Association between Heavy Metal Exposure and Dyslipidemia among Korean Adults: From the Korean National Environmental Health Survey, 2015-2017.

Cardiovascular disease (CVD) is a leading cause of death in Korea. Dyslipidemia, characterized by the presence of abnormal lipid levels, has been suggested as an early diagnostic and preventable factor for CVD. Recent studies have shown that exposure to lead (Pb), cadmium (Cd), and mercury (Hg) affects lipid metabolism. This study aimed to verify the association between heavy metal concentrations and serum lipid profiles in the general population. A representative sample of 2591 Korean adults from the Korean National Environmental Health Survey (2015−2017) was analyzed. The associations between heavy metals [Blood Pb (BPb), blood Hg (BHg), urinary Hg (UHg), urinary Cd (UCd)] and serum lipid profiles [total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), non-low level of high-density lipoprotein cholesterol (Non-HDL-C)] were assessed using regression analysis. After adjusting for demographic and socioeconomic factors, the proportional changes in serum lipid levels were significantly associated with increases in BPb, BHg, and UHg levels (p for trend < 0.05). Overall, BPb, BHg, and Uhg levels positively correlated with dyslipidemia, whereas UCd levels did not show a significant association. Our results suggest that heavy metal exposure, at low levels, may contribute to an increased prevalence of dyslipidemia in Korean adults.

Urinary levels of phthalate, bisphenol, and paraben and allergic outcomes in children: Korean National Environmental Health Survey 2015-2017.

BACKGROUND: Phthalates, bisphenols and parabens have been widely used in household and personal-care products. Their endocrine disrupting, sensitizing and antimicrobial properties might play a role in the occurrence of allergic diseases. However, the effects of these chemicals, particularly on humans, are relatively underexplored. OBJECTIVES: This study aimed to report the concentrations of phthalate, bisphenol and paraben in urine of Korean children, and assess their relationship with allergic outcomes. METHODS: Data obtained from nationally representative Korean children, a total of 1458 children between 3 and 11 years of age recruited in the Korean National Environmental Health Survey (3 rd round of KoNEHS 2015-2017), were analyzed. Associations of urinary phthalate metabolites, bisphenols, and parabens levels with atopic dermatitis and allergic rhinitis was examined by grouped into preschool (aged 3-5 years) and school children (aged 6-11 years). Allergic outcomes were obtained through questionnaires answered by their caregivers. RESULTS: Atopic dermatitis was associated with urinary metabolites of DEHP, BzBP, DINP, and DIDP, and MeP and PrP in preschool children, BPA and PrP in school children. Allergic rhinitis was associated with MeP and PrP in preschool children, and metabolites of DEHP, MeP and PrP in school children. The association of urinary chemicals with atopic dermatitis and allergic rhinitis were different by gender, especially in preschool children. CONCLUSION: Urinary phthalates, BPA and parabens levels in the Korean children were related with atopic dermatitis and allergic rhinitis. Considering the importance of allergic diseases in children, the public health implications of exposure to these chemicals warrant further studies. Given the cross-sectional design and confounding variables, the results of this study should be interpreted with caution.

Association between Pb, Cd, and Hg Exposure and Liver Injury among Korean Adults.

BACKGROUND: Exposure to lead (Pb), cadmium (Cd), and mercury (Hg) has been reported to be associated with liver-related diseases. However, studies examining the association between heavy metal exposure and liver injury in a large population are scant and characterized by inconsistent results. This study aimed to evaluate the association between levels of heavy metal exposure and liver injury in the general population. METHODS: Data for 2953 participants aged 19 years or more obtained from the Korean National Environmental Health Survey (KoNEHS) Cycle 3 (2015-2017) were used. The associations between levels of blood or urine heavy metals (Pb, Cd, and Hg) and liver function biomarkers [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT)] were evaluated using multiple linear regression analysis. RESULTS: Regarding the blood Pb (BPb), AST was higher in those of the 4th quartile, ALT was higher in those of the 2nd and 4th quartiles, and GGT was higher in those of the 3rd and 4th quartiles than in the 1st quartile. For urinary Cd (UCd), AST was higher in those of the 4th quartile; ALT was higher in those of the 2nd, 3rd, and 4th quartiles; and GGT was higher in the 4th quartile than in the 1st quartile. For the blood Hg (BHg), AST was higher in those of the 2nd and 4th quartile, ALT was higher in those of the 2nd, 3rd, and 4th quartiles; and GGT was higher in those of the 3rd and 4th quartiles than in the 1st quartile. There was no significant difference between urinary Hg (UHg) and liver function markers. CONCLUSION: Heavy metal exposure showed an association with liver injury among the general adult population in Korea. Further studies are required to clarify the relationship between heavy metals and liver injury.

Copper-zinc imbalance induces kidney tubule damage and oxidative stress in a population exposed to chronic environmental cadmium.

PURPOSE: This cross-sectional study aimed to assess the effect of environmental cadmium (Cd) exposure and essential metal imbalance on renal tubular damage and oxidative stress in 979 adults living in a Cd-polluted area near an abandoned copper (Cu) refinery. METHODS: We analyzed urinary Cd concentrations, renal tubular damage and oxidative stress markers, such as beta-2 microglobulin (ß2-MG) and N-acetyl-ß-D-glucosaminidase (NAG) activity and urine malondialdehyde (MDA) levels. The serum copper-to-zinc ratio (CZR) was used as an essential metal imbalance indicator. We divided the subjects into two Cd exposure groups based on the reference level of urinary Cd for renal dysfunction (2 µg/g creatinine). RESULTS: The geometric mean concentration of urinary Cd in all subjects was 2.25 µg/g creatinine. In both low and high Cd exposure groups, urinary Cd levels were positively correlated with urinary NAG activity, but not with serum CZR. After multivariate adjustment, serum CZR was strongly associated with urinary ß2-MG levels in the low Cd exposure group (ß = 1.360, P = 0.019) and was significantly associated with urinary MDA levels, regardless of Cd exposure level. In addition, the risk of renal tubular damage was significantly associated with urinary Cd level, particularly in the lowest or highest CZR tertile groups. CONCLUSIONS: Essential metal imbalance may be a determinant of oxidative stress and renal tubular damage in a chronically Cd-exposed population, and proper zinc supplementation will be effective in preventing adverse health effects due to Cd exposure.

Urinary 3-phenoxybenzoic acid levels and the association with thyroid hormones in adults: Korean National Environmental Health Survey 2012-2014.

BACKGROUND: Owing to insecticidal activity at low doses with relatively low toxicity in humans, synthetic pyrethroids have been used widely for pest control in agricultural and domestic settings. Pyrethroids are suspected for potential endocrine disruption. However, the thyroid disrupting effects of pyrethroids, particularly in humans, is relatively underexplored. OBJECTIVES: This study aimed to report 3-phenoxybenzoic acid (3-PBA) concentrations in urine, and assess its association with serum thyroid hormone (TH) levels in a representative adult population of Korea. METHODS: Data obtained from representative Korean adults recruited in the Korean National Environmental Health Survey (2nd round, 2012-2014) were analyzed. Urinary 3-PBA levels were associated with serum thyroxine (T4), total triiodothyronine (T3), and thyroid-stimulating hormone (TSH) levels among the Korean adult population. RESULTS: Urinary 3-PBA levels among Korean adults were >3 times higher than those reported in Canada and the United States. Urinary 3-PBA levels showed negative association with serum T4, and this pattern was not changed after stratification by sex. For T3, the association varied by sex and exposure levels. Male demonstrated the same inverse association between urinary 3-PBA and T3, but female did not show such association. Among adults in the lower half of urinary 3-PBA levels, the association with T3 was significant, while that among the remainder was marginal. The association with T4 remained significant on sensitivity analysis, after controlling for other urinary chemicals. CONCLUSION: Urinary 3-PBA levels in the general Korean adult population were found to be generally higher than those of other countries, and were associated with decreased TH levels. Considering the importance of THs, the public health implications of pyrethroid insecticide exposure warrant further studies.

Comparison of Short-Term Associations between PM2.5 Components and Mortality across Six Major Cities in South Korea.

Association between short-term exposure to fine particulate matter (PM2.5) and mortality or morbidity varies geographically, and this variation could be due to different chemical composition affected by local sources. However, there have been only a few Asian studies possibly due to limited monitoring data. Using nationwide regulatory monitoring data of PM2.5 chemical components in South Korea, we aimed to compare the associations between daily exposure to PM2.5 components and mortality across six major cities. We obtained daily 24-h concentrations of PM2.5 and 11 PM2.5 components measured from 2013 to 2015 at single sites located in residential areas. We used death certificate data to compute the daily counts of nonaccidental, cardiovascular, and respiratory deaths. Using the generalized additive model, we estimated relative risks of daily mortality for an interquartile range increase in each pollutant concentration, while controlling for a longer-term time trend and meteorology. While elemental carbon was consistently associated with nonaccidental mortality across all cities, nickel and vanadium were strongly associated with respiratory or cardiovascular mortality in Busan and Ulsan, two large port cities. Our study shows that PM2.5 components responsible for PM2.5-associated mortality differed across cities depending on the dominant pollution sources, such as traffic and oil combustion.

Urinary phthalate metabolite and bisphenol A levels in the Korean adult population in association with sociodemographic and behavioral characteristics: Korean National Environmental Health Survey (KoNEHS) 2012-2014.

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.

Neurodevelopment for the first three years following prenatal mobile phone use, radio frequency radiation and lead exposure.

BACKGROUND: Studies examining prenatal exposure to mobile phone use and its effect on child neurodevelopment show different results, according to child's developmental stages. OBJECTIVES: To examine neurodevelopment in children up to 36 months of age, following prenatal mobile phone use and radiofrequency radiation (RFR) exposure, in relation to prenatal lead exposure. METHODS: We analyzed 1198 mother-child pairs from a prospective cohort study (the Mothers and Children's Environmental Health Study). Questionnaires were provided to pregnant women at ≤20 weeks of gestation to assess mobile phone call frequency and duration. A personal exposure meter (PEM) was used to measure RFR exposure for 24h in 210 pregnant women. Maternal blood lead level (BLL) was measured during pregnancy. Child neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant Development-Revised at 6, 12, 24, and 36 months of age. Logistic regression analysis applied to groups classified by trajectory analysis showing neurodevelopmental patterns over time. RESULTS: The psychomotor development index (PDI) and the mental development index (MDI) at 6, 12, 24, and 36 months of age were not significantly associated with maternal mobile phone use during pregnancy. However, among children exposed to high maternal BLL in utero, there was a significantly increased risk of having a low PDI up to 36 months of age, in relation to an increasing average calling time (p-trend=0.008). There was also a risk of having decreasing MDI up to 36 months of age, in relation to an increasing average calling time or frequency during pregnancy (p-trend=0.05 and 0.007 for time and frequency, respectively). There was no significant association between child neurodevelopment and prenatal RFR exposure measured by PEM in all subjects or in groups stratified by maternal BLL during pregnancy. CONCLUSIONS: We found no association between prenatal exposure to RFR and child neurodevelopment during the first three years of life; however, a potential combined effect of prenatal exposure to lead and mobile phone use was suggested.

Associations between urinary phthalate metabolites and bisphenol A levels, and serum thyroid hormones among the Korean adult population - Korean National Environmental Health Survey (KoNEHS) 2012-2014.

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.

Association between phthalate exposure and lower handgrip strength in an elderly population: a repeated-measures study.

BACKGROUND: Decreased muscle strength can lead to adverse health outcomes in the elderly. A potential association between phthalate exposure and muscle strength was suggested previously, but has not been investigated directly. We hypothesized that phthalate exposure is associated with lower handgrip strength and that the association is modified by the dietary omega-6 to omega-3 ratio. METHODS: We analyzed 1,228 participants (≥60 years of age) recruited in Seoul and Asan, Republic of Korea. The study participants were surveyed up to three times between 2012 and 2015. At every survey, we collected urine samples and measured handgrip strength twice for each hand. The associations between urine phthalate metabolite concentrations and handgrip strength were evaluated using linear mixed models. Based on dietary information from 391 individuals who participated in the first survey in Seoul, we evaluated the heterogeneity of the association for those with high and low omega-6 to omega-3 ratios, using 8.81 (the 75th quantile) as a cutoff value. RESULTS: Log-transformed creatinine-adjusted concentrations of mono-(2-ethyl-5-oxohexyl phthalate (MEOHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-n-butyl phthalate (MnBP) were inversely associated with all measured handgrip strengths (ß = -0.69 to -0.42, all p-values < 0.05). Associations between phthalate biomarkers and handgrip strength did not differ by sex. When the dietary subgroup was stratified by the omega-6 to omega-3 ratio, the associations were stronger among participants with high ratios. CONCLUSIONS: We found inverse associations between phthalate biomarkers and handgrip strength in the elderly; this association was modified by the dietary omega-6 to omega-3 ratio.

Association by Spatial Interpolation between Ozone Levels and Lung Function of Residents at an Industrial Complex in South Korea.

Spatial interpolation is employed to improve exposure estimates and to assess adverse health effects associated with environmental risk factors. Since various studies have reported that high ozone (O3) concentrations can give rise to adverse effects on respiratory symptoms and lung function, we investigated the association between O3 levels and lung function using a variety of spatial interpolation techniques and evaluated how different methods for estimating exposure may influence health results for a cohort from an industrial complex (Gwangyang Bay) in South Korea in 2009. To estimate daily concentrations of O3 in each subject, four different methods were used, which include simple averaging, nearest neighbor, inverse distance weighting, and kriging. Also, to compare the association between O3 levels and lung function by age-groups, we explored ozone's impacts on three age-related groups: children (9-14 years), adults (15-64 years), and the elderly (≥65 years). The overall change of effect size on lung function in each age group tended to show similar patterns for lag and methods for estimating exposure. A significant negative association was only observed between O3 levels and FVC and FEV1 for most of the lag and methods in children. The largest effect of O3 levels was found at the average for the lung function test day and last 2 days (0-2 days). In conclusions, the spatial interpolation methods may benefit in providing individual-level exposure with appropriate temporal resolution from ambient monitors. However, time-activity patterns of residents, monitoring site locations, methodological choices, and other factors should be considered to minimize exposure misclassification.

Environmental Exposure to Arsenic, Lead, and Cadmium in People Living near Janghang Copper Smelter in Korea.

Concentrations of heavy metals exceed safety thresholds in the soil near Janghang Copper Refinery, a smelter in Korea that operated from 1936 to 1989. This study was conducted to evaluate the level of exposure to toxic metals and the potential effect on health in people living near the smelter. The study included 572 adults living within 4 km of the smelter and compared them with 413 controls group of people living similar lifestyles in a rural area approximately 15 km from the smelter. Urinary arsenic (As) level did not decrease according to the distance from the smelter, regardless of gender and working history in smelters and mines. However, in subjects who had no occupational exposure to toxic metals, blood lead (Pb) and cadmium (Cd) and urinary Cd decreased according to the distance from the smelter, both in men and women. Additionally, the distance from the smelter was a determinant factor for a decrease of As, Pb, and Cd in multiple regression models, respectively. On the other hands, urinary Cd was a risk factor for renal tubular dysfunction in populations living near the smelter. These results suggest that Janghang copper smelter was a main contamination source of As, Pb, and Cd, and populations living near the smelter suffered some adverse health effects as a consequence. The local population should be advised to make efforts to reduce exposure to environmental contaminants, in order to minimize potential health effects, and to pay close attention to any health problems possibly related to toxic metal exposure.

Early snapshot on exposure to environmental chemicals among Korean adults-results of the first Korean National Environmental Health Survey (2009-2011).

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.

Association of urinary 3-phenoxybenzoic acid levels with self-reported depression symptoms in a rural elderly population in Asan, South Korea.

OBJECTIVES: This study aimed to evaluate the association between presence of depression symptoms and the exposure level to insecticides among aged population in rural area, determined via measured levels of urinary 3-phenoxybenzoic acid (3-PBA), after controlling for socioeconomic confounding factors. METHODS: Using a cross-sectional study design, we randomly recruited participants for our study (161 male and 239 female) from rural areas of Asan, Chungnam, Korea. Environmental risk factor exposure was assessed using a questionnaire, and gas chromatography- mass spectrometry was used to analyze urinary 3-PBA levels. We used a logistic regression analysis to assess the association of urinary 3-PBA levels with the presence of self-reported depression symptoms. RESULTS: After controlling for creatinine levels, the median (interquartile range) concentration of 3-PBA was approximately 1.5 times (p<0.05) higher among female (1.54 [0.90 to 2.35]) µg/g) than among male (1.06 [0.64 to 1.81] µg/g). Our study found that among female participants, the unit increase in 3-PBA levels exhibited a likely positive association (odds ratio, 1.12; 95% confidence interval, 1.00 to 1.25) with an increased risk of presence of self-reported depression symptoms, after adjusting for socioeconomic insurance type, daily physical condition, marital status, smoking status, and age. CONCLUSIONS: Given our finding of a potential association between the presence of selfreported depression symptoms and 3-PBA levels, precautions should be considered to minimize exposure to insecticides and thus protect the health of aged residents in rural areas.

Indoor total volatile organic compounds exposure at 6 months followed by atopic dermatitis at 3 years in children.

BACKGROUND: Exposure to indoor air pollutants is thought to cause allergic inflammation. Volatile organic compounds (VOCs) are one of the aggravating factors of asthma and other allergic diseases. However, the influence of VOCs on development of atopic dermatitis is ambiguous in the clinical field. We therefore investigated the associations of indoor total volatile organic compounds (TVOCs) and development of atopic dermatitis in young Korean children. METHODS: From the birth cohort of a MOthers and Children's Environmental Health (MOCEH) study, 257 infants, whose parents agreed with the environmental measurement, were enrolled. Total VOCs were measured in infant's bedrooms at the age of 6 month. A total of 105 parents answered a questionnaire at 36 month. Concentrations of TVOCs were divided into two groups by third quartile (75th). Associations between the high VOCs exposure group and development of atopic dermatitis at the age of 36 months were estimated by multivariate logistic regression. RESULTS: The average concentration of TVOCs was 174.7 ± 115.1 ㎍/m(3) . We defined the high TVOCs exposure group by those with more than 75 percentile of the distribution (242.1 ㎍/m(3) ). An increased risk of atopic dermatitis was observed in the high TVOCs exposure group, after adjustment for parents history of allergy, household income, breast-feeding longer than 6 month (OR = 3.116, 95% Cl 1.041-9.323). Risk of atopic dermatitis was increased when the family bought new furniture within 1 yr. CONCLUSION: Our results showed that exposure to high concentration of VOCs during infancy, an indoor pollutant, increased the risk of atopic dermatitis at 36 months.

Association of bisphenol A exposure with overweight in the elderly: a panel study.

Bisphenol A (BPA) is an ubiquitous chemical, which is an endocrine disruptor. Recent epidemiological studies have suggested a relationship between BPA exposure and body weight. However, most of these studies were cross-sectional and not on elderly people. We conducted a panel study with repeated measurements to evaluate the relationship between BPA and overweight in elderly people. A total of 560 elderly participants aged ≥60 years were recruited in Seoul from 2008 to 2010. Urinary BPA levels and body mass index (BMI, kg/m(2)) were measured at every visit. We defined a BMI ≥25 as overweight and examined the relations between urinary BPA and BMI or overweight. Repeated measures analysis was performed after adjusting for age, sex, low-density lipoprotein cholesterol levels, alcohol consumption, regular exercise, total calorie intake, fatty acid intake, urinary cotinine levels, and the status of diabetes mellitus. The geometric mean of BPA was 0.67 µg/g creatinine. The odds ratio (OR) of overweight was 1.17 (95 % confidence interval [CI] 1.04-1.32) per interquartile range increase of log-transformed BPA. When stratified based on sex, we observed a significant association in women (OR 1.25; 95 % CI 1.09-1.45) but not in men (OR 0.97; 95 % CI 0.77-1.22). The ORs of overweight increased with quartiles of BPA in women (quartile 2 vs 1: OR 1.54; 95 % CI 1.02-2.32, 3 vs 1: OR 1.70; 95 % CI 1.10-2.62, and 4 vs 1: OR 1.81; 95 % CI 1.13-2.92). Our results suggest that urinary BPA levels are significantly associated with overweight in elderly women but not elderly men.

Temporal changes in urinary levels of cadmium, N-acetyl-ß-d-glucosaminidase and ß2-microglobulin in individuals in a cadmium-contaminated area.

Cadmium (Cd) is a metal that is toxic to renal tubules. If renal tubules are damaged by Cd, urinary excretion of N-acetyl-ß-D-glucosaminidase (NAG) and beta 2-microglobulin (ß2-MG) increases. The aim of this study was to describe the changing patterns of urinary Cd, NAG, and ß2-MG levels over a 3-year period in individuals living in a Cd-contaminated area. This follow-up study included 191 residents (65.6±9.3 years) who were living in the vicinity of a copper refinery. Urinary levels of Cd, NAG activity, and ß2-MG levels were measured, and their determinants and changing patterns were analyzed statistically. The natural logarithm of urinary Cd levels decreased significantly over time. Sex and intake of locally cultivated rice were significant determinants of urinary Cd concentration. Urinary NAG activity decreased over time. Age and urinary Cd concentration were significant determinants of urinary NAG activity in subjects with urinary Cd concentrations >5µg/g creatinine. In subjects whose urinary Cd concentrations were >2µg/g creatinine, diabetes was found to be a significant risk factor for high urinary NAG activity. The slope for temporal changes in urinary ß2-MG levels was negative in subjects whose urinary Cd levels were <2µg/g creatinine but was positive in those whose urinary Cd levels were 2-5µg/g creatinine or >5µg/g creatinine. The urinary ß2-MG levels found in individuals whose urinary Cd levels were >2µg/g creatinine suggest that previous Cd-induced renal tubular damage had occurred.

Differences in the susceptibility to cadmium-induced renal tubular damage and osteoporosis according to sex.

This study aimed to estimate the risks for renal tubular damage and osteoporosis in individuals with long-term environmental Cd exposure. This cross-sectional study comprised 1086 residents living in the vicinity of a copper refinery plant. As the urinary Cd levels increased, the proportion of female subjects with ß2-MG ≥300 µg/g creatinine also increased significantly, but this was not observed in the male subjects. The prevalence of osteoporosis was significantly higher in men with urinary Cd >5 µg/g creatinine than in those with urinary Cd ≤5 µg/g creatinine. This difference was not observed in the corresponding female groups. The association between increased urinary excretion of ß2-MG and decreased BMD was statistically significant only in the female subjects. We suggest that an increased Cd body burden directly decreases the BMD in male subjects; however, in female subjects, it first induces renal microtubular damage, which can lead to osteoporosis.

Korea National Survey for Environmental Pollutants in the Human Body 2008: heavy metals in the blood or urine of the Korean population.

BACKGROUND: Recently, there have been several nationwide episodes involving imported toys contaminated with toxic metals and environmental hormones. In addition, cadmium intoxication has occurred due to soil contamination with cadmium from abandoned metal mines. OBJECTIVES: To investigate the distribution, extent and factors influencing the levels of toxic metals in the blood or urine of the Korean general population over twenty years of age, we studied the blood or urine concentrations of heavy metals in a representative sample of 5087 Koreans in 2008. METHODS: Multiple biological substrates were collected from each participant to determine the most suitable samples for an environmental health survey system. Information regarding exposure conditions of all subjects was collected by questionnaire-based interviews. RESULTS: The geometric means of the blood lead, mercury and manganese levels were 19.1, 3.23 and 10.8 µg/L, respectively. The geometric means of urinary arsenic and cadmium concentrations were 43.5 and 0.65 µg/L, respectively. Blood mercury and urinary arsenic levels in the Korean general population were significantly higher than in European and American populations. CONCLUSIONS: The higher levels of blood mercury and urinary arsenic could be explained by the greater seafood consumption among the Korean population. This biomonitoring study of blood or urine heavy metals in the Korean general population provides important reference data stratified by demographic and lifestyle factors that will be useful for the ongoing surveillance of environmental exposure of Koreans to toxic metals.

Asian Dust Storm and pulmonary function of school children in Seoul.

Health effects of the Asian Dust Storm (ADS) have not been evaluated adequately, even though it may affect health of people in East Asia. This study was conducted to evaluate whether the ADS affects particulate air pollution and pulmonary function of children. We studied 110 school children in Seoul, Korea with daily measurement of peak expiratory flow rate (PEFR) from May 13 to June 15, 2007. PM(2.5), PM(10) and metals bound to the particles were also determined daily during the study period in Ala Shan and Beijing (China) as well as in Seoul (Korea). Three-day back trajectories showed that air parcels arrived at Seoul mostly from the desert areas in China and Mongolia through eastern China during ADS event affecting levels of particulate pollutants in the areas. Analysis of metals bound to the particulates showed that natural metal levels were much higher than the anthropogenic metal levels. We found that ambient concentrations of PM(2.5) and PM(10) were not significantly associated with PEFR in school children except asthmatics during the study period (P>0.05). However, most of the metal concentrations bound to the particulates were significantly associated with decrease of the children's PEFR (P<0.05). The effect of anthropogenic metals was not different from natural components of metals for reduction of PEFR. This result indicates that exposure to the metals bound to particles during the ADS period reduces children's pulmonary function, but there was no difference of potency for reduction of the pulmonary function between natural and anthropogenic metal components.