• Journal of Science and Technology Studies
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• v.18 no.1
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• pp.63-127
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• 2018

This paper discuses how toxic humidifier disinfectants were produced and distributed by bypassing tightly regulated laws from 1994 when the first humidifier disinfectant was made until 2011 when it was found to be the cause of the untreated interstitial lung disease. Rather than presupposing immoral entrepreneurs or incompetent civil servants as the cause of this disaster, this paper focuses on the bureaucratic character of the corporate organization that sold the humidifier disinfectant and the government that approved it, and shows that communication in these bureaucratic organizations was hampered and thus defective. It emphasizes the fact that the bureaucracy and secrecy of these organizations are the major cause of the humidifier disinfectant disaster. An analysis of the bureaucratic characteristic of the organization can reveal what improvements should be made in the corporation and in the government in order not to recur this disaster.

• Journal of Environmental Health Sciences
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• v.45 no.4
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• pp.381-393
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• 2019

Objectives: The purpose of this study was to assess the association between the use of humidifier disinfectant (HD) and bronchiolitis and allergic rhinitis diagnoses in Korean children. Methods: This study used data from the $8^{th}$ panel study on Korean children in 2015. Of these 2150 cases, 1598 cases were used for the final study. Diagnoses of bronchiolitis and allergic rhinitis by medical doctors were self-reported as outcome variables. Whether children had used HDs or not, the periods of using HDs were used as independent variables. Results: A total of 77.0% had used a humidifier, and the rate of HD usage among humidifier users was found to be 35.4%. When comparing 'children who had used HDs for less than 12 months' and 'children who had used HDs for more than 12 months' with 'children who had not used HDs', the adjusted odds ratio (OR)s for 'bronchiolitis' were 1.38 (95% confidence interval (CI), 1.36-1.40) and 1.80 (95% CI, 1.71-1.89), respectively. When comparing 'children who had used HDs for less than 12 months' and 'children who had used HDs for more than 12 months' with 'children who had not used HDs', the adjusted ORs for 'allergic rhinitis' were 1.44 (95% CI, 1.42-1.46) and 1.43 (95% CI, 1.37-1.49), respectively. Conclusions: The period of using HDs was statistically significantly associated with increased odds of bronchiolitis and allergic rhinitis. The results of this study will provide a very useful scientific basis for establishing the environmental health policy and using the educational data related to the use of humidifier disinfectant in the future.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.764-764
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• 2020

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.513-520
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• 2021

Background: Benzalkonium chloride (BKC) has been extensively used as a preservative in industrial products and in hygiene, medical, and cosmetic applications. Humidifier disinfectant (HD) products containing BKC have been used in South Korea. Objectives: This study was aimed to review types of products containing BKC, to summarize the regulations in the US, EU, Japan, and South Korea, and to review the health effects associated with the use of HD. Methods: We reviewed and summarized documents which were searched through PubMed and Google Scholar with the key words: BKC and asthma/contact dermatitis, humidifier disinfectant-associated lung injury (HDLI), and more. Results: Regulations in most countries including South Korea do not allow its use as disinfectants in spray-type of products for medicine, cosmetics, and household products. Two types of HD containing BKC (800~1,270 ppm) were marketed in South Korea from 1996~2003. Health effects reported from people who used products containing BKC were allergic contact dermatitis, erythema, and respiratory disease, including asthma. Two people who responded as HD users containing BKC only were confirmed to have developed asthma. HD-associated lung injury (HDLI) was reported by consumers who used both HD containing polyhexamethylene guanidine (PHMG) and HD containing BKC. Conclusions: In conclusion, the use of BKC as a biocide has to be controlled considering the route and pattern of exposure. Products containing BKC as preservatives were reviewed with exposure routes and sites in the human body such as skin, eyes, and the respiratory tract. HD containing BKC was clinically evaluated to be associated with asthma.

• Journal of Environmental Health Sciences
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• v.49 no.3
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• pp.159-168
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• 2023

Background: An ongoing environmental exposure assessment of humidifier disinfectants (HDs) has been conducted since November 2011 among individuals who experienced HD exposure-related adverse health effects. It is being performed in order to determine and quantify exposure to humidifier disinfectants in victims and their families. To date, the assessment has encompassed Cycles I-to-V. There is no report summarizing the characteristics of the subjects from the overall cycles. Objectives: We intended to examine the individual characteristics related to demographics, HD usage, and HD exposure using integrated data from Cycles I-to-V of the environmental exposure assessment of HDs and the changes with the cycles. Methods: We included 7,543 individuals who participated in Cycles I-to-V of the environmental exposure assessment of HDs. We summarized the participants' characteristics regarding their demographics (e.g., sex, education level, and age), HD usage history (e.g., product name, ingredient, and frequency of HD use), and HD exposure (e.g., daily time of HD use, cumulative time of HD use, and exposure intensity). In addition, their characteristics were compared across the cycles of the exposure assessment. Results: Among the 7,543 participants from Cycles I-to-V, there were more male participants than females (51.05% overall), except for Cycles I and III. Across all cycles, a higher proportion of survivors was observed than deceased individuals. While PHMG was the most prevalent ingredient in HDs throughout all the cycles, its proportion gradually decreased over the course of the examination cycles. Participants in Cycle I reported longer daily times of HD use compared to those in the subsequent cycles. On the other hand, cumulative time of HD use was shorter in the earlier cycles than in the later cycles. Conclusions: Using the integrated data from the full cycles of the environmental exposure assessment, this study identified changes in demographic characteristics as well as the HD exposure characteristics between the participants across different cycles.

• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.1-8
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• 2022

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.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.505-512
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• 2021

Background: The occurrence of environmental disease is known to be associated with chronic exposure to toxic chemicals, including waterborne contaminants, air/indoor pollutants, asbestos, ingredients in humidifier disinfectants, etc. Objectives: In this study, we reviewed toxicological studies related to environmental disease as defined by the Environmental Health Act in Korea and toxic chemicals. We also suggested a direction for future toxicological research necessary for the prevention and management of environmental disease. Methods: Trends in previous studies related to environmental disease were investigated through PubMed and Web of Science. A detailed review was provided on toxicological studies related to the humidifier disinfectants. We identified adverse outcome pathways (AOPs) that can be linked to the induction of environmental diseases, and proposed a chemical screening system that uses AOP, chemical toxicity big data, and deep learning models to select chemicals that induce environmental disease. Results: Research on chemical toxicity is increasing every year, but there is a limitation to revealing a clear causal relationship between exposure to chemicals and the occurrence of environmental disease. It is necessary to develop various exposure- and effect-biomarkers related to disease occurrence and to conduct toxicokinetic studies. A novel chemical screening system that uses AOP and chemical toxicity big data could be useful for selecting chemicals that cause environmental diseases. Conclusions: From a toxicological point of view, developing AOP related to environmental diseases and a deep learning-based chemical screening system will contribute to the prevention of environmental diseases in advance.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.141-146
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• 2016

In South Korea, many cases of humidifier disinfectant-associated lung injury (HDLI) have been reported among people who used humidifier products containing humidifier disinfectant (HD). The objectives of this study are to estimate both airborne HD concentration in the room where HD was used and the amount of humidifier disinfectant absorbed into the respiratory system. Information and data on the HDs were collected using a structured questionnaire and home environmental investigations include the volume of HD (ml) and hours used per day, concentration of disinfectants contained in the HD brand (${\mu}g/ml$), volume of the room ($m^3$), assumed ventilation rate ($m^3/hr$) and breathing rate assumed ($m^3/hr$). We used children aged under five years old as a sample and estimated both airborne HD concentrations and amount of HD absorbed into the respiratory system. The estimated airborne concentration of HD in the room ranged from 68 to $369{\mu}g/m^3$ for PHMG (polyhexamethylene guanidine phosphate) and from 16 to $239{\mu}g/m^3$ for PGH (oligo (2-(2-ethoxy) ethoxyethyl guanidine). The amount of HD absorbed in the respiratory system per day was estimated to range from 227 to $1,225{\mu}g$ for PHMG and from 53 to $794{\mu}g$ for PGH. In conclusion, a great amount of HD was likely absorbed into respiratory system, likely beyond the level of the capacity of the immune system to remove the HD absorbed.

• Tuberculosis and Respiratory Diseases
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• v.80 no.4
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• pp.351-357
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• 2017

In 2011, a cluster of peripartum patients were admitted to the intensive care unit of a tertiary hospital in Seoul with signs and symptoms of severe respiratory distress of unknown etiology. Subsequent epidemiological and animal studies suggested that humidifier disinfectant (HD) might represent the source of this pathology. Epidemiological studies, animal studies, and dose-response analysis demonstrated a strong association between HD use and lung injuries. The diagnostic criteria for HD-associated lung injury (HDALI) was defined on the basis of the clinical, pathological, and radiological attributes of the patients. The clinical spectrum of HDALI appears to range from asymptomatic to full-blown acute respiratory failure, and some patients have required actual lung transplantation for survival. The overall mortality of the exposed population was not significant, although peripartum patients and children who were admitted to the intensive care unit did show high mortality rates. Persistent clinical findings such as diffuse ill-defined centrilobular nodules and restrictive lung dysfunction were observed in some of the survivors. The findings of this review emphasize the importance of assessment of the level of toxicity of chemical inhalants utilized in a home setting, as well as the need to identify and monitor afflicted individuals after inhalational injury.

• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.335-343
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• 2020

Objectives: The Korean Ministry of Environment has identified cases of people suspected of suffering lung disease potentially caused by polyhexamethylene guanidine (PHMG) used in humidifier disinfectants (HDs). Exposure assessment for the HDs was conducted using a questionnaire during face-to-face interview. The main purposes of this study were to develop a methodology to effectively classify levels of exposure to HDs based on a questionnaire. Methods: We first identified the overall participants' exposure characteristics by HD exposure levels; Second, we selected misclassified subjects and investigated characteristics of overestimated and underestimated subjects, focusing on exposure cases to PHMG-containing HDs. An inhalation reference concentration (RfC) for PHMG was produced on the basis of inhalation toxicity values. We made a cross-tabulation of the exposure classes (Exposure classes 1-to-4) by clinical classes based on the RfC. When the value of the exposure class minus the clinical class was 0 or 1, we assumed these were true values. When the value was ≥2 and ≤ -2, we assigned these cases to the overestimation group and underestimation group, respectively. Results: The overestimated group may have already recovered and responded excessively due to psychological anxiety or in order to receive compensation. On the other hand, relatively high mortality rates and surrogate responses for those under 10 years of age may have resulted in inaccurate exposure assessment for underestimated groups. For the characteristics of exposure, it was shown that for the underestimated group, the exposure was relatively weaker than the overestimated group, even though a high overall clinical rating was determined. Conclusions: This study may suggest ways to reduce bias and overcome the limitations of current HD exposure assessment.