Large-scale human casualties have been reported following exposure to humidifier disinfectants (HDs), with chronic fatigue syndrome (CFS) identified as a potential long-term health outcome. This study aimed to elucidate the mechanistic link between HD exposure and CFS onset, focusing on mitochondrial and neurophysiological dysfunction. Mitochondrial morphology in peripheral blood mononuclear cells (PBMCs) was examined in patients with CFS and documented HD exposure (HD-CFS). To validate clinical findings, polyhexamethyleneguanidine-phosphate (PHMG-p), a major HD component, was intratracheally administered to mice, which were then subjected to fatigue-related behavioral assessment. In PBMCs, mitochondrial morphology, membrane potential, oxidative phosphorylation (OXPHOS) protein expression, and transcriptomic alterations were assessed. Brain tissues were evaluated for neuroglial activity, blood-brain barrier (BBB) integrity, and OXPHOS protein expression. PBMCs from patients with HD-CFS exhibited significantly increased mitochondrial abnormalities. In mice, PHMG-p exposure caused mitochondrial abnormalities, decreased the expression of OXPHOS complexes, and downregulated the expression of genes related to mitochondrial membrane potential. Neurological assessments revealed glymphatic dysfunction, BBB disruption, and reduced OXPHOS complex expression in the hypothalamus. These findings suggest that PHMG-p contributes to CFS pathogenesis by inducing mitochondrial and neurological dysfunction. This study highlights the potential long-term health risks of HD exposure and identifies PHMG-p as a candidate environmental trigger in CFS.

Background: Although the association between handgrip strength and glycemic control has been reported, studies conducted exclusively within specific occupational groups remain limited. To explore the association between handgrip strength and metabolic health in industrial settings, this study examined the relationship between relative handgrip strength and glycated hemoglobin (HbA1c) among male automobile manufacturing workers using vibration tools in South Korea. Methods: Using 66,212 occupational health examination records collected at Inha University Hospital between January 2024 and April 2025, a total of 3,365 workers with HbA1c and handgrip strength measurements were identified. After excluding duplicates (n = 1,536), female workers (n = 2), and records without Hb and estimated glomerular filtration rate, 1,823 male participants were included in the final analysis. Relative handgrip strength was calculated as the maximum value of bilateral grip strength divided by body mass index. Multiple linear regression analyses were conducted to assess the association between relative handgrip strength and HbA1c, adjusting for age, smoking status, alcohol consumption, current hypertension, current dyslipidemia, current hypoglycemic-agents use, family diabetes history, leisure-time physical activity, and resistance exercise. Results: Relative handgrip strength was inversely associated with HbA1c levels (B: -0.060; 95% confidence interval [CI]: -0.081 to-0.039; p < 0.001). The association was strongest among normoglycemic participants (B: -0.185; 95% CI: -0.305 to-0.065; p = 0.003). Effect size was reduced but significantly associated among individuals with pre-diabetes (B: -0.115; 95% CI: -0.180 to-0.050; p < 0.001) and further attenuated to a borderline significance in individuals with diabetes (B: -0.023; 95% CI: -0.050 to 0.003; p = 0.082). These findings indicate that greater muscle strength relative to body size is related to better glycemic control. Conclusions: Handgrip strength was associated with HbA1c levels in industrial workers. This study suggests that handgrip strength may provide complementary information on metabolic health in occupational settings.

Background: Humans are exposed to mercury primarily in its highly toxic form, methyl mercury, which is known to have adverse effects on various organs and systems. The negative impact of mercury exposure on the growth, development, and mental health of children, from infancy to adolescence, is well-documented. However, there are no internationally standardized safe limits for mercury exposure. This study investigated the impact of dietary habits and higher body mass index (BMI) on blood mercury levels in adolescents.Methods: This study analyzed the data from the 4th Korean National Environmental Health Survey (KoNEHS) 2018–2020. The focus was on 825 middle and high school students aged 13–18 years, whose blood mercury levels were measured. A survey on dietary and lifestyle habits was also conducted. Blood mercury levels were categorized by geometric median values, and associations with overweight status and seafood consumption were examined using a generalized linear model.Results: The geometric mean blood mercury level for the entire sample was 1.37 μg/L, with levels of 1.31 μg/L in normal-weight individuals and 1.43 μg/L in overweight individuals, showing a statistically significant difference between the two groups. After adjusting for other variables, blood mercury levels were significantly associated with overweight status (estimate: 0.084; p = 0.018; 95% confidence interval [CI]: 0.015–0.153), consumption of large fish and tuna more than once a week (estimate: 0.18; p = 0.001; 95% CI: 0.077–0.284), and consumption of fish once a week or more (estimate: 0.147; p = 0.004; 95% CI: 0.043–0.250).Conclusions: In adolescents, a higher BMI and an increased consumption of large fish, tuna, and fish were associated with higher blood mercury levels. Notably, a stronger association was found between large fish consumption and blood mercury levels in the overweight group. These findings suggest the need to moderate seafood consumption and establish more proactive mercury exposure standards for adolescents.

BACKGROUND:PM2.5 (particulate matter less than 2.5 μm) causes various health problems. Recent studies suggest that long-term exposure to PM2.5 may have a negative impact on vision. This study examined the effects of long-term exposure to concentrations of PM2.5 exceeding Korean standards on myopia prevalence. METHODS:This study was conducted on adults aged 40-69 years. The PM2.5 concentrations were calculated as the 1-5-year moving averages based on the participants' residential areas. The relationships between the PM2.5 levels, categorized by the annual average concentration standard in Korea, and the prevalence of myopia were analyzed using binary logistic regression. The results were evaluated using the 95% confidence interval. RESULTS:PM2.5 concentrations averaged over 1-3 years were not significantly associated with the prevalence of myopia. On the other hand, the prevalence of myopia was significantly higher in areas where the 4-5-year moving average PM2.5 levels exceeded the Korean standards. These findings suggest that long-term exposure to PM2.5 may have a detrimental effect on vision. CONCLUSIONS:This study revealed the impact of long-term PM2.5 exposure on the prevalence of myopia, highlighting the importance of managing PM2.5 levels. Nevertheless, further cohort studies focusing on adults and in-depth research into the effects of long-term exposure will be necessary.

Background:Studies on the association between job satisfaction and depression have often been reported. However, no study has examined how job satisfaction impacts depression while considering satisfaction with other aspects of life. In this study, we evaluated the effect of job satisfaction on depression after adjusting for satisfaction with other domains of life.Methods:We used data from the 16th wave of the Korean Welfare Panel Study. A total of 3568 current employees without depression who completed a survey were included. Depression was measured using the abbreviated version of the CES-D scale. Various types of satisfaction, including job satisfaction, were measured using single-item questions and a 5-point Likert scale. The association between job satisfaction and depression after considering satisfaction with other life domains was analyzed using a multiple logistic regression model.Results:Crude models showed a significant association between job satisfaction and depression in males (odds ratio [OR]: 7.90; 95% confidence interval [CI]: 4.11-15.23) and females (OR: 7.12; 95% CI: 4.40-11.50). When adjusted for sociodemographic factors, health-related factors, and work-related factors, the association remained significant in males (OR: 6.20; 95% CI: 3.10-12.41) and females (OR: 6.28; 95% confidence interval (CI): 3.79-10.40). However, when satisfaction with other life domains was included, the association remained significant only in females (OR: 3.55; 95% CI: 1.93-6.50).Conclusions:This study shows an association between job satisfaction and depression in Korean employees. However, when satisfaction with other life domains was considered, this association remained significant only in women. Regular screening of job satisfaction should be considered as a means of preventing and managing depression among female employees.

Background:Studies on the association between occupational stress and depression have been frequently reported. However, the cross-sectional designs of studies limited insight into causal associations. In this study, we investigated the longitudinal association between occupational stress and new-onset depression among employees in a single manufacturing plant.Methods:The annual health checkup data of employees at a manufacturing plant in Korea were collected. A total of 1,837 male employees without depression who completed a health checkup during two consecutive years were included. Occupational stress was measured using a short form of the Korea Occupational Stress Scale (KOSS-SF), and depression was assessed using a Patient Health Questionnaire-2. The association between occupational stress change over the two years and newly developed depression was investigated using two logistic regression models.Results:Across all sub-factors of KOSS-SF, employees who reported increased occupational stress had a higher risk of new-onset depression. Newly developed depression was significantly associated with job demand (odds ratio [OR]: 4.34; 95% confidence interval [CI]: 2.37-7.96), job insecurity (OR: 3.21; 95% CI: 1.89-5.48), occupational climate (OR: 3.18; 95% CI: 1.91-5.31), lack of reward (OR: 2.28; 95% CI: 1.26-4.12), interpersonal conflict (OR: 2.14; 95% CI: 1.18-3.86), insufficient job control (OR: 1.93; 95% CI: 1.05-3.56), and the organizational system (OR: 1.84; 95% CI: 1.01-3.36).Conclusions:For every sub-factor of the KOSS-SF, occupational stress increase and persistent high stress were associated with the risk of developing new-onset depression. Among the seven sub-factors, job demand had the most significant effect. Our results show that occupational stress should be managed to promote employee mental healthcare.

Background Although many studies have been conducted on worker fatigue and sickness absence, the association between fatigue and sickness absence is unclear in Korean workers. This study was conducted to investigate the effect of worker fatigue on future sickness absence. Methods The study was conducted on workers who received medical check-ups at a university hospital for two consecutive years (2014–2015). During check-ups in the first year, the Fatigue Severity Scale (FSS) was used to assess fatigue levels, and during check-ups in the second year, sickness absence was surveyed to determine whether they had been absent from work due to physical or mental illness during previous 12 months. The χ2 test was used to analyze relationships between sociodemographic and occupational characteristics, fatigue levels, and sickness absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors. Results A total of 12,250 workers were included in the study, and 396 (3.2%) workers experienced more than one day of sickness absence during the study period. Adjusted ORs for sickness absence were 3.35 (95% confidence interval [CI]: 2.64–4.28) in the moderate-fatigue group and 6.87 (95% CI: 4.93–9.57) in the high-fatigue group versus the low-fatigue group. For men in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 3.40 (95% CI: 2.58–4.48) and 8.94 (95% CI: 6.12–13.07), and for women in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 2.93 (95% CI: 1.68–5.10) and 3.71 (95% CI: 1.84–7.49), respectively. Conclusions Worker fatigue is associated with sickness absence during the following 12 months, and this association appears to be stronger for men than women. These results support the notion that sickness absence can be reduced by evaluating and managing work-related fatigue.

Health damage from humidifier disinfectants is an unprecedented environmental health disaster. Humidifier disinfectants were used broadly in Korea from 1994 to 2011. Most studies have focused on respiratory problems because of the exposure route and primary respiratory symptoms. This overlooks the previous research results that humidifier disinfectants could move to extrapulmonary organs and induce toxic effects. Thus, the objective of this study was to examine toxic hepatitis cases developed after inhaling humidifier disinfectant. We focused on the indications of toxic hepatitis in two pediatric cases and one female adult case. All patients were exposed to humidifier disinfectants in a residential space. These disinfectants all contained polyhexamethylene guanidine (PHMG). Rapid increases in blood hepatic enzyme levels were seen. Two patients were discharged after treatment. Death occurred in one patient who was diagnosed with fulminant hepatitis of unknown cause. This human case series study supports prior knowledge that hepatotoxicity can occur by inhaling humidifier disinfectant.

Some survivors of humidifier disinfectants (HDs) complain of chronic, inexplicable fatigue, and post-exertional malaise (PEM). Two-day cardiopulmonary exercise tests (CPETs) performed 24 hours apart (2-day CPET protocol) are increasingly employed to evaluate PEM and related disabilities among individuals with chronic fatigue syndrome (CFS). The purpose of this study was to assess the reproducibility of CPET variables in individuals who had been exposed to HD and to show that 2-day CPET is an objective means of differentiating between fatigue conditions in people with CFS symptoms who have been exposed to HDs. Twenty-nine HD survivors with CFS symptoms were enrolled in this study. To document and assess PEM in CFS, a 2-day CPET was conducted to measure baseline functional capacity (CPET1) and provoke PEM. Twenty-four hours later, a second CPET assessed changes in related variables, focusing on PEM effects on functional capacity. This CPET also measured changes in energy production and physiological function, objectively documenting PEM effects. In the 2-day CPET, the peak oxygen consumption (VO2peak), VO2 at ventilatory threshold (VO2@VT), time to reach VO2peak, and time to reach VO2@VT were significantly decreased (p<0.001). The peak O2 pulse and O2 pulse at VT also decreased significantly (p<0.001). A 6-minute walk test revealed significantly decreased distance (p<0.01). This is the first study to conduct a 2-day consecutive CPET in previously exposed HD participants with CFS symptoms. Our results confirm previous work that demonstrated abnormal responses to PEM in CFS patients. Therefore, a 2-day CPET is an objective measure to differentiate fatigue conditions in people with CFS symptoms who have been exposed to HDs.

Background: Many studies have been conducted on presenteeism and absenteeism, but the relationship between presenteeism and absenteeism is unclear. This study was undertaken to investigate the effect of presenteeism on future absenteeism.Methods: This study was conducted on non-white collar workers that underwent general health examinations in 2014 and 2015. We asked subjects to fill out a questionnaire about their experiences of presenteeism for the past one year in 2014. In 2015, it was checked whether the same subjects had any experience of absence from work due to injury or disease during the past year. The chi 2 test was used to analyze relationships between sociodemographic and occupational characteristics, presenteeism, and absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors.Results: A total of 12,572 workers were included in the study. For workers who experienced presenteeism, the OR for injury absence was 2.705 (95% confidence interval [CI]: 2.044- 3.581), and the OR for disease absence was 4.906 (95% CI: 3.996-6.024) after adjusting for sociodemographic and occupational confounding factors. For men that experienced presenteeism, the OR for injury absence was 3.035 (95% CI: 2.258-4.081), and the OR for disease absence was 5.508 (95% CI: 4.340-6.989). For women that experienced presenteeism, the OR for injury absence was 1.322 (95% CI: 0.577-3.028), which was not significant, and the OR for disease absence was 3.629 (95% CI: 2.405-5.475).Conclusions: This study suggests that presenteeism can influence future absenteeism. The effect of presenteeism may depend on cause of absence. Men who experienced presenteeism showed greater effects on injury and disease absence than women. For women, experience of presenteeism had a significant effect on disease absence but not on injury absence.

The mixture of 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT, chloromethylisothiazolinone) and 2-methyl-4-isothiazolin-3-one (MIT, methylisothiazolinone) is a commonly used biocide in consumer products. Despite the health issues related to its usage in cosmetics and humidifier disinfectants (HD), understanding its adverse outcome is still limited. Using in vitro cell lines and ex vivo rat models, we examined the effects of CMIT/MIT on the cellular redox homeostasis and energy metabolism in the brain microvascular endothelium, a highly restrictive interface between the bloodstream and brain. In murine bEND.3 and human hCMEC/D3, CMIT/MIT significantly amplified the mitochondrial-derived oxidative stress causing disruption of the mitochondrial membrane potential and oxidative phosphorylation at a sub-lethal concentration (1 μg/mL) or treatment duration (1 h). In addition, CMIT/MIT significantly increased a dynamic imbalance between mitochondrial fission and fusion, and endogenous pathological stressors significantly potentiated the CMIT/MIT-induced endothelial dysfunction. Notably, in the brain endothelium isolated from intravenously CMIT/MIT-administered rats, we observed significant mitochondrial damage and decreased tight junction protein. Taken together, we report that CMIT/MIT significantly impaired mitochondrial function and dynamics resulting in endothelial barrier dysfunction, giving an insight into the role of mitochondrial damage in CMIT/MIT-associated systemic health effects.

Objectives:The purpose of this study is to reveal the circumstances under which the cases of harm to health caused by humidifier disinfectant were neglected and show the points where the number of victims and the degree of damage could have been reduced.In addition, it attempts to describe how damage management proceeded immediately after the incident and actually exacerbated the damage.Finally, it explores the unfortunate aspects of the recent trial.By doing so, it attempts to take this as an opportunity to consider whether a tragic event such as the humidifier disinfectant incident could occur in the future. Methods:This study collected and analyzed data on chemical material characteristics related to humidifier disinfectants, data on health effect characteristics, data on related laws and regulations from the Ministry of Environment, data related to the damage investigation by the Korea Environmental Industry and Technology Institute, and current contents. Results:The lack of related systems and laws is the area where the greatest responsibility for the cause of the humidifier disinfectant disaster falls, so it is difficult for the government to escape this responsibility.Establishing a dedicated department to identify the prevalence of certain diseases within the functions of the Health Insurance Review and Assessment Service to monitor health can greatly contribute to the prevention and management of diseases through early detection and management of group outbreaks caused by harmful factors.Humidifier disinfectant damage relief should have been expanded earlier beyond HDLI (humidifier disinfectant lung injury) to include non-specific diseases such as asthma, pneumonia, and interstitial pneumonia.The scope of relief benefits should have also been expanded earlier to include the payment of disability benefits.Fortunately, with the 2020 revision of the Special Act, the conditions for estimating causal relations were eased and individual screening systems such as health impact assessment were reorganized along with the introduction of a rapid screening system. Conclusions:The management system for chemical substances in a country is clearly of paramount importance, and the ministry in charge must have a response system in case of damage to health effects.Administration that looks at the victims' situation from their point of view is needed, and technical countermeasures are required to quickly recognize the prevalence of certain diseases.

Background: The aim of this study is to investigate the relationship between fatigue and occupational injury. Methods: This study was conducted at a university hospital in 2014 and 2015. In 2014, the fatigue severity scale (FSS) was used to evaluate workers' fatigue levels. Later, when the same workers were examined in 2015, a questionnaire survey was conducted to determine whether they had experienced absences or treatment for work-related accidents. The chi(2) test was used to analyse the relationship between demographic characteristics, fatigue levels, and occupational injuries. After controlling for confounders, a logistic regression analysis was performed to calculate the odds ratios (ORs). Results: In 2014, 19,218 workers were screened during health examination and their fatigue level were evaluated using FSS questionnaires. in 2015, workers' occupational injury was evaluated. In result, men in the moderate- and high-fatigue groups, after adjusting for age, smoking and drinking habits, chronic diseases, and occupational factors such as size of company industrial classification and type of work (shift or non-shift), adjusted ORs for hospital treatment due to occupational injury were 1.76 (95% confidence interval [CI]: 1.39-2.24) and 2.61 (95% CI:1.68-4.06), respectively. Among men in the medium- and high-fatigue groups, the adjusted ORs for absence due to occupational injury were 2.06 (95% CI: 1.52-2.80) and 3.65 (95% CI: 2.20-6.05), respectively. No significant association was observed between fatigue and occupational injury in women. Conclusions: Male workers with high fatigue levels have a higher risk of experiencing work injuries. This study suggests that active intervention be considered to prevent injuries in workers with high scores on workplace fatigue evaluation scales.

OBJECTIVES: We aimed to determine the characteristics of the deceased victims of deaths caused by exposure to humidifier disinfectants, and present the distribution of the victims' data submitted for damage application, demographic characteristics, imaging findings, characteristics of humidifier disinfectant exposure, and distribution of the causes of death. METHODS: An integrated database of victims was established using the medical records data of 1,413 victims submitted during the application for death damage caused by exposure to humidifier disinfectants, and the demographic characteristics, medical records, imaging findings, exposure characteristics, and cause of death were examined. RESULTS: The average numbers of data submissions of each applicant for death damage were 3.0 medical use records. A total of 608 (43.0%) victims had more than one finding of acute, subacute, or chronic interstitial lung diseases. The average daily and cumulative use times of the victims were 14.40 and 24,645.81 hours, respectively, indicating greater exposure in this group than in the survivors. The humidifier disinfectants' components comprised polyhexamethylene guanidine (72.8%), chloromethylisothiazolinone/methylisothiazolinone (10.5%), other components (15.0%), and oligo-[2-(2-ethoxy)-ethoxyethyl] guanidine chloride (1.5%). The components' distribution was 67.8% for single-component use, which was higher than that in the survivors (59.8%). The distribution of the causes of death were: respiratory diseases (54.4%), neoplasms (16.8%), and circulatory diseases (6.3%). Other interstitial lung diseases (65.5%) were the most common cause of death among those who died due to respiratory diseases. CONCLUSIONS: Careful discussions of appropriate remedies should be conducted based on a comprehensive understanding of the characteristics of the deceased victims, considering their specificities and limitations.

Background: The relationship between smoking status or second-hand smoking and occupational injuries has been the subject of considerable study, but few have studied the relationship between nicotine dependence and occupational injuries. The objective of this study was to investigate the relationship between nicotine dependence and occupational injury among employees at a range of Korean companies. Methods: Initially, the personal and occupational characteristics and nicotine dependences of workers were measured, and 12 months later a survey was used to determine whether subjects had experienced any occupational injury. This study was conducted in several workplaces on 6,893 male workers in manufacturing and service industries that received health screening at Inha University Hospital in Incheon. Results: The adjusted odds ratios (ORs) of occupational injury in the low, moderate, and high nicotine dependence groups were 1.38 (95% confidence interval [CI]: 1.04-1.84), 1.52 (95% CI: 1.10-2.10), and 1.71 (95% CI: 0.92-3.19), respectively. For smokers only, adjusted ORs tended to increase linearly ( p for trend < 0.05). When only smokers were included, analysis of continuous FTND (Fagerstrom Test of Nicotine Dependence) scores showed that adjusted OR increased by 1.10 (95% CI: 1.03-1.19) per FTND point. After stratifying the data by working type and working hours per week, the non-shift work group maintained this relationship (OR: 1.13, 95% CI: 1.04-1.24) and OR was higher in the group that works more than 60 hours per week with FTND score as a continuous variable (OR: 1.24, 95% CI: 1.07-1.44). Conclusions: The study shows nicotine dependency might affect occupational injury. From a short-term perspective, addressing worker's nicotine dependence by giving an adequate break time or smoking area might reduce work-related injuries.

Humidifier disinfectant damages caused by the misuse of humidifier disinfects, such as polyhexamethylene guanidine (PHMG), resulted in chemical disasters in South Korea in 2011. About four million people were exposed to humidifier disinfectants (HDs) in the 17 years between 1994 and 2011. Although fatal lung damage was initially reported, investigations into the victims’ injuries revealed that the damage was not limited to the lungs, but that systemic damage was also confirmed. Considering the spread of HD from the lungs to the whole body, the toxic effects of PHMG from reactive oxygen species (ROS), NOTCH signaling pathways, and mitochondrial dysfunction resulted in endothelial damage in the lungs, blood vessels, liver, kidneys, bone marrow, nerves, and muscles. The main toxic mechanisms involved in HD damage may be the NOTCH pathway and mitochondrial damage. There are many case reports which include neurologic disorders (ADHD, depression, posttraumatic stress disorder), muscular disorder (exercise intolerance, myalgia), energy metabolism disorder (chronic fatigue syndrome), and immunologic disorder (rheumatoid arthritis) in HDs victims. These case reports involve multi-system involvement in HDs victims. Further well-designed study is needed to clarify whether mitochondrial dysfunction is associated with multi-organs involvement in HDs victims.

Background: The Mothers and Children's Environmental Health study (MOCEH) is a multi-centric prospective birth cohort study investigating effects of various environmental pollutants like heavy metals, endocrine disruptors, air pollutants, nutrition and lifestyle on birth outcomes, growth and development, health and disease of children. In this study, we report all the outcomes from the MOCEH study describing the different environmental pollutants affecting children's health and disease. Methods: In MOCEH study, 1,751 pregnant women in their first trimester were recruited at 3 centers from 2006 to 2010 in South Korea. The children were followed from birth up to 6 years. Information on health outcomes of children including birth parameters, demographic characteristics, medical and child-rearing history, and nutritional status, were repeatedly obtained through the follow-ups by questionnaires administration, clinical evaluation, and biological specimen collection and measurements. Prenatal and postnatal measurement in biospecimen, i.e., lead, mercury, cadmium, manganese, 1-hydroxypyrene, 2-naphthol, malonadialdehyde, hippuric acid, bisphenol A and phthalate metabolites, and measurement in air samples, i.e., particulate matter, nitrogen dioxide, and total volatile organic compounds were performed. Results: The results show the adverse effect of prenatal exposure to heavy metals like mercury, lead and cadmium on children's physical, cognitive and neurobehavioral development. Exposure to endocrine disruptors, air pollution, second hand smoke, and mother's lifestyle during pregnancy affects children's growth and development. We also identified specific window periods of exposure of pollutants significantly related to children's health outcomes. Conclusion: The collective results from MOCEH study provide strong scientific evidence that exposures to prenatal and postnatal environmental pollutants have a negative effect on growth and development of children, which will be useful in implementing effective national policy to improve children's environmental health.

Background: To compare the chest computed tomography (CT) images of children and adults in families with clusters of humidifier disinfectant-related lung injury (HDLI) after cessation of exposure to humidifier disinfectant (HD). Methods: We reviewed medical records of 19 families with 43 patients (21 adults, 22 children) among families, which had at least one adult and one child with HDLI. Each family was exposed to the same HD exposure environment. Results: In adults, centrilobular nodules were predominant (95.2%) in chronic HDLI findings after cessation of exposure to HD, however, in children, normal pattern was most prevalent on chest CT (45.5%), followed by centrilobular nodule (36.4%), bizarre lung cysts (36.4%), and reticulation (13.6%). Conclusion: Unlike the known chronic HDLI finding of adults, centrilobular nodules were only present in 36.4% of children. The frequency of bizarre lung cysts were significantly greater in children than that in adults after cessation of similar exposure to HD. Thus, bizarre lung cysts may be useful as another novel finding of chronic HDLI in children who have no history of pulmonary infection or other perinatal disorder such as hyaline membrane disease or other interstitial lung disease.