidence and mortality risk based on the national database, along with estimated LARs, we finally estimated population attributable fraction (PAF) of cancer incidence and mortality. RESULTS: The PAF for diagnostic medical radiation exposure among all cancers of Koreans was 0.9% for incidence and mortality, resulting 1,915 cancer cases and 637 cancer deaths a year. The PAF in females was higher than those in males: 1.2% and 1.7% (incidence and mortality) versus 0.6% (same in incidence and mortality), respectively. CONCLUSION: The estimated PAF for diagnostic medical radiation in Korea in 2013 was higher than those reported in the UK in 2004. Optimized management of diagnostic medical radiation use is important in Korea.

Premature Deaths Attributable to Long-term Exposure to Ambient Fine Particulate Matter in the Republic of Korea.

BACKGROUND: Ambient fine particulate matter (PM2.5) is the major environmental health risk factor in Korea. Exposure to PM2.5 has been a growing public concern nationwide. With the rapid aging of the Korean population, the health effects attributable to long-term exposure to PM2.5 were expected to increase further in the future. We aimed to estimate premature deaths attributable to long-term exposure to ambient PM2.5 in Korea. METHODS: A modelled estimation of long-term exposure to PM2.5 was used to calculate the nationwide exposure level. Hazard ratios of long-term exposure to PM2.5 were obtained from a large prospective cohort study in North America. Modified cause of death (CoD) data, which applied the garbage code reclassification algorithm, were used to calculate premature deaths attributable to long-term exposure to PM2.5. RESULTS: From 1990 to 2013, the average population-weighted PM2.5 concentration in Korea was 30.2 µg/m3. The estimated number of premature deaths was 17,203 (95% confidence interval [CI], 11,056-22,772). The most common CoD was ischemic stroke (5,382; 3,101-7,403), followed by cancer of trachea, bronchus, and lung (4,958; 2,857-6,820), hemorrhagic stroke (3,452; 1,989-4,748), and ischemic heart disease (3,432; 1,383-5,358). CONCLUSION: Premature deaths due to long-term exposure to PM2.5 accounted for 6.4% of all deaths in Korea. However, individual efforts alone cannot prevent the effects of air pollution. This disease burden study can serve as a basis for the establishment of government policies and budgets and can be used to assess the effectiveness of environmental health policies.

Estimation of the National Burden of Disease and Vulnerable Population Associated with Natural Disasters in Korea: Heavy Precipitation and Typhoon.

BACKGROUND: Despite its growing significance, studies on the burden of disease associated with natural disasters from the perspective of public health were few. This study aimed at estimating the national burden of disease associated with typhoons and torrential rains in Korea. METHODS: During the period of 2002-2012, 11 typhoons and five torrential rains were selected. Mortality and morbidities were defined as accentual death, injury and injury-related infection, and mental health. Their incidences were estimated from National Health Insurance Service. Case-crossover design was used to define the disaster-related excess mortality and morbidity. Disability-adjusted life years (DALYs) were directly assessed from excess mortality and morbidity. RESULTS: The burden of disease from typhoons increased with the intensity, with 107.7, 30.6, and 36.6 DALYs per 100,000 per event for strong, moderate, and weak typhoons, respectively. Burden of disease from torrential rains were 56.9, 52.8, and 26.4 DALYs per 100,000 per event for strong, moderate, and weak episodes, respectively. Mental disorders contributed more years lived with disability (YLDs) than did injuries in most cases, but the injury-induced YLDs associated with strong typhoon and torrential rain were higher than those of lower-intensity. The elderly was the most vulnerable to most types of disaster and storm intensities, and males younger than 65 years were more vulnerable to a strong torrential rain event. CONCLUSION: The intensity of torrential rain or typhoon was the strongest determinant of the burden of disease from natural disasters in Korea. Population vulnerable may vary depending on the nature and strength of the disasters.

Current and Projected Burden of Disease From High Ambient Temperature in Korea.

BACKGROUND: The objective of the present study was to estimate the current and projected burden of disease from high ambient temperature using population-based data sources of nationwide mortality and morbidity in Korea. METHODS: Disability-adjusted life years (DALY) were estimated using noninjury-related deaths, and cerebrovascular and cardiovascular diseases from recently released nationwide health and mortality databases. Years of life lost and years lost due to disability were measured based on the point prevalence and number of deaths during the study period. Future DALY attributable to heat waves were estimated from projected populations, and temperature predictions for the years 2030 and 2050 were under Representative Concentration Pathways (RCP) 4.5 and 8.5 with summertime temperatures above threshold. RESULTS: Relative risks (RR) of total mortality and of cardiovascular disease were 1.02 (95% CI, 1.01, 1.02) and 1.08 (95% CI, 1.06, 1.09) for each 1°C increase in temperature above threshold, respectively. The morbidity of heat-related disease was RR 1.67 (95% CI, 1.64, 1.68) for each 1°C increase in temperature above threshold. DALY for all-cause death were 0.49 DALY/1000 in 2011, 0.71 (0.71) DALY/1000 in 2030 and 0.77 (1.72) DALY/1000 in 2050 based on RCP 4.5 (RCP 8.5). DALY for cardio- and cerebrovascular diseases were 1.24 DALY/1000 in 2011, 1.63 (1.82) DALY/1000 in 2030, and 1.76 (3.66) DALY/1000 in 2050 based on RCP 4.5 (RCP 8.5). CONCLUSIONS: Future excess mortality due to high ambient temperature is expected to be profound in Korea. Efforts to mitigate climate change can provide substantial health benefits via reducing heat-related mortality.

The influence of climatic factors on the development of hemorrhagic fever with renal syndrome and leptospirosis during the peak season in Korea: an ecologic study.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) and leptospirosis are seasonal rodent-borne infections in the Republic of Korea (Korea). The occurrences of HFRS and leptospirosis are influenced by climatic variability. However, few studies have examined the effects of local climatic variables on the development of these infections. The purpose of this study was to estimate the effect of climatic factors on the occurrence of HFRS and leptospirosis in Korea. METHODS: Daily records on human cases of HFRS and leptospirosis between January 2001 to December 2009 were analyzed. The associations of climatic factors with these cases in high incidence provinces were estimated using the time-series method and multivariate generalized linear Poisson models with a maximal lag of 12 weeks. RESULTS: From 2001 to 2009, a total of 2912 HFRS and 889 leptospirosis cases were reported, with overall incidences of 0.67 and 0.21 cases per 100,000, respectively, in the study areas. The increase in minimum temperature (1 °C) at a lag of 11 weeks was associated with 17.8% [95% confidence interval (CI): 15.1, 20.6%] and 22.7% (95% CI: 16.5, 29.3%) increases in HFRS and leptospirosis cases, respectively. A 1-h increase in the daily sunshine was related to a 27.5% (95% CI: 18.2, 37.6%) increase in HFRS at a lag of 0 week. A 1% increase in daily minimum relative humidity and a 1 mm increase in daily rainfall were associated with 4.0% (95% CI:1.8, 6.1) and 2.0% (95% CI: 1.2, 2.8%) increases in weekly leptospirosis cases at 11 and 6 weeks later, respectively. A 1 mJ/m2 increase in daily solar radiation was associated with a 13.7% (95% CI: 4.9, 23.2%) increase in leptospirosis cases, maximized at a 2-week lag. CONCLUSIONS: During the peak season in Korea, climatic factors play a significant role in the development of HFRS and leptospirosis. The findings of this study may be applicable to the forecasting and prediction of disease outbreaks.

Exposure to phthalates and bisphenol A are associated with atopic dermatitis symptoms in children: a time-series analysis.

BACKGROUND: Despite increasing evidence on the relationship between exposure to phthalates and bisphenol A with allergies and asthma, reports on atopic dermatitis (AD) with these chemicals are few. We assessed the association between AD symptoms and the exposure to phthalates and bisphenol A and in children. METHODS: We surveyed 18 boys with AD (age 3-7 years) in a day care center in Seoul between May 2009 and April 2010. AD symptoms were recorded by using a daily symptom diary. We collected 460 series of pooled urine twice a day, in the morning and afternoon, over 230 working days and measured the concentrations of mono-2-ethyl-5-oxohexyl phthalate (5-oxo-MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (5-OH-MEHP), mono-isobutyl phthalate (MnBP) and bisphenol A glucuronide (BPAG) in the pooled urine. Logistic regression was used for statistical analysis. RESULTS: Most phthalate metabolite levels were higher in the morning than in the afternoon (p < 0.0001). There was seasonal variation in the levels of phthalates and bisphenol A metabolites. Levels of 5-OH-MEHP, MnBP, and BPAG were highest in summer (p < 0.0001). Manifestation of AD symptoms was associated with an increase in urinary levels of MnBP (adjusted odds ratio, aOR = 2.85, 95% CI: 1.12-7.26 per 1 µg/L of MnBP) and BPAG (aOR = 1.79, 95% CI: 0.91-3.52 per 1 µg/L BPAG) on the same day. The levels of MnBP and BPAG in the previous day increased AD symptoms (aOR = 2.74, 95% CI: 1.21-6.20, for 1 µg/L of MnBP and aOR = 2.01, 95% CI: 1.08-3.74 for 1 µg/L BPAG). CONCLUSION: Our results suggest that exposure to phthalates and bisphenol A is associated with aggravation of AD symptoms in children.

Association of carbon monoxide levels with allergic diseases in children.

BACKGROUND: Air pollution is regarded as a potential reason for the development or aggravation of allergic diseases. OBJECTIVE: To investigate the relationship between exposure to outdoor air pollution during the first year of life and the development of allergic diseases, and to determine the association between outdoor air pollution near the residence and recent symptoms of allergic diseases in children. METHODS: A nationwide cross-sectional survey was conducted in 6- to 7-year-old children. Among them, subjects who had been born (n = 1828) or lived (n = 1894) within 2 km of the nearest air quality monitoring sites were selected. The prevalence of allergic diseases was assessed by using questionnaires. Each subject was examined by pediatricians to determine the presence of eczema. Publicly available data were used regarding the daily ambient concentrations of sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide (CO), and particulate matter. RESULTS: For a 100 ppb increase in the mean daily CO level during the first year of life, the adjusted odds ratio for lifetime allergic rhinitis was 1.10 (95% confidence interval, 1.03-1.19). For a 1 ppm increase in the annual average CO level during the past 12 months, the adjusted odds ratio for the presence of atopic dermatitis on the day of the survey was 8.11 (95% confidence interval, 1.06-62.12). However, the other air pollutants showed no statistical significance. CONCLUSIONS: Higher exposure to CO during infancy increased the risk of development of allergic rhinitis. The risk of current atopic dermatitis symptoms increased in children who were exposed to higher CO levels during the past 12 months.

Affecting Factors of Secondhand Smoke Exposure in Korea: Focused on Different Exposure Locations.

Exposure to secondhand smoke (SHS) not only can cause serious illness, but is also an economic and social burden. Contextual and individual factors of non-smoker exposure to SHS depend on location. However, studies focusing on this subject are lacking. In this study, we described and compared the factors related to SHS exposure according to location in Korea. Regarding individual factors related to SHS exposure, a common individual variable model and location-specific variable model was used to evaluate SHS exposure at home/work/public locations based on sex. In common individual variables, such as age, and smoking status showed different relationships with SHS exposure in different locations. Among home-related variables, housing type and family with a single father and unmarried children showed the strongest positive relationships with SHS exposure in both males and females. In the workplace, service and sales workers, blue-collar workers, and manual laborers showed the strongest positive association with SHS exposure in males and females. For multilevel analysis in public places, only SHS exposure in females was positively related with cancer screening rate. Exposure to SHS in public places showed a positive relationship with drinking rate and single-parent family in males and females. The problem of SHS embodies social policies and interactions between individuals and social contextual factors. Policy makers should consider the contextual factors of specific locations and regional and individual context, along with differences between males and females, to develop effective strategies for reducing SHS exposure.

Survival in Subcortical Vascular Dementia: Predictors and Comparison to Probable Alzheimer's Disease in a Tertiary Memory Clinic Population.

BACKGROUND: Subcortical vascular dementia (SVaD) is one of the most common dementias, after Alzheimer's disease (AD) dementia. Few survival analyses in SVaD patients have been reported. METHODS: The dates and causes of death of 146 SVaD and 725 AD patients were included. We used the Cox proportional hazards model to compare survival between SVaD and AD patients and to explore possible factors related to survival of SVaD patients. RESULTS: The median survival time after the onset of SVaD (109 months) was shorter than that recorded for AD (152 months). The most common cause of death in SVaD was stroke (47.1%). Factors associated with shorter survival in SVaD were late onset, male sex, worse baseline cognition, absence of hypertension and a family history of stroke. CONCLUSIONS: Stroke prevention may be important in SVaD treatment because 47.1% of SVaD patients died of stroke. A family history of stroke and absence of hypertension were associated with a shorter survival in SVaD, suggesting the existence of genetic or unknown risk factors.

A cluster of lung injury cases associated with home humidifier use: an epidemiological investigation.

BACKGROUND: In April 2011 a tertiary hospital in Seoul, Korea reported several cases of severe respiratory distress of unknown origin in young adults. METHODS: To find the route of transmission, causative agent and patient risk factors of the outbreak, an investigation of the epidemic was initiated. Clinicopathological conferences led to the suspicion that the cases related to an inhalation injury. An age- and sex-matched case-control study was therefore performed to examine the inhalation exposure of the patients to various agents. RESULTS: Of the 28 confirmed cases, 18 agreed to participate. A total of 121 age- and sex-matched controls with pulmonary, allergic or obstetric disease were selected. All patients and controls completed questionnaires with questions about exposure to various inhalants. The crude ORs for patient exposure to indoor mould, humidifier use, humidifier detergent use and insecticide use were 4.4 (95% CI 1.5 to 13.1), 13.7 (95% CI 1.8 to 106.3), 47.3 (95% CI 6.1 to 369.7) and 3.9 (95% CI 1.3 to 11.7), respectively. However, when considered concurrently, indoor mould and insecticide use lost statistical significance. Moreover, humidifier use was ruled out as the cause because of a lack of biological plausibility and the weak strength of the association. This suggested that humidifier disinfectant was the cause of the outbreak. This information led the Korean government to order the removal of humidifier detergents from the market. In the years following the ban, no additional cases were detected. CONCLUSIONS: Epidemiological evidence strongly suggests that the lung injury outbreak was caused by humidifier detergent use at home.

Clinical characteristics of patients with treated epilepsy in Korea: a nationwide epidemiologic study.

OBJECTIVE: Although a number of epidemiologic studies have been conducted on the prevalence and incidence of epilepsy around the world, only a few studies have investigated the clinical characteristics of patients with epilepsy in a population-based sample. The purpose of the present study was to describe the clinical characteristics of treated patients with epilepsy in Korea via a nationwide medical records survey. METHODS: The study population was obtained through a nationwide database registered to the Health Insurance Review and Assessment service. Patients were recruited from clinics and hospitals in each cluster according to region and referral level by random selection from a preallocated sample of patients. All patients were being treated with antiepileptic drug medication with or without a diagnosis code for epilepsy or seizure between January 2009 and December 2009. Among the 6,436 selected patients, 2,150 met the diagnostic criteria for epilepsy and were included in our survey on the clinical characteristics of patients who were with treated epilepsy. RESULTS: The proportion of male patients with epilepsy in this study was higher (1,226; 57.0%) than that of female patients. In addition, 10.6% of patients were first diagnosed with epilepsy in 2009, and 53.6% of patients experienced at least one seizure over the course of 2009; 78.1% were classified as having localization-related epilepsy, whereas 7.3% were considered to have generalized epilepsy. Thirty-five percent of patients were thus classified as idiopathic or cryptogenic cases. The most common cause of symptomatic epilepsy was trauma (10.0%), followed by stroke (9.6%), central nervous system (CNS) infection (5.7%), and hippocampal sclerosis (4.9%). SIGNIFICANCE: This is the first nationwide study of the clinical characteristics of treated epilepsy in Korea using a national database validated by medical records survey. The etiologies of epilepsy and epilepsy syndrome classifications were comparable to those previously reported in other developed countries.