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Asbestos is a carcinogen associated with lung cancer, but few studies have examined the increased risk of lung cancer due to environmental asbestos exposure. We performed a systematic review and meta-analysis to evaluate the association between environmental asbestos exposure and lung cancer. We searched for articles on non-occupational or environmental asbestos exposure and lung cancer in PubMed, EMBASE, CINAHL and Web of Science databases. Our review included 15 studies, and except studies on ingestion exposure we performed a meta-analysis for 13 studies with respect to the type of exposure (neighbourhood and domestic/household exposure). Subgroup analyses and meta-regression were also performed. A significant increase in the risk of lung cancer was found for neighbourhood exposure (1.48, 95% CI 1.18 to 1.86), while the risk was not significantly increased for domestic/household exposure (1.04, 95% CI 0.85 to 1.27). With regard to neighbourhood exposure, naturally occurring asbestos and women were both associated with a higher risk of lung cancer; however, such an increase was not significantly greater compared with that associated with other sources of asbestos exposure and men. Although cautious interpretation is needed due to the large degree of heterogeneity and the small number of included studies, our findings imply that living near the source of asbestos increases the risk of lung cancer.

Background Formaldehyde exposure is associated with nasopharyngeal cancer and leukemia. Previously-described links between formaldehyde exposure and lung cancer have been weak and inconsistent. We performed a systematic review and meta-analysis to evaluate quantitatively the association between formaldehyde exposure and lung cancer. Methods We searched for articles on occupational formaldehyde exposure and lung cancer in PubMed, EMBASE, Web of Science, and CINAHL databases. In total, 32 articles were selected and 31 studies were included in a meta-analysis. Subgroup analyses and quality assessments were also performed. Results The risk of lung cancer among workers exposed to formaldehyde was not significantly increased, with an overall pooled risk estimate of 1.04 (95% confidence interval [CI], 0.97-1.12). The pooled risk estimate of lung cancer was increased when higher exposure studies were considered (1.19; 95% CI, 0.96-1.46). More statistically robust results were obtained when high quality (1.13; 95% CI, 1.08-1.19) and recent (1.13; 95% CI, 1.07-1.19) studies were used in deriving pooled risk estimates. Conclusions No significant increase in the risk of lung cancer was evident in the overall pooled risk estimate; even in higher formaldehyde exposure groups. Our findings do not provide strong evidence in favor of formaldehyde as a risk factor for lung cancer. However, since risk estimates were significantly increased for high-quality and recent studies, the possibility that exposure to formaldehyde can increase the risk of lung cancer might still be considered.

Backdground Phthalates and bisphenol A (BPA) have been used in a variety of consumer products and are detected widely in both humans and the environment. Demographic and socio-economic characteristics that affect exposure to these chemicals have been investigated among several general populations; however, nationally-representative population-based studies are limited to Canada, Germany, and the USA. Moreover, relatively little is known about the socio-demographic characteristics that influence exposure to these chemicals among nationally representative populations of Asia. Methods Data are obtained from the Korean National Environmental Health Survey (2012–2014). In total, 6,478 adults (aged 19 and older) were recruited and sampled for urinary levels of major phthalate metabolites and bisphenol A. In addition, demographic and socio-economic parameters were determined from questionnaire data and the characteristics associated with urinary concentrations of the target chemicals were assessed. Results Urinary levels of bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) metabolites of Korean adults were generally higher, but those of mono-benzyl phthalate (MBzP) were lower, and BPA were similar or higher than those reported from national biomonitoring programs in the United States and Canada. Similar to other nationally representative populations, females and older adults showed higher creatinine-adjusted phthalate metabolite and BPA levels among the Korean population. Meanwhile, monthly household income and education were negatively associated with urinary phthalate metabolites. Among personal care products, nail polish use was positively associated with both phthalate metabolites and BPA concentrations in urine. Conclusion Our observations based on a nationally representative population of Korea show that socio-demographic determinants for these urinary chemicals vary by country, and should be considered for developing appropriate mitigation measures and policies.

The use of asbestos has been banned since 2009 in South Korea. However, there is still a risk of exposure to environmental asbestos originating from abandoned asbestos mines. We constructed a retrospective dynamic cohort using the National Health Insurance Database of South Korea. We determined the risk of developing asbestos-related diseases (ARDs) among residents living near asbestos mines compared with those living in the control area and the general population. The risks of asbestosis (adjusted hazards ratio [HR] 65.40, 95% CI = 35.02&ndash, 122.12) and pleural plaques (adjusted HR 3.55, 95% CI = 1.96&ndash, 6.41) were significantly increased among residents living near the asbestos mines compared with the control area. The risk of malignant mesothelioma was increased near asbestos mines compared with the control area, however, it was not significant (adjusted HR 1.83, 95% CI = 0.61&ndash, 5.47). When a separate analysis according to sex was conducted, the risk of mesothelioma among male residents was statistically significant (adjusted HR 8.30, 95% CI = 1.04&ndash, 66.63), and the standardized incidence ratio (SIR) was significantly increased (SIR 3.48, 95% CI = 1.50&ndash, 6.85). The risk of ARDs was increased due to environmental asbestos exposure near abandoned asbestos mines in South Korea.

From 2002 through 2015, hundreds of people died of fatal lung injuries associated with the use of humidifier disinfectants (HDs) in Korea. Several chemical disinfectants used for household humidifiers were later clinically confirmed to cause HD-associated lung injury (HDLI). The aim of this study is to evaluate the registered lung disease cases and to compare the distribution of HDLI patients, including deaths, by HD use characteristics including types of HD and HD brands categorized by age group. A total of 530 registered were clinically examined through two rounds of investigations conducted from July 2013 until April 2015. Information on HD use was obtained from a structured questionnaire and home investigations. Approximately one-half of the patients (n=221) were clinically confirmed to be associated with the use of HDs. Pregnant women (n=35, 16%) and pre-school children≤6years old (n=128, 58%) accounted for most of the HD-associated lung injury patients (n=163, 74%). Sixty-seven percent of HDLI patients developed HDLI after less than one year of HD use. HD products containing polyhexamethylene guanidine phosphate (PHMG) were the most frequently used among confirmed HDLI patients (n=123, 55.7%), followed by oligo (2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). Other HDs did not appear to be linked to HDLI. The majority of the HDLI patients (n=85, 38.5%) was found to use only Oxy Saksak® products containing PHMG. The development of HDLI was clinically found to be associated with the use of several HD products containing PHMG and PGH, and to lesser extent, CMIT/MIT.

Background Phthalates and bisphenol A (BPA) have been used extensively in many consumer products, resulting in widespread exposure in the general population. Studies have suggested associations between exposure to phthalates and BPA, and serum thyroid hormone levels, but confirmation on larger human populations is warranted. Methods Data obtained from nationally representative Korean adults (n = 6003) recruited for the second round of the Korean National Environmental Health Survey (KoNEHS), 2012–2014, were employed. Three di-(2-ethylhexyl) phthalate (DEHP) metabolites, along with benzyl-butyl phthalate (BBzP) and di-butyl phthalate (DBP) metabolites, and BPA were measured in subjects' urine. Thyroxine (T4), total triiodothyronine (T3), and thyroid-stimulating hormone (TSH) were measured in serum. The associations between urinary phthalates or BPA and thyroid hormone levels were determined. Results Urinary phthalate metabolites were generally associated with lowered total T4 or T3, or increased TSH levels in serum. Interquartile range (IQR) increases of mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were associated with a 3.7% increase of TSH, and a 1.7% decrease of total T4 levels, respectively. When grouped by sex, urinary MEHHP levels were inversely associated with T4 only among males. Among females, mono-benzyl phthalate (MBzP) and mono- n -butyl phthalate (MnBP) levels were inversely associated with TSH and T3, respectively. In addition, negative association between BPA and TSH was observed. Conclusions Several phthalates and BPA exposures were associated with altered circulatory thyroid hormone levels among general Korean adult population. Considering the importance of thyroid hormones, public health implications of such alteration warrant further studies.

Malignant mesothelioma (MM) is a cancer that is largely caused by exposure to asbestos. Although asbestos is no longer used in South Korea, the incidence of MM continues to increase due to its long latent period. We aimed to update the previous prediction of MM incidence until 2038. We predicted the incidence of MM over the next 20 years (2019–2038) in South Korea using Møller’s age–period–cohort (APC) model and a Poisson regression model based on asbestos consumption. The APC model predicted that the crude incidence rate would increase sharply in men and slowly in women. Despite the sex discrepancy in the rate of increase, the incidence rate for both sexes is expected to continue increasing until 2038. In the Poisson model, the crude incidence rate was predicted to increase continuously until 2038, and far more cases of MM were predicted to occur compared with the results of the APC model. When compared with actual incidence data, the APC model was deemed more suitable than the Poisson model. The APC model predicted a continuous increase over the next 20 years with no peak, suggesting that the incidence of MM will continue to rise far into the future.

Background: A 20-year follow-up study on cancer incidence among people living near nuclear power plants in South Korea ended in 2011 with a finding of significantly, but inconsistently, elevated thyroid cancer risk for females. Reanalysis of the original study was carried out to examine the dose–response relationship further, and to investigate any evidence of detection bias. Methods: In addition to replicating the original Cox proportional hazards models, nested case-control analysis was carried out for all subjects and for four different birth cohorts to examine the effects of excluding participants with pre-existing cancer history at enrollment. The potential for detection bias was investigated using the records of medical utilization and voluntary health checks of comparison groups. Results: The overall risk profile of the total sample was similar to that of the original study. However, in the stratified analysis of four birth cohorts, the cancer risk among people living near nuclear power plants became higher in younger birth cohorts. This was especially true for thyroid cancers of females (hazard ratio (HR) 3.38) and males (HR 1.74), female breast cancers (HR 2.24), and radiation-related cancers (HR 1.59 for males, HR 1.77 for females), but not for radiation-insensitive cancers (HR 0.59 for males, HR 0.98 for females). Based on medical records and health check reports, we found no differences between comparison groups that could have led to detection bias. Conclusions: The overall results suggest elevated risk of radiation-related cancers among residents living near nuclear power plants, controlling for the selective survival effect. This is further supported by the lack of evidence of detection bias and by records of environmental exposure from radiation waste discharge.

Humidifier disinfectant lung injury is an acute lung disease attributed to recurrent inhalation of certain disinfectant aerosols emitted from room humidifiers. An outbreak of this toxic lung injury occurred in South Korea from 1995 until all humidifier disinfectant products were recalled from the consumer market by the government in 2011.A nationwide study was conducted to ascertain and classify all potential cases of humidifier disinfectant lung injury in Korea and to assess dose-response relationships.By several mechanisms, clinicians and the general public were invited to report all suspected cases of humidifier disinfectant lung injury to public health officials in South Korea. A committee was convened to define diagnostic criteria based on pathologic, radiologic, and clinical findings for index cases, combined with assessment of environmental exposure to humidifier disinfectants. Clinical review and environmental assessments were performed and later combined to determine overall likelihood of disease for each study participant, classified as definite, probable, possible, or unlikely. Survival time from exposure to onset of symptoms was analyzed to assess dose-response relationships. Three broad categories of risk factors were examined: (1) biological susceptibility, (2) temporal cycle of exposure and recovery, and (3) spatial conditions and density of disinfectant.Of 374 possible cases identified and reviewed, 329 were unanimously classified by the diagnostic committee, as follows: 117 definite, 34 probable, 38 possible and 140 unlikely cases. A total of 62 individuals with definite or probable disease died. Risk factors examined for polyhexamethyleneguanidine phosphate exposure that were found to be significant in shortening survival included age 4 years or younger at onset, use of disinfectant for 7 days per week, airborne density of 800 μg/m(3) or more of disinfectant, and daily exposure 11 or more hours in duration.Dose-response analysis indicated that development of humidifier disinfectant lung injury and death were associated strongly with recurrent, intense, acute exposure without sufficient recovery time between exposures, more so than long-term cumulative exposure. These findings may explain some reversible or clinically unapparent cases among coexposed family members.

The oil tanker Hebei Spirit spilled 12,547kL of oil near the western coastline of Korea on December 7, 2007. We aimed to investigate the relationship between oil spill exposure and oxidative stress in residents living near the affected area.Study subjects were 671 residents who participated in a health examination between February and September 2009. As surrogates for oil spill exposure, we used the total duration of clean-up work and levels of urinary metabolites of polycyclic aromatic hydrocarbons (PAHs), 1-hydroxypyrene (1-OHP) and 2-naphthol (2-NAPH). Oxidative stress was measured using urinary levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), indicators of lipid peroxidation and oxidative DNA damage, respectively.Levels of oxidative stress biomarkers were significantly increased with longer involvement in clean-up work over one year after the Hebei Spirit oil spill (MDA, p-trend0.0001; 8-OHdG, p-trend0.0001). As more time elapsed since the last involvement in clean-up, the total duration of clean-up work participation and levels of PAH metabolites (1-OHP and 2-NAPH), as well as levels of the oxidative stress biomarkers (MDA and 8-OHdG) decreased further. The level of 1-OHP had a significant positive correlation with the total duration of clean-up work involvement, with a higher level found in those who participated in clean-up for100 days. Increasing levels of 1-OHP were significantly associated with increased MDA and 8-OHdG after adjusting for covariates, while the strength of association weakened as time passed since the last participation in clean-up work. The significance of the association was maintained for up to 12 months after the last clean-up work.The results suggested that oil exposure from prolonged clean-up activity likely induced oxidative stress in clean-up participants up to at least one year after the last exposure.

ObjectivesThe purpose of this study was to investigate the combined effect of exposure to perceived risk at work and unstable employment on self-rated health in both Korea and the European Union.DesignCross-sectional study.SettingWe conducted the analyses using employees data from the third Korean Working Conditions Survey (KWCS) conducted in 2011 and the fifth European Working Conditions Survey (EWCS) conducted in 2010.ParticipantsEmployees of the third KWCS and the fifth EWCS from 35 European countries were the participants of the study.Primary outcome measuresEmployment status was divided into two categories: stable and unstable employment. Perceived risk regarding safety and health at work were assessed. Primary health outcomes were poor or moderate self-rated health. Exposures and health status were assessed via a questionnaire.ResultsAmong Korean employees, the OR of poor self-rated health was 2.00 (95% CI: 1.80 to 2.22) for those with perceived risk at work, 1.18 (95% CI: 1.09 to 1.28) for those with unstable employment and 3.22 (95% CI: 2.72 to 3.81) for those with both perceived risk at work and unstable employment. Relative excess risk due to interaction (RERI) was 1.03 (95% CI: 0.48 to 1.58). Among European employees, the OR for poor self-rated health was 3.20 (95% CI: 2.93 to 3.49) for those with perceived risk at work, 1.04 (95% CI: 0.97 to 1.13) for those with unstable employment and 3.41 (95% CI: 2.93 to 3.98) for those with both perceived risk at work and unstable employment. The RERI was 0.18 (95% CI: −0.36 to 0.71).ConclusionsAmong Korean employees, a supra-additive interaction between perceived risk at work and unstable employment on poor self-rated health was observed. Conversely, a supra-additive interaction was not observed among European employees.

The objective of this study was to assess the association between exposure to polycyclic aromatic hydrocarbons (PAHs) and oxidative stress among shipyard workers.We recruited 82 painting workers in a shipyard and age/sex matched 137 office workers from the same shipyard company. Urine samples were used to assess for 1-hydroxypyrene (1-OHP) as an exposure biomarker for PAHs and to assess for 8-iso-prostaglandin F2α (iPF) as a biomarker for oxidative stress. Demographics, smoking, alcohol consumption, and working conditions information were obtained from a questionnaire survey.Geometric mean concentration (±standard deviation) of urinary 1-OHP among painting workers (587.9 ± 3.45 ng/g creatinine) was approximately 6.9 times higher than that among office workers (85.6 ± 2.09 ng/g creatinine; P value0.001). Compared to the office workers (163.5 ± 1.84 ng/g creatinine), the painting workers (190.6 ± 1.64 ng/g creatinine) had significantly higher urinary levels of iPF (P value = 0.044). Smokers had significantly higher urinary levels of iPF than nonsmokers in both painting workers (smokers 217.0 ± 1.63; nonsmokers 159.2 ± 1.52 ng/g creatinine; P value = 0.011) and office workers (smokers 181.3 ± 1.79; nonsmokers 138.4 ± 1.90 ng/g creatinine; P value = 0.015). Smokers among office workers had higher urinary levels of iPF than nonsmokers among painting workers, but difference was not significant.Our results demonstrated that among shipyard workers, painting works were significantly associated with the exposure to PAHs, compared with the office works. However, iPF should be cautiously used to characterize the oxidative stress associated with the occupational PAHs exposure, because iPF is substantially affected by other factors such as smoking status.

While exposure to ambient fine particles2.5 μm in aerodynamic diameter (PM2.5) has well-established health effects, there is limited quantitative evidence that links specific sources of PM2.5 with those effects. This study was designed to examine the risks of exposure to chemical species and source-specific PM2.5 mass on mortality in Seoul, Korea, a highly populated city.We compare daily mortality counts with PM2.5 chemical speciation data collected every 3 days, as well as nine sources of PM2.5 mass resolved by a positive matrix factorization receptor model, from March 2003 through November 2007. A Poisson generalized linear model incorporating natural splines was used to evaluate associations of PM2.5 chemical species and sources with mortality.PM2.5 mass and several chemical species were associated with mortality. Organic carbon, elemental carbon, and lead were associated with mortality outcomes when using multipollutant models adjusted for other chemical species levels. Source-apportioned PM2.5 derived from mobile sources (ie, gasoline and diesel emissions) and biomass burning was associated with respiratory mortality and cardiovascular mortality, respectively. There were moderate associations of industry and of roadway emissions with cardiovascular mortality.Local combustion sources may be particularly important contributors to PM2.5, leading to adverse health effects.

Social inequality in adverse birth outcomes has been demonstrated in several countries. The present study examined the separate and joint effects of parental education and work in order to investigate the causal pathways of social class effects on adverse birth outcomes in Korea. The occurrence of low birth weight, preterm births, and intrauterine growth retardation was examined among 7,766,065 births in Korea from 1995 to 2008. The effect of social inequality, as represented by parental education and work, was examined against adverse birth outcomes using multivariate logistic regression after controlling for other covariates. Parental education had the most significant and greatest effect on all three adverse outcomes, followed by parental work and employment, which had lesser effects. For adverse birth outcomes, the gap between educational levels increased steadily in Korea from 1995 to 2008. Throughout the analysis, the effect of maternal manual work on adverse birth outcomes was apparent in the study results. Given this evidence of social inequality in education and employment, social interventions should aim at more in-depth and distal determinants of health.

Perfluoroalkyl acids (PFAAs) have been used in various industrial and consumer products for decades, and have consequently been detected in human blood worldwide. In the present study, general adult population in Daegu, Korea (n=140, >20 years of old) was recruited, collected for serum, and analyzed for 13 major PFAAs. The influence of dietary and water consumption on serum PFAA levels was also evaluated. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) were frequently detected with relatively higher concentrations in blood serum. Most PFAA concentrations except for PFOA were detected in higher concentrations among males, and were positively correlated with age and body mass index (BMI). PFOA concentrations were relatively higher among the female of childbearing age, e.g., 20-49years old, raising concerns on potential impacts on fetus through transplacental transfer or lactation. In addition, the concentrations of PFOA in Daegu population were higher than other areas of Korea, suggesting a presence of distinctive sources in the area. Among food items, potato consumption was identified to be significant contributor to serum PFOA. For PFUnDA and PFTrDA levels, intake of fish/shellfish was positively associated. The results of this study will be useful in developing public health management options for PFAAs.

Recent epidemiologic studies have shown that individuals with periodontitis have a significantly increased risk of metabolic syndrome (MetS). Chronic infection and subsequent production of systemic inflammatory markers may be associated with this increased risk. The aim of present study is to determine whether the presence of periodontitis and MetS is associated with a group or an individual of C-reactive protein (CRP), interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α (TNF-α), and homocysteine (HCY) in the serum of a Korean population.Medical and periodontal parameters, including CRP, IL-1β, IL-6, IL-8, TNF-α, and HCY, were evaluated in 118 individuals (73 healthy; 20 with periodontitis only; 13 with MetS only; and 12 with both). The community periodontal index was used to assess periodontitis. Age, sex, monthly household income, smoking, and drinking were evaluated as confounders. Analysis of covariance, linear regression analysis, and factor analysis were applied.The group of serologic cytokines was synergistically associated with the periodontitis-MetS coexistence. TNF-α and IL-6 were two representing serologic cytokines in the group.Our results suggest that a group of systemic biologic markers represented by TNF-α and IL-6 might mediate the association between MetS and periodontitis adjusted for various confounders. Additional evidence is needed to generalize our results more widely.

Although ambient particulate pollutants have been shown to exacerbate existing allergic symptoms of mucous membranes including rhinitis and asthma, the effects on skin such as atopic dermatitis in childhood deserve further study. We investigated the effects of urban particulate pollutants including ultrafine particles on atopic severity in children with atopic dermatitis. We included 41 schoolchildren, 8-12 years old, who had been diagnosed with atopic dermatitis. For 67 consecutive days, all of them measured their symptoms in a diary. To assess exposure, the daily ambient mass concentrations of particulate matter less than 10, 2.5 and 1 μm (PM(10), PM(2.5) and PM(1), respectively) and concentrations of submicron particles (0.01- 1 μm) were measured at a local school. The mean mass concentrations of PM(10), PM(2.5) and PM(1) were 74.0, 57.8 and 50.8 μg/m(3), respectively. The mean concentrations were 41,335/cm(3) ultrafine particles (UFPs) and 8577/cm(3) accumulation mode (0.1-1 μm) particles. Significant associations were found between the concentrations of ultrafine particles and the itchiness symptom in children with atopic dermatitis. An interquartile range (IQR) increase in previous day ultrafine particles concentration (IQR: 28-140/m(3)) was significantly associated with a 3.1% (95% confidence interval, 0.2-6.1) increase in the itch symptom score for children with atopic dermatitis. The results suggested that the concentration of ambient ultrafine particles may exacerbate skin symptoms in children with atopic dermatitis.

An association between cadmium exposure and bone mineral density (BMD) has been demonstrated in elderly women, but has not been well studied in youths and men. Some studies report either no or a weak association between cadmium exposure and bone damage.This study was designed to investigate the relationship between the urinary cadmium (U-Cd) levels and BMD of females and males of all ages.A total of 804 residents near an industrial complex were surveyed in 2007. U-Cd and BMD on the heel (non-dominant calcaneus) were analyzed with AAS-GTA and Dual-Energy X-ray absorptiometry, respectively. Demographic characteristics were collected by structured questionnaires. Osteoporosis and osteopenia were defined by BMD cut-off values and T-scores set by the WHO; T score-1, normal; -2.5T score-1, osteopenia; and T score-2.5, osteoporosis. Logistic and multiple linear regressions were applied to estimate the association between U-Cd levels and BMD.The U-Cd levels in females (0.64 μg/g creatinine) were higher than those in males (0.48 μg/g creatinine) (p0.001). With the logistic regression model, osteopenia was associated with high U-Cd levels (≥ 1.0 μg/g creatinine) in females (OR=2.92; 95% CI, 1.51-5.64) and in males (OR=3.37; 95% CI, 1.09-10.38). With the multiple linear regression model, the BMD of the adult group was negatively associated with U-Cd (0.05), gender (female, p0.001) and age (p0.001). The BMD of participants who were ≤ 19 years of age was negatively associated with gender (female, p0.01), whereas it was positively associated with age and BMI (p0.001). BMD was not associated with exercise, smoking habits, alcohol consumption, job or parental education.Results suggested that U-Cd might be associated with osteopenia as well as osteoporosis in both male and female adults. Age and female gender were negatively associated with BMD in the adult group, whereas age was positively associated with BMD in the youth group. Cadmium exposure may be a potential risk factor for lower-BMD and osteopenia symptoms as well as for osteoporosis symptoms.

Han D-H, Lim S-Y, Sun B-C, Paek D-M, Kim H-D. Visceral fat area defined obesity and periodontitis among Koreans. J Clin Periodontol 2010; 37: 172–179. doi: 10.1111/j.1600-051X.2009.01515.x. Abstract Aim: Although the association of periodontitis with body mass index (BMI)-defined obesity has been studied, it remains controversial. Hence, this study aims to determine whether the obesity is associated with periodontitis among Koreans and to determine the most significant indicator of the obesity on the link. Materials and Methods: From the Sihwa–Banwol Environmental Health Cohort, 1046 subjects 15 years of age or older were cross-sectionally surveyed. All participants underwent periodontal and medical health examinations. Age, gender, monthly family income, smoking, drinking, frequency of daily teeth brushing and physical activity were evaluated through interviews. The community periodontal index (CPI) was used to assess periodontitis. BMI, waist circumference (WC), waist hip ratio and visceral fat area (VFA) were used to assess obesity. Multivariate linear and logistic regression analyses were applied. Results: BMI, WC and VFA had a dose–effect relationship with the number of sextants with periodontitis. Although subgroup analysis revealed several significant associations between obesity and periodontitis (CPI 3–4), the greatest association between VFA and periodontitis was found in males, age 45–54 (odds ratio=3.30; 95% confidence interval: 1.53–7.09). Conclusions: Obesity was associated with periodontitis. VFA was the most suitable indicator of obesity in relation to periodontitis. Obesity may be a substantial risk factor for periodontitis.

This study evaluated age-related changes in bone mineral density (BMD) and identified the peak bone mineral density (PBMD) in Koreans. We recruited 2929 subjects, ranging in age from 5 to 86 years, from three regions: Seoul, Siwha, and Gwangyang. The BMD at the distal radius and calcaneus were measured with dual-energy X-ray absorptiometry, and anthropometric measures were also obtained. PBMD was calculated from the highest mean in each age group. The PBMD at the distal radius was 0.514 +/- 0.06 g/cm(2) in females and 0.598 +/- 0.07 g/cm(2) in males. Peak ages for both sexes were the thirties. For the calcaneus, PBMD was 0.509 +/- 0.09 g/cm(2) in females and 0.629 +/- 0.09 g/cm(2) in males. Peak ages were the thirties for females and the twenties for males. These results could facilitate international or interracial comparisons and be used as reference data to screen for osteoporosis in Koreans.

The aim of this study was to explore an association between psychosocial stress at work in married men and their spouses' prolonged time to pregnancy (TTP).All married male workers of a large Korean petrochemical enterprise and their wives fulfilling the selection criteria were included. Main selection criteria were lack of use of contraceptives and experienced pregnancy in recent past. Data were available from 322 couples. Psychosocial stress at work was measured by the effort-reward imbalance questionnaire. Prolonged TTP was measured by the "TTP questionnaire".After adjustment for confounding effects of demographic and life-style characteristics and benzene exposure, delayed TTP, defined by frequency of first-cycle pregnancy, was associated with one standard deviation (SD) increase of the effort-reward ratio in the chronically stressed group of married men (OR = 0.47; 95% CI = 0.22-0.99) in logistic regression analysis. A similar, but somewhat weaker effect, was found for the overall group (OR = 0.67; 95% CI = 0.47-0.94).Paternal stress at work, as measured by effort-reward imbalance, seemed to be associated with a decreased number of conceptions in the first menstrual cycle.

Heart rate variability (HRV) is a noninvasive physiological marker used to assess autonomic nervous function and can be recorded over the short or long term. Long-term recording is a good method for assessing mortality and patient prognosis, while short-term measurement is widely used due to practical advantages and reproducibility. However, little is known about whether a short-term assessment reflects the variation in the overall heart rate of workers. This study evaluated the relationship between the 24-hour and 5-minute HRV, which was selected from a 24-hour recording. The study population was 153 male workers at the National Rail Company in Korea, who had their heart rates assessed for 24 hours. In the time and frequency domains, the correlations of the HRV between 24 hours and 5 minutes were calculated for the entire time and limited times (09:00-17:00). We found modest correlations in the time (R = 0.614-0.668) and frequency (R = 0.508-0.817) domains, but the best correlation was for the high-frequency spectra (HF; R = 0.817). Our findings suggest that the short-term HRV remains stable and may be applicable for screening the variation in the heart rate of workers, although not all of the correlations were sufficiently strong.

We assessed the relationship between particle air pollution and changes in lung function in children as measured by spirometry over time. Data were collected from air pollution and family health examinations of 181 subjects, aged 9–19 years, in a Korean community. The children performed lung function tests, and their height and weight were measured. Their parents responded to an interview regarding the children's history of disease. Data on air pollution were obtained from the Environmental Management Corporation, which is part of the Korean Ministry of the Environment. We found evidence that the declines in forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) were significantly associated with the PM10 concentration for 37–60 hr preceding the lung function tests. The associations were consistent in the two-pollutant models. Our findings suggest that exposure to PM10 may increase the risk of adverse health effects in children with respiratory symptoms or diseases. Pediatr Pulmonol. 2008; 43:476–480. © 2008 Wiley-Liss, Inc.

Although bone mineral density (BMD) measurements of peripheral bone have been widely used due to practical and economic factors, a consensus does not exist as to whether the dominant or nondominant side is preferable for diagnosing osteoporosis and predicting fracture risk. Thus, we evaluated BMD differences of the distal radius and calcaneus between dominant and nondominant sides in the Korean population. Data were collected from 1794 subjects (979 females and 815 males) aged 4-86 yr, who were not taking any medication that affected bone metabolism or had a history of fracture. All subjects completed a questionnaire, and anthropometric and BMD measurements were taken. BMD values at the distal radii and calcanei were measured by dual-energy X-ray absorptiometry using a Lunar instrument. Significant correlations were observed between the dominant and nondominant distal radii (r=0.92; p

Background Chemical exposure may cause serious adverse health effects. Under the Environmental Health Act in Korea, the first national survey, Korean National Environmental Health Survey (KoNHES), was conducted, and dozens of major environmental chemicals were measured among Korean adults between 2009 and 2011. Objectives To understand the levels of exposure to environmental chemicals among general Korean adults population, and to identify factors that may influence the levels of exposure. Methods The blood and urine samples were collected from Korean adults with 19 years of age and older (n = 6311), and were analyzed for a number of environmental chemicals including metals, bisphenol A (BPA), and metabolites of polycyclic aromatic hydrocarbons (PAHs), phthalates, a pyrethroid insecticide (3-PBA) and several volatile organic carbons (VOCs). Demographic and other behavioral factors were asked through questionnaire. Results Among general Korean adults, mercury, arsenic, cadmium, and metabolite of DBP (MnBP) were higher than those reported in other nationwide surveys of Canada, Germany, and USA. Most target chemicals except for MEOHP and 3-PBA showed significant differences on the exposure levels by sex Conclusion This is the first nationwide reconnaissance on exposure to environmental chemicals among general Korean population. Chemicals with high occurrence level will be further investigated to identify exposure sources and possible health outcomes, and eventually to develop measures to mitigate exposure.

Objectives: Analysis of heart rate variability (HRV) is useful for measuring cardiovascular autonomic function. The effects of blood metals on cardiovascular autonomic function have not been studied extensively. The objective of the present study was to determine the association between the concentrations of blood metals, including toxic and essential trace elements, and cardiovascular autonomic function, based on HRV, in subjects without clinical cardiovascular diseases. Methods: The subjects were public officials and their family members (n = 331) in a district of Seoul, Republic of Korea. Age, height, weight, smoking habits, medical history, blood pressure, electrocardiogram (ECG) recording, and chest X-ray were assessed by means of a self-administered questionnaire and medical examination. Blood metal concentrations (blood Pb, As, and Cd; serum Al, Co, Cu, and Zn) were measured by inductively coupled plasma-mass spectrometry. HRV parameters (low frequency, LF; high frequency, HF; total power spectrum, TPS) were measured with LRR-03 and MemCalc software (GMS, Japan). Results: The concentrations of each of the blood metals were almost within normal ranges. Age and heart rate were negatively associated with LF, HF, and TPS (P< 0.01). Whole-blood Cd concentrations were negatively associated with LF (P< 0.01) and HF (P< 0.05). Serum Zn concentrations were positively associated with LF and TPS (P< 0.01). Conclusion: Our study suggests that levels of blood metals even within normal ranges may affect heart rate variability.

Chronic exposure is often assessed using a single measurement per individual or group. However, daily levels of personal exposure can vary greatly. Chronic exposure classification by a single measurement could be significantly affected by the interpersonal and daily variations of exposures. The purpose of this study is to determine the effect of using a single personal exposure measurement on estimating long-term exposure. This study used measurements of consecutive 14 daily personal exposures to nitrogen dioxide (NO(2)) and sulfur dioxide (SO(2)) of 50 individuals in Yeochun, Korea. The daily personal exposures were measured by passive samplers. Personal exposure to NO(2) was associated with gas cooking, and personal exposure to SO(2) was associated with ambient air pollution. Mixed effects models indicated that daily variability was greater than interpersonal variability for both the pollutants. Effectiveness of using single-day personal measurements for long-term population mean exposure was supported by relatively consistent daily population averages, but multiple-day measurements might be warranted for characterizing individual exposures or high-end population exposures such as the 95th percentile. Although classification of high and low exposure groups by 1-day exposure and by 14-day exposure produced similar group totals, 20% of individual NO(2) exposures and 31% of individual SO(2) exposures were misclassified using 1-day exposures. Average values of 1-day exposure and 14-day exposure were significantly different, but the difference decreased by an increase in the number of measurements for the short-term exposure. The findings were similar for both NO(2) and SO(2), although the two air pollutants have different sources and behaviors.

Objectives. Mass poisoning by carbon disulfide (CS2) occurred in a viscose-rayon factory in Korea. Including 38 who had died, 830 employees were diagnosed as CS2 poisoned. We evaluated the heart-rate variability (HRV) among CS2-poisoned subjects, to discover whether CS2 may affect HRV and whether its toxic effect persists after exposure has ceased. Methods. The case group comprised 71 retired male workers with CS2 poisoning. The control group comprised 127 public officials of the same age-range who had no history of organic-solvent exposure and cardiovascular diseases. Information on individual age, height, weight, cigarette smoking, alcohol drinking, regular exercise, medical and occupational history, and ECG recordings of the two groups were collected through medical examination and self-administered questionnaire. Time (maximum, average, minimum RR interval) and frequency domain measures [low (LF), high (HF), and total power spectrum (TPS)] of the two groups were analyzed. Results. In univariate analysis, time domain measures of the two groups did not differ significantly, while frequency domain measures in the case group was significantly lower than in the control group except for HF power. In multivariate analysis, previous history of CS2 poisoning was inversely related to all frequency domain measures and significantly affected LF power. Conclusions. This study suggests that CS2 may cause heart-rate impairment and its toxic effect persists after exposure has ceased. Based on this study, HRV measurement can be considered as a useful tool to assess toxic effects of CS2 both in current and retired workers.

Background In South Korea, a cluster of acute lung disease patients included lung injury disease suspected of being caused by the use of humidifier disinfectants. We examined the relationship between humidifier disinfectant exposure and clinically diagnosed humidifier disinfectant-associated lung injury (HDLI) in a family-based study. Methods This case-control study included 169 clinically confirmed HDLI cases and 303 family controls who lived with the HDLI patients. A range of information on exposure to humidifier disinfectants was obtained using a structured questionnaire and field investigations. Odds ratios (ORs) and confidence intervals (CIs) were estimated using unconditional logistic regression models that were adjusted for age, sex, presence of a factory within 1 km of residence, and the number of household chemical products used. Results HDLI risk increased approximately two-fold or more among the highest quartile compared with the lowest quartile in terms of the hours sleeping in a room with an operating humidifier treated with disinfectant (adjusted OR = 2.0, 95 % CI = 1.1-3.7), average hours of disinfectant-treated humidifier use per day (adjusted OR = 2.1, 95 % CI = 1.0-4.5), airborne disinfectant intensity (adjusted OR = 2.6, 95% CI = 1.2-5.3), and cumulative disinfectant inhalation level (adjusted OR = 2.0, 95% CI = 1.0-4.1). HDLI risk increased as the distance of the bed from humidifier gets shorter; compared with longer distance (> 1 m), the odds ratio was 2.7 for 0.5 to 1 m (95 % CI = 1.5-5.1) and 13.2 for

Both smoking and air pollution impair lung function, but little information is available regarding the combined effects on the pulmonary system. The potential effects of smoking and sulfur dioxide (SO2) were examined on lung function. Data were collected from family health examinations of 867 subjects, aged 20–86 yr, in a Korean community. The subjects responded to a questionnaire interview and completed lung function tests. Data on SO2 exposure were obtained from the Environmental Management Corporation. Studies sshowed that exposure to SO2 induced a short, marked decrease in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) in smokers compared with nonsmokers. The effect lasted up to 30 h after exposure. Consequently, preventive efforts are necessary to reduce the risks that air pollution and smoking pose to the respiratory system.

The effects of particulate pollutants on lung function in children with atopic dermatitis (AD) remain to be determined. The authors investigated the short-term effects of ambient particles on peak expiratory flow rate (PEFR) in 84 children with and without AD. Daily particulates less than 10, 2.5, and 1 μm (PM(10), PM(2.5), and PM(1)) and number concentrations of submicron particles were measured. The authors observed elevated levels of PM(10), PM(2.5), and PM(1), and accumulation-mode particles were associated with decreased PEFR in children with AD. The PEFR decrements were -2.89 L/min (95% confidence interval [CI], -4.93 to -0.89) for an interquartile-range increase of previous-day PM(10), -2.79 L/min (95% CI, -4.89 to -0.69) for PM(2.5), and -2.71 L/min (95% CI, -4.81 to -0.61) for PM(1). These results suggest that ambient fine particles may affect the pulmonary function in children with AD. The respiratory health of children with atopic skin disorders renders them more vulnerable to ambient particles than healthy subjects.

Background In a study of asbestos industry transfers in Asia, we examined the transfer of health and safety measures at the time of industry transfer and resulting health outcomes thereafter. Methods Field surveys were conducted in Japan, Germany, Indonesia, and South Korea over a 5 year period beginning in 2007. The surveys involved interviews and field assessments of health and safety conditions. Results Even when there were transfers of entire engineering plant processes, we observed that the health and safety measures that should have accompanied the transfer, including technical capacities of risk assessment and management, regulatory protection, and cultural practices, were not actually transferred. According to work environment assessment records, there were differences in airborne asbestos levels of approximately 5–6 fibers/cc between the exporting and importing sides of the transfer. This amounted to a 10 years of time delay in comparable health and safety conditions. These differences resulted in repeated adverse health consequences at each factory operation site. Conclusions Dangerous transfers of asbestos industry technology have occurred repeatedly over the years with the result that Asia has become the largest consumer of asbestos in the world. No effective internationally accepted safety measures have been introduced in the region. The study results support the need for both improved public awareness and international cooperation, such as sharing of substitute material technologies by the exporting countries, and provide the rationale for the creation of an Asian fund for asbestos victims. Am. J. Ind. Med. 56:335–346, 2013. © 2012 Wiley Periodicals, Inc.

Background Metabolic syndrome (MetS) may be associated with periodontitis. This study aimed to investigate whether the existence of periodontitis and MetS is cross-sectionally associated with matrix metalloproteinase (MMP) in gingival crevicular fluid (GCF) among community Koreans. Materials and Methods Medical and periodontal parameters were evaluated by physicians and dentists in 314 subjects (199 healthy, 58 only periodontitis, 34 only MetS and 23 both). The community periodontal index was used to assess periodontitis. MMP-8, 9, 13 were determined by enzyme-linked immunosorbent assay. Age, gender, monthly household income, smoking and drinking were interviewed as confounders. Analysis of covariance (ANCOVA) was applied. Gender-stratified analyses were applied. Results After controlling for various confounders, MMP-8, MMP-9 and MMP-13 in GCF were significantly associated with periodontitis in both genders and MMP-9, MMP-13 were associated with MetS in women. MMP-8, MMP-9 and MMP-13 showed association with periodontitis–MetS coexistence non-synergistically in both genders. MMP-9 was synergistically associated with periodontitis–MetS coexistence in women. Conclusion Our results suggest that MMP-8, MMP-9, MMP-13 in GCF were independently related to coexistence of periodontitis and MetS. MMP-9 and MMP-13 could be an appropriate common indicator of periodontitis and MetS in women. Further studies might guarantee that MMPs in GCF could screen periodontitis and MetS.

AIM Several studies have suggested that metabolic disorders are related to periodontitis. The objective of this study is to assess whether periodontitis is associated with the metabolic syndrome (MetS) among Koreans. MATERIAL AND METHODS This case-control study was performed among 167 cases with MetS and 166 healthy controls from Shiwha-Banwol Environmental Health Cohort (N = 1853). The community periodontal index (CPI) was used to assess periodontitis (CPI 3-4). MetS was an outcome variable and periodontitis was a main explanatory variable. Age-gender-matched conditional logistic regression models were applied. Monthly household income, smoking, drinking, physical activity and diabetes mellitus were factored as confounders. We also performed stratified analyses according to confounders. RESULTS Those with periodontitis are more likely to be patients with MetS than those without periodontitis. The adjusted odds ratio of periodontitis for MetS was 1.76. There was no significant dose-effect response on the relationship between the number of sextants with periodontitis and MetS. Links became higher in adults aged 45-60 years and adults without diabetes mellitus. CONCLUSIONS These results suggest that periodontitis could be an independently related factor on MetS. Hence, dentists and physicians should be aware of the importance of periodontitis as a potential source of inflammatory burden.

Perfluorinated compounds (PFCs) have been frequently detected in both the environment and biota, and have become a growing concern. However, information is limited on the potential sources and human health implications of such exposure. We evaluated the exposure levels of 13 major PFCs among a population (n=633, >12 years of age) in a mid-sized city of Korea, and investigated for their potential dietary sources and the impact on thyroid hormone concentrations. For this purpose, we collected blood samples from a general population in Siheung, Korea and measured for 13 PFCs, total thyroxine (T4), and thyroid stimulating hormone (TSH). In addition, a questionnaire survey on diet was conducted. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in relatively greater concentrations than the other 9 PFCs in the blood serum. Males tend to have greater concentrations than females for most PFCs, and the concentrations were elevated as age increased up to 50s. Body mass index (BMI) was also shown to influence the serum concentrations of several PFCs. After adjustment for age, sex, and BMI, the consumption of vegetable, potato, fish/shellfish, and popcorn was identified to be significantly related with concentrations of major PFCs in blood. Among the studied PFCs, the concentrations of perfluorotridecanoic acid (PFTrDA) were negatively correlated with total T4, and positively with TSH levels, especially among females. The result of this study will provide information useful for developing public health and safety management measures for PFCs. Keywords: Food, Inadvertent intake, Exposure, Thyroid stimulating hormone, Thyroxine

Because metabolic syndrome (MS) is pro-inflammatory and periodontitis is inflammatory, we issued the hypothesis that MS (the explanatory variable) is associated with periodontitis (the outcome variable). This study aimed to examine the link between MS and periodontitis among Koreans.From the Shiwha-Banwol Environmental Health Study, 1046 subjects aged 18 years or older were cross-sectionally surveyed. All participants underwent comprehensive dental and medical health examinations. The community periodontal index was used to assess periodontitis. Age, gender, monthly family income, smoking, drinking, frequency of daily teeth brushing, and physical activity were evaluated as confounders.MS was strongly associated with periodontitis [odds ratio (OR): 1.7, 95% confidence interval (CI): 1.22-2.37], and MS with more components had a higher association. The association was higher for elders aged 65 years or more, males, and smokers. MS including both high glucose and hypertension had a higher association with the OR of 2.19 (95% CI: 1.23-3.90) comparing with other types of MS.Our results suggested that MS might be associated with periodontitis and the association was confounded by age, gender, and smoking. MS with high glucose and hypertension showed the higher impact on this link.

The oral effect of chronic low-level mercury exposure is not completely understood. This study examined whether mercury exposure is associated with periodontitis.This study cross-sectionally surveyed 1,328 residents (598 males and 730 females) from the prospective Shiwha and Banwol cohort in Korea from July 2005 to August 2006 at baseline. Two dentists assessed periodontitis, an outcome, using the Community Periodontal Index (CPI): CPI 3 or 4 and CPI 0 to 2 were classified as periodontitis and non-periodontitis, respectively. The hair mercury level, the predictor, was analyzed. The mercury level was categorized according to the reference dose of the Environmental Protection Agency of the United States: normal =1 ppm and high =or =1 ppm. Age, gender, economic status, smoking, frequency of daily toothbrushing, diabetes mellitus, hyperlipidemia, and obesity were assessed as confounders. Logistic regression analysis was used to evaluate the adjusted association. Subgroup analyses for gender were also performed.Mercury exposure was independently associated with periodontitis (odds ratio = 3.17). Males with high mercury levels had a 50.0% higher probability of having periodontitis than females with normal mercury levels. Of them, the interaction effect between the body burden of mercury and gender was 39.0%. The odds ratio between periodontitis and high mercury levels was higher for males than females (95% confidence interval: 0.99 to 2.23 versus 0.59 to 1.26, respectively).These results suggest that mercury exposure had an independent association with periodontitis. High body-burden mercury in males might be a contributory factor linked with periodontitis.

Background The effect of mercury on the cardiovascular system has been recently reported, but the mechanisms and its nature, especially in low dose ranges, still need to be confirmed. In this cross-sectional study, the hair mercury was analyzed in relation to the cardiac autonomic activity among community residents nearby to an industrial complex in Korea. Methods A hair sample was obtained from the occiput and was analyzed using a DMA-80 (Milestone ® , Italy) mercury analyzer. We measured cardiovascular risk factors, including serum total cholesterol, serum triglyceride, HDL cholesterol, systolic and diastolic blood pressure, body mass index (BMI), past history of hypertension, diabetes, and dyslipidemia as potential confounders. As an end point, heart rate variability was assessed for 5 min, in time and frequency domains, using SA-3000P (Medi-core ® , Korea). For the time domain, standard deviation of the NN intervals (SDNN) was measured. For the frequency domains, very low frequency (VLF, ≤0.04 Hz), low frequency (LF, 0.04–0.15 Hz), high frequency (HF, 0.15–0.4 Hz), total power (TP, ≈≤0.4 Hz), LF/HF ratio, LF norm (LF/LF + HF), and HF norm (HF/LF + HF) were measured. The association between hair mercury concentration and heart rate variability was assessed after controlling for covariates, including age, gender, socioeconomic status, and other relevant cardiovascular risk factors. Results In total, 1589 subjects with a mean age of 33 years (range: 5–83) were included in the final analysis. Hair mercury concentration ranged from 0.01 to 13.36 ppm with a geometric mean of 0.83 μg/g. The hair mercury level was elevated for males, adults, and fish (especially sashimi) consumers, and higher household income group. When age was categorized into decades and analyzed separately, mercury significantly reduced HF measure in the second decade of age in Siwha area ( β = −0.193, p = 0.0469) and in the first decade of age in Banwol area ( β = −0.520, p = 0.0129). HF parameter decreased by 8.4% [95% confidence interval: 2.2–15.1%] with an 1 ppm increase in hair mercury concentration after adjusting for other selected variables in the multiple linear regression analysis. Conclusions The results suggest that mercury may affect the cardiac autonomic activity through parasympathetic dysfunction even at low exposure levels.

Urinary 1-hydroxypyrene (1-OHP) is a biomarker of exposure to polycyclic aromatic hydrocarbons (PAH). Effect of residence on children's PAH exposure was reported among children living near a polluted area. Instead of a snapshot assessment, however, a temporal history of exposure characteristics needs to be assessed in the studies of chronic disease development such as cancer. The urinary 1-OHP measurements were repeated to determine regional effect of ambient air pollution on 1-OHP levels over extended periods. Two sites were chosen: (a) one site located near the steel mill (“nearby” site) and (b) the other site located at a longer distance from the mill (“remote” site). Spot urinary 1-OHP levels were measured from 72 children for 3 consecutive days per month, repeated over 9-month period. Compared with remote site, the nearby site had increased the urinary 1-OHP level by 62.3% [95% confidence interval (95% CI), 39.8-88.3%]. Other statistically significant factors that contributed to the level include sex [16.5% (95% CI, 1.2-34.1%) higher for girls than boys], consumption of charbroiled meat [16.5% (95% CI, 1.1-34.2%) higher], and an increase in PM10 [10.1% (95% CI, 4.8-15.7%) higher for the interquartile range increment]. Controlling for covariates, the 1-OHP levels were increased in the summer and fall compared with winter. The magnitude of the effects of both seasons had diminished after adjusting for PM10. This is the first report providing seasonal and regional contributors to environmental PAH exposure, assessed by urinary 1-OHP, with higher 1-OHP levels during summer when ambient pollution was also high. (Cancer Epidemiol Biomarkers Prev 2009;18(1):96–101)

Objectives: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results: The mean blood cadmium level was 1.67 µg/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 µg/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose–response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions: Cadmium exposures at the current level may have increased the blood pressure of Korean general population.

Background: This study examined the relationship between metabolic syndrome (MetS) and heart rate variability (HRV) in Korean adults. Methods: Data were collected from family health examinations performed from December 2003 through January 2004, and 1,041 subjects consisting of males and females aged 20–87 years were included in this study. Measurement of the 5-minute HRV and several examinations for MetS were completed. The HRV was analyzed in both the time domain with the standard deviation of NN (SDNN) intervals and the frequency domain with the low frequency (LF) and high frequency (HF) components. MetS was defined by the criteria of the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) and the International Diabetes Federation (IDF). Results: There were significant differences in the MetS components and HRV indices between the two groups (with vs without MetS). The adjusted means of the HRV indices in the group with MetS were significantly lower than those in the group without MetS (P < 0.05). Furthermore, a significant negative correlation was found between all components of MetS and the HRV indices; additionally, as the number of MetS components increased, the HRV indices gradually decreased. Conclusions: Decreased cardiac autonomic tone was strongly associated with an increased cardiovascular risk, and HRV measurement could become an indispensable part of evaluating one's risk of cardiovascular disease, though we currently do not have sufficient information to identify the cutoff values for the HRV indices.

Air pollution, both particulate and gaseous, is known to cause adverse health effects and is associated with increased cardiovascular mortality and morbidity. With a growing recognition in the importance of the autonomic nervous system in air pollution, we examined the effects of air pollutants, namely, particulate matter (PM10), sulfur dioxide (SO2), and nitric dioxide (NO2), on cardiac autonomic function by measuring heart-rate variability (HRV) among community residents. This study was conducted at Taein Island, located off the southern coast of South Korea; 1349 subjects (596 males and 753 females) were included in this analysis. Subjects responded to the interview about general characteristics and an HRV examination was conducted. Exposure data were collected from the Environmental Management Corporation during the same period of HRV measurement. Linear regression analyses were carried out to evaluate the association over 72 h, and the parameters of HRV indices were presented as the percentage change. The exposures to PM(10), SO(2), and NO2 were associated with reduced HRV indices, and significant decreases in the standard deviation of the normal to normal interval (SDNN) and low frequency (LF) domain effect, and the effect was largely continued until 12 h. Our results suggest that air pollutants stimulate the autonomic nervous system and provoke an imbalance in cardiac autonomic control. Thus, these subclinical effects may lead to pathological consequences, particularly in high-risk patients and susceptible subjects.

The immune system is one of the targets most sensitive to lead toxicity, and the association between lead exposure and serum immunoglobulin E (IgE) has been published. Recent studies also reported that lead caused the development of IgE-mediated allergy. To investigate whether blood lead levels contribute to other allergic conditions, we examined the effect of blood lead on bronchial responsiveness (BR) in the general population. We performed a cross-sectional study with adults aged 19 to 58 years in a Korean community. Blood lead level and the methacholine provocation test were performed. The overall mean blood lead level was 2.9 microg/dl, and the mean BR index was 1.14. The percent of subjects with clinically diagnosed asthma was 21 (4%) and there was no difference in blood lead level with and without asthma. In the multiple regression model, the elevation of blood lead level was related to the increase of BR after adjusting for age, sex, height, smoking status, and the presence of asthma. Blood lead level was significantly associated with increased BR that came from the elevation of the IgE level with lead exposure. Lead may contribute to the increase of asthma and other allergic conditions.

Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and increased cancer risk has been reported among neighborhoods previously. In this study, we tried to assess the exposure to PAHs among residents nearby to a large steel mill in Korea by measuring urinary 1-hydroxypyrene (1-OHP).Two separate areas at different distances from a steel mill but on the same wind direction were chosen to evaluate the environmental exposures to polycyclic aromatic hydrocarbons. Three-hundred and fifty children living in the vicinity of steel plant ("nearby" group) and 606 children residing much farther from the factory ("remote" group) participated. Urine was collected on three consecutive days, and questionnaires about exposure to passive smoking and food consumption as well as demographics were obtained. Routine monitoring data of ambient pollutants were obtained and particulate matter less than 10 microm (PM10) was analyzed with multiple regressions to assess the associations with urinary 1-OHP.The geometric mean concentration of urinary 1-OHP among nearby group (0.048+/-1.878 micromol/mol creatinine, GM+/-GSD) was approximately 1.3 times higher than that among remote group (0.036+/-2.425 micromol/mol creatinine, GM+/-GSD), and using multiple regression techniques, the difference was significant (P0.0001) after adjusting for confounding variables. When different periods before the sampling of urine were examined, PM10 averages over 2 days, 3 days, and 1 week prior to urine sampling showed significant associations with urinary 1-OHP levels.Our findings are consistent with the interpretation that residents nearby to a steel mill are exposed to PAHs through ambient exposures.

To evaluate the criterion validity, factorial validity, and internal consistency of Korean version of effort-reward imbalance (ERI) for the scales of effort, reward, and overcommitment as well as to examine the effect of psychosocial factors on physical and mental illness among petroleum refinery workers in South Korea.The Korean version of ERI questionnaire was constructed using the translation and back-translation technique, and its psychometric properties were explored among 908 male workers in a large petroleum refinery in South Korea in 2002. Cronbach's alpha coefficient was used to test internal consistency. An exploratory factor analysis was conducted on all items of the instrument. Confirmatory factor analyses were conducted on each dimension of effort, reward and overcommitment. Physical and mental health was measured by self-rated health (SF-8). The lowest tertiles of the scores were defined as illness. Multiple logistic regression models were used to test the effect of job stress on the physical and mental health (criterion validity of ERI scales).The Cronbach's alpha coefficients for effort, reward, and overcommitment were 0.71, 0.86, and 0.75, respectively, indicating satisfactory internal consistency. Exploratory factor analysis found three latent factors, which closely corresponded to the theoretical structure of the ERI model. Acceptable construct validity was shown using confirmatory factor analysis. The highest tertile of effort-reward ratio was significantly associated with physical illness (OR 2.4, 95% CI 1.7-3.6) and mental illness (OR 2.9, 95% CI 2.0-4.2), compared to lower tertiles. Overcommitment was significantly associated with mental illness, but not with physical illness.These findings contribute to the validity and reliability of the Korean ERI questionnaire. Importantly, in the context of a rapid change in the labour market, the lack of reciprocity between efforts and rewards at work is strongly associated with self-rated physical and mental health.

The study examined the relationship between low blood lead levels and the physical growth of children in Seoul, Korea. Data were collected from 108 children (62 boys, 46 girls) aged 5-13 years, and the mean of the blood lead levels was 2.4microg/100ml (SD=0.7). The data analyzed included the blood lead levels, height, total arm length, weight, body mass index (BMI), and father's level of education. We used four multiple linear regression models with height, total arm length, weight, and BMI as the dependent variables, and age, sex, father's level of education, and blood lead levels as independent variables. In the multiple linear regression analysis, we found statistically significant, negative associations of height (p

This study investigated parent–child association of neurobehavioral functions including cognitive and motor abilities. Seventy-one families, consisting of parents and one or two children were included in the study. We examined neurobehavioral performance with the Korean version of The Swedish Performance Evaluation System (SPES-K), on four items; simple reaction time, symbol-digit, digit span (forward), and finger tapping (dominant and nondominant hands). Generalized estimating equations (GEE) models were used to investigate the familial aggregation. For simple reaction time and symbol digit that reflect both cognitive and motor functions, mother's test results were significantly associated with children's (p = 0.032, 0.007, respectively). For digit span which reflects short term memory, father's test results were significantly associated with children's (p = 0.005). Finger tapping did not show parental effects. We concluded that there were significant and specific parental effects on children's neurobehavioral function.

Debate continues as to whether low blood lead level, even below 5 microg/dl, impairs neurodevelopmental function in children. This study assessed the association between neurodevelopmental performance and lead exposure below 5 microg/dl in Korean children. Data were collected from 61 children, aged 7-16 years with a mean blood lead level of 2.9 microg/dl, who participated with their mothers. Neurodevelopmental function was measured with computer-based neurobehavioral tests. The analyzed data included children's performances on five neurobehavioral tests as the dependent variables, and children's blood lead level, sex, age, and mother's performance as the four independent variables. For simple reaction time and digit span, which, respectively reflect attention and short-term memory, there was a small and significant association between the children's neurodevelopmental performance and their blood lead levels (p=0.05, 0.08, respectively). Our study suggests that low blood lead below 5 microg/dl can influence children's neurobehavioral performance.

This study investigated the relationship between neurobehavioral performance and pulmonary function in young and middle adults. Data were collected from 178 subjects (88 male, 90 female) aged 20-50 years. Neurobehavioral performance was assessed by the Korean version of The Swedish Performance Evaluation System (SPES-K), on five items: simple reaction time, symbol digit, digit span, and finger tapping speed for dominant and non-dominant hands. Pulmonary function, as indicated by the 1-s forced expiratory volume (FEV1), was measured according to American Thoracic Society criteria and the potential association was analyzed by linear regression. For simple reaction time, symbol digit, and digit span, the performance of subjects with FEV1 levels exceeding 3.29 l was 2-4% greater than those with the lowest levels of less than 2.60 l, after controlling for the effects of age, sex, education, smoking, and height. Finger tapping speed, however, did not show any significant association. These findings suggest that pulmonary function may influence neurobehavioral performance, especially cognitive abilities, throughout adulthood.