Choong-Hee Park

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 childrens 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 childrens pulmonary function, but there was no difference of potency for reduction of the pulmonary function between natural and anthropogenic metal components.

Risk assessment of low-level cadmium and arsenic on the kidney.

Cadmium (Cd) and arsenic (As) are widely distributed in the environment and are known human carcinogens. Several studies reported that chronic exposure to Cd and As produced renal injuries in humans. As one of the mechanisms, oxidative stress was suggested to play a role in the early process of Cd- and/or As-induced tubular damage in the kidney. This study was performed to evaluate the significance of urinary biomarkers, role of oxidative stress, and effect of coexposure to environmental low-level exposure to Cd and/or As in the general population. Urine samples were collected from 290 adults (86 males and 204 females). Urinary concentrations of Cd and As were measured, and kidney biomarkers of toxicity such as ß2-microglobulin and N-acetyl-β-D-glucosaminidase (NAG) activity determined in urine. Urinary malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels were measured as oxidative stress indices. The mean concentration of Cd was 1.21 μg/L, 0.84 μg/g creatinine, and As was 5.7 μg/L, 3.95 μg/g creatinine in urine. NAG, MDA, and 8-OHdG were positively correlated with both Cd and As in urine. Positive correlations were also observed between NAG and oxidative indices. The effects of coexposure to Cd and As on biomarkers are more pronounced than for exposure to each metal alone. These findings suggest that chronic exposure to low levels of Cd and/or As might produce tubular damage in the kidney through oxidative stress in humans.

Temporal changes in urinary levels of cadmium, N-acetyl-β-d-glucosaminidase and β2-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-β-D-glucosaminidase (NAG) and beta 2-microglobulin (β2-MG) increases. The aim of this study was to describe the changing patterns of urinary Cd, NAG, and β2-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 β2-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 β2-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 β2-MG levels found in individuals whose urinary Cd levels were >2μg/g creatinine suggest that previous Cd-induced renal tubular damage had occurred.

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

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.

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 β₂-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 β₂-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.

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.

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 childs 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 Childrens 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 24 h 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. HighlightsRFR exposure was measured by mobile phone use questionnaire and 24‐h personal exposure meter among pregnant women.Child neurodevelopment was assessed by trained examiners at 6, 12, 24, and 36 months of age.Associations were not observed between prenatal exposure to RFR and child neurodevelopment during the first three years.A potential combined effect of prenatal exposure to lead and mobile phone use was suggested.

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.

Evalution of Acid Deposition in Korea

This study was carried out to evaluate acid depositions and to understand their effect. Wet precipitation has been collected at twenty-four sites in Korea for one year of 1999. The ion concentrations such as H+, Na+, K+, Mg2+, NH4+, Ca2+, Cl−, NO3− and SO42− were chemically analyzed and determined. Precipitation had wide range of pH(3.5∼8.5), and volume-weighted average was 5.2. The contribution amounts of Cl−, SO42− and NO3− in anion were shown to be 54%, 32%, and 14%, respectively and those of Na+ and NH4+ in cation were 32% and 25%. The ratios of Cl− and Mg2+ to Na+ in precipitation were similar to those of seawater, which imply that great amount of Cl− and Mg2+ in precipitation could be originated from seawater. The concentration of H+ is little related with SO42−, NO3− and Cl− ions, whereas nss−SO42− and NO3− are highly correlated with NH4+, which could suggest that great amount of SO42− and NO3− exist in the form of ammonium associated salt. The annual wet deposition amounts (g m−2year−1) of SO42−, NO3−, Cl−, H+, NH4+, Na+, K+, Ca2+ and Mg2+ were estimated as 0.88∼4.89, 0.49∼4.37, 0.30∼9.80, 0.001∼0.031, 0.06∼2.15, 0.27∼4.27, 0.10∼3.81, 0.23∼1.59 and 0.03∼0.63.

Status and Prospects of the Korean National Environmental Health Survey (KoNEHS)

National Institute of Environmental Research, Environmental Health Research Division, Korea ABSTRACTObjectives: The purpose of this review is to suggest future directions for the Korean Environmental HealthSurvey (KoNEHS) in terms of an environmental health monitoring system and recent environmental healthissues in Korea.Methods: The national scale biomonitoring program and environmental health researches which conducted byMinistry of Environment was reviewed for this study. The scope, contents and utilization of results of KoNEHSas a biomonitoring program and other basic function for environmental health monitoring was analyzed.Results: Biomonitoring survey was conducted for basic functions, such as evaluating exposure levels ofenvironmental chemicals and analyzing exposure factors. In order to expand the basic purposes of KoNEHS, thebiomonitoring function should be strengthened by enlarging the range of chemicals analyzed and including allage groups in the biomonitoring and health status monitoring functions by using official health-care andmortality data. Exposure factors such as time-activity patterns and micro-environmental pollution levels werestudied. The data from the environmental health study were established into a standardized database system forsupporting environmental health policy. A definition and concept of environmental health services should beestablished. Conclusion: To achieve the aims of environmental health, changes in environmental health status and relatedfactors must be observed and predicted reflecting real conditions. In this regard, improving the methodology andsystem through diverse approaches is necessary for KoNEHS.Keywords: Environmental health survey, Biomonitoring, Methodology, Exposure factor