Cesium-137 Contaminated Roads and Health Problems in Residents: an Epidemiological Investigation in Seoul, 2011.

BACKGROUND: In 2011, two roads in a residential area in Seoul were found to be contaminated with the radionuclide cesium-137 (137Cs). In response to public concerns, an epidemiological study was conducted. METHODS: The standardized cancer incidence ratios in the affected and neighboring regions were calculated based on the central cancer registry. Households in the region were sampled using the random stratified sampling technique, and questionnaires were administered to family members, via home visit and via students in elementary to high schools. Information on duration of residency and frequency of use of the roads was applied to calculate cumulative radiation exposure dose from the roads, alongside with the reported 137Cs contamination amounts. Information on past medical history, perceived risk, anxiety and psychological stress was also obtained. Of the 31,053 residents, 8,875 were analyzed. To examine possible associations between radiation exposure and health problems, logistic regression adjusted for covariates were performed with consideration of the sampling design, population weight and stratification. RESULTS: No significant association was found between self-informed diseases, including cancers, and estimated radiation exposure dose. According to an increase of radiation level, a significant increase in anxiety in all and a decline in the psychosocial wellbeing of the adults was noted. The risk perception level was higher in the elderly, females, the less educated, and the highest exposed individuals. CONCLUSION: This study provides a basis for risk communication with residents and community environmental health policy.

Association between periodontitis and blood lipid levels in a Korean population.

BACKGROUND: Hyperlipidemia is a known risk factor for cardiovascular diseases. A common biologic mechanism between systemic diseases, such as cardiovascular diseases, and periodontal diseases has been suggested. The aim of this study is to examine the association between blood lipid profile and periodontitis. METHODS: The study included 6,905 Korean adults, aged ≥ 20 years. Individuals with incomplete data on blood lipid levels, those who lacked results of periodontitis examination using the Community Periodontal Index system in the Fifth Korean National Health and Nutrition Examination Survey for 2010 and 2012 and those diagnosed with diabetes mellitus, hypertension, and hyperlipidemia were excluded from the study. All analyses involved complex sampling design. The association was assessed using multiple logistic regression analysis adjusted for covariates. RESULTS: Women with low high-density lipoprotein (HDL) cholesterol levels showed a significantly higher risk of periodontitis (odds ratio (OR) [95% confidence interval (CI)]: 1.65 [1.03 to 2.66] for the lowest group) than those with high HDL levels. Women with high low-density lipoprotein (LDL) cholesterol levels showed a higher risk of the disease (OR [95% CI]: 2.38 [1.01 to 5.60] for the highest group) than those with low LDL levels. There were significant dose-response relationships between disease risk and levels of HDL and LDL (P trend of 0.001 and 0.04, respectively). There was no significant difference in the risk between pre- and postmenopausal women. Men did not show any significant association between blood lipid levels and periodontitis. CONCLUSION: There was a significant association between periodontitis and low HDL and high LDL cholesterol levels in women. J Periodontol 2018;89:000-000.

Gender difference in the effects of lead exposure at different time windows on neurobehavioral development in 5-year-old children.

BACKGROUND: Although the association between lead exposure and children's neurodevelopment has been studied, gender differences remain to be investigated. We examined the effects of lead exposure on the neurobehavioral development of 5-year-old children to identify the vulnerable time window of exposure and potential gender difference. METHOD: A total of 1751 pregnant women and children participated in the prospective birth cohort study, Mothers and Children's Environmental Health study, since 2006. Lead levels were measured in the maternal blood in early and late pregnancies, in cord blood at birth, and in 2-, 3-, and 5-year-old children's blood. The behavior of 575 children aged 5years were assessed using the Korean Child Behavior Checklist. The association between the blood lead level at each time window and behavior was examined using a generalized linear model adjusted for potential confounders and covariates. RESULTS: Lead levels at late pregnancy were significantly associated with increased risk of behavioral problems in males. Lead levels in 2- and 5-year-old children's blood significantly increased behavioral risks in females: for a 1-µg/dL increase in blood lead levels, the score for total behavioral problems increased by 3.00 (95% confidence interval [CI]: 0.56-5.45) during the late pregnancy in males, whereas it increased by 3.82 (95% CI: 1.25-6.39) at 2years and by 5.72 (95% CI: 0.44-10.99) at 5years in females with a stronger effect in attention and sleep problems. CONCLUSION: Effects of lead toxicity on children's neurobehavioral development showed gender differences. Males were more susceptible to prenatal exposure, while females were more susceptible to postnatal exposure with stronger effects in attention and sleep problems.

Multiple assessment methods of prenatal exposure to radio frequency radiation from telecommunication in the Mothers and Children's Environmental Health (MOCEH) study.

OBJECTIVES: To evaluate prenatal exposure to radiofrequency radiation (RFR) from telecommunication using a mobile phone questionnaire, operator data logs of mobile phone use and a personal exposure meter (PEM). MATERIAL AND METHODS: The study included 1228 mother-infants pairs from the Mothers and Children's Environmental Health (MOCEH) study - a multicenter prospective cohort study ongoing since 2006, in which participants were enrolled at ≤ 20 weeks of pregnancy, with a follow-up of a child birth and growth to assess the association between prenatal environmental exposure and children's health. The questionnaire included the average calling frequency per day and the average calling time per day. An EME Spy 100 PEM was used to measure RFR among 269 pregnant women from November 2007 to August 2010. The operators' log data were obtained from 21 participants. The Spearman's correlation test was performed to evaluate correlation coefficient and 95% confidence intervals between the mobile phone use information from the questionnaire, operators' log data, and data recorded by the PEM. RESULTS: The operators' log data and information from the self-reported questionnaire showed significantly high correlations in the average calling frequency per day (ρ = 0.6, p = 0.004) and average calling time per day (ρ = 0.5, p = 0.02). The correlation between information on the mobile phone use in the self-reported questionnaire and exposure index recorded by the PEM was poor. But correlation between the information of the operators' log data and exposure index for transmission of mobile communication was significantly high: correlation coefficient (p-value) was 0.44 (0.07) for calling frequency per day, and it was 0.49 (0.04) for calling time per day. CONCLUSIONS: The questionnaire information on the mobile phone use showed moderate to high quality. Using multiple methods for exposure assessment might be better than using only one method. Int J Occup Med Environ Health 2016;29(6):959-972.

Association of current phthalate exposure with neurobehavioral development in a national sample.

BACKGROUND: Previous studies have indicated that phthalate exposure may influence the development of children, but the current data are limited, and controversy remains regarding the sex-specific and age-specific effects of phthalate exposure. METHODS: We investigated the sex- and age-specific associations of current phthalate exposure with neurobehavioral development scores in a nationally representative sample of 6-18-year-olds participating in the Korean Environmental Health Survey in Children and Adolescents (KorEHS-C). Neurobehavioral development was assessed using the Korean Child Behavior Checklist (CBCL, N=1723) and the Korean Attention Deficit Hyperactivity Disorder Rating Scale (ARS, N=867). We measured the concentrations of phthalate metabolites in urine samples using high-performance liquid chromatography tandem mass spectrometry. The associations between urine phthalate metabolite concentrations and neurobehavioral development were examined by survey regression analysis for complex sampling and penalized regression splines using a generalized additive model. RESULTS: Survey regression analysis revealed that a higher mono-n-butyl phthalate (MnBP) level was associated with social (ß=0.60; 95% confidence interval=0.15-1.05), thought (0.55; 0.08-1.03), and attention (0.68; 0.21-1.14) problems on the CBCL. A significant association was found between the MnBP level and the ARS hyperactivity subscale score (0.42; 0.05-0.58). Higher levels of MnBP (0.87; 0.20-1.54), mono-2-ethyl-5-oxohexyl phthalate (MEOHP, 0.61; 0.11-1.11) and mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP, 0.51; 0.04-0.97) were associated with an increase in thought problems among the girls. Among the younger children aged 6-11 years, significant positive associations between the MnBP (0.71; 0.09-1.33), MECPP (0.74, 0.14-1.34), MEOHP (0.65; 0.10-1.20), and MEHHP (0.71; 0.21-1.21) levels and social problems and between the MnBP (1.11; 0.37-1.84), MEOHP (0.64; 0.13-1.15), and MEHHP (0.66; 0.18-1.14) levels and attention problems were observed. The penalized regression splines for the age-specific relationships between the urinary MnBP, MEOHP, and MEHHP levels and social and attention problems exhibited positive supralinear relationships with downward curvature in the 6-11 year age group. In contrast, the score for social problems exhibited nearly linear relationships with these levels in the 12-18 year age group. CONCLUSIONS: In this national sample, increased phthalate exposure exhibited supralinear associations with social, thought and attention problems in children aged 6-11 years, who showed greater vulnerability to phthalate exposure. The results highlight the need for the environmental regulation of phthalate exposure in younger children, even at low dosages.

Representative levels of blood lead, mercury, and urinary cadmium in youth: Korean Environmental Health Survey in Children and Adolescents (KorEHS-C), 2012-2014.

BACKGROUND: This study examined levels of blood lead and mercury, and urinary cadmium, and associated sociodemographic factors in 3-18 year-old Korean children and adolescents. MATERIALS AND METHODS: We used the nationally representative Korean Environmental Health Survey in Children and Adolescents data for 2012-2014 and identified 2388 children and adolescents aged 3-18 years. The median and 95th percentile exposure biomarker levels with 95% confidence intervals (CIs) were calculated. Multivariate regression analyses were performed on log transformed exposure biomarker levels adjusted for age, sex, area, household income, and father's education level. The median exposure biomarker levels were compared with data from Germany, the US, and Canada, as well as the levels of Korean children measured at different times. RESULTS: The median levels of blood lead and mercury, as well as urinary cadmium were 1.23µg/dL, 1.80µg/L, and 0.40µg/L (95% CIs, 1.21-1.25, 1.77-1.83, and 0.39-0.41, respectively). The blood lead levels were significantly higher in boys and younger children (p<0.0001) and children with less educated fathers (p=0.004) after adjusting for covariates. Urinary cadmium level increased with age (p<0.0001). The median levels of blood mercury and urinary cadmium were much higher in Korean children and adolescents than those in their peers in Germany, the US, and Canada. Blood lead levels tended to decrease with increasing age and divergence between the sexes, particularly in the early teen years. Median levels of blood lead and urinary cadmium decreased since 2010. CONCLUSION: Sociodemographic factors, including age, sex, and father's education level were associated with environmental exposure to heavy metals in Korean children and adolescents. These biomonitoring data are valuable for ongoing surveillance of environmental exposure in this vulnerable population.

Association between blood cadmium level and bone mineral density reduction modified by renal function in young and middle-aged men.

The association between cadmium exposure and bone mineral density (BMD) has not been well studied in young and middle-aged men. This study examined the relationship between the level of blood Cd (BCd) and BMD in a young to middle-aged representative male population while considering renal function. Using data from the 4th Korea National Health and Nutrition Examination Survey, 2008-2009, 1275 adult men aged 20-64 years were analyzed. BCd was measured by atomic absorption spectrophotometry and renal function was assessed by the estimated glomerular filtration rate (eGFR) with CKD-EPI formula. The risk of lower bone density was increased according to the increase in BCd levels after adjusting for eGFR and covariates, in which a significant interaction between BCd and eGFR existed. Significant negative associations between BCd and BMD were found: beta (p-value) were -0.03 (0.02), -0.04 (0.004) and -0.03 (0.04) in total femur, lumbar spine and femoral neck, respectively, which were limited to the people with eGFR≤lower 25%. Although, a causal relationship could not be determined because of a cross-sectional design in the present study, the results suggest low level Cd toxicity to bone via low eGFR and that measures to reduce environmental Cd exposure may be helpful to prevent bone loss in men.

Assessment of radiation exposure from cesium-137 contaminated roads for epidemiological studies in Seoul, Korea.

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 ((137)Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the (137)Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of (137)Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

Epidemiological characteristics of mobile phone ownership and use in korean children and adolescents.

OBJECTIVES: As public concern on possible harmful effects of mobile phone in children has been raised, information of epidemiological characteristics of mobile phone use in children and adolescents will be essential for public health policy. METHODS: Using three databases (n=21,693) collected from 2008 to 2011, we examined characteristics of mobile phone ownership and use, and socioeconomic positions (SEP) in Korean children and adolescents. RESULTS: The ownership rate and the amount of mobile phone use were higher in females than males, in higher school grades than lower grades, and at 2011 than 2008. The average age of first mobile phone ownership was shown to decrease from 12.5 years in currently high school students to 8.4 years in currently elementary school students at 2011. More than 90% of children in the 5th grade owned a mobile phone. More children owned a mobile phone in lower SEP communities than in higher SEP. Children with parents educated less than those with parents educated more were more likely to own and use mobile phone. CONCLUSIONS: Considering the epidemiological characteristics of mobile phone use, precautionary measures to prevent unnecessary exposure to mobile phones are needed in children and adolescents.