Gaps in universal health coverage in South Korea: Association with depression onset in a community cohort.

BACKGROUND: While controversies on limitation of coverage by the national health insurance and relatively high direct or "out-of-pocket" household payments by the national health insurance in South Korea still remain, potential unfavorable influence of the insufficiency of the universal health coverage on depression has not yet been evaluated. METHODS AND FINDINGS: Baseline information were obtained from a community cohort (The Korean Genome and Epidemiology Study) of middle-aged subjects without depression at enrollment period (2001-2002). Subjects were followed-up biennially, and new onset depression was assessed using Becks Depression Inventory at 2nd round follow-up (2005-2006). Influence of direct medical expenditure on depression onset was investigated in all subjects and in stratified groups of different income level. Increasing risk of depression onset was observed for increased medical expenditure (OR [95% CI];1.44 [0.97-2.13], 1.90 [1.19-3.05], 1.71 [1.01-2.91] for spending <50000 KRW, 50000-100000 KRW, and ≥100000 KRW, respectively, vs. almost no expenditure per month; P for trend = 0.012), after adjusting for covariates such as monthly income and chronic disease history. Similar associations were observed in subjects less than or at average national income, but results were not significant in subgroup with monthly income above national average. CONCLUSIONS: Even with the universal coverage, high co-payments and uninsured services in the Korean health insurance system yet possibly make the insured pay much for medical service utilization. This might have led to onset of an unfavorable health condition such as depression.

Risk assessment for phthalate exposures in the elderly: A repeated biomonitoring study.

Recent studies indicated that exposure to phthalates affects the development of a variety of diseases in the elderly population. However, limited information was available about the variability of phthalate daily intakes (DIs) and the proportion of the population that is highly exposed to phthalates. Therefore, we measured the levels of three phthalate metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-n-butyl phthalate (MnBP) in 4014 urine samples repeatedly collected from 1646 elderly people. The DIs of di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were calculated using urinary MEHHP, MEOHP, and MnBP levels, and then the proportion of the population that was highly exposed to DEHP and DnBP was calculated. The intra-class correlation (ICC) for MEHHP, MEOHP, and MnBP levels was 0.07, 0.02, and 0.03, respectively, and exposures to DEHP and DnBP were strongly correlated with each other (correlation coefficient=0.89 and p-value<0.0001). The geometric mean of estimated DI was 8.8µg/kgbody-weight/day (range 0.005-3382.0) for DEHP and 1.5µg/kgbody-weight/day (range 0.0002-1076.8) for DnBP. The percentages of urine samples with DEHP > reference dose (RfD, 20µg/kgbody-weight/day) and DnBP > tolerable daily intake (TDI, 10µg/kgbody-weight/day) were 20.2% and 3.6%, respectively. The Korean elderly were co-exposed to DEHP and DnBP, and the variation of DEHP and DnBP metabolite levels was mainly attributed to intra-individual variation, rather than inter-individual variation. Furthermore, Korean elderly were exposed to the hazards of DEHP and DnBP based on the high level of the exceedance rate over TDI or RfD for DEHP and DnBP. Since the elderly are very susceptible to environmental pollutants, the harmful effects of DEHP and DnBP in the elderly population should be further studied in the future.

Effects of perceived job insecurity on depression, suicide ideation, and decline in self-rated health in Korea: a population-based panel study.

PURPOSE: To investigate the effects of job security on new development of depressive episode, suicide ideation, and decline in self-rated health. METHODS: Data from the Korea Welfare Panel Study from 2012 to 2015 were analysed. A total of 2912 waged workers self-assessed their depressive episode, suicide ideation, and health annually by answering the questionnaire. Participants were divided into three groups according to the level of job security: high, intermediate and low. To evaluate the influence of job security, we performed survival analysis after stratification by gender with adjustment for covariates. The result was further stratified by whether the respondent was the head of household. RESULTS: After adjusting for covariates, men in low job security group showed significantly higher hazard ratios (HRs) for depression (HR 1.27, 95% CI 1.01-1.60), suicide ideation (HR 3.25, 95% CI 1.72-6.16), and decline in self-rated health (HR 1.73, 95% CI 1.16-2.59). Women showed significantly higher HR of depression in the intermediate (HR 1.37, 95% CI 1.01-1.87) and low (HR 1.50, 95% CI 1.12-1.99) job security group. Male head of household with low job security showed significantly higher HR of depression, suicide ideation, and decline in self-rated health. Non-head-of-household women with intermediate and low job security showed higher risk of depression than those with high job security. CONCLUSIONS: We found that perceived job insecurity is associated with the new development of depressive episode, suicide ideation, and decline in self-rated health.

Maternal Stress and Depressive Symptoms and Infant Development at Six Months: the Mothers and Children's Environmental Health (MOCEH) Prospective Study.

Our objective is to evaluate the relationships between prenatal maternal stress and depressive symptoms, respectively, and infant neurodevelopment at 6 months, adjusted for heavy metals and oxidative stress. This research is a part of a multi-center birth cohort study in South Korea. Information on stress and depressive symptoms was collected during the first trimester using Psychosocial Well-Being Index Short Form (PWI-SF) and Center for Epidemiological Studies Depression Scale (CES-D). The Korean Bayley Scales of Infant Development-II assessment (BSID-II), which includes the standardized mental development index (MDI) and psychomotor developmental index (PDI), and Korean Ages & Stages Questionnaires (K-ASQ) were applied to infants at six months of age. A higher index score indicates better development. Among 641 babies, 320 were female (50%). Maternal PWI ≥ 29 (vs. PWI ≤ 18) during early pregnancy was associated with a decrease in MDI scores of 5.37 points (P = 0.02) after adjusting for socioeconomic factors. Maternal CES-D ≥ 26 (vs. CES-D ≤ 10) during early pregnancy was associated with a decrease in MDI scores of 8.18 points (P = 0.01). The associations remained significant even after adjustment for lead, cadmium, and MDA levels (P < 0.05). However, no association was found between maternal PWI/CES-D and PDI score. No interaction was observed between stress and lead exposure. We found an inverse association between prenatal maternal stress and depressive symptoms, and MDI scores in 6-month-old infants after adjustment for prenatal lead exposure, which is known to affect cognitive function negatively.

Increased prevalence of some birth defects in Korea, 2009-2010.

BACKGROUND: Birth defects are a leading cause of neonatal and infant mortality, and several studies have indicated an increase in the prevalence of birth defects; more recent investigations have suggested that the trends of some defects are increasing in rapidly industrialized areas. This study estimates the prevalence rate and types of birth defects in Korea. METHODS: This study used medical insurance benefit data of 403,250 infants aged less than one year from the National Health Insurance Corporation from seven metropolitan areas in Korea for 2009 and 2010. RESULTS: The prevalence rate of birth defects was 548.3 per 10,000 births (95% CI: 541.1-555.6), 306.8 among boys and 241.5 among girls. Anomalies of the circulatory system (particularly septal defects) were the most common (180.8 per 10,000), followed by defects of the genitourinary tract (130.1 per 10,000) (particularly obstructive genitourinary and undescended testis), musculoskeletal system (105.7 per 10,000), digestive system (24.7 per 10,000), and central nervous system (15.6 per 10,000). CONCLUSIONS: Relatively higher rates of some birth defects were found in the metropolitan areas. The high differences of birth prevalences for septal heart defects and undescended testis are probably due in part to progress in clinical management and more frequent prenatal diagnosis. Environmental exposure might play a critical role in the development of some birth defects. In attempting to describe the prevalence and spatio-temporal variations of birth defects in Korea, establishment of a registry system of birth defects and environmental surveillance are needed.

Ten-year trends in urinary concentrations of triclosan and benzophenone-3 in the general U.S. population from 2003 to 2012.

Despite their popular use and emerging evidences of adverse health effects, consequent trends in population level triclosan and benzophenone-3 exposure have been poorly evaluated. Therefore, we examined temporal trends of urinary triclosan and benzophenone-3 concentration in the general U.S. population by combining five cycles of National Health and Nutritional Examination Survey (NHANES, 2003-2012) data. We calculated percent changes and the least square geometric means (LSGMs) of urinary triclosan and benzophenone-3 concentration from 10,232 participants by using multivariable regression models. As a result, LSGM concentration of urinary triclosan and benzophenone-3 did not show statistically significant changes over the study period. [Percent change (95% CI): Triclosan, -7.35% (-20.86, 8.47); Benzophenone-3, 7.08% (-27.88, 58.99)] However, we found decreasing trend of urinary triclosan concentration and increasing trend of urinary benzophenone-3 concentration since 2005-2006. Socio-demographic factors which affected urinary concentration of triclosan and benzophenone-3 persisted throughout 10 year study period. Highest income group showed higher level of urinary triclosan and benzophenone-3 concentration. Overall concentration of benzophenone-3 was higher in female than in male, and higher in non-Hispanic Whites than any other races/ethnicities.

Health Impact Assessment of PM10 and PM2.5 in 27 Southeast and East Asian Cities.

OBJECTIVE: We aimed to evaluate the annual health impacts of particulate matter (PM) less than 10 µm diameter (PM10) and less than 2.5-µm diameter (PM2.5) in 27 cities in Southeast and East Asian countries (Japan, the Philippines, the Republic of Korea, Singapore, and Vietnam) for the year 2009 (n = 50,756,699). METHODS: We estimated the number of cases attributable to long-term exposure. We used a scenario that reduced the annual mean values for PM10 and PM2.5 to 20 and 10 µg/m, respectively. RESULTS: A reduction in long-term exposure to PM10 and PM2.5 would have postponed 8% to 9% of all-cause mortality or about 37,000 deaths. One third of them were associated with cardiopulmonary mortality and one ninth of them were associated with lung cancer mortality. CONCLUSIONS: Current air pollution levels in Southeast and East Asian countries have a nonnegligible public health impact.

Maternal iron intake at mid-pregnancy is associated with reduced fetal growth: results from Mothers and Children's Environmental Health (MOCEH) study.

BACKGROUND: Iron supplementation is a common recommendation for pregnant women to prevent iron deficiency during pregnancy. There is an increasing concern about excessive iron consumption as a general iron prophylaxis by pregnant women without any due consideration about their dietary iron intake or iron status. Our present study investigated the association between total iron intake from diet and supplements and fetal growth in 337 pregnant women at mid-pregnancy in South Korea. METHODS: Iron intake from diet and supplements was examined by a 24-hour recall method. Subjects were divided into three groups based on tertiles of total iron intake levels. Fetal biometry was assessed by ultrasonography at mid-pregnancy. RESULTS: About 99% of the non-supplement users had iron intake below the recommended nutrient intake (RNI) for pregnant women (24 mg), whereas 64.9% of supplement users had iron intake above the upper level (UL) (45 mg). In the babies of mothers in the third tertile of iron intake (>17.04 mg), biparietal diameter, abdominal circumference, and femur length were lower by 0.41 cm (P =0.019), 0.41 cm (P = 0.027), and 0.07 cm (P = 0.051), respectively, than the babies of mothers in the second tertile of iron intake (11.49 ~ 17.04 mg). CONCLUSION: These results suggest that excessive maternal iron intake at mid-pregnancy is associated with reduced fetal growth. Iron supplementation for pregnant women should be individualized according to their iron status. Appropriate diet education is needed for pregnant women so that they can consume adequate amounts of iron from food and supplements.

Assessment of exposure to heavy metals and health risks among residents near abandoned metal mines in Goseong, Korea.

Metal contamination from mining activity is of great concern because of potential health risks to the local inhabitants. In the present study, we investigated the levels of Cd, Cu, As, Pb, and Zn in environmental samples and foodstuffs grown in the vicinity of the mines in Goseong, Korea, and evaluated potential health risks among local residents. Soils near the mines exceeded the soil quality standard values of Cu, As, and Zn contamination. The concentrations of Cd, Cu, Pb, and Zn in crop samples collected from the study area were significantly higher than those of the reference area. Some rice samples collected from the study area exceeded the maximum permissible level of 0.2 mg Cd/kg. The intake of rice was identified as a major contributor (≥75%) to the estimated daily intake among the residents. The average estimated daily intakes of metals were, however, below the provisional tolerable daily intake.

Association between environmental tobacco smoke exposure of children and parental socioeconomic status: a cross-sectional study in Korea.

INTRODUCTION: It has been reported that most environmental tobacco smoke (ETS) exposure of children occurs at home, and lower parental socioeconomic status (SES) increases the risk of this exposure. We estimated the independent and interactive effects of parental SES and residential area SES on ETS exposure of children at home. METHODS: We evaluated whether ETS exposure was associated with parental SES by entering data from 7,059 school-aged children in Korea into fixed effects models. The empirical model, including the interaction variable of the level of deprivation of each residential area, was fitted with parental SES. RESULTS: After adjustment for possible confounding variables, low paternal education (odds ratio [OR], 1.81; 95% CI, 1.30-2.54) and highly deprived areas (OR, 1.34; 95% CI, 1.06-1.69) were significantly associated with the ETS exposure of children, especially among children whose fathers had <12 years of education and lived in the most deprived area (OR, 2.04; 95% CI, 1.04-4.02). CONCLUSIONS: Our findings suggest that the SES of residential areas may influence the ETS exposure of children directly, as well as interactively with parental SES, in Korea. Findings from this study will help inform policy decision makers that intervention to promote smoking cessation should consider not only the SES of individuals but also that of residential areas.

The Mothers and Children's Environmental Health (MOCEH) study.

The MOCEH study is a prospective hospital- and community-based cohort study designed to collect information related to environmental exposures (chemical, biological, nutritional, physical, and psychosocial) during pregnancy and childhood and to examine how exposure to environmental pollutants affects growth, development, and disease. The MOCEH network includes one coordinating center, four local centers responsible for recruiting pregnant women, and four evaluation centers (a nutrition center, bio-repository center, neurocognitive development center, and environment assessment center). At the local centers, trained nurses interview the participants to gather information regarding their demographic and socioeconomic characteristics, complications related to the current gestation period, health behaviors and environmental factors. These centers also collect samples of blood, placenta, urine, and breast milk. Environmental hygienists measure each participant's level of exposure to indoor and outdoor pollutants during the pre- and postnatal periods. The participants are followed up through delivery and until the child is 5 years of age. The MOCEH study plans to recruit 1,500 pregnant women between 2006 and 2010 and to perform follow-up studies on their children. We expect this study to provide evidence to support the hypothesis that the gestational environment has an effect on the development of diseases during adulthood. We also expect the study results to enable evaluation of latency and age-specific susceptibility to exposure to hazardous environmental pollutants, evaluation of growth retardation focused on environmental and genetic risk factors, selection of target environmental diseases in children, development of an environmental health index, and establishment of a national policy for improving the health of pregnant women and their children.

[Environmental health surveillance of low birth weight in Seoul using air monitoring and birth data].

OBJECTIVES: The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight. METHODS: We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within 37-44 weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for CO, SO(2), NO(2), and PM(10) concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1. RESULTS: LBW risk (by Gu, or district) was significantly increased to 1.113(95% CI=1.111-1.116) for CO, 1.004 (95% CI=1.003-1.005) for NO(2), 1.202(95% CI=1.199-1.206) for SO(2), and 1.077(95% CI=1.075-1.078) for PM(10) with each interquartile range change. Personal LBW risk was significantly increased to 1.081(95% CI=1.002-1.166) for CO, 1.145(95% CI=1.036-1.267) for SO(2), and 1.053(95% CI=1.002-1.108) for PM(10) with each interquartile range change. Personal LBW risk was increased to 1.003(95% CI=0.954-1.055) for NO(2), but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions. CONCLUSIONS: Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition, environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.