Environmental Tobacco Smoke Exposure at Home and Attributable Problem Behaviors in Korean Children and Adolescents for 2012–2014 in a Nationally Representative Survey

BACKGROUND: This study aimed to examine the environmental tobacco smoke (ETS) exposure at home and associated problem behaviors in Korean children and adolescents. METHODS: Approximately 2,167 children aged 3–18 years were included in the study after excluding 163 active smokers from the Korean Environmental Health Survey in Children and Adolescents (2012–2014). ETS data were obtained using a questionnaire; problem behaviors were measured using the Child Behavior Checklist administered to parents. The relationship between ETS exposure and problem behavior was evaluated using a survey regression model adjusted for region, age, sex, income, and father's education. The population-attributable fraction (PAF%) was calculated based on problem behaviors related to ETS exposure at home. RESULTS: The rates of ETS exposure at home were 20%, 28%, and 39% in children aged 3–5, 6–11, and 12–18 years, respectively; ETS exposure at home was associated with behavioral problems: the exposed group having higher total behavioral problem score (95% confidence interval [CI]) than the non-exposed by 2.46 (0.60–4.32) and 2.74 (0.74–4.74) in children aged 6–11 and 12–18 years, respectively, with no significant association in those aged 3–5 years. The PAF% (95% CI) of total problem behaviors for ETS exposure at home were 2.68 (−10.11–17.78), 10.66 (3.25–17.55), and 11.62 (3.03–18.96) in children aged 3–5, 6–11, and 12–18 years, respectively. Children with externalizing problems had higher PAF% than those with internalizing problems. CONCLUSION: In Korea, ETS exposure at home is associated with problem behaviors in children and adolescents with about more than 10% population attributable fraction.

Estimation of Cancer Incidence and Mortality Risks Attributed to Diagnostic Medical Radiation Exposure in Korea, 2013

BACKGROUND: Radiation exposure from medical procedures has been rapidly increasing. We purposed to estimate the fraction of cancer incidence and mortality attributed to diagnostic medical radiation exposure in Korea. METHODS: Using information on diagnostic medical radiation exposure from various sources including national health examination (National Health Insurance Service), private health examination, and conscription health examination; the annual mean exposed organ dose (mGy) from all diagnostic medical radiation use, grouped by sex and 5-year age ranges up to 80 years, was calculated. Cancer incidence and mortality lifetime attributable risks (LARs) up to 85 years using estimated exposed organ doses and biological effects of ionizing radiation (BEIR) VII model (excess relative risk and excess absolute risk) were estimated. Using background cancer incidence and mortality risk based on the national database, along with estimated LARs, we finally estimated population attributable fraction (PAF) of cancer incidence and mortality. RESULTS: The PAF for diagnostic medical radiation exposure among all cancers of Koreans was 0.9% for incidence and mortality, resulting 1,915 cancer cases and 637 cancer deaths a year. The PAF in females was higher than those in males: 1.2% and 1.7% (incidence and mortality) versus 0.6% (same in incidence and mortality), respectively. CONCLUSION: The estimated PAF for diagnostic medical radiation in Korea in 2013 was higher than those reported in the UK in 2004. Optimized management of diagnostic medical radiation use is important in Korea.

The relationship between spontaneous abortion and female workers in the semiconductor industry

BACKGROUND: This study investigated the relationship between job type and the risk for spontaneous abortion to assess the reproductive toxicity of female workers in the semiconductor industry. METHODS: A questionnaire survey was administered to current female workers of two semiconductor manufacturing plants in Korea. We included female workers who became pregnant at least 6 months after the start of their employment with the company. The pregnancy outcomes of 2,242 female workers who experienced 4,037 pregnancies were investigated. Personnel records were used to assign the subjects to one of three groups: fabrication process workers, packaging process workers, and clerical workers. To adjust for within-person correlations between pregnancies, a generalized estimating equation was used. The logistic regression analysis was limited to the first pregnancy after joining the company to satisfy the assumption of independence among pregnancies. Moreover, we stratified the analysis by time period (pregnancy in the years prior to 2008 vs. after 2009) to reflect differences in occupational exposure based on semiconductor production periods. RESULTS: The risk for spontaneous abortion in female semiconductor workers was not significantly higher for fabrication and packaging process workers than for clerical workers. However, when we stratified by time period, the odds ratio for spontaneous abortion was significantly higher for packaging process workers who became pregnant prior to 2008 when compared with clerical workers (odds ratio: 2.21; 95% confidence interval: 1.01–4.81). CONCLUSIONS: When examining the pregnancies of female semiconductor workers that occurred prior to 2008, packaging process workers showed a significantly higher risk for spontaneous abortions than did clerical workers. The two semiconductor production periods in our study (prior to 2008 vs. after 2009) had different automated processes, chemical exposure levels, and working environments. Thus, the conditions prior to 2008 may have increased the risk for spontaneous abortions in packaging process workers in the semiconductor industry. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40557-017-0204-x) contains supplementary material, which is available to authorized users.

Mercury Exposure in Association With Decrease of Liver Function in Adults: A Longitudinal Study / 예방의학회지

OBJECTIVES: Although mercury (Hg) exposure is known to be neurotoxic in humans, its effects on liver function have been less often reported. The aim of this study was to investigate whether total Hg exposure in Korean adults was associated with elevated serum levels of the liver enzymes aspartate aminotransferase (AST), alanine transaminase (ALT), and gamma-glutamyltransferase (GGT). METHODS: We repeatedly examined the levels of total Hg and liver enzymes in the blood of 508 adults during 2010-2011 and 2014-2015. Cross-sectional associations between levels of blood Hg and liver enzymes were analyzed using a generalized linear model, and nonlinear relationships were analyzed using a generalized additive mixed model. Generalized estimating equations were applied to examine longitudinal associations, considering the correlations of individuals measured repeatedly. RESULTS: GGT increased by 11.0% (95% confidence interval [CI], 4.5 to 18.0%) in women and 8.1% (95% CI, -0.5 to 17.4%) in men per doubling of Hg levels, but AST and ALT were not significantly associated with Hg in either men or women. In women who drank more than 2 or 3 times per week, AST, ALT, and GGT levels increased by 10.6% (95% CI, 4.2 to 17.5%), 7.7% (95% CI, 1.1 to 14.7%), and 37.5% (95% CI,15.2 to 64.3%) per doubling of Hg levels, respectively, showing an interaction between blood Hg levels and drinking. CONCLUSIONS: Hg exposure was associated with an elevated serum concentration of GGT. Especially in women who were frequent drinkers, AST, ALT, and GGT showed a significant increase, with a significant synergistic effect of Hg and alcohol consumption.

Short-term Effect of Fine Particulate Matter on Children's Hospital Admissions and Emergency Department Visits for Asthma: A Systematic Review and Meta-analysis / 예방의학회지

OBJECTIVES: No children-specified review and meta-analysis paper about the short-term effect of fine particulate matter (PM2.5) on hospital admissions and emergency department visits for asthma has been published. We calculated more precise pooled effect estimates on this topic and evaluated the variation in effect size according to the differences in study characteristics not considered in previous studies. METHODS: Two authors each independently searched PubMed and EMBASE for relevant studies in March, 2016. We conducted random effect meta-analyses and mixed-effect meta-regression analyses using retrieved summary effect estimates and 95% confidence intervals (CIs) and some characteristics of selected studies. The Egger's test and funnel plot were used to check publication bias. All analyses were done using R version 3.1.3. RESULTS: We ultimately retrieved 26 time-series and case-crossover design studies about the short-term effect of PM2.5 on children's hospital admissions and emergency department visits for asthma. In the primary meta-analysis, children's hospital admissions and emergency department visits for asthma were positively associated with a short-term 10 μg/m3 increase in PM2.5 (relative risk, 1.048; 95% CI, 1.028 to 1.067; I2=95.7%). We also found different effect coefficients by region; the value in Asia was estimated to be lower than in North America or Europe. CONCLUSIONS: We strengthened the evidence on the short-term effect of PM2.5 on children's hospital admissions and emergency department visits for asthma. Further studies from other regions outside North America and Europe regions are needed for more generalizable evidence.