Ki-Do Eum - Academia.edu (original) (raw)

Papers by Ki-Do Eum

Environmental health perspectives, Sep 16, 2023

International Archives of Occupational and Environmental Health, Apr 19, 2008

The aim of this study was to explore an association between psychosocial stress at work in marrie... more The aim of this study was to explore an association between psychosocial stress at work in married men and their spouses' prolonged time to pregnancy (TTP). All married male workers of a large Korean petrochemical enterprise and their wives fulfilling the selection criteria were included. Main selection criteria were lack of use of contraceptives and experienced pregnancy in recent past. Data were available from 322 couples. Psychosocial stress at work was measured by the effort-reward imbalance questionnaire. Prolonged TTP was measured by the "TTP questionnaire". After adjustment for confounding effects of demographic and life-style characteristics and benzene exposure, delayed TTP, defined by frequency of first-cycle pregnancy, was associated with one standard deviation (SD) increase of the effort-reward ratio in the chronically stressed group of married men (OR = 0.47; 95% CI = 0.22-0.99) in logistic regression analysis. A similar, but somewhat weaker effect, was found for the overall group (OR = 0.67; 95% CI = 0.47-0.94). Paternal stress at work, as measured by effort-reward imbalance, seemed to be associated with a decreased number of conceptions in the first menstrual cycle.

ABSTRACT OBJECTIVES: This study explored the associations between social class, job insecurity, a... more ABSTRACT OBJECTIVES: This study explored the associations between social class, job insecurity, and job strain among Korean workers. METHODS: Data on 6143 participants (253 health care workers, 5113 subway workers, and 777 petrochemical refinery workers) from three Korean job-stress studies were used. Job strain and job insecurity were measured with the job content questionnaire. Job strain was defined as a continuous variable according to the demand-to-control ratio and as a binary variable as the highest quartile of this ratio. Social class was defined by indicators of socioeconomic status. The combined effects of job insecurity and socioeconomic status were examined with generalized linear models and logistic regression models. RESULTS: Job insecurity was relatively higher than in other countries (scale mean 5.8). Higher job insecurity was associated with lower social class, and it appeared to partially mediate the effect of socioeconomic status on job strain. Job insecurity and low social class independently elevated job strain. Job strain was the highest among those with a low social class and job insecurity for each socioeconomic indicator. According to the logistic regression models, the odds ratio for high strain was 2.0 (P<0.05) for low job security and low education, 2.4 (P<0.05) for low job security and low income, and 2.4 (P<0.05) for low job security and low occupational class, when compared with the baseline values. CONCLUSIONS: Low social class is associated with higher job strain. Job insecurity is higher among persons in a lower social class, the highest job strain occurring among workers with both factors. Job insecurity appears to intensify the overall effect of social class on job strain.

Environmental health perspectives, Aug 23, 2021

Environmental health perspectives, Aug 17, 2016

Environmental health perspectives, Sep 19, 2013

Environmental health perspectives, Sep 18, 2022

Environmental Health Perspectives, May 1, 2021

Background: Studies have evaluated environmental exposure to toxic metals such as arsenic (As), c... more Background: Studies have evaluated environmental exposure to toxic metals such as arsenic (As), cadmium (Cd), manganese (Mn), or lead (Pb) on birth size; however, information on potential effects of exposures to metal mixtures is limited. Objectives: We assessed the association between metal mixtures (As, Cd, Mn, Pb) in umbilical cord blood and neonate size in Bangladeshi children. Methods: In this birth cohort study, pregnant women who were ≥18 years of age with an ultrasound-confirmed singleton pregnancy of ≤16wk gestation were recruited from two Bangladesh clinics between 2008 and 2011. Neonate size metrics were measured at the time of delivery. Metals in cord blood were measured using inductively coupled plasma mass spectrometry. We employed multivariable linear regression and Bayesian kernel machine regression (BKMR) to estimate associations of individual metals and metal mixtures with birth size parameters. Results: Data from 1,088 participants was assessed. We found a significant negative association between metal mixture and birth length and head circumference when all metal concentrations were above the 60th and 55th percentiles, respectively, compared with the median. An interquartile range (IQR) increase in log Cd concentration {log[Cd (in micrograms per deciliter)] IQR=2.51} was associated with a 0.13-standard deviation (SD) decrease in mean birth length (95% CI: −0.25, −0.02) and a 0.17-SD decrease in mean head circumference (95% CI: −0.28, −0.05), based on linear regression models adjusted for covariates and the other metals. An IQR increase in log Mn concentration {log[Mn (in micrograms per deciliter)] IQR=0.69} was associated with a 0.07-SD decrease in mean birth weight (95% CI: −0.15, 0.002). Discussion: Metal mixtures in cord blood were associated with reduced birth size in Bangladeshi children. Results from linear regression models adjusted and the BKMR mixtures analyses suggest adverse effects of Cd and Mn, as individual metal exposures, on birth size outcomes. https://doi.org/10.1289/EHP7502

Environmental health perspectives, Sep 24, 2018

Introduction: Associations between long-term ozone (O3) exposure and cause-specific mortality hav... more Introduction: Associations between long-term ozone (O3) exposure and cause-specific mortality have been demonstrated, although with varying exposure metrics and confounders.Methods: We assessed the...

한국보건교육·건강증진학회 학술대회 발표논문집, Nov 1, 2007

This study aimed to explore the sex differences in the relationship between acute exposure to air... more This study aimed to explore the sex differences in the relationship between acute exposure to air pollution and respiratory disease in children. Despite a relatively high prevalence of respiratory disease in boys, the significance of air pollutions were only apparent in girls. These results suggest that sex is an important determinant for air pollution-induced respiratory problems.

Journal of Exposure Science and Environmental Epidemiology, Apr 16, 2019

Journal of Neurology, Neurosurgery, and Psychiatry, Jul 13, 2015

Neurotoxicology, Mar 1, 2007

Exposure to organic solvents, which are widely used in industry, can lead to dysfunction of the n... more Exposure to organic solvents, which are widely used in industry, can lead to dysfunction of the nervous system. However, controversy continues about the nature of early-stage damage to the nervous system from low-grade chronic exposure to organic solvents. Since loss of color-vision can be a sensitive early marker of neurotoxic damage, the main aim of this study was to investigate the association between low-level chronic exposure to organic solvents, especially benzene, and acquired dyschromatopsia. The study initially comprised 1236 workers who were employed at a large petrochemical distillation factory. After excluding those workers who may have had color-vision impairment due to congenital or acquired eye diseases and those with other medical conditions, 908 males who had worked for at least 6 months were included in the final analysis. Those who worked only in the office were categorized as nonexposed, while those who worked at outside facilities were divided into three groups of approximately equal size according to their estimated cumulative exposure levels to benzene (low, medium, high). Color-vision was assessed using the Lanthony D-15 desaturated panel color test. The results showed that the color-confusion index (CCI) was positively related to age. In the qualitative assessment of types of color-vision loss, the prevalence of total dyschromatopsia was significantly higher with increasing cumulative exposure levels in the left eye (p<0.05) but not in the right eye. The significance for the prevalence of type III dyschromatopsia was borderline in the left eye (p=0.0571). The relationship between acquired dyschromatopsia and exposure level also showed an increase in the odds ratio in the left eye but not in the right eye. Taken together, these results suggest that chronic low-level exposure to benzene can lead to acquired dyschromatopsia.

Environmental Health, Feb 17, 2020

Occupational and Environmental Medicine, May 23, 2022

Environmental health perspectives, Sep 24, 2018

Introduction. Long-term exposure to fine particulate matter (PM2.5) has been consistently associa... more Introduction. Long-term exposure to fine particulate matter (PM2.5) has been consistently associated with mortality; however, our understanding of how these associations are modified by certain cha...

Environmental health perspectives, Sep 18, 2022

Environmental health perspectives, Aug 17, 2016

International Archives of Occupational and Environmental Health, Mar 15, 2007

Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and incr... more Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and increased cancer risk has been reported among neighborhoods previously. In this study, we tried to assess the exposure to PAHs among residents nearby to a large steel mill in Korea by measuring urinary 1-hydroxypyrene (1-OHP). Two separate areas at different distances from a steel mill but on the same wind direction were chosen to evaluate the environmental exposures to polycyclic aromatic hydrocarbons. Three-hundred and fifty children living in the vicinity of steel plant ("nearby" group) and 606 children residing much farther from the factory ("remote" group) participated. Urine was collected on three consecutive days, and questionnaires about exposure to passive smoking and food consumption as well as demographics were obtained. Routine monitoring data of ambient pollutants were obtained and particulate matter less than 10 microm (PM10) was analyzed with multiple regressions to assess the associations with urinary 1-OHP. The geometric mean concentration of urinary 1-OHP among nearby group (0.048+/-1.878 micromol/mol creatinine, GM+/-GSD) was approximately 1.3 times higher than that among remote group (0.036+/-2.425 micromol/mol creatinine, GM+/-GSD), and using multiple regression techniques, the difference was significant (P<0.0001) after adjusting for confounding variables. When different periods before the sampling of urine were examined, PM10 averages over 2 days, 3 days, and 1 week prior to urine sampling showed significant associations with urinary 1-OHP levels. Our findings are consistent with the interpretation that residents nearby to a steel mill are exposed to PAHs through ambient exposures.

International Archives of Occupational and Environmental Health, Feb 16, 2007

To evaluate the criterion validity, factorial validity, and internal consistency of Korean versio... more To evaluate the criterion validity, factorial validity, and internal consistency of Korean version of effort-reward imbalance (ERI) for the scales of effort, reward, and overcommitment as well as to examine the effect of psychosocial factors on physical and mental illness among petroleum refinery workers in South Korea. The Korean version of ERI questionnaire was constructed using the translation and back-translation technique, and its psychometric properties were explored among 908 male workers in a large petroleum refinery in South Korea in 2002. Cronbach's alpha coefficient was used to test internal consistency. An exploratory factor analysis was conducted on all items of the instrument. Confirmatory factor analyses were conducted on each dimension of effort, reward and overcommitment. Physical and mental health was measured by self-rated health (SF-8). The lowest tertiles of the scores were defined as illness. Multiple logistic regression models were used to test the effect of job stress on the physical and mental health (criterion validity of ERI scales). The Cronbach's alpha coefficients for effort, reward, and overcommitment were 0.71, 0.86, and 0.75, respectively, indicating satisfactory internal consistency. Exploratory factor analysis found three latent factors, which closely corresponded to the theoretical structure of the ERI model. Acceptable construct validity was shown using confirmatory factor analysis. The highest tertile of effort-reward ratio was significantly associated with physical illness (OR 2.4, 95% CI 1.7-3.6) and mental illness (OR 2.9, 95% CI 2.0-4.2), compared to lower tertiles. Overcommitment was significantly associated with mental illness, but not with physical illness. These findings contribute to the validity and reliability of the Korean ERI questionnaire. Importantly, in the context of a rapid change in the labour market, the lack of reciprocity between efforts and rewards at work is strongly associated with self-rated physical and mental health.

Environmental health perspectives, Sep 16, 2023

International Archives of Occupational and Environmental Health, Apr 19, 2008

The aim of this study was to explore an association between psychosocial stress at work in marrie... more The aim of this study was to explore an association between psychosocial stress at work in married men and their spouses' prolonged time to pregnancy (TTP). All married male workers of a large Korean petrochemical enterprise and their wives fulfilling the selection criteria were included. Main selection criteria were lack of use of contraceptives and experienced pregnancy in recent past. Data were available from 322 couples. Psychosocial stress at work was measured by the effort-reward imbalance questionnaire. Prolonged TTP was measured by the "TTP questionnaire". After adjustment for confounding effects of demographic and life-style characteristics and benzene exposure, delayed TTP, defined by frequency of first-cycle pregnancy, was associated with one standard deviation (SD) increase of the effort-reward ratio in the chronically stressed group of married men (OR = 0.47; 95% CI = 0.22-0.99) in logistic regression analysis. A similar, but somewhat weaker effect, was found for the overall group (OR = 0.67; 95% CI = 0.47-0.94). Paternal stress at work, as measured by effort-reward imbalance, seemed to be associated with a decreased number of conceptions in the first menstrual cycle.

ABSTRACT OBJECTIVES: This study explored the associations between social class, job insecurity, a... more ABSTRACT OBJECTIVES: This study explored the associations between social class, job insecurity, and job strain among Korean workers. METHODS: Data on 6143 participants (253 health care workers, 5113 subway workers, and 777 petrochemical refinery workers) from three Korean job-stress studies were used. Job strain and job insecurity were measured with the job content questionnaire. Job strain was defined as a continuous variable according to the demand-to-control ratio and as a binary variable as the highest quartile of this ratio. Social class was defined by indicators of socioeconomic status. The combined effects of job insecurity and socioeconomic status were examined with generalized linear models and logistic regression models. RESULTS: Job insecurity was relatively higher than in other countries (scale mean 5.8). Higher job insecurity was associated with lower social class, and it appeared to partially mediate the effect of socioeconomic status on job strain. Job insecurity and low social class independently elevated job strain. Job strain was the highest among those with a low social class and job insecurity for each socioeconomic indicator. According to the logistic regression models, the odds ratio for high strain was 2.0 (P<0.05) for low job security and low education, 2.4 (P<0.05) for low job security and low income, and 2.4 (P<0.05) for low job security and low occupational class, when compared with the baseline values. CONCLUSIONS: Low social class is associated with higher job strain. Job insecurity is higher among persons in a lower social class, the highest job strain occurring among workers with both factors. Job insecurity appears to intensify the overall effect of social class on job strain.

Environmental health perspectives, Aug 23, 2021

Environmental health perspectives, Aug 17, 2016

Environmental health perspectives, Sep 19, 2013

Environmental health perspectives, Sep 18, 2022

Environmental Health Perspectives, May 1, 2021

Background: Studies have evaluated environmental exposure to toxic metals such as arsenic (As), c... more Background: Studies have evaluated environmental exposure to toxic metals such as arsenic (As), cadmium (Cd), manganese (Mn), or lead (Pb) on birth size; however, information on potential effects of exposures to metal mixtures is limited. Objectives: We assessed the association between metal mixtures (As, Cd, Mn, Pb) in umbilical cord blood and neonate size in Bangladeshi children. Methods: In this birth cohort study, pregnant women who were ≥18 years of age with an ultrasound-confirmed singleton pregnancy of ≤16wk gestation were recruited from two Bangladesh clinics between 2008 and 2011. Neonate size metrics were measured at the time of delivery. Metals in cord blood were measured using inductively coupled plasma mass spectrometry. We employed multivariable linear regression and Bayesian kernel machine regression (BKMR) to estimate associations of individual metals and metal mixtures with birth size parameters. Results: Data from 1,088 participants was assessed. We found a significant negative association between metal mixture and birth length and head circumference when all metal concentrations were above the 60th and 55th percentiles, respectively, compared with the median. An interquartile range (IQR) increase in log Cd concentration {log[Cd (in micrograms per deciliter)] IQR=2.51} was associated with a 0.13-standard deviation (SD) decrease in mean birth length (95% CI: −0.25, −0.02) and a 0.17-SD decrease in mean head circumference (95% CI: −0.28, −0.05), based on linear regression models adjusted for covariates and the other metals. An IQR increase in log Mn concentration {log[Mn (in micrograms per deciliter)] IQR=0.69} was associated with a 0.07-SD decrease in mean birth weight (95% CI: −0.15, 0.002). Discussion: Metal mixtures in cord blood were associated with reduced birth size in Bangladeshi children. Results from linear regression models adjusted and the BKMR mixtures analyses suggest adverse effects of Cd and Mn, as individual metal exposures, on birth size outcomes. https://doi.org/10.1289/EHP7502

Environmental health perspectives, Sep 24, 2018

Introduction: Associations between long-term ozone (O3) exposure and cause-specific mortality hav... more Introduction: Associations between long-term ozone (O3) exposure and cause-specific mortality have been demonstrated, although with varying exposure metrics and confounders.Methods: We assessed the...

한국보건교육·건강증진학회 학술대회 발표논문집, Nov 1, 2007

This study aimed to explore the sex differences in the relationship between acute exposure to air... more This study aimed to explore the sex differences in the relationship between acute exposure to air pollution and respiratory disease in children. Despite a relatively high prevalence of respiratory disease in boys, the significance of air pollutions were only apparent in girls. These results suggest that sex is an important determinant for air pollution-induced respiratory problems.

Journal of Exposure Science and Environmental Epidemiology, Apr 16, 2019

Journal of Neurology, Neurosurgery, and Psychiatry, Jul 13, 2015

Neurotoxicology, Mar 1, 2007

Exposure to organic solvents, which are widely used in industry, can lead to dysfunction of the n... more Exposure to organic solvents, which are widely used in industry, can lead to dysfunction of the nervous system. However, controversy continues about the nature of early-stage damage to the nervous system from low-grade chronic exposure to organic solvents. Since loss of color-vision can be a sensitive early marker of neurotoxic damage, the main aim of this study was to investigate the association between low-level chronic exposure to organic solvents, especially benzene, and acquired dyschromatopsia. The study initially comprised 1236 workers who were employed at a large petrochemical distillation factory. After excluding those workers who may have had color-vision impairment due to congenital or acquired eye diseases and those with other medical conditions, 908 males who had worked for at least 6 months were included in the final analysis. Those who worked only in the office were categorized as nonexposed, while those who worked at outside facilities were divided into three groups of approximately equal size according to their estimated cumulative exposure levels to benzene (low, medium, high). Color-vision was assessed using the Lanthony D-15 desaturated panel color test. The results showed that the color-confusion index (CCI) was positively related to age. In the qualitative assessment of types of color-vision loss, the prevalence of total dyschromatopsia was significantly higher with increasing cumulative exposure levels in the left eye (p<0.05) but not in the right eye. The significance for the prevalence of type III dyschromatopsia was borderline in the left eye (p=0.0571). The relationship between acquired dyschromatopsia and exposure level also showed an increase in the odds ratio in the left eye but not in the right eye. Taken together, these results suggest that chronic low-level exposure to benzene can lead to acquired dyschromatopsia.

Environmental Health, Feb 17, 2020

Occupational and Environmental Medicine, May 23, 2022

Environmental health perspectives, Sep 24, 2018

Introduction. Long-term exposure to fine particulate matter (PM2.5) has been consistently associa... more Introduction. Long-term exposure to fine particulate matter (PM2.5) has been consistently associated with mortality; however, our understanding of how these associations are modified by certain cha...

Environmental health perspectives, Sep 18, 2022

Environmental health perspectives, Aug 17, 2016

International Archives of Occupational and Environmental Health, Mar 15, 2007

Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and incr... more Steel mills are known to be a source of ambient polycyclic aromatic hydrocarbons (PAHs), and increased cancer risk has been reported among neighborhoods previously. In this study, we tried to assess the exposure to PAHs among residents nearby to a large steel mill in Korea by measuring urinary 1-hydroxypyrene (1-OHP). Two separate areas at different distances from a steel mill but on the same wind direction were chosen to evaluate the environmental exposures to polycyclic aromatic hydrocarbons. Three-hundred and fifty children living in the vicinity of steel plant ("nearby" group) and 606 children residing much farther from the factory ("remote" group) participated. Urine was collected on three consecutive days, and questionnaires about exposure to passive smoking and food consumption as well as demographics were obtained. Routine monitoring data of ambient pollutants were obtained and particulate matter less than 10 microm (PM10) was analyzed with multiple regressions to assess the associations with urinary 1-OHP. The geometric mean concentration of urinary 1-OHP among nearby group (0.048+/-1.878 micromol/mol creatinine, GM+/-GSD) was approximately 1.3 times higher than that among remote group (0.036+/-2.425 micromol/mol creatinine, GM+/-GSD), and using multiple regression techniques, the difference was significant (P<0.0001) after adjusting for confounding variables. When different periods before the sampling of urine were examined, PM10 averages over 2 days, 3 days, and 1 week prior to urine sampling showed significant associations with urinary 1-OHP levels. Our findings are consistent with the interpretation that residents nearby to a steel mill are exposed to PAHs through ambient exposures.

International Archives of Occupational and Environmental Health, Feb 16, 2007

To evaluate the criterion validity, factorial validity, and internal consistency of Korean versio... more To evaluate the criterion validity, factorial validity, and internal consistency of Korean version of effort-reward imbalance (ERI) for the scales of effort, reward, and overcommitment as well as to examine the effect of psychosocial factors on physical and mental illness among petroleum refinery workers in South Korea. The Korean version of ERI questionnaire was constructed using the translation and back-translation technique, and its psychometric properties were explored among 908 male workers in a large petroleum refinery in South Korea in 2002. Cronbach's alpha coefficient was used to test internal consistency. An exploratory factor analysis was conducted on all items of the instrument. Confirmatory factor analyses were conducted on each dimension of effort, reward and overcommitment. Physical and mental health was measured by self-rated health (SF-8). The lowest tertiles of the scores were defined as illness. Multiple logistic regression models were used to test the effect of job stress on the physical and mental health (criterion validity of ERI scales). The Cronbach's alpha coefficients for effort, reward, and overcommitment were 0.71, 0.86, and 0.75, respectively, indicating satisfactory internal consistency. Exploratory factor analysis found three latent factors, which closely corresponded to the theoretical structure of the ERI model. Acceptable construct validity was shown using confirmatory factor analysis. The highest tertile of effort-reward ratio was significantly associated with physical illness (OR 2.4, 95% CI 1.7-3.6) and mental illness (OR 2.9, 95% CI 2.0-4.2), compared to lower tertiles. Overcommitment was significantly associated with mental illness, but not with physical illness. These findings contribute to the validity and reliability of the Korean ERI questionnaire. Importantly, in the context of a rapid change in the labour market, the lack of reciprocity between efforts and rewards at work is strongly associated with self-rated physical and mental health.