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Background: Children in the affected area were exposed to large amounts of volatile organic compounds (VOCs) from the Hebei Spirit oil spill accident. Objectives: We investigated the lung function loss from the exposure to VOCs in a longitudinal panel of 224 children 1, 3, and 5 years after the VOC exposure event. Methods: Atmospheric estimated concentration of total VOCs (TVOCs), benzene, toluene, ethylbenzene, and xylene for 4 days immediately after the accident were calculated for each village (n = 83) using a modeling technique. Forced expiratory volume in 1 s (FEV1) as an indicator of airway status was measured 1, 3, and 5 years after the exposure in 224 children 4~9 years of age at the exposure to the oil spill. Multiple linear regression and linear mixed models were used to evaluate the associations, with adjustment for smoking and second-hand smoke at home. Results: Among the TVOCs (geometric mean: 1319.5 mg/m3·4 d), xylene (9.4), toluene (8.5), ethylbenzene (5.2), and benzene (2.0) were dominant in the order of air concentration level. In 224 children, percent predicted FEV1 (ppFEV1), adjusted for smoking and second-hand smoke at home, was 100.7% after 1 year, 96.2% after 3 years, and 94.6% after 5 years, and the loss over the period was significant (p < 0.0001). After 1 and 3 years, TVOCs, xylene, toluene, and ethylbenzene were significantly associated with ppFEV1. After 5 years, the associations were not significant. Throughout the 5 years’ repeated measurements in the panel, TVOCs, xylene, toluene, and ethylbenzene were significantly associated with ppFEV1. Conclusions: Exposure to VOCs from the oil spill resulted in lung function loss among children, which remained significant up to 5 years after the exposure.

Asbestos is a carcinogen associated with lung cancer, but few studies have examined the increased risk of lung cancer due to environmental asbestos exposure. We performed a systematic review and meta-analysis to evaluate the association between environmental asbestos exposure and lung cancer. We searched for articles on non-occupational or environmental asbestos exposure and lung cancer in PubMed, EMBASE, CINAHL and Web of Science databases. Our review included 15 studies, and except studies on ingestion exposure we performed a meta-analysis for 13 studies with respect to the type of exposure (neighbourhood and domestic/household exposure). Subgroup analyses and meta-regression were also performed. A significant increase in the risk of lung cancer was found for neighbourhood exposure (1.48, 95% CI 1.18 to 1.86), while the risk was not significantly increased for domestic/household exposure (1.04, 95% CI 0.85 to 1.27). With regard to neighbourhood exposure, naturally occurring asbestos and women were both associated with a higher risk of lung cancer; however, such an increase was not significantly greater compared with that associated with other sources of asbestos exposure and men. Although cautious interpretation is needed due to the large degree of heterogeneity and the small number of included studies, our findings imply that living near the source of asbestos increases the risk of lung cancer.

This study aims to explore income-based disparities in breast cancer (BC) incidence and stage at presentation in a national population in South Korea, where a National Cancer Screening Program (NCSP) has been implemented.In 2007, new patients with BC were identified using the Korea Central Cancer Registry database. We calculated adjusted odds ratios (aORs) to evaluate the association between individual income level and the risk of distant stage BC at presentation, adjusting for women's age, body mass index, disability registration, employment, region of residence, and year of diagnosis.The cumulative age-standardized incidence of BC in the 11 years was highest among women in the richest quintile (2,040 per 100,000 women for 11 years), whereas the proportion of distant stage at presentation was the highest (10.2%) among the medical aid beneficiaries. The aOR of distant stage diagnosis at presentation was higher for lower-income quintiles, and the risk was the highest in the medical aid beneficiaries (aOR, 2.25; 95% confidence interval, 1.97-2.58) than in the richest quintile. The income-based gradient in aORs for distant stage did not differ between younger (40 years) and older patients.A higher risk of distant stage BC at presentation among the lower-income and medical aid groups in the context of a NCSP was observed. A more focused approach toward women in lower-income groups is necessary to alleviate the disparity in the risk of advanced BC.

To assess the socioeconomic gradient in the risk of distant-stage cervical cancer (CC) at presentation and mortality within five years after introducing a national cancer screening program (NCSP).All new CC cases from 2007 to 2017 were retrieved from the Korea Central Cancer Registry data linked to the National Health Information Database of National Health Insurance Service in South Korea. The cumulative incidence of CCs, adjusted odds ratios (OR) of distant metastases at presentation, and adjusted all-cause mortality hazard ratios (HR) within five years were assessed according to income gradients.The age-standardized cumulative incidence of CC ranged from 48.9 to 381.5 per 100,000 women, with the richest quintile having the highest incidence. Of 31,391 new cases, 8.6% had distant metastasis on presentation, most frequently among medical aid beneficiaries (9.9%). The OR for the distant stage was higher when the income level was lower (1.46, 95% confidence interval [CI]: 1.28, 1.67, for the lowest compared to the richest) or the women were medical aid beneficiaries (1.50, 95% CI: 1.24, 1.82). The five-year mortality was higher in the lower-income quintiles and among medical aid beneficiaries than in the richest quintile.The incidence of CC was higher in the richest quintile than in the lower-income quintiles, while the risk of distant-stage CC and mortality was higher when the level of income was lower in the context of the NCSP. A more focused approach is needed to further reduce the disparity in the timely diagnosis and treatment of CC patients.

Background Formaldehyde exposure is associated with nasopharyngeal cancer and leukemia. Previously-described links between formaldehyde exposure and lung cancer have been weak and inconsistent. We performed a systematic review and meta-analysis to evaluate quantitatively the association between formaldehyde exposure and lung cancer. Methods We searched for articles on occupational formaldehyde exposure and lung cancer in PubMed, EMBASE, Web of Science, and CINAHL databases. In total, 32 articles were selected and 31 studies were included in a meta-analysis. Subgroup analyses and quality assessments were also performed. Results The risk of lung cancer among workers exposed to formaldehyde was not significantly increased, with an overall pooled risk estimate of 1.04 (95% confidence interval [CI], 0.97-1.12). The pooled risk estimate of lung cancer was increased when higher exposure studies were considered (1.19; 95% CI, 0.96-1.46). More statistically robust results were obtained when high quality (1.13; 95% CI, 1.08-1.19) and recent (1.13; 95% CI, 1.07-1.19) studies were used in deriving pooled risk estimates. Conclusions No significant increase in the risk of lung cancer was evident in the overall pooled risk estimate; even in higher formaldehyde exposure groups. Our findings do not provide strong evidence in favor of formaldehyde as a risk factor for lung cancer. However, since risk estimates were significantly increased for high-quality and recent studies, the possibility that exposure to formaldehyde can increase the risk of lung cancer might still be considered.

Asbestos exposure is associated with mesothelioma and cancer of the lung, larynx and ovary. However, the association between asbestos exposure and colorectal cancer is controversial despite several systematic reviews of the literature, including a number of meta-analyses. We performed a systematic review and meta-analysis to evaluate quantitatively the association between exposure to asbestos and colorectal cancer. We searched for articles on occupational asbestos exposure and colorectal cancer in PubMed, EMBASE and Web of Science published before April 2018. In total, 44 articles were selected and 46 cohort studies were analysed. The overall pooled risk estimates and corresponding 95% CIs of the association between occupational asbestos exposure and colorectal cancer were calculated using a random-effects model. Subgroup analyses and sensitivity tests were also performed. There was a significantly increased risk of colorectal cancer mortality among workers exposed to asbestos occupationally, with an overall pooled SMR of 1.16 (95% CI: 1.05 to 1.29). The pooled SMR for colorectal cancer was elevated in studies in which the asbestos-associated risk of lung cancer was also elevated (1.43; 95% CI: 1.30 to 1.56). This implies that the risk of colorectal cancer mortality increases as the level of asbestos exposure rises. A sensitivity analysis showed robust results and there was no publication bias. Although the effect size was small and the heterogeneity among studies was large, our findings indicate that occupational exposure to asbestos is a risk factor for colorectal cancer.

Backdground Phthalates and bisphenol A (BPA) have been used in a variety of consumer products and are detected widely in both humans and the environment. Demographic and socio-economic characteristics that affect exposure to these chemicals have been investigated among several general populations; however, nationally-representative population-based studies are limited to Canada, Germany, and the USA. Moreover, relatively little is known about the socio-demographic characteristics that influence exposure to these chemicals among nationally representative populations of Asia. Methods Data are obtained from the Korean National Environmental Health Survey (2012–2014). In total, 6,478 adults (aged 19 and older) were recruited and sampled for urinary levels of major phthalate metabolites and bisphenol A. In addition, demographic and socio-economic parameters were determined from questionnaire data and the characteristics associated with urinary concentrations of the target chemicals were assessed. Results Urinary levels of bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) metabolites of Korean adults were generally higher, but those of mono-benzyl phthalate (MBzP) were lower, and BPA were similar or higher than those reported from national biomonitoring programs in the United States and Canada. Similar to other nationally representative populations, females and older adults showed higher creatinine-adjusted phthalate metabolite and BPA levels among the Korean population. Meanwhile, monthly household income and education were negatively associated with urinary phthalate metabolites. Among personal care products, nail polish use was positively associated with both phthalate metabolites and BPA concentrations in urine. Conclusion Our observations based on a nationally representative population of Korea show that socio-demographic determinants for these urinary chemicals vary by country, and should be considered for developing appropriate mitigation measures and policies.

This study aimed to establish a health and medical foundation for forest healing programs and provide a basis for developing an evaluation system for such programs. While the number of visitors to forests and interest in forest healing effects are increasing, few studies have examined the various indicators of the persistent changes in forest healing effects. Therefore, this study conducted pre-, post-, and follow-up experiments on 87 health and clinical indicators in a sample of 88 adolescent participants. The relationships between pre-, post-, and follow-up experiment results for each indicator were analyzed. Of the 87 indicators, 46 showed significant changes, including systolic blood pressure, diastolic blood pressure, cholesterol, serotonin, vitamin D, CD16+CD56 count, interferon-γ, resilience, and self-esteem. The findings are significant for studying diverse participants and indicators and lay the foundation for developing forest healing programs by clarifying aspects such as the indicators suitable for short-term observation versus the indicators requiring long-term observation. Based on these analyses, the results of this study are expected to be useful when conducting research to establish an evidence-based forest healing program in the future.

The use of asbestos has been banned since 2009 in South Korea. However, there is still a risk of exposure to environmental asbestos originating from abandoned asbestos mines. We constructed a retrospective dynamic cohort using the National Health Insurance Database of South Korea. We determined the risk of developing asbestos-related diseases (ARDs) among residents living near asbestos mines compared with those living in the control area and the general population. The risks of asbestosis (adjusted hazards ratio [HR] 65.40, 95% CI = 35.02&ndash, 122.12) and pleural plaques (adjusted HR 3.55, 95% CI = 1.96&ndash, 6.41) were significantly increased among residents living near the asbestos mines compared with the control area. The risk of malignant mesothelioma was increased near asbestos mines compared with the control area, however, it was not significant (adjusted HR 1.83, 95% CI = 0.61&ndash, 5.47). When a separate analysis according to sex was conducted, the risk of mesothelioma among male residents was statistically significant (adjusted HR 8.30, 95% CI = 1.04&ndash, 66.63), and the standardized incidence ratio (SIR) was significantly increased (SIR 3.48, 95% CI = 1.50&ndash, 6.85). The risk of ARDs was increased due to environmental asbestos exposure near abandoned asbestos mines in South Korea.

Objectives:The aim of this study was to investigate the combined effects of long working hours and low job control on self-rated health.Methods:We analyzed employees’ data obtained from the third Korean Working Conditions Survey (KWCS). Multiple survey logistic analysis and postestimation commands w

Various effects of forest healing on health have been reported, but a certification system to assess the effectiveness of forest healing programs does not exist. In this study, a systematic review (SR) on the “health benefits of forests” and “meta-analysis of forest therapy” was conducted after analyzing the status and level of evidence of 75 forest healing programs that were conducted post-certification in South Korea. The SR for “health benefits of forests” distinguished between activities and time, resulting in 90.9% of walking activities for more than an hour under psychological health, and 100.0% of exercise activities for less than an hour under physiological health. However, the effect of indirect activities performed for more than an hour was unknown. Thus, we confirmed that many indoor activities in the field had low effect size or no established basis regarding the feasibility of its operation. The SR on “meta-analysis of forest therapy” to check whether the program was effective. The highest number of healing effects were obtained for blood pressure (32), followed by psychological depression (24). The findings of this can serve as baseline data to facilitate future development and dissemination of evidence-based forest healing programs.

From 2002 through 2015, hundreds of people died of fatal lung injuries associated with the use of humidifier disinfectants (HDs) in Korea. Several chemical disinfectants used for household humidifiers were later clinically confirmed to cause HD-associated lung injury (HDLI). The aim of this study is to evaluate the registered lung disease cases and to compare the distribution of HDLI patients, including deaths, by HD use characteristics including types of HD and HD brands categorized by age group. A total of 530 registered were clinically examined through two rounds of investigations conducted from July 2013 until April 2015. Information on HD use was obtained from a structured questionnaire and home investigations. Approximately one-half of the patients (n=221) were clinically confirmed to be associated with the use of HDs. Pregnant women (n=35, 16%) and pre-school children≤6years old (n=128, 58%) accounted for most of the HD-associated lung injury patients (n=163, 74%). Sixty-seven percent of HDLI patients developed HDLI after less than one year of HD use. HD products containing polyhexamethylene guanidine phosphate (PHMG) were the most frequently used among confirmed HDLI patients (n=123, 55.7%), followed by oligo (2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). Other HDs did not appear to be linked to HDLI. The majority of the HDLI patients (n=85, 38.5%) was found to use only Oxy Saksak® products containing PHMG. The development of HDLI was clinically found to be associated with the use of several HD products containing PHMG and PGH, and to lesser extent, CMIT/MIT.

Background Phthalates and bisphenol A (BPA) have been used extensively in many consumer products, resulting in widespread exposure in the general population. Studies have suggested associations between exposure to phthalates and BPA, and serum thyroid hormone levels, but confirmation on larger human populations is warranted. Methods Data obtained from nationally representative Korean adults (n = 6003) recruited for the second round of the Korean National Environmental Health Survey (KoNEHS), 2012–2014, were employed. Three di-(2-ethylhexyl) phthalate (DEHP) metabolites, along with benzyl-butyl phthalate (BBzP) and di-butyl phthalate (DBP) metabolites, and BPA were measured in subjects' urine. Thyroxine (T4), total triiodothyronine (T3), and thyroid-stimulating hormone (TSH) were measured in serum. The associations between urinary phthalates or BPA and thyroid hormone levels were determined. Results Urinary phthalate metabolites were generally associated with lowered total T4 or T3, or increased TSH levels in serum. Interquartile range (IQR) increases of mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were associated with a 3.7% increase of TSH, and a 1.7% decrease of total T4 levels, respectively. When grouped by sex, urinary MEHHP levels were inversely associated with T4 only among males. Among females, mono-benzyl phthalate (MBzP) and mono- n -butyl phthalate (MnBP) levels were inversely associated with TSH and T3, respectively. In addition, negative association between BPA and TSH was observed. Conclusions Several phthalates and BPA exposures were associated with altered circulatory thyroid hormone levels among general Korean adult population. Considering the importance of thyroid hormones, public health implications of such alteration warrant further studies.

Child abuse was suspected in a case of out-of-hospital arrest with minor brain injuries. Confronted with continued disputes on pathophysiologic correlates even after autopsy, to assist the differentiation of potential causes of sudden cardiopulmonary arrest in children, we tried to identify the mechanism of cardiopulmonary arrest in brain injuries from different causes. Systematic review was carried out in two stages. First, major external causes of cardiopulmonary arrest among children and infants were identified from Pubmed and Google Scholar search, and then the exact sequence of cardiopulmonary arrest, and their pathophysiologic features were identified based on articles of animal models of brain injury. From the review, we have identified four major groups of external circumstances for rather sudden cardiopulmonary arrest from brain damage in children, after excluding congenital and other unrelated diseases; 1) impact brain apnea, 2) anoxic insults, 3) drug or other substance induced central nervous system depression, and 4) traumatic brain damage. Each group has different features in the course of cardiac and respiratory arrests. Based on this review of pathophysiologic features of cardio-respiratory responses from external causes, we have presented a suspected, but unlikely, child abuse case of respiratory arrest from brain injury. The social consequences of both unknowingly missing, and falsely incriminating the abuse can be grave, and the identification of the mechanisms of cardiopulmonary arrest from brain injury can be important for the differentiation of various potential causes.

Background The organizational justice model can evaluate job stressor from decision-making process, attitude of managerial or senior staff toward their junior workers, and unfair resource distribution. Stress from organizational injustice could be harmful to workers' mental health. The purpose of this study is to explore the association between organizational justice and depressive symptoms in a securities company. Methods To estimate organizational justice, a translated Moorman's organizational justice evaluation questionnaire (Korean) was employed. Cronbach's α coefficient was estimated to assess the internal consistency of the translated questionnaire. To assess depressive symptoms, the Center for Epidemiologic Studies Depression (CES-D) scale was used. The link between the sub-concepts of the organizational justice model and depressive symptoms was assessed utilizing multiple logistic regression models. Results The risk of depressive symptoms was significantly higher among workers with higher levels of all subcategory of organizational injustice. In the full adjusted model odds ratio (OR) of higher level of procedural injustice 2.79 (95% confidence interval [CI], 1.58-4.90), OR of the higher level of relational injustice 4.25 (95% CI, 2.66-6.78), OR of higher level of distributional injustice 4.53 (95% CI, 2.63-7.83) respectively. Cronbach's α coefficient of the Korean version was 0.93 for procedural justice, 0.93 for relational justice, and 0.95 for distributive justice. Conclusions A higher level of organizational injustice was linked to higher prevalence of depressive symptoms among workers in a company of financial industry.

Malignant mesothelioma (MM) is a cancer that is largely caused by exposure to asbestos. Although asbestos is no longer used in South Korea, the incidence of MM continues to increase due to its long latent period. We aimed to update the previous prediction of MM incidence until 2038. We predicted the incidence of MM over the next 20 years (2019–2038) in South Korea using Møller’s age–period–cohort (APC) model and a Poisson regression model based on asbestos consumption. The APC model predicted that the crude incidence rate would increase sharply in men and slowly in women. Despite the sex discrepancy in the rate of increase, the incidence rate for both sexes is expected to continue increasing until 2038. In the Poisson model, the crude incidence rate was predicted to increase continuously until 2038, and far more cases of MM were predicted to occur compared with the results of the APC model. When compared with actual incidence data, the APC model was deemed more suitable than the Poisson model. The APC model predicted a continuous increase over the next 20 years with no peak, suggesting that the incidence of MM will continue to rise far into the future.

이 연구는 근로자의 고용상태에 따라 사고 이후 사회경제적 상태에 어떠한 영향을 주는지 알아보기 위해 연구되었다. 노동패널(2001-2006) 자료를 이용하여, 2001년 근로자들의 경제활동 상태, 고용상태가 연구기간 내 어떻게 변화했는 지 알아보았다. 추적관찰 동안, 경제활동 그룹에 비해 실직 그룹에서 사고로 인한 장애를 더 많이 겪은 것으로 나타 났다. 더구나, 실직그룹에서 산업재해율도 가장 높았다. 고용 상태별로 보면, 일용직, 무임금 근로자들이 장애를 더 많이 겪은 것으로 나타났다. 또한 이들은 사고를 겪은 후, 비활동경제상태 또는 실직자가 되었다. 다른 근로자그룹과 비교해서 비활동경제 그룹, 실직자, 일용직, 무임금 가족근로자가 사고율도 높았는데 이는 결과적으로 이들의 사회경 제적 상태를 더 악화시켰다.

We recently established a novel disease entity presented as progressive respiratory failure associated with the inhalation of humidifier disinfectants. In April 2011, we encountered a series of peripartum patients with complaints of respiratory distress of unknown etiology, which was an uncommon phenomenon. Accordingly, we created a multidisciplinary team comprising intensivists, radiologists, pathologists, epidemiologists, and the Korea Centers for Disease Control and Prevention (KCDC). Further, we defined the disease entity and performed a case-control study, epidemiologic investigation, and animal study to determine the etiology. The study findings indicated that the lung injury outbreak was related to the inhalation of humidifier disinfectants and showed that household chemical inhalation can cause severe respiratory failure. Following the withdrawal of humidifier disinfectants from the Korean market in 2012, no such cases were reported. This tragic event is a warning that appropriate safety regulations and monitoring for potential toxic household chemicals are critical to protect public health.

Background Discrimination is a representative social determinant of health. Presenteeism is defined as presenting to work despite of illness and is an indicator of group health. We investigated the association of discrimination and presenteeism with cardiovascular disease using Korean data. Methods This study used the fourth Korea Working Conditions Survey (2014) data of 27,662 wage workers (employees). Presenteeism and discrimination related to age, sex, education, birth region, and employment type were ascertained. Self-reported cardiovascular disease was also assessed using the survey questionnaire. General and occupational characteristics found to be significant in univariate analyses were entered into a multivariate logistic regression analysis of the association of discrimination and presenteeism with cardiovascular disease. We also calculated the odds ratios of multiple discriminations and/or presenteeism for cardiovascular disease. Results In the univariate analyses, sex, age, education, monthly income, employment type, occupation, hours worked per week, workplace scale, and shift work were significantly associated with cardiovascular disease. A multivariate logistic regression analysis adjusted for general and occupational characteristics showed that discrimination and presenteeism were significantly associated with cardiovascular disease. Finally, the association with cardiovascular disease was strongest when both multiple discriminations and presenteeism were present. Conclusions Discrimination and presenteeism are associated with cardiovascular disease, and this association was stronger in the presence of multiple types of discrimination and presenteeism.

Background: Nearby citizens were exposed to large volumes of volatile organic compounds (VOCs) for four days after the Hebei Spirit oil spill.Objectives: To investigate the cross-sectional and long...

On December 7th, 2007, an estimated 12,547 kL of crude oil was spilled from the collision of Hebei Spirit near residential area. Our previous study demonstrated worsening of children's asthma symptoms one year after the accident. This study investigated long-term effect of the oil spill on children's asthma symptoms up to five years after the accident. All elementary and middle school students in the exposure area were surveyed on one year (n = 655), three years (664), and five years (611) after the accident. Oil spill exposure was estimated using two estimates including distance from the oil spill (A) and modeled estimates of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds (B), and each was dichotomously categorized (A: high-exposure vs low-exposure; B: ≥20 mg/m3 vs

Background The Korea Radiation Effect & Epidemiology Cohort - The resident cohort (KREEC-R) study concluded that there is no epidemiological or causal evidence supporting any increase in cancer risks resulting from radiation from Korean nuclear power plants (NPPs). But the risks of thyroid cancer in women were significantly higher in residents living near NPPs than control. Debate about the cause of the pattern of thyroid cancer incidence in women is ongoing and some researchers argue that detection bias influenced the result of KREEC-R study. Therefore there was a need to investigate whether residents living near NPPs who were assessed in the KREEC-R were actually tested more often for thyroid cancer. We evaluated the possibility of detection bias in the finding of the KREEC-R study based on materials available at this time. Methods Using the KREEC-R raw data, we calculated age standardized rates (ASRs) of female thyroid cancer and re-analyzed the results of survey on the use of medical services. We also marked the administrative districts of residents who received the Radiation Health Research Institute (RHRI) health examinations and those in which thyroid cancer case occurred as per the Chonnam National University Research Institute of Medical Sciences (RIMS) final report on maps where the locations of NPPs and 5 km-radii around them were also indicated. And we compared the incidence rates of Radiation-induced cancer measured between the first period when RHRI health examinations were not yet implemented, and the second period when the RHRI health examinations were implemented. Results The ASR for the far-distance group, which comprised residents living in areas outside the 30 km radius of the NPPs, increased rapidly after 2000; however, that of the exposed group, which comprised residents living within a 5 km radius of the NPPs, started to increase rapidly even before 1995. The frequencies of the use of medical services were significantly higher in the intermediate proximate group, which comprised residents living within a 5–30 km radius of the NPPs, than in the exposed group in women. In case of female thyroid cancer, the second period ASR was higher than the first period ASR, but in case of female liver cancer and female stomach cancer no significant difference were observed between the periods. On map, many administrative districts of residents who received RHRI health examinations and most administrative districts in which thyroid cancer case occurred on RIMS final report were outside 5 km-radii around NPPs. Conclusions We could not find any evidence supporting the assertion that detection bias influenced the increased risks of female thyroid cancer observed in the exposed group of the KREEC-R study, as opposed to the control group.

Background: A 20-year follow-up study on cancer incidence among people living near nuclear power plants in South Korea ended in 2011 with a finding of significantly, but inconsistently, elevated thyroid cancer risk for females. Reanalysis of the original study was carried out to examine the dose–response relationship further, and to investigate any evidence of detection bias. Methods: In addition to replicating the original Cox proportional hazards models, nested case-control analysis was carried out for all subjects and for four different birth cohorts to examine the effects of excluding participants with pre-existing cancer history at enrollment. The potential for detection bias was investigated using the records of medical utilization and voluntary health checks of comparison groups. Results: The overall risk profile of the total sample was similar to that of the original study. However, in the stratified analysis of four birth cohorts, the cancer risk among people living near nuclear power plants became higher in younger birth cohorts. This was especially true for thyroid cancers of females (hazard ratio (HR) 3.38) and males (HR 1.74), female breast cancers (HR 2.24), and radiation-related cancers (HR 1.59 for males, HR 1.77 for females), but not for radiation-insensitive cancers (HR 0.59 for males, HR 0.98 for females). Based on medical records and health check reports, we found no differences between comparison groups that could have led to detection bias. Conclusions: The overall results suggest elevated risk of radiation-related cancers among residents living near nuclear power plants, controlling for the selective survival effect. This is further supported by the lack of evidence of detection bias and by records of environmental exposure from radiation waste discharge.

Humidifier disinfectant lung injury is an acute lung disease attributed to recurrent inhalation of certain disinfectant aerosols emitted from room humidifiers. An outbreak of this toxic lung injury occurred in South Korea from 1995 until all humidifier disinfectant products were recalled from the consumer market by the government in 2011.A nationwide study was conducted to ascertain and classify all potential cases of humidifier disinfectant lung injury in Korea and to assess dose-response relationships.By several mechanisms, clinicians and the general public were invited to report all suspected cases of humidifier disinfectant lung injury to public health officials in South Korea. A committee was convened to define diagnostic criteria based on pathologic, radiologic, and clinical findings for index cases, combined with assessment of environmental exposure to humidifier disinfectants. Clinical review and environmental assessments were performed and later combined to determine overall likelihood of disease for each study participant, classified as definite, probable, possible, or unlikely. Survival time from exposure to onset of symptoms was analyzed to assess dose-response relationships. Three broad categories of risk factors were examined: (1) biological susceptibility, (2) temporal cycle of exposure and recovery, and (3) spatial conditions and density of disinfectant.Of 374 possible cases identified and reviewed, 329 were unanimously classified by the diagnostic committee, as follows: 117 definite, 34 probable, 38 possible and 140 unlikely cases. A total of 62 individuals with definite or probable disease died. Risk factors examined for polyhexamethyleneguanidine phosphate exposure that were found to be significant in shortening survival included age 4 years or younger at onset, use of disinfectant for 7 days per week, airborne density of 800 μg/m(3) or more of disinfectant, and daily exposure 11 or more hours in duration.Dose-response analysis indicated that development of humidifier disinfectant lung injury and death were associated strongly with recurrent, intense, acute exposure without sufficient recovery time between exposures, more so than long-term cumulative exposure. These findings may explain some reversible or clinically unapparent cases among coexposed family members.

The oil tanker Hebei Spirit spilled 12,547kL of oil near the western coastline of Korea on December 7, 2007. We aimed to investigate the relationship between oil spill exposure and oxidative stress in residents living near the affected area.Study subjects were 671 residents who participated in a health examination between February and September 2009. As surrogates for oil spill exposure, we used the total duration of clean-up work and levels of urinary metabolites of polycyclic aromatic hydrocarbons (PAHs), 1-hydroxypyrene (1-OHP) and 2-naphthol (2-NAPH). Oxidative stress was measured using urinary levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), indicators of lipid peroxidation and oxidative DNA damage, respectively.Levels of oxidative stress biomarkers were significantly increased with longer involvement in clean-up work over one year after the Hebei Spirit oil spill (MDA, p-trend0.0001; 8-OHdG, p-trend0.0001). As more time elapsed since the last involvement in clean-up, the total duration of clean-up work participation and levels of PAH metabolites (1-OHP and 2-NAPH), as well as levels of the oxidative stress biomarkers (MDA and 8-OHdG) decreased further. The level of 1-OHP had a significant positive correlation with the total duration of clean-up work involvement, with a higher level found in those who participated in clean-up for100 days. Increasing levels of 1-OHP were significantly associated with increased MDA and 8-OHdG after adjusting for covariates, while the strength of association weakened as time passed since the last participation in clean-up work. The significance of the association was maintained for up to 12 months after the last clean-up work.The results suggested that oil exposure from prolonged clean-up activity likely induced oxidative stress in clean-up participants up to at least one year after the last exposure.

In 2009, asbestos was finally banned in Korea, about 70 years after the first opening of asbestos mines under Japanese control. After having presented the history of asbestos industry, together with its regulations and health effects over time, we constructed narrative analyses of how the asbestos issue under the prevailing risk system was managed by whom and for what purpose, to provide context for the change. We could identify five different phases: laissez-faire, politico-technical, economic–managerial, health-oriented cultural, and human rights-based post-cultural risk systems. The changes leading to the asbestos ban evolved over different phases, and each phase change was necessary to reach the final ban, in that, without resolving the previous issues by examining different categories of potential alternatives, either the final ban was not possible or, even if instituted, could not be sustained. An asbestos ban could be introduced when all the alternatives to these issues, including legitimate political windows, economic rationalizations, health risk protections, and human rights sensitivities, were available. We think the alternatives that we had were not in perfect shape, but in more or less loosely connected forms, and hence we had to know how to build solidarities between different stakeholders to compensate for the imperfections.

Backgroud Malignant mesothelioma is a malignant tumour on the pleura or the peritoneum caused mostly by asbestos. Although asbestos is not currently used in Korea, the incidence of mesothelioma is increasing due to its long latent period. This study was the first to predict the future incidence of malignant mesothelioma in Korea over the next 20 years. Method Mesothelioma incidence data from 1995–2014 was acquired from the Korea Central Cancer Registry (KCCR). Demographic data was acquired from the Korean Statistical Information Service (KOSIS) for 1995–2034. An APC model with Moller’s power-link function was utilised to estimate the future incidence of mesothelioma. Result It was predicted that 2684 and 1270 new cases of mesothelioma in men and women would occur over the next 20 years. For both sexes, the mesothelioma incidence rate was predicted to be greater in 2030–2034 (men, 0.622; women, 0.224) compared to that in 2010–2014 (men, 0.280; women, 0.152). The age-standardised incidence rate (ASR) was predicted to be slightly greater in 2030–2034 (men, 0.229; women, 0.109) relative to the rate in 2010–2014 (men, 0.216; women, 0.104) in both sex. The changes in mesothelioma incidence were mostly caused by changes in the population structure of Korea due to ageing and not by changes in the mesothelioma risk ratio. Conclusion The projected mesothelioma incidence continuously increases in Korea over the next 20 years. Although it was not related to an increase in the mesothelioma risk ratio, continuous preventive efforts are necessary.

The objective of this study was to assess the association between exposure to polycyclic aromatic hydrocarbons (PAHs) and oxidative stress among shipyard workers.We recruited 82 painting workers in a shipyard and age/sex matched 137 office workers from the same shipyard company. Urine samples were used to assess for 1-hydroxypyrene (1-OHP) as an exposure biomarker for PAHs and to assess for 8-iso-prostaglandin F2α (iPF) as a biomarker for oxidative stress. Demographics, smoking, alcohol consumption, and working conditions information were obtained from a questionnaire survey.Geometric mean concentration (±standard deviation) of urinary 1-OHP among painting workers (587.9 ± 3.45 ng/g creatinine) was approximately 6.9 times higher than that among office workers (85.6 ± 2.09 ng/g creatinine; P value0.001). Compared to the office workers (163.5 ± 1.84 ng/g creatinine), the painting workers (190.6 ± 1.64 ng/g creatinine) had significantly higher urinary levels of iPF (P value = 0.044). Smokers had significantly higher urinary levels of iPF than nonsmokers in both painting workers (smokers 217.0 ± 1.63; nonsmokers 159.2 ± 1.52 ng/g creatinine; P value = 0.011) and office workers (smokers 181.3 ± 1.79; nonsmokers 138.4 ± 1.90 ng/g creatinine; P value = 0.015). Smokers among office workers had higher urinary levels of iPF than nonsmokers among painting workers, but difference was not significant.Our results demonstrated that among shipyard workers, painting works were significantly associated with the exposure to PAHs, compared with the office works. However, iPF should be cautiously used to characterize the oxidative stress associated with the occupational PAHs exposure, because iPF is substantially affected by other factors such as smoking status.

While exposure to ambient fine particles2.5 μm in aerodynamic diameter (PM2.5) has well-established health effects, there is limited quantitative evidence that links specific sources of PM2.5 with those effects. This study was designed to examine the risks of exposure to chemical species and source-specific PM2.5 mass on mortality in Seoul, Korea, a highly populated city.We compare daily mortality counts with PM2.5 chemical speciation data collected every 3 days, as well as nine sources of PM2.5 mass resolved by a positive matrix factorization receptor model, from March 2003 through November 2007. A Poisson generalized linear model incorporating natural splines was used to evaluate associations of PM2.5 chemical species and sources with mortality.PM2.5 mass and several chemical species were associated with mortality. Organic carbon, elemental carbon, and lead were associated with mortality outcomes when using multipollutant models adjusted for other chemical species levels. Source-apportioned PM2.5 derived from mobile sources (ie, gasoline and diesel emissions) and biomass burning was associated with respiratory mortality and cardiovascular mortality, respectively. There were moderate associations of industry and of roadway emissions with cardiovascular mortality.Local combustion sources may be particularly important contributors to PM2.5, leading to adverse health effects.

Ambient fine and ultrafine particles (UFPs) in urban air are known to contribute to inflammatory and allergic disease. It has been suggested that oxidative stress is an underlying mechanism for the detrimental health effects. The objective of this study was to investigate the short-term effect of ambient UFPs and particulate polycyclic aromatic hydrocarbons (PAHs) on urinary 8-hydroxyl-2-deoxyguanosine (8-OHdG) concentrations in children with and without eczema. Spot urine samples were collected from 84 children twice weekly for 61 days and 8-OHdG content was measured. Significant associations were found between the ambient UFPs and particle bound PAHs and increase in urinary 8-OHdG levels. An inter-quartile range (IQR) increase in the UFP concentration in the 24-h (IQR, 32,300/m 3 ) period preceding urine collection was significantly associated with a 5.7% (95% confidence interval [CI], 0.16–1.27%) increase in the urinary 8-OHdG level children with AD. In children without eczema, such short-term effect of previous day UFPs on urinary 8-OHdG was not observed. There were no significant positive associations between the mass fraction of PMs and urinary 8-OHdG. The results suggest that short-term exposure to ambient UFPs plays a critical role in PM induced oxidative stress in children with eczema.

Malignant mesothelioma is a malignant tumor on the pleura or the peritoneum caused mostly by asbestos. Although asbestos is not currently used in South Korea, the incidence of mesothelioma is increasing due to its long latent period. This study predicted the incidence of malignant mesothelioma in South Korea over the next 20 years using an age-period-cohort (APC) model. Data regarding mesothelioma incidence from 1994–2013 were acquired from the Korea Central Cancer Registry (KCCR). Demographic data, including prospective resident data, were acquired from the Korean Statistical Information Service (KOSIS) for 1994–2033. An APC model with Moller’s power-link function was utilized to predict the incidence of mesothelioma. It was predicted that 2,380 and 1,199 new cases of mesothelioma in men and women, respectively, would occur over the next 20 years. For both sexes, the mesothelioma incidence rate was predicted to be greater in 2029–2033 compared to that in 2009–2013 (men, 0.282 vs 0.563; women, 0.155 vs 0.217). For men, the age-standardized incidence rate was predicted to be slightly greater in 2029–2033 relative to the rate in 2009–2013 (0.228 vs 0.235), while the age-standardized incidence rate in women decreased within the same timeframe (0.113 vs 0.109). The changes in mesothelioma incidence were mostly caused by changes in the population structure due to aging and not by changes in the mesothelioma risk ratio. The results of this study project a continuous increase in mesothelioma incidence in South Korea over the next 20 years. Although the projected increase in mesothelioma incidence was not related to an increase in the mesothelioma risk ratio, continuous preventive efforts are necessary to reduce the exposure to asbestos and prevent the trend from worsening.

Social inequality in adverse birth outcomes has been demonstrated in several countries. The present study examined the separate and joint effects of parental education and work in order to investigate the causal pathways of social class effects on adverse birth outcomes in Korea. The occurrence of low birth weight, preterm births, and intrauterine growth retardation was examined among 7,766,065 births in Korea from 1995 to 2008. The effect of social inequality, as represented by parental education and work, was examined against adverse birth outcomes using multivariate logistic regression after controlling for other covariates. Parental education had the most significant and greatest effect on all three adverse outcomes, followed by parental work and employment, which had lesser effects. For adverse birth outcomes, the gap between educational levels increased steadily in Korea from 1995 to 2008. Throughout the analysis, the effect of maternal manual work on adverse birth outcomes was apparent in the study results. Given this evidence of social inequality in education and employment, social interventions should aim at more in-depth and distal determinants of health.

Background Sleep disorder is a disease that causes reduction in quality of life and work efficiency of workers. This study was performed to investigate the relationship between job-related stress factor and sleep disorder among wageworkers in Korea. Methods This study was based on analysis of the 3rd Korean working conditions survey. We analyzed 35,902 workers whose employment status is wageworker. We classified the job-related stress factor into 12 sections. Logistic regression was performed to estimate the relationship between job-related stress factor and sleep disorder and Odds ratio and 95 % CI were calculated using the SPSS version 23.0 program. Results Many categories of Job-related stress factor were correlated with sleep disorder (8 of 12 for women, 10 of 12 for men). The results of the regression analysis, corrected for general and occupational characteristics, indicated that sleep disorder was significantly correlated with the following categories of job-related stress: discrimination experience (OR 3.37, 95 % CI = 2.49 ~ 4.56 in women, OR 1.96, 95 % CI = 1.53 ~ 2.51 in men), direct customer confrontation (OR 2.72, 95 % CI = 1.91 ~ 3.86 in women, OR 1.99, 95 % CI = 1.45 ~ 2.72 in men), emotional stress (OR 2.01, 95 % CI = 1.30 ~ 3.09 in men), work dissatisfaction (detailed) (OR 1.99, 95 % CI = 1.36 ~ 2.93 in men), work dissatisfaction (overall) (OR 2.30, 95 % CI = 1.66 ~ 3.20 in women, OR 2.40, 95 % CI = 1.88 ~ 3.08 in men), expression of opinion difficulty (OR 0.66, 95 % CI = 0.48 ~ 0.92 in women, OR 0.57, 95 % CI = 0.45 ~ 0.73 in men). Conclusion A number of studies have reported that stress affects sleep disorder. In this study, many factors suspected to increase the risk of sleep disorder were added to previously known job stress factors. In particular, this study found a strong correlation between work-associated sleep disorder and relational and organizational job stress factors. Sleep disorder may lead to large decreases in workers’ quality of life and work efficiency. Awareness and interventions are therefore required to reduce workplace stress; additional research of this topic is also required. Electronic supplementary material The online version of this article (doi:10.1186/s40557-016-0131-2) contains supplementary material, which is available to authorized users.

Perfluoroalkyl acids (PFAAs) have been used in various industrial and consumer products for decades, and have consequently been detected in human blood worldwide. In the present study, general adult population in Daegu, Korea (n=140, >20 years of old) was recruited, collected for serum, and analyzed for 13 major PFAAs. The influence of dietary and water consumption on serum PFAA levels was also evaluated. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) were frequently detected with relatively higher concentrations in blood serum. Most PFAA concentrations except for PFOA were detected in higher concentrations among males, and were positively correlated with age and body mass index (BMI). PFOA concentrations were relatively higher among the female of childbearing age, e.g., 20-49years old, raising concerns on potential impacts on fetus through transplacental transfer or lactation. In addition, the concentrations of PFOA in Daegu population were higher than other areas of Korea, suggesting a presence of distinctive sources in the area. Among food items, potato consumption was identified to be significant contributor to serum PFOA. For PFUnDA and PFTrDA levels, intake of fish/shellfish was positively associated. The results of this study will be useful in developing public health management options for PFAAs.