Social Inequities in the Survival of Liver Cancer: A Nationwide Cohort Study in Korea, 2007-2017.

BACKGROUND: To analyze the effects of socioeconomic status (type of insurance and income level) and cancer stage on the survival of patients with liver cancer in Korea. METHODS: A retrospective cohort study was constructed using data from the Healthcare Big Data Platform project in Korea between January 1, 2007, and December 31, 2017. A total of 143,511 patients in Korea diagnosed with liver cancer (International Classification of Diseases, 10th Revision [ICD-10] codes C22, C220, and C221) were followed for an average of 11 years. Of these, 110,443 died. The patient's insurance type and income level were used as indicators of socioeconomic status. Unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using a Cox proportional hazards regression model to analyze the relationship between the effects of sex, age, and cancer stage at first diagnosis (Surveillance, Epidemiology, and the End Results; SEER), type of insurance, and income level on the survival of patients with liver cancer. The interactive effects of the type of insurance, income level, and cancer stage on liver cancer death were also analyzed. RESULTS: The lowest income group (medical aid) showed a higher risk for mortality (HR (95% CI); 1.37 (1.27-1.47) for all patients, 1.44 (1.32-1.57) for men, and 1.16 (1.01-1.34) for women) compared to the highest income group (1-6) among liver cancer (ICD-10 code C22) patients. The risk of liver cancer death was also higher in the lowest income group with a distant cancer stage (SEER = 7) diagnosis than for any other group. CONCLUSION: Liver cancer patients with lower socioeconomic status and more severe cancer stages were at greater risk of death. Reducing social inequalities is needed to improve mortality rates among patients in lower social class groups who present with advanced cancer.

Widening Social Inequalities in Cancer Mortality of Children Under 5 Years in Korea.

BACKGROUND: To investigate the effect of parental social class on cancer mortality in children under 5 in Korea, two birth cohorts were constructed by linking national birth data to under-5 death data from the Statistics Korea for 1995-1999 (3,323,613 births) and 2010-2014 (2,297,876 births). METHODS: The Cox proportional hazards model adjusted for covariates was used in this study. RESULTS: Social inequalities of under-5 cancer mortality risk in paternal education and paternal employment status were greater in 2010-2014 than in 1995-1999. The gap of hazard ratio (HR) of under-5 cancer mortality between lower (high school or below) and higher (university or higher) paternal education increased from 1.23 (95% confidence interval, 1.041.46) in 1995-1999 to 1.45 (1.11-1.97) in 2010-2014; the gap of HR between parents engaged in manual work and non-manual work increased from 1.32 (1.12-1.56) in 1995-1999 to 1.45 (1.12-1.89) in 2010-2014 for fathers, and from 1.18 (0.7-1.98) to 1.69 (1.03-2.79) for mothers. When the parental social class was lower, the risk of under-5 cancer mortality was higher in not only adverse but normal births. CONCLUSION: Social inequalities must be addressed to reduce the disparity in cancer mortality of children under 5 years old.

Exposure to Crude Oil-Related Volatile Organic Compounds Associated with Lung Function Decline in a Longitudinal Panel of Children.

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.

Income Disparity in Breast Cancer Incidence and Stage at Presentation: A National Population Study of South Korea.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Income-based disparities in the risk of distant-stage cervical cancer and 5-year mortality after the introduction of a National Cancer Screening Program in Korea.

OBJECTIVES: This study assessed the socioeconomic gradient in the risk of distant-stage cervical cancer (CC) at presentation and 5-year mortality for new CC patients after the introduction of a national Cancer Screening Program (NCSP) in Korea. METHODS: All new CC cases from 2007 to 2017 were retrieved from the Korea Central Cancer Registry database linked with the National Health Information Database of the National Health Insurance Service. The age-standardized cumulative incidence of CC, adjusted odds ratios (ORs) of distant metastasis at presentation, and adjusted all-cause mortality hazard ratios (HRs) within 5 years post-diagnosis were assessed according to the income gradient. RESULTS: The 11-year 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, which was most frequent among Medical Aid beneficiaries (9.9%). Distant-stage CC was more likely when the income level was lower (OR, 1.46; 95% confidence interval [CI]), 1.28 to 1.67 for the lowest compared to the richest) and among Medical Aid beneficiaries (OR, 1.50; 95% CI, 1.24 to 1.82). The 5-year mortality was greater in the lower-income quintiles and Medical Aid beneficiaries than in the richest quintile. CONCLUSIONS: 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 for women in lower income quintiles in the context of the NCSP. A more focused approach is needed to further alleviate disparities in the timely diagnosis and treatment of CC.

Environmental exposure to asbestos and the risk of lung cancer: a systematic review and meta-analysis.

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.

Future Incidence of Malignant Mesothelioma in South Korea: Updated Projection to 2038.

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.

Incidence of Cancer and Asbestos-Related Diseases among Residents Living near Abandoned Asbestos Mines in South Korea: A Retrospective Cohort Study Using National Health Insurance Database.

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 = 35.02-122.12) and pleural plaques (adjusted HR 3.55, 95% CI = 1.96-6.41) 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 = 0.61-5.47). 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 = 1.04-66.63), and the standardized incidence ratio (SIR) was significantly increased (SIR 3.48, 95% CI = 1.50-6.85). The risk of ARDs was increased due to environmental asbestos exposure near abandoned asbestos mines in South Korea.

Occupational exposure to formaldehyde and risk of lung cancer: A systematic review and meta-analysis.

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.

Changes of 30 years in the recognized occupational diseases of Korea: Lessons from the system change perspective.

Thirty years ago, in 1988 of Korea, street demonstrations for the recognition of a 15-year-old boy's death as occupational mercury poisoning had shattered the taboo against occupational disease, and since then, the volume and contents of recognized diseases had changed a lot. Here we tried to ascertain and explain the changes from the system viewpoint. The system of risk management at work was analyzed in narrative terms of what, how, who, and why of the occupational disease managements, then and now, and we conclude the system of last 30 years was to manage the benevolent benefit to the victims for politico-economic purposes. Despite a big shift in outer appearance, the changes in the inner operation were small, and we propose to adopt newer approaches of more health and safety oriented together with human rights.

Exposure to asbestos and the risk of colorectal cancer mortality: a systematic review and meta-analysis.

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.

Hebei Spirit oil spill and its long-term effect on children's asthma symptoms.

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 < 20 mg/m3). Asthma symptoms were evaluated using a standard questionnaire. Oil spill exposure estimates were associated with asthma symptoms on one year (odds ratio (95% confidence interval) A: 1.9 (1.1-3.1); B: 1.6 (0.9-2.7)), three years (A: 1.9 (1.1-3.2); B: 1.3 (0.8-2.2)), and five years (A: 1.2 (0.7-1.9); B: 1.8 (1.1-2.8)) after the oil spill. Significant longitudinal relationship between oil spill exposure estimates and asthma symptoms was also observed (A: 1.6 (1.2-2.2); B: 1.6 (1.1-2.1)). Overall, the effect of oil spill exposure estimates was more severe on younger children. Oil spill exposure estimates were associated with asthma symptoms in children up to five years after the oil spill.

Increased risk of thyroid cancer in female residents nearby nuclear power plants in Korea: was it due to detection bias?

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.

Reanalysis of Epidemiological Investigation of Cancer Risk among People Residing near Nuclear Power Plants in South Korea.

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.

Health effects of environmental pollution in population living near industrial complex areas in Korea.

Several epidemiological studies have reported an association between environmental pollution and various health conditions in individuals residing in industrial complexes. To evaluate the effects of pollution from industrial complex on human health, we performed a pooled analysis of environmental epidemiologic monitoring data for residents living near national industrial complexes in Korea. The respiratory and allergic symptoms and the prevalence of acute and chronic diseases, including cancer, were used as the outcome variables for health effects. Multiple logistic regression analysis was used to analyze the relationship between exposure to pollution from industrial complexes and health conditions. After adjusting for age, sex, smoking status, occupational exposure, level of education, and body mass index, the residents near the industrial complexes were found to have more respiratory symptoms, such as cough (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.06 to 1.31) and sputum production (OR, 1.13; 95% CI, 1.03 to 1.24), and symptoms of atopic dermatitis (OR, 1.10; 95% CI, 1.01 to 1.20). Among residents of the industrial complexes, the prevalence of acute eye disorders was approximately 40% higher (OR, 1.39; 95% CI, 1.04 to 1.84) and the prevalence of lung and uterine cancer was 3.45 times and 1.88 times higher, respectively, than those among residents of the control area. This study showed that residents living in the vicinity of industrial complexes have a high risk of acute and chronic diseases including respiratory and allergic conditions. These results can be used as basic objective data for developing health management measures for individuals residing near industrial complexes.

The Asbestos Ban in Korea from a Grassroots Perspective: Why Did It Occur?

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.

Estimated future incidence of malignant mesothelioma in South Korea: Projection from 2014 to 2033.

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 Møller'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.

Types of household humidifier disinfectant and associated risk of lung injury (HDLI) in South Korea.

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.

Early snapshot on exposure to environmental chemicals among Korean adults-results of the first Korean National Environmental Health Survey (2009-2011).

BACKGROUND: Chemical exposure may cause serious adverse health effects. Under the Environmental Health Act in Korea, the first national survey, Korean National Environmental Health Survey (KoNHES), was conducted, and dozens of major environmental chemicals were measured among Korean adults between 2009 and 2011. OBJECTIVES: To understand the levels of exposure to environmental chemicals among general Korean adults population, and to identify factors that may influence the levels of exposure. METHODS: The blood and urine samples were collected from Korean adults with 19 years of age and older (n=6311), and were analyzed for a number of environmental chemicals including metals, bisphenol A (BPA), and metabolites of polycyclic aromatic hydrocarbons (PAHs), phthalates, a pyrethroid insecticide (3-PBA) and several volatile organic carbons (VOCs). Demographic and other behavioral factors were asked through questionnaire. RESULTS: Among general Korean adults, mercury, arsenic, cadmium, and metabolite of DBP (MnBP) were higher than those reported in other nationwide surveys of Canada, Germany, and USA. Most target chemicals except for MEOHP and 3-PBA showed significant differences on the exposure levels by sex CONCLUSION: This is the first nationwide reconnaissance on exposure to environmental chemicals among general Korean population. Chemicals with high occurrence level will be further investigated to identify exposure sources and possible health outcomes, and eventually to develop measures to mitigate exposure.