Publications by authors named "Yun-Chul Hong"

350 Publications

Short-term exposure to air pollution and hospital admission for heart failure among older adults in metropolitan cities: a time-series study.

Int Arch Occup Environ Health 2021 Jun 5. Epub 2021 Jun 5.

Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.

Purpose: We aimed to investigate the association between air pollution concentration levels and hospital admissions for heart failure (HF) among older adults in metropolitan cities in South Korea.

Methods: We used hospital admission data of 1.8 million older adults in seven metropolitan cities from 2008 to 2016, derived from the National Health Insurance Service of South Korea. Daily HF admission data were linked to air pollutants concentrations for the respective dates, including particulate matter less than 2.5 μm in size (PM), 10 μm (PM), sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), and ozone. We estimated the association between air pollutants and daily HF admissions using quasi-Poisson generalized additive models for each city.

Results: During the study period, 142,490 hospital admissions for HF were noted. Increases of 10 μg/m of PM and PM, and 10 ppb of SO, NO, and CO were associated with an increased risk of HF admission by 0.93% ([95% confidence intervals 0.51-1.36], 0.55% [0.31-0.80], 6.04% [2.15-10.08], 1.10% [0.38-1.82], and 0.05% [0.01-0.09]), respectively, on the same day. Increases in mean exposure to PM, PM, and SO for 8 days from the concurrent day were also significantly associated with HF admissions. During the warm season, the risk of HF admissions increased shortly after an increase in PM, whereas prolonged effects were observed during the cold season.

Conclusion: Our study suggests the adverse effects of air pollution on HF. Moreover, the evidence of seasonality may help tailor protection guidelines for older adults.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00420-021-01724-9DOI Listing
June 2021

Association Between Sleep Duration and Intelligence Quotient in 6-Year-Old Children.

Int J Behav Med 2021 Jun 2. Epub 2021 Jun 2.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.

Background: Sufficient sleep during childhood is important for cognitive functions such as learning and successful school performance. This study aimed to investigate the effects of sleep duration on the intelligence quotient (IQ) of 6-year-old children and aimed to analyze whether these effects differed by sex.

Methods: The IQ of 538 6-year-old Korean participants from the cohort study, "The Environment and Development of Children," was measured during follow-up using the Korean Educational Developmental Institute's Wechsler Intelligence Scale for Children. The total, verbal, and performance IQ scores were evaluated. The relationship between sleep duration and IQ scores after adjusting for maternal age, maternal educational level, maternal occupation, maternal IQ, exposure to secondhand smoking, gestational age, and monthly age and birth season was also assessed.

Results: Longer sleep duration was significantly associated with improved verbal IQ measures (β 0.55; p value 0.030). After stratifying participants by sex, a significant association was observed between sleep duration and total, verbal, and performance IQ scores in boys (total IQ 2.49, p value 0.012; verbal IQ 0.75, p value: 0.037; performance IQ 0.73, p value 0.048), but not in girls.

Conclusions: The results indicated that only boys show a significant association between IQ scores and sleep duration. These findings support the hypothesis that sleep duration is associated with IQ, in a sex dependent manner. Future studies are needed for a thorough evaluation of the connection between sleep duration and health outcome in young children.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12529-021-09996-8DOI Listing
June 2021

Reply to Brzozek et al. Comment on "Choi et al. Cellular Phone Use and Risk of Tumors: Systematic Review and Meta-Analysis. 2020, , 8079".

Int J Environ Res Public Health 2021 May 24;18(11). Epub 2021 May 24.

Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul 110-744, Korea.

We appreciate Christopher Brzozek and his colleagues' interest [...].
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18115581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8197078PMC
May 2021

Association between weekly fruit and vegetable consumption and depressive symptoms: results from the Korean Elderly Environmental Panel study.

Epidemiol Health 2021 20;43:e2021029. Epub 2021 Apr 20.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.

Objectives: Although previous studies have investigated the correlation between fruit and vegetable consumption and depression, the results remain inconclusive. The present study aimed to investigate the association between weekly fruit and vegetable consumption and depressive symptoms in elderly Koreans.

Methods: A multiple covariate linear regression analysis was performed using the data of 1,226 elderly individuals ≥ 60 years of age who participated in the Korean Elderly Environmental Panel II study from 2012 to 2014. Depressive symptoms were evaluated using the Korean version of the Short form Geriatric Depression Scale (SGDS-K). Generalized linear mixed-effects models were constructed to analyze the repeated measurements of 305 people who participated in the survey every year.

Results: After adjusting for confounders, SGDS-K scores were negatively associated with the frequency of weekly fruit consumption as follows (β [95% confidence interval; CI]: -0.17 [-0.28 to -0.05], -0.17 [-0.27 to -0.07], -0.42 [-0.54 to 0.29], and -0.33 [-0.44 to -0.21]) for less than 1 time/wk, 1-3 times/wk, 4-6 times/wk, and daily, respectively, compared to no consumption. The SGDS-K scores were also negatively associated with the frequency of vegetable consumption (β [95% CI]: -0.86 [-1.18 to -0.55], -0.18 [-0.35 to -0.01], -0.36 [-0.53 to -0.18], and -0.15 [-0.29 to 0.00]) in the above order, respectively.

Conclusions: Fruit consumption was inversely associated with depression levels in a dose-dependent manner. Although there was no dose-response relationship between vegetable consumption and the level of depression, it was negatively associated with SGDS-K scores.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4178/epih.e2021029DOI Listing
June 2021

Particulate air pollution and survival after stroke in older adults: A retrospective cohort study in Korea.

Environ Res 2021 Jun 18;197:111139. Epub 2021 Apr 18.

Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, South Korea; Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark. Electronic address:

Although many studies have evaluated the effects of ambient particulate matter with diameters of less than 2.5 μm (PM) on stroke mortality in the general population, little is known about the mortality effects of PM in post-stroke populations. Therefore, a retrospective cohort was constructed using information from the health insurance database to evaluate whether exposure to PM is associated with increased mortality in aged stroke survivors residing in seven Korean metropolitan cities. A total of 45,513 older adults (≥65 years) who visited emergency rooms due to stroke and who were discharged alive between 2008 and 2016 were followed up. By using district-level modeled PM concentrations and a time-varying Cox proportional hazard model, associations between 1-month and 2-month moving average PM exposures and mortality in stroke survivors were evaluated. The annual average concentration of PM was 27.9 μg/m in the seven metropolitan cities, and 14,880 subjects died during the follow-up period. A 10 μg/m increase in the 1-month and 2-month moving average PM exposures was associated with mortality hazard ratios of 1.07 (95% confidence interval: 1.05, 1.09) and 1.06 (95% confidence interval: 1.03, 1.08), respectively. The effects of PM were similar across types of stroke (ischemic and hemorrhagic), age groups (65-74, 75-84, and ≥85), and income groups (low and high) but were greater in women than in men. This study highlights the adverse health effects of ambient PM in post-stroke populations. Active avoidance behaviors against PM are recommended for aged stroke survivors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envres.2021.111139DOI Listing
June 2021

Reply to Comment on Choi, Y.-J., et al. Cellular Phone Use and Risk of Tumors: Systematic Review and Meta-Analysis. 2020, , 8079.

Int J Environ Res Public Health 2021 03 23;18(6). Epub 2021 Mar 23.

Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul 110-744, Korea.

We appreciate Frank de Vocht and Martin Röösli's interest [...].
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18063326DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8005003PMC
March 2021

Association between Phthalate Exposure and Frailty among Community-Dwelling Older Adults: A Repeated Panel Data Study.

Int J Environ Res Public Health 2021 02 18;18(4). Epub 2021 Feb 18.

Department of Preventive Medicine, Seoul National University College of Medicine, 103 Daehakno, Jongrogu, Seoul 03080, Korea.

Only a few studies have examined the impacts of environmental exposure on frailty. This study investigated the association between phthalates and frailty among community-dwelling older adults. The Korean Elderly Environmental Panel II (KEEP II) study is a repeated panel data study of 800 community-dwelling older adults in South Korea. Frailty was measured with five items defined by Fried and colleagues. Environmental pollutants in the form of two types of metabolites for Di-ethylhexyl phthalate (DEHPs)-Mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono (2-ethyl-5-oxohexyl) phthalate (MEOHP)-were obtained from urine specimens. Analyses were performed using repeated linear mixed models. The concentration levels of both MEOHP and MEHHP in urine were significantly higher in the pre-frail or frail group than its counterparts. While adjusting for covariates, MEOHP level was positively associated with the likelihood of being pre-frail or frail in both males and females; the concentration level of MEHHP also had a positive impact on the likelihood of being pre-frail or frail in females. The DEHP metabolite concentrations were significantly lower among adults with daily fruit consumption in both males and females. DEHPs, measured by metabolite concentrations, may increase the risk of frailty among older men and women; further studies are necessary. The preventive effects of nutrition on DEHP risk should also be further investigated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18041985DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922338PMC
February 2021

Associations Between Thyroid Hormone Levels and Urinary Concentrations of Bisphenol A, F, and S in 6-Year-old Children in Korea.

J Prev Med Public Health 2021 Jan 23;54(1):37-45. Epub 2020 Nov 23.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.

Objectives: Bisphenol A (BPA) is used in the electrical, mechanical, medical, and food industries. Previous studies have suggested that BPA is an endocrine disruptor. Regulation of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). However, few studies have investigated the associations of BPF and BPS with thyroid dysfunction in children. Our study investigated the associations of prenatal BPA and early childhood BPA, BPF, and BPS exposure with thyroid function in 6-year-old children.

Methods: Prenatal BPA concentrations were measured during the second trimester of pregnancy in an established prospective birth cohort. We measured urinary BPA, BPF, and BPS concentrations and thyroid hormone levels (thyroid-stimulating hormone, total T3, and free T4) in 6-year-old children (n=574). We examined the associations between urinary bisphenol concentrations and percentage change of thyroid hormone concentrations using multivariate linear regression. We also compared thyroid hormone levels by dividing the cohort according to BPA, BPF, and BPS concentrations.

Results: The associations between prenatal BPA and total T3 levels were statistically significant in all models, except for girls when using a crude model. The associations between urinary BPA and BPS concentrations and levels of all thyroid hormones were not statistically significant. However, we observed that lower free T4 levels (-1.94%; 95% confidence interval, -3.82 to -0.03) were associated with higher urinary BPF concentrations in girls only.

Conclusions: Our findings identified significant associations between prenatal BPA exposure and total T3 levels in all children and between BPF exposure and free T4 levels in girls only.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3961/jpmph.20.310DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7939752PMC
January 2021

Types of COVID-19 clusters and their relationship with social distancing in the Seoul metropolitan area, South Korea.

Int J Infect Dis 2021 May 17;106:363-369. Epub 2021 Feb 17.

Center for Healthy Society and Education, Seoul National University College of Medicine, Seoul, 03087, Seoul, Republic of Korea; Department of Family Medicine, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea. Electronic address:

Background: The complete contact tracing of coronavirus disease-19 (COVID-19) cases in South Korea allows a unique opportunity to investigate cluster characteristics. This study aimed to investigate all reported COVID-19 clusters in the Seoul metropolitan area from January 23 to September 24, 2020.

Methods: Publicly available COVID-19 data was collected from the Seoul Metropolitan City and Gyeonggi Province. Community clusters with ≥5 cases were characterized by size and duration, categorized using K-means clustering, and the correlation between the types of clusters and the level of social distancing investigated.

Results: A total of 134 clusters comprised of 4033 cases were identified. The clusters were categorized into small (type I and II), medium (type III), and large (type IV) clusters. A comparable number of daily reported cases in different time periods were composed of different types of clusters. Increased social distancing was related to a shift from large to small-sized clusters.

Conclusions: Classification of clusters may provide opportunities to understand the pattern of COVID-19 outbreaks better and implement more effective suppression strategies. Social distancing administered by the government may effectively suppress large clusters but may not effectively control small and sporadic clusters.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijid.2021.02.058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7889017PMC
May 2021

Prenatal heavy metal exposures and atopic dermatitis with gender difference in 6-month-old infants using multipollutant analysis.

Environ Res 2021 04 16;195:110865. Epub 2021 Feb 16.

Occupational and Environmental Medicine, College of Medicine, Ewha Womans University, Seoul, Republic of Korea; Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea; Ewha Medical Research Institute, College of Medicine, Ewha Womans University, Seoul, Republic of Korea. Electronic address:

Background: Prenatal exposure to heavy metals during critical developmental phases has been implicated in allergic phenotypes. However, few studies have been conducted on the gender-specific association of prenatal heavy metal exposure with atopic dermatitis (AD) in infants.

Objective: To examine the gender-specific association of prenatal exposure to multiple heavy metals with AD incidence in 6-month-old infants using data from the Mothers and Children's Environmental Health (MOCEH).

Methods: We evaluated 738 mother-child pairs from the MOCEH study, an ongoing prospective birth cohort. The concentrations of three heavy metals (lead, mercury and cadmium) in maternal blood samples were measured during early and late pregnancy. Each quartile of heavy metal concentration was used to consider the possible nonlinear association with AD. For assessing the multi-pollutant model, we constructed the multivariate regression model including all three heavy metals at both early and late pregnancy. Further, the group Lasso model was used to perform the variable selection with categorized exposures and assess the effect of multiple pollutants including their pairwise interactions.

Results: A total of 200 incident cases of AD were diagnosed in 6-month-old infants. In the multivariate regression model of the boy group, adjusted odds ratios comparing the second, third and fourth quartile of lead exposure in boys with the first quartile were 1.83 (95% CI: 1.00, 3.38), 1.04 (0.91, 3.32) and 2.40 (1.18, 4.90), respectively. However, the only second quartile of lead exposure compared to first quartile was significantly associated with AD in girls. In addition, the results of the group Lasso model were similar with the results of multivariate regression model.

Conclusion: The results suggest that lead exposure in late pregnancy increases risk of AD in 6-month-old boys although the strength of association is weak. Further studies are needed to confirm the susceptibility window and gender differences in lead-induced AD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envres.2021.110865DOI Listing
April 2021

Long-term exposure to fine particulate matter and incident asthma among elderly adults.

Chemosphere 2021 Jun 11;272:129619. Epub 2021 Jan 11.

Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark. Electronic address:

Rationale: Although an association of fine particulate matter (PM) with asthma incidence has been assumed, there is insufficient evidence regarding the effect of long-term exposure to PM on incident asthma among elderly adults.

Objectives: This study aimed to investigate an association between long-term exposure to PM and incident asthma among elderly adults in South Korea.

Methods: Adults ≥65 years of age (n = 1,220,645) who did not visit hospitals for asthma during a washout period (between 2008 and 2010) were followed up until 2016 using data from the National Health Insurance System in South Korea. Incident asthma was defined as the number of patients with a primary diagnostic code of asthma who visited hospitals more than twice. We linked the health data with district-level PM concentrations and estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for incident asthma after adjusting for potential confounders in time-varying Cox proportional hazard models.

Measurements And Main Results: Over 5,942,256 person-years, 54,522 patients developed asthma, with an incidence of 9.2 cases/1000 person-years. A 10 μg/m increase in the 36-month mean PM concentration was significantly associated with a 9% increase in incident asthma (HR = 1.09, 95% CI: 1.04-1.14). This association was found to be robust for different definitions of incident asthma and washout periods.

Conclusion: Long-term exposure to PM was associated with the incidence of asthma in elderly adults. This finding provides evidence of an association between PM and adult-onset asthma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2021.129619DOI Listing
June 2021

Sub-multiplicative interaction between polygenic risk score and household coal use in relation to lung adenocarcinoma among never-smoking women in Asia.

Environ Int 2021 02 29;147:105975. Epub 2020 Dec 29.

Department of Internal Medicine, Kaohsiung Medical University Hospital, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

We previously identified 10 lung adenocarcinoma susceptibility loci in a genome-wide association study (GWAS) conducted in the Female Lung Cancer Consortium in Asia (FLCCA), the largest genomic study of lung cancer among never-smoking women to date. Furthermore, household coal use for cooking and heating has been linked to lung cancer in Asia, especially in Xuanwei, China. We investigated the potential interaction between genetic susceptibility and coal use in FLCCA. We analyzed GWAS-data from Taiwan, Shanghai, and Shenyang (1472 cases; 1497 controls), as well as a separate study conducted in Xuanwei (152 cases; 522 controls) for additional analyses. We summarized genetic susceptibility using a polygenic risk score (PRS), which was the weighted sum of the risk-alleles from the 10 previously identified loci. We estimated associations between a PRS, coal use (ever/never), and lung adenocarcinoma with multivariable logistic regression models, and evaluated potential gene-environment interactions using likelihood ratio tests. There was a strong association between continuous PRS and lung adenocarcinoma among never coal users (Odds Ratio (OR) = 1.69 (95% Confidence Interval (CI) = 1.53, 1.87), p=1 × 10). This effect was attenuated among ever coal users (OR = 1.24 (95% CI: 1.03, 1.50), p = 0.02, p-interaction = 6 × 10). We observed similar attenuation among coal users from Xuanwei. Our study provides evidence that genetic susceptibility to lung adenocarcinoma among never-smoking Asian women is weaker among coal users. These results suggest that lung cancer pathogenesis may differ, at least partially, depending on exposure to coal combustion products. Notably, these novel findings are among the few instances of sub-multiplicative gene-environment interactions in the cancer literature.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envint.2020.105975DOI Listing
February 2021

Short-Term Exposure to Fine Particulate Matter and Hospitalizations for Acute Lower Respiratory Infection in Korean Children: A Time-Series Study in Seven Metropolitan Cities.

Int J Environ Res Public Health 2020 12 28;18(1). Epub 2020 Dec 28.

Department of Public Health, University of Copenhagen, 1599 Copenhagen, Denmark.

Although several studies have evaluated the association between fine particulate matter (PM) and acute lower respiratory infection (ALRI) in children, their results were inconsistent Therefore, we aimed to evaluate the association between short-term exposure to PM and ALRI hospitalizations in children (0-5 years) living in seven metropolitan cities of Korea. The ALRI hospitalization data of children living in seven metropolitan cities of Korea from 2008 to 2016 was acquired from a customized database constructed based on National Health Insurance data. The time-series data in a generalized additive model were used to evaluate the relationship between ALRI hospitalization and 7-day moving average PM exposure after adjusting for apparent temperature, day of the week, and time trends. We performed a meta-analysis using a two-stage design method. The estimates for each city were pooled to generate an average estimate of the associations. The average PM concentration in 7 metropolitan cities was 29.0 μg/m and a total of 713,588 ALRI hospitalizations were observed during the 9-year study period. A strong linear association was observed between PM and ALRI hospitalization. A 10 μg/m increase in the 7-day moving average of PM was associated with a 1.20% (95% CI: 0.71, 1.71) increase in ALRI hospitalization. While we found similar estimates in a stratified analysis by sex, we observed stronger estimates of the association in the warm season (1.71%, 95% CI: 0.94, 2.48) compared to the cold season (0.31%, 95% CI: -0.51, 1.13). In the two-pollutant models, the PM effect adjusted by SO was attenuated more than in the single pollutant model. Our results suggest a positive association between PM exposure and ALRI hospitalizations in Korean children, particularly in the warm season. The children need to refrain from going out on days when PM is high.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18010144DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795137PMC
December 2020

Associations between surrounding residential greenness and intelligence quotient in 6-year-old children.

Sci Total Environ 2021 Mar 6;759:143561. Epub 2020 Nov 6.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, South Korea; Environmental Health Center, Seoul National University College of Medicine, Seoul, South Korea; Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, South Korea. Electronic address:

Background: Residential greenness has been reported to be positively associated with health benefits for children, including improved cognitive function. We investigated the association between the intelligence quotient (IQ) of 6-year-old children in Seoul, South Korea and surrounding greenness currently and during the mothers' pregnancy. We also analyzed whether these effects differed by the type of greenness, such as natural or built greenness.

Methods: This study considered 189 mother-child dyads from the Environment and Development of Children Cohort study, who lived in Seoul during the prenatal period and when the child was 6 years old. We defined surrounding greenness using Landsat image data from Korean Arirang satellite images with buffers within 100 m - 2000 m of the radius of each participant's residential address. We separately analyzed two types of greenness, namely natural and built greenness. The children's IQ (total, verbal, and performance IQ) was measured using the Korean Educational Developmental Institute's Wechsler Intelligence Scale for Children.

Results: Prenatal exposure to built greenness in 500 m and 1000 m buffers was associated with children's total IQ in a full model [difference in IQ (95% CI): 3.46(0.68, 6.24) and 3.42 (0.53, 6.31) per interquartile increase in proportion of greenness]. However, postnatal exposure to built greenness in all buffers was associated in children's total IQ. We found a stronger association between children's total IQ and built greenness rather than natural greenness.

Conclusions: We found that 6-year-old children tended to score higher on total IQ if they lived in greener neighborhoods. The results provide further evidence of the health benefits of greenness and provide support for urban planning and public health to build healthy urban cities for children and pregnant women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2020.143561DOI Listing
March 2021

Cellular Phone Use and Risk of Tumors: Systematic Review and Meta-Analysis.

Int J Environ Res Public Health 2020 11 2;17(21). Epub 2020 Nov 2.

Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul 110-744, Korea.

We investigated whether cellular phone use was associated with increased risk of tumors using a meta-analysis of case-control studies. PubMed and EMBASE were searched from inception to July 2018. The primary outcome was the risk of tumors by cellular phone use, which was measured by pooling each odds ratio (OR) and its 95% confidence interval (CI). In a meta-analysis of 46 case-control studies, compared with never or rarely having used a cellular phone, regular use was not associated with tumor risk in the random-effects meta-analysis. However, in the subgroup meta-analysis by research group, there was a statistically significant positive association (harmful effect) in the Hardell et al. studies (OR, 1.15-95% CI, 1.00 to 1.33- = 10), a statistically significant negative association (beneficial effect) in the INTERPHONE-related studies (case-control studies from 13 countries coordinated by the International Agency for Research on Cancer (IARC); (OR, 0.81-95% CI, 0.75 to 0.89- = 9), and no statistically significant association in other research groups' studies. Further, cellular phone use with cumulative call time more than 1000 h statistically significantly increased the risk of tumors. This comprehensive meta-analysis of case-control studies found evidence that linked cellular phone use to increased tumor risk.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph17218079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663653PMC
November 2020

Long-term exposure to moderate fine particulate matter concentrations and cause-specific mortality in an ageing society.

Int J Epidemiol 2021 01;49(6):1792-1801

Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.

Background: Long-term exposure to particulate matter <2.5 μm in size (PM2.5) is considered a risk factor for premature death. However, only a few studies have been conducted in areas with moderate PM2.5 concentrations. Moreover, an ageing society may be more susceptible to environmental exposure and future burden of mortality due to PM2.5.

Methods: This study estimates hazard ratios (HRs) for all-cause and cause-specific mortality from long-term exposure to moderate PM2.5 concentrations in the elderly populations of seven cities in South Korea. We also projected nationwide elderly mortality caused by long-term exposure to PM2.5, accounting for population ageing until 2045. Mortality in 1 720 230 elderly adults aged ≥65 years in 2008 was monitored across 2009-16 and linked to modelled PM2.5 concentrations.

Results: A total of 421 100 deaths occurred in 2009-16, and the mean of annual PM2.5 concentration ranged between 21.1 and 31.9 μg/m3 in most regions. The overall HR for a 10 μg/m3 increase in a 36-month PM2.5 moving average was 1.024 (95% confidence intervals: 1.009, 1.039). We estimated that 11 833 all-cause nationwide elderly deaths were attributable to PM2.5 exposure. Annual death tolls may increase to 17 948 by 2045. However, if PM2.5 is reduced to 5 μg/m3 by 2045, the tolls may show a lower increase to 3646.

Conclusions: Long-term exposure to moderately high levels of PM2.5 was associated with increased mortality risk among the elderly. Thus, PM2.5 reduction in response to the projected ageing-associated mortality in South Korea is critical.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ije/dyaa146DOI Listing
January 2021

Household insecticide use and urinary 3-phenoxybenzoic acid levels in an elder population: a repeated measures data.

J Expo Sci Environ Epidemiol 2020 Oct 6. Epub 2020 Oct 6.

Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, 110-799, Republic of Korea.

Background: Pyrethroids are associated with adverse health consequences, even at low-dose exposures. However, there is limited evidence on pyrethroids exposure levels among vulnerable elder population and on their exposure sources.

Objective: We tried to determine pyrethroids exposure levels among Korean elders and their exposure sources.

Methods: We measured levels of 3-phenoxybenzoic acid (3-PBA), a pyrethroids metabolite, in urines repeatedly collected from 1239 Korean rural and urban elders; we also explored exposure sources for pyrethroids using questionnaire data.

Results: Our participants had high levels of 3-PBA with 446 (36.0%) of elders with 3-PBA level over 2 ng/mL of 95th percentile of the German representative populations. After adjustment for sex, age, smoking status, visit episode, and surveyed season using linear mixed effect models, household insecticide spray use was significantly associated with 3-PBA level (β = 0.03 and p = 0.02) and the association was apparent only for females (β = 0.03 and p = 0.03). In the analyses for nonlinear relationships using generalized additive mixed models, there was a J-shape change in 3-PBA level by insecticide spray use (p < 0.01 both in total population and in females).

Significance: Household insecticide spray was a predominant exposure source for pyrethroids at community level among Korean elders, warning more stringent control for frequently exposed environmental factors for pyrethroids including insecticide spray.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41370-020-00276-3DOI Listing
October 2020

Burnout as a Mediator in the Relationship between Work-Life Balance and Empathy in Healthcare Professionals.

Psychiatry Investig 2020 Sep 17;17(9):951-959. Epub 2020 Sep 17.

Human Rights Center, Seoul National University Hospital, Seoul, Republic of Korea.

Objective: This cross-sectional study aimed to 1) explore the relationships among work-life balance (WLB), burnout, and empathy and 2) investigate the roles of the subtypes of burnout relating to WLB and empathy.

Methods: A total of 105 health care professionals from a general hospital in Seoul were assessed using the Maslach Burnout Inventory, Jefferson Scale of Physician Empathy, and a one-sentence-question on subjective WLB. Multiple questions on psychiatric problems, including sleep problems, anxiety, depressive symptom, and alcohol problems, were also included.

Results: In the mediation analyses, personal achievement was considered as a potential mediating variable between WLB and empathy. The direct effect (β=3.93, 95% CI: 1.21-6.64) and the indirect effect (β=1.95, 95% CI: 0.52-3.76) of WLB on empathy were also significant.

Conclusion: Interventions encouraging personal achievement may help mitigate burnout of health professionals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.30773/pi.2020.0147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7538247PMC
September 2020

Integration of multiomic annotation data to prioritize and characterize inflammation and immune-related risk variants in squamous cell lung cancer.

Genet Epidemiol 2021 Feb 14;45(1):99-114. Epub 2020 Sep 14.

Faculty of Medical Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.

Clinical trial results have recently demonstrated that inhibiting inflammation by targeting the interleukin-1β pathway can offer a significant reduction in lung cancer incidence and mortality, highlighting a pressing and unmet need to understand the benefits of inflammation-focused lung cancer therapies at the genetic level. While numerous genome-wide association studies (GWAS) have explored the genetic etiology of lung cancer, there remains a large gap between the type of information that may be gleaned from an association study and the depth of understanding necessary to explain and drive translational findings. Thus, in this study we jointly model and integrate extensive multiomics data sources, utilizing a total of 40 genome-wide functional annotations that augment previously published results from the International Lung Cancer Consortium (ILCCO) GWAS, to prioritize and characterize single nucleotide polymorphisms (SNPs) that increase risk of squamous cell lung cancer through the inflammatory and immune responses. Our work bridges the gap between correlative analysis and translational follow-up research, refining GWAS association measures in an interpretable and systematic manner. In particular, reanalysis of the ILCCO data highlights the impact of highly associated SNPs from nuclear factor-κB signaling pathway genes as well as major histocompatibility complex mediated variation in immune responses. One consequence of prioritizing likely functional SNPs is the pruning of variants that might be selected for follow-up work by over an order of magnitude, from potentially tens of thousands to hundreds. The strategies we introduce provide informative and interpretable approaches for incorporating extensive genome-wide annotation data in analysis of genetic association studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/gepi.22358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7855632PMC
February 2021

Dietary patterns are associated with attention-deficit hyperactivity disorder (ADHD) symptoms among preschoolers in South Korea: a prospective cohort study.

Nutr Neurosci 2020 Sep 4:1-9. Epub 2020 Sep 4.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, South Korea.

Objectives: Attention-deficit hyperactivity disorder (ADHD) is a prevalent neurobehavioral disorder in children. There are limited studies for diet or dietary supplement effects on ADHD in preschool children in Asia. This study aimed to determine the association between dietary patterns in 4-year-old children and ADHD symptoms in 6-year-old children.

Methods: We estimated dietary intake in 4-year-old children using a food frequency questionnaire. Using 33 food groups, major dietary patterns were identified in relation to the consumption of sweets, vegetables, meats, and carbohydrates. Parents of 6-year-old children used the Korean version of the ADHD Rating Scale for ADHD symptom assessment.

Results: A sweet dietary pattern was associated with a higher risk of attention deficit (AD) (relative risk [RR], 1.34; confidence interval [CI], 1.17-1.55), hyperactivity (RR, 1.40; CI, 1.19-1.64), and ADHD symptoms (RR, 1.37; CI, 1.23-1.52). A vegetable dietary pattern was associated with a lower risk of ADHD symptoms (RR, 0.81; CI, 0.72-0.90). Food item analysis of the sweet dietary pattern showed that intake scores for chocolate, chips, and fruit jams positively correlated with AD, hyperactivity, and ADHD symptoms.

Discussion: These findings can be useful to further understand the roles of dietary factors in ADHD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/1028415X.2020.1786789DOI Listing
September 2020

Adverse effects of prenatal mercury exposure on neurodevelopment during the first 3 years of life modified by early growth velocity and prenatal maternal folate level.

Environ Res 2020 12 12;191:109909. Epub 2020 Jul 12.

Department of Occupational and Environmental Medicine, College of Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, Republic of Korea. Electronic address:

Background And Aims: Previous studies have suggested that mercury exposure and folate levels during pregnancy may influence early childhood neurodevelopment. Rapid catch-up growth in children is associated with an increased risk of pathological nervous system development. We evaluated whether the association between prenatal folate and mercury-related neuropsychological dysfunction was modified by growth velocity during childhood.

Methods: The Mothers and Children's Environmental Health (MOCEH) birth cohort study began in 2006 and by 2010, 1751 women had been enrolled before the second trimester of their pregnancy along with their partners. Participants visited the research center at birth and 6, 12, 24, and 36 months. We measured mercury levels in maternal and cord blood and folate in maternal serum. Questionnaires to evaluate the environment and health of their child were administered and anthropometric factors including body weight and height were measured. Certified investigators used the Bayley test to measure neurobehavioral outcomes. We calculated postnatal growth change as the change in infant weight for-age z-score between birth and 3 years. Multiple linear regression and mixed models were used to examine the association between mercury exposure and children's neurodevelopment as well as the modifying effects of folate and growth velocity.

Results: A total of 30.6% of children experienced rapid growth during the first 3 years of life. Median values of mercury in the low folate group were significantly higher in rapid growers (3.41 μg/L in maternal blood and 5.63 μg/L in cord blood) than in average/slow growers (3.05 μg/L in maternal blood and 5.19 μg/L in cord blood). Rapid growers were also significantly associated with decreased psychomotor development scores during the first 3 years of life and with having mothers who had low prenatal folate levels, even after adjusting for potential confounders.

Conclusion: Prenatal mercury exposure adversely affects infant neurodevelopment and is associated with rapid growth during the first 3 years of life. This effect was limited to children whose mothers had low prenatal folate levels, suggesting a protective effect of folate against developmental neurotoxicity due to mercury exposure and rapid catch-up growth.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envres.2020.109909DOI Listing
December 2020

Association between short-term air pollution exposure and attention-deficit/hyperactivity disorder-related hospital admissions among adolescents: A nationwide time-series study.

Environ Pollut 2020 Nov 11;266(Pt 1):115369. Epub 2020 Aug 11.

Division of Public Health and Preventive Medicine, Seoul National University Hospital, Seoul, Republic of Korea; Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address:

Long-term air pollution exposure has been suggested to increase the risk of attention-deficit/hyperactivity disorder (ADHD). However, the association between short-term air pollution exposure and ADHD-related outcomes is still unknown. We investigated the associations between short-term exposure to particulate matter with an aerodynamic diameter ≤10 μm (PM), nitrogen oxide (NO), and sulfur dioxide (SO) and hospital admissions with a principal diagnosis of ADHD among adolescents (age 10-19 years) in 16 regions of the Republic of Korea from 2013 to 2015. We estimated the region-specific relative risks (RRs) and 95% confidence intervals (CIs) from quasi-Poisson regressions adjusted for potential confounders, considering single-day and moving average lag. Consequently, we performed meta-analyses to pool the region-specific estimates. The risks of ADHD-related hospital admissions were increased in the single-day and moving average lag models for PM (largest association for lag 1 in the single-day lag model, RR = 1.12, 95% CI: 1.05, 1.20; lag 0-2 in the moving average lag model, RR = 1.17, 95% CI: 1.07, 1.27), NO (lag 3, RR = 1.47, 95% CI: 1.25, 1.73; lag 1-3, RR = 1.68, 95% CI: 1.38, 2.04), and SO (lag 1, RR = 1.27, 95% CI: 1.14, 1.41; lag 1-3, RR = 1.29, 95% CI: 1.12, 1.49). The associations were similar between boys and girls, but they were stronger among adolescents aged 15-19 years than those aged 10-14 years for NO and SO. In conclusion, the results indicate that short-term exposure to PM, NO, and SO may be a risk factor for the exacerbation of ADHD symptoms, leading to hospitalization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envpol.2020.115369DOI Listing
November 2020

Prenatal exposure to traffic-related air pollution and risk of congenital diseases in South Korea.

Environ Res 2020 12 15;191:110060. Epub 2020 Aug 15.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, 03080, South Korea; Environmental Health Center, Seoul National University College of Medicine, Seoul, 03080, South Korea; Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, 03080, South Korea. Electronic address:

Background: Previous studies have suggested links between exposure to ambient air pollutants and increased risk of congenital heart defects. However, few studies have investigated the association between other congenital diseases and traffic-related air pollution. In this study, we assessed the relationship between prenatal exposure to fine particulate matter (PM) and nitrogen dioxide (NO) with congenital diseases in South Korea.

Methods: Patients with one or more congenital diseases and a control group of patients with non-infective gastroenteritis and colitis with a case:control ratio of 1:3 were obtained from the National Health Insurance Service data for 2008-2013 in South Korea. We estimated the associations of PM and NO exposures with congenital diseases using generalized estimation equations after controlling for covariates.

Results: Maternal PM exposure during the first and second trimester showed positive associations with overall congenital diseases, with changes of 14.7% (95% confidence intervals (CI), 9.3%, 20.3%) and 16.2% (95% CI, 11.0%, 21.7%), respectively, per 11.1 μg/m and 10.2 μg/m increase of PM interquartile range (IQR). Similarly, NO exposure during the first and second trimester was associated with increased numbers of overall congenital anomalies, with 8.2% (95% CI, 4.2%, 12.3%) and 15.6% (95% CI, 9.3%, 22.2%) more cases, respectively, per 10.6 ppb increase of NO. We found that maternal PM exposure during the first and second trimesters of pregnancy was significantly associated with increased risk of specific congenital diseases, including subtypes affecting the circulatory, genitourinary, and musculoskeletal system. However, no significant associations were observed during the third trimester. Maternal NO exposure across the entire pregnancy was associated with malformations of the musculoskeletal system.

Conclusions: Our study identified significant links between in utero exposure to PM and NO and certain congenital diseases, and suggests that stricter controls on PM and NO concentrations are required.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envres.2020.110060DOI Listing
December 2020

Changes in Adrenal Androgens and Steroidogenic Enzyme Activities From Ages 2, 4, to 6 Years: A Prospective Cohort Study.

J Clin Endocrinol Metab 2020 10;105(10)

Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea.

Context: The levels of adrenal androgens are increased through the action of steroidogenic enzymes with morphological changes in the adrenal zona reticularis.

Objective: We investigated longitudinal changes in androgen levels and steroidogenic enzyme activities during early childhood.

Design And Participants: From a prospective children's cohort, the Environment and Development of Children cohort, 114 boys and 86 girls with available blood samples from ages 2, 4, and 6 years were included.

Outcome Measurements: Serum concentrations of adrenal androgens using liquid chromatography-tandem mass spectrometry and steroidogenic enzyme activity calculated by the precursor/product ratio.

Results: During ages 2 to 4 years, 17,20-lyase and dehydroepiandrosterone (DHEA) sulfotransferase activities increased (P < 0.01 for both in boys). During ages 4 to 6 years, 17,20-lyase activity persistently increased, but 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD activities decreased (P < 0.01 for all). Serum DHEA sulfate (DHEA-S) levels persistently increased from 2, 4, to 6 years, and DHEA, 17-hydroxyprogesterone, and androstenedione levels increased during ages 4 to 6 years (P < 0.01 for all). Serum DHEA-S levels during early childhood were associated with body mass index z-scores (P = 0.001 in only boys).

Conclusion: This study supports in vivo human evidence of increased 17,20-lyase and DHEA sulfotransferase activities and decreased 3β-HSD activity during early childhood.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/clinem/dgaa498DOI Listing
October 2020

Prevalence, associated factors, and comorbidities of tinnitus in adolescents.

PLoS One 2020 31;15(7):e0236723. Epub 2020 Jul 31.

Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.

The aim of this study was to investigate the prevalence of tinnitus among adolescents, and the factors known or hypothesized to be associated with tinnitus. Based on random sampling of school types and regions, a nationwide hearing survey of the first-year middle and high school students of South Korea was performed. The subjects underwent an otologic examination followed by pure tone audiometry up to 8 kHz. Questionnaires about the factors associated with hearing and tinnitus were completed by the students and their parents. Among the 1,593 subjects who completed the questionnaire and underwent pure tone audiometry, the prevalence of tinnitus was 46.0% and that of severe tinnitus was 9.1%. Tinnitus was associated with age, female gender, history of ear infection and sinusitis, leisure noise exposure due to karaoke and local-area-network gaming, alcohol consumption, and cigarette smoking. Noticeable hearing loss was not detected but participants with tinnitus complained of difficulty with sound localization, hearing in noise, and verbal working memory and were more susceptible to fatigue. The subjects with tinnitus also suffered more physical and mental health problems than did those without tinnitus. Thus, protection of the ears from noise and appropriate counseling should be considered for adolescents with tinnitus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236723PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7394400PMC
September 2020

Decrease in Ambient Fine Particulate Matter during COVID-19 Crisis and Corresponding Health Benefits in Seoul, Korea.

Int J Environ Res Public Health 2020 07 22;17(15). Epub 2020 Jul 22.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul 03080, Korea.

Both domestic emissions and transported pollutants from neighboring countries affect the ambient fine particulate matter (PM) concentration of Seoul, Korea. Diverse measures to control the coronavirus disease 2019 (COVID-19), such as social distancing and increased telecommuting in Korea and the stringent lockdown measures of China, may reduce domestic emissions and levels of transported pollutants, respectively. In addition, wearing a particulate-filtering respirator may have decreased the absolute PM exposure level for individuals. Therefore, this study estimated the acute health benefits of PM reduction and changes in public behavior during the COVID-19 crisis in Seoul, Korea. To calculate the mortality burden attributable to PM, we obtained residents' registration data, mortality data, and air pollution monitoring data for Seoul from publicly available databases. Relative risks were derived from previous time-series studies. We used the attributable fraction to estimate the number of excessive deaths attributable to acute PM exposure during January to April, yearly, from 2016 to 2020, and the number of mortalities avoided from PM reduction and respirator use observed in 2020. The average PM concentration from January to April in 2020 (25.6 μg/m) was the lowest in the last 5 years. At least -4.1 μg/m (95% CI: -7.2, -0.9) change in ambient PM in Seoul was observed in 2020 compared to the previous 4 years. Overall, 37.6 (95% CI: 32.6, 42.5) non-accidental; 7.0 (95% CI: 5.7, 8.4) cardiovascular; and 4.7 (95% CI: 3.4, 6.1) respiratory mortalities were avoided due to PM reduction in 2020. By considering the effects of particulate respirator, decreases of 102.5 (95% CI: 89.0, 115.9) non-accidental; 19.1 (95% CI: 15.6, 22.9) cardiovascular; and 12.9 (95% CI: 9.2, 16.5) respiratory mortalities were estimated. We estimated that 37 lives were saved due to the PM reduction related to COVID-19 in Seoul, Korea. The health benefit may be greater due to the popular use of particulate-filtering respirators during the COVID-19 crisis. Future studies with daily mortality data are needed to verify our study estimates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph17155279DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7432095PMC
July 2020

Effect of prenatal bisphenol A exposure on early childhood body mass index through epigenetic influence on the insulin-like growth factor 2 receptor (IGF2R) gene.

Environ Int 2020 10 6;143:105929. Epub 2020 Jul 6.

Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul 03080, Republic of Korea; Section of Environmental Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen 1014, Denmark. Electronic address:

Objectives: Epigenetic mechanisms have been suggested to play a role in the link between in utero exposure to bisphenol A (BPA) and pediatric obesity; however, there is little evidence regarding this mechanism in humans. We obtained data on obesity-associated CpG sites from a previous epigenome-wide association study, and then examined whether methylation at those CpG sites was influenced by prenatal BPA exposure. We then evaluated the relationship between CpG methylation status and body mass index (BMI) in a prospective children's cohort at ages 2, 4, 6, and 8 years.

Methods: Methylation profiles of 59 children were longitudinally analyzed at ages 2 and 6 years using the Infinium Human Methylation BeadChip. A total of 594 CpG sites known to be BMI or obesity-associated sites were tested for an association with prenatal BPA levels, categorized into low and high exposure groups based on the 80th percentile of maternal BPA levels (2.68 μg/g creatinine), followed by an analysis of the association between DNA methylation and BMI from ages 2-8.

Results: There was a significant increase in the methylation levels of cg19196862 (IGF2R) in the high BPA group at age 2 years (p = 0.00030, false discovery rate corrected p < 0.10) but not at age 6. With one standard deviation increase of methylation at cg19196862 (IGF2R) at age 2 years, the linear mixed model analysis revealed that BMI during ages 2-8 years significantly increased by 0.49 (95% confidence interval; 0.08, 0.90) in girls, but not in boys. The indirect effect of prenatal BPA exposure on early childhood BMI through methylation at cg19196862 (IGF2R) at age 2 years was marginally significant.

Conclusions: Prenatal exposure to BPA may influence differential methylation of IGF2R at age 2. This result indicates that a possible sensitive period of DNA methylation occurs earlier during development, which may affect BMI until later childhood in a sex-specific manner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envint.2020.105929DOI Listing
October 2020

Impact of environmental exposure to persistent organic pollutants on lung cancer risk.

Environ Int 2020 10 2;143:105925. Epub 2020 Jul 2.

Division of Cancer Prevention & Early Detection, National Cancer Control Institute, National Cancer Center, Goyang-si, Gyeonggi-do 10408, Republic of Korea; Department of Cancer Control and Population Health, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Gyeonggi-do 10408, Republic of Korea. Electronic address:

Background: Recent studies suggest that high pre-diagnostic serum concentrations of persistent organic pollutants (POPs) might result in the development of cancers in the general population. However, the association between pre-diagnostic serum POP concentrations and lung cancer risk has not been studied. Here, we evaluated associations between low-dose environmental exposure to POPs and risk of lung cancer using pre-diagnostic serum samples in a case-cohort study based on a population-based prospective cohort.

Methods: We conducted a case-cohort study based on the Korean National Cancer Center Community Cohort, from which we included 118 lung cancer cases and 252 controls. Serum concentrations of POPs were measured by high resolution gas chromatography/high-resolution mass spectrometry, and data were analyzed using multivariable Cox proportional-hazards regression models.

Results: Risk of lung cancer increased per unit increase in the natural log-transformed concentrations of the sum of chlordane congeners, total PCBs, and all PCBs subgrouped by the number of chlorines or ortho- substituted chlorines on the molecules, except for tri/tetrachlorobiphenyls, in all models. Among individual POP analytes with a detection rate >80%, after Bonferroni adjustment, only trans-nonachlor was associated with lung cancer risk. In categorical models, risk of lung cancer was associated with serum concentration of chlordane (4th vs. 1st quartile, hazard ratio [95% confidence interval], 8.79 [2.77-27.97]). Dose-dependent relationships were also found between risk of lung cancer and serum concentrations of PCBs regardless of their degree of chlorination, substitution pattern, or binding affinity to receptors (total PCBs, P = 0.002; mid-chlorinated PCBs, P = 0.004; high-chlorinated PCBs, P < 0.001; non- and mono-ortho PCBs, P = 0.031; di-ortho PCBs, P = 0.003; PCBs with dioxin-like activity, P = 0.011; non-dioxin-like non-/mono-ortho PCBs, P = 0.060).

Conclusions: Serum concentrations of chlordane and PCBs are associated with risk of lung cancer in the general population, even decades after the ban on their production and use.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envint.2020.105925DOI Listing
October 2020

Long-term exposure to fine particulate matter and development of chronic obstructive pulmonary disease in the elderly.

Environ Int 2020 10 30;143:105895. Epub 2020 Jun 30.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, South Korea; Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, South Korea; Environmental Health Center, Seoul National University College of Medicine, Seoul, South Korea. Electronic address:

Background: Studies evaluating the role of long-term exposure to fine particulate matter (PM) on chronic obstructive pulmonary disease (COPD) development showed inconsistent results and were limited to Western countries. We aimed to determine the association between long-term exposure to PM and COPD development in metropolitan cities in Korea, which have higher PM levels than those in Western country studies.

Methods: We constructed a retrospective cohort (elderly aged over 65 years who resided in 7 metropolitan cities in 2008) using Korea health insurance data. A total of 687,940 elderlies who had not visited hospitals due to COPD for 3 years (from 2008 to 2010) were followed-up from 2011 to 2016. The first hospital visit due to COPD during the follow-up period was regarded as COPD development. Daily district-level PM concentrations were estimated by chemical transport model and 60-month moving average PM were assigned to each subject in time-varying Cox proportional hazard model.

Results: The mean concentration of modelled PM in 7 metropolitan cities during the study period (from 2006 to 2016) was 28.0 μg/m and 259,700 subjects newly visited the hospital due to COPD. COPD hospital visit hazard ratio for a 10 μg/m increase in 60-month moving average PM concentration was 1.09 (95% confidence interval: 1.07, 1.11). Risks remained unchanged following different PM exposure levels (48-month moving average, and average PM concentrations for 2008 and 2008-2010) and in subgroup analysis by subject characteristics (sex, age, and income groups).

Discussion: By following-up 687,940 elderly subjects who resided in metropolitan cities in Korea for 6 years, long-term PM exposure showed association with COPD development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envint.2020.105895DOI Listing
October 2020

Effects of short-term fine particulate matter exposure on acute respiratory infection in children.

Int J Hyg Environ Health 2020 08 15;229:113571. Epub 2020 Jun 15.

Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea; Division of Public Health and Preventive Medicine, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea. Electronic address:

Background: Previous studies on the association between fine particulate matter (PM) exposure and acute respiratory infection in children are scarce and present inconsistent results. We estimated the association between short-term PM exposure and acute respiratory infection among children aged 0-4 years using a difference-in-differences approach.

Methods: We used data on the daily PM concentrations, hospital admissions for acute respiratory infection, and meteorological factors of the 15 regions in the Republic of Korea (2013-2015). To estimate the cumulative effects, we used a difference-in-differences approach generalized to multiple spatial units (regions) and time periods (day) with distributed lag non-linear models.

Results: With PM levels of 20.0 μg/m as a reference, PM levels of 30.0 μg/m were positively associated with the risk of acute upper respiratory infection (relative risk (RR) = 1.048, 95% confidence interval (CI): 1.028, 1.069) and bronchitis or bronchiolitis (RR = 1.060, 95% CI: 1.038, 1.082) but not with the risk of acute lower respiratory infection and pneumonia. PM levels of 40.0 μg/m were also positively associated with the risk of acute upper respiratory infection (RR = 1.083, 95% CI: 1.046, 1.122) and bronchitis or bronchiolitis (RR = 1.094, 95% CI: 1.054, 1.136).

Conclusions: We found the associations of short-term PM exposure with acute upper respiratory infection and bronchitis or bronchiolitis among children aged 0-4 years. As causal inference methods can provide more convincing evidence of the effects of PM levels on respiratory infections, public health policies and guidelines regarding PM need to be strengthened accordingly.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijheh.2020.113571DOI Listing
August 2020