• Journal of Environmental Science International
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• v.22 no.12
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• pp.1589-1598
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• 2013

The objective of this study was to evaluate associations between airborne manganese and blood manganese in a general population of South Korean adults. The concentrations of airborne manganese in total suspended particulate (TSP) were calculated from data obtained from ambient air-monitoring stations (AAMSs) located in South Korea. Blood manganese data obtained Korean National Health and Nutrition Examination Survey (KNHANES) using a rolling sampling design involving a complex, stratified, multistage, probability cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. Airborne manganese geometric means was 46.10 $ng/m^3$, blood manganese geometric means were 1.19 ${\mu}g/d{\ell}$ for male and 1.40 ${\mu}g/d{\ell}$ for female. In multiple linear regression analysis of log transformed blood manganeseas a continuous variable on airborne manganese, after adjusting for covariates including gender, age, job, smoking and drinking status, education level, BMI (body mass index). Airborne manganese was positively associated with blood manganese with statistical significance. The present study confirms that airborne manganese is a possible contributor to the increase of blood manganese in the adult general population.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.53.1-53.15
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• 2023

Background: Plastics are high-molecular-weight materials composed of long carbon chains. They are prevalent in daily life, present in various items such as food containers and microwavable packaging. Phthalates, an additive used to enhance their flexibility, are endocrine-disrupting chemicals. We utilized the data from the Korean National Environmental Health Survey (KoNEHS) cycle 3, representing the general South Korean population, to investigate the relationship between the use of plastics in refrigerator food storage and phthalate exposure. Methods: We assessed 3,333 adult participants (aged ≥ 19 years) including 1,526 men and 1,807 women, using data from KoNEHS cycle 3. Using the 75th percentile concentration, urine phthalate metabolites were categorized into high and low-concentration groups. χ² test was conducted to analyze variations in the distribution of each variable, considering sociodemographic factors, health-related factors, food intake, the use of plastics, and the concentration of urine phthalate metabolites as the variables. To calculate odds ratios (ORs) for the high-concentration group of urine phthalate metabolites based on the use of plastics in refrigerator food storage, logistic regression analysis was conducted. Results: In men, the use of plastics in refrigerator food storage had significantly higher adjusted ORs compared to those using the others. The adjusted ORs were calculated as follows: mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) had an OR of 1.35 (95% confidence interval [CI]: 1.05-1.72), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) had an OR of 1.48 (95% CI: 1.16-1.88), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) had an OR of 1.32 (95% CI: 1.04-1.66), ∑di(2-ethylhexyl) phthalate (∑DEHP) had an OR of 1.37 (95% CI: 1.08-1.74) and mono-n-butyl phthalate (MnBP) had an OR of 1.44 (95% CI: 1.13-1.84). Conclusion: The concentrations of urine phthalate metabolites (MEHHP, MEOHP, MECPP, ∑DEHP, and MnBP) were significantly higher in men who used plastics in refrigerator food storage compared to those using the others.

• Safety and Health at Work
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• v.11 no.1
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• pp.97-102
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• 2020

Background: It is well known that the prevalence of obesity in Korea is increasing over time, however it is not known how the trends among occupational groups and sex differ in such increasing trends. This study was designed to provide recent trends of obesity among workers in Korea and to identify whether there were differences among occupational groups. Methods: We used data from the Korean National Health and Nutrition Examination Survey, Phases I to VI (19982015), to analyze trends in the prevalence of obesity in adult Korean workers. Obesity was defined as a body mass index of 25 kg/㎡ or higher. Occupations were classified into 3 groups: (a) nonmanual workers, (b) service/sales workers, and (c) manual workers. Results: During the period of the Korean National Health and Nutrition Examination Survey Phases I to VI, the prevalence of obesity in male workers increased in all occupations (31.1% to 39.5% in manual workers, 32.3% to 38.2% in service/sales workers, and 25.3% to 39.7% in manual workers). However, female workers did not show any particular tendency toward obesity, except for a significant decrease in the prevalence rate in service/sales workers (30.8% to 23.9%, p for trend = 0.0048). Conclusion: The trends of obesity prevalence by sex and occupation were different. For male manual workers, the prevalence rate increased steadily during the data period, while it decreased steadily in female sales/service workers.

• Journal of Environmental Health Sciences
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• v.40 no.6
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• pp.492-501
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• 2014

Objectives: The purpose of this study was to assess the validity of self-reported cigarette smoking status and investigate factors associated with the accuracy self-reported and measured urinary cotinine in Korean adults. Methods: We used data from the $1^{st}$ Korean National Environmental Health Survey (2009-2011) among adults aged ${\geq}19$ years (N=6,246). The survey examined self-reported smoking status, and urinary cotinine was regarded as the biomarker of exposure to tobacco smoke. Urinary cotinine was analyzed using a gas chromatography-mass spectrometry (GC/MS) and data analysis was conducted using IBM SPSS version 20.0, which uses the sample weight and calculates variance estimates to adjust for the unequal probability of selection into the survey. Results: We calculated a cut-off point (53.3 ug/L) by using a ROC (Receiver Operating Characteristic) curve. The smoking prevalence was 24.6% based on self-reported data and 28.2% based on urinary cotinine concentrations. When we assessed the agreement between self-reported and urinary cotinine, we found an average agreement of 97.7% among self-reported smokers and 94.5% among self-reported non-smokers. Among self-reported smokers, factors affected the discrepancy were age, household economic status and average number of cigarettes smoked per day. On the other hand, gender, former smoking experience, and exposure to SHS (second hand smoke) were associated with discrepancies among self-reported non-smokers. Conclusion: These results suggest that self-reported data on smoking status provide a valid estimate of actual smoking status. In future research, we will conduct a continuous monitoring study for reliability verification of the data to reduce potential interpretation errors.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.87-100
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• 2021

Objectives: The purpose of this study was to analyze the factors affecting Bisphenol A (BPA) exposure in children and adolescents using the results of the Korean National Environmental Health Survey (KoNEHS) cycle 3. Methods: A total of 2,380 subjects (n=571, 887, and 922 for 3-5, 6-11, and 12-17 years of age, respectively) were analyzed using an environmental exposure survey and environmental chemical substances concentration levels. Univariable linear regression analysis was performed to determine associated variables such as sex, age, income level, housing type, secondhand smoke time, cup noodles and canned food consumption, seafood consumption, new furniture (within the previous six months), drinking water type, and consumption of herbal medicines. Variables with p-values of less than 0.2 were extracted from the results and a multivariable linear regression analysis was performed using stepwise selection. Results: Univariable linear regression analysis showed positive associations between BPA concentration levels and variables including sex, age, secondhand smoke time, new furniture (within the previous six months), renovated living space (within the previous six months), fish and shellfish consumption, plastic-bottled drink consumption, and herbal medicine. As a result of performing multivariable linear regression analysis, the lower was the age the higher was the concentration of BPA levels. Additionally, women showed higher BPA levels than those of men. The more frequently fish was consumed, the higher was the BPA concentration. Moreover, higher BPA concentrations were observed when taking herbal medicine. Conclusions: The main factors affecting BPA concentration levels were age, gender, and consumption of fish and herbal medicine.

• Journal of Environmental Health Sciences
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• v.42 no.6
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• pp.385-395
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• 2016

Objectives: The aim of this study was to assess exposure to VOCs and PAHs and the health effects on volunteers who participated in an oil spill cleanup in Yeosu. Methods: Atmospheric VOCs were evaluated in the vicinity of the accident site and questionnaire surveys were conducted to identify personal characteristics and acute health symptoms of clean-up workers seven days after the accident. The levels of metabolites of VOCs (t,t-MA, HA, PGA, MA, MHA) and PAHs (2-NAP, 1-OHP, 2-HF, 1-HPH), oxidative stress markers (TABARS, 8-OHdG) in the urine of workers were analyzed. Their correlation was determined by multiple regression analysis with SAS ver. 9.4. Results: Although the concentration of atmospheric VOCs in the residential areas were low at the time of survey, the levels of VOCs and PAHs metabolites in clean-up workers were higher than those in the control group after clean-up activities. The levels of urinary VOC and PAH metabolites were significantly increased after clean-up compared to those measured before participation. The thiobarbituric acid reactive substance (TBARS) concentrations were also increased and showed significant correlations with those of metabolites of benzene. Conclusion: This study shows that oil spill clean-up activities affect exposure to VOCs and PAHs and the health of clean-up workers. The results suggest the need for check-ups of participants in oil spill cleaning work.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.4.1-4.11
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• 2015

Objectives: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). Methods: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. Results: Pb and Cd were the highest (median value) in the seaweed ($94.2{\mu}g/kg$ for Pb; $594{\mu}g/kg$ for Cd), and Hg was the highest in the fish ($46.4{\mu}g/kg$). The dietary exposure level (median value) of Pb was $0.14{\mu}g/kg$ body weight (bw)/d, $0.18{\mu}g/kg$ bw/d for Cd, and $0.07{\mu}g/kg$ bw/d for Hg. Those with a blood Pb level of less than $5.00{\mu}g/dL$ (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than $0.30{\mu}g/L$ (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than $5.00{\mu}g/L$ (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. Conclusions: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.1-10
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• 2015

Objectives: The purpose of this study was to propose an indirect exposure assessment method using a questionnaire survey at a time when direct exposure assessment would be impossible after a chemical accident. Methods: About two weeks after an accident, a questionnaire survey was performed with 1,264 persons from the local community. Variables related to exposure were extracted from the survey contents, weighted and then graded for comparison with subjective symptoms in order to evaluate the extent of exposure. Survey items suitable for reflecting the previous exposure level during the accident were extracted, weighted and divided into quartile ranges. Subjective symptoms showed an increasing tendency with higher exposure level when compared with final exposure level (p<0.01). Results: For the relationship between the final exposure grade and subjective symptoms, as the exposure grade was increasing the rates complaining of symptom also showed an increasing tendency. However, when adjusted for demographic characteristics, there was a tendency for the eye irritation symptom to appear higher in women, and respiratory organ irritation appeared higher in smokers. Conclusions: When the problem of recall bias is considered, this study may not have completely unraveled exposure and the characteristics of the participants can affect subjective symptoms. Nevertheless, the exposure rating method of using a questionnaire showed a significant relationship with symptom level. It can be deemed that assessment of past exposure may be successfully evaluated by questionnaire in cases such as chemical accidents.

• Journal of Environmental Health Sciences
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• v.46 no.1
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• pp.35-44
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• 2020

Objectives: The purpose of this study was to compare the health status of residents who were exposed to the Iksan industrial area in the living environment and those who were not exposed to such a source of industrial activity through a questionnaire survey designed to appraise the residents' health levels. Method: The authors conducted a health questionnaire survey of 1,012 residents around Iksan regarding their personal information, physician-diagnosed disease history, odors experienced, and more. Logistic regression was performed to identify the associations between hazardous chemical exposure and physician-diagnosed diseases. Result: Logistic regression shows significant differences in allergic rhinitis, cardiovascular disease, hypertension, dyslipidemia, liver disease, and osteoporosis. Odors were experienced by 88.0% of the survey group. The seasons were summer (71%) and spring (24.9%). Conclusion: For allergic rhinitis, cerebral cardiovascular disease, and hypertension, which were significantly higher in the case group than in the control group in the disease diagnosis and disease treatment history of physicians, it was difficult to completely eliminate the association with odor exposure in the Iksan Industrial Complex. It is considered that it has affected nearby residents. This study means that a correlation between chronic diseases has been found through regression analysis, and furthermore, this result can be used as a basis for sampling for secondary epidemiological surveys.

• Journal of Preventive Medicine and Public Health
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• v.46 no.2
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• pp.96-104
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• 2013

Objectives: The inherent nature of the Korean National Health and Nutrition Examination Survey (KNHANES) design requires special analysis by incorporating sample weights, stratification, and clustering not used in ordinary statistical procedures. Methods: This study investigated the proportion of research papers that have used an appropriate statistical methodology out of the research papers analyzing the KNHANES cited in the PubMed online system from 2007 to 2012. We also compared differences in mean and regression estimates between the ordinary statistical data analyses without sampling weight and design-based data analyses using the KNHANES 2008 to 2010. Results: Of the 247 research articles cited in PubMed, only 19.8% of all articles used survey design analysis, compared with 80.2% of articles that used ordinary statistical analysis, treating KNHANES data as if it were collected using a simple random sampling method. Means and standard errors differed between the ordinary statistical data analyses and design-based analyses, and the standard errors in the design-based analyses tended to be larger than those in the ordinary statistical data analyses. Conclusions: Ignoring complex survey design can result in biased estimates and overstated significance levels. Sample weights, stratification, and clustering of the design must be incorporated into analyses to ensure the development of appropriate estimates and standard errors of these estimates.