• Journal of Environmental Health Sciences
• /
• v.44 no.2
• /
• pp.107-114
• /
• 2018

Objectives: The objectives of this study are to describe strategy for exposure assessment of humidifier disinfectant (HD) used in the national program to associate the use of HD with lung injury. Methods: Strategy and method employed to evaluate HD use characteristics were developed to associate health effects including HD associated with lung injury (HDLI). We developed HD-specific questionnaire to assess potential HD exposure, which was consistently used in the national program. Trained environmental health scientists visited the residences of registered subjects and investigated HD use characteristics. Results: Major HD exposure related variables were type of HD brand/s used; HD volume added to the humidifier, frequency of HD addition, and time spent in room/s with the humidifier; duration of HD use in the household in average months/year, weeks/month, and days/week; average sleeping hours in a room with an operating humidifier containing a disinfectant; number of HD brands used and type of HD; average distance of the bed from the humidifier in meters. Conclusions: We concluded that estimated airborne HD concentration was significantly associated with the risk of HDLI.

• Journal of Environmental Health Sciences
• /
• v.46 no.5
• /
• pp.481-494
• /
• 2020

Objectives: No study has been conducted to review characteristics of humidifier disinfectants (HD) products, such as real numbers, levels and types of HD substances contained, or the volume marketed. We aimed to review the characteristics of HD through a literature review. Methods: We collected literature reporting the names, numbers, and ingredients of HD and discussed them with a focus on the number of HD products and the chemicals used as a disinfectant. Results: A total of eight publications has reported the names of HD brands or types of disinfectants from 2011 to 2020. To date, a total of 40 HD products have been used, excluding four products. Eight HD products used polyhexamethylene guanidine phosphate (PHMG) and 14 used a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) as disinfectants. Benzalkonium chloride (BKC) and sodium dichloroisocyanurate (NaDCC) were also used as a disinfectant in several HD products. A total of 19 HD products were associated with the development of HD associated lung injury (HDLI). The Oxy Saksak HD product containing PHMG showed the highest number of HD associated health effects. The type of disinfectant from a total of 14 HD products has not been identified. Conclusions: A total of 40 HD products have been marketed in South Korea since 1994. Further studies should be conducted to identify the association of product characteristics, including type of HD ingredients, with health effects.

• Environmental Analysis Health and Toxicology
• /
• v.31
• /
• pp.14.1-14.4
• /
• 2016

A total of 221 patients were evaluated to be humidifier disinfectant associated with lung injury (HDLI) through two rounds of programs through April 2015. The humidifier disinfectant (HD) brands most often associated with HDLI were found to be Oxy (n=151, 68 %) and Cefu (n=26, 17 %). Polyhexamethylene guanidine used for disinfectant for four types of HD brands including Oxy was found to be associated with the highest number of HDLI cases (n=188). Further programs are operating to identify various health effects including lung injury which may be associated with the use of HD. Not only national agencies, but also pertinent environmental health societies should cooperate in the necessary investigations so that this tragedy can be properly addressed and future incidents concerning chemicals and chemical-containing products can be prevented.

• Journal of Environmental Health Sciences
• /
• v.46 no.5
• /
• pp.495-503
• /
• 2020

Objective: This study aimed to compare the characteristics of humidifier disinfectant-like products (HD-like products) and humidifier disinfectant products (HD products) and introduce actual cases of the usage of HD-like products in hospitals based on an on-site investigation. Methods: The characteristics, chemical components, and usage of HD-like products (Hichlor or Biospot) and HD products (N-with) containing NaDCC (sodium dichloroisocyanurate) were compared. In the process of conducting the on-site investigation, four hospitals were identified as previously using HD-like products. Each on-site investigation to identify the use of HD-like products was composed of four parts: 1) hospital infection control guidelines, 2) manual for humidifiers in patient's rooms, 3) interviews with nursing staff, infection managers, and purchase managers, 4) searching on the product purchase system. Results: Although HD-like products (Hichlor and Biospot) and HD products (N-with) were sold for different usage purposes, they were all white-colored and coin-shaped foaming tablets with the same chemical component, NaDCC. The manual for using HD-like products and HD products was similar (inserting the tablet in a humidifier container with water). Among the four hospitals, one had used Hichlor in the same manner as HD (N-with) by inserting a tablet in 1L of water in a filled humidifier container and Biospot as a kind of detergent for humidifier container cleaning. Another two hospitals had used Biospot and/or Aniosyme as a kind of detergent for humidifier container cleaning. The other hospital had used unknown product in the same manner as N-with, so we thus assumed it was either an HD products (N-with) or HD-like products (Hichlor, Biospot). Conclusion: This study raises the possibility of the development of adverse health effects similar to exposure to an HD-products when exposed to an HD-like products and the possibility of further use in other medical institutions or multi-use facilities. Therefore, an expansion of the investigation is needed in order to confirm whether there have been similar cases in the past.

• Journal of Environmental Health Sciences
• /
• v.42 no.6
• /
• pp.365-374
• /
• 2016

Objectives: Studies are needed to examine the characteristics of health effects reported by people who used humidifier disinfectant (HD), including the distribution of victims. Methods: We analyzed the distribution of health effects including lung injury that were asserted by a total of 699 individuals who registered with the first through third national programs to determine health effects associated with the use of HD. Results: We found that HD-associated lung injury (HDLI) occurred every year from 2002 through 2011, and in 2011 for 37.2% (n=96) of the total of 258 clinically evaluated HDLI victims. More than half of the victims responded that they were victimized between 2010 and 2011. This was consistent among all classifications by sex, age, HD brand and HD chemical ingredient. Conclusion: This study assumed that the major reason for the outbreak of the health effect between 2010 and 2011 could be the variations in concentrations and physical properties related to polyhexamethylene guanidine (PHMG). Further studies are necessary to examine if some factors related to the chemical disinfectants contained in HD brands may have caused the massive outbreak of health effects including HDLI.

• Journal of Environmental Health Sciences
• /
• v.45 no.4
• /
• pp.310-320
• /
• 2019

Objectives: The purpose of this study is to identify the causes of the retardation of administrative relief under the Special Act on Remedy for Damages Caused by Humidifier Disinfectant and to suggest the systematic refurbishment of this act for the quick and fair of relief of damages. Methods: This study was conducted through the application of the case study, literature review and systematic interpretation of law methods. Results: The disease subject to administrative relief under the Special Act is defined as health damage causally associated to a substantial degree with exposure to humidifier disinfectant. This definition is a strict requirement in light of the legislative purpose of prompt and fair relief of damages. Furthermore, the damage relief committee established under the Special Act judged causal relationships according to a rigorous standard in terms of medical certainty. This medical evidence-based judgment is a result of the committee's failure to understand the normative meaning and function of a causal relationship as an outcome of inference based on empirical rules and common sense. Conclusions: Humidifier disinfectant health damage should be defined as a health-related injury capable of occurring or deteriorating after exposure to humidifier disinfectant (HD). If the fact that a particular injury occurred or worsened after exposure to HD was found, then the damage can be presumed as being caused by HD. However, this might not be the case when the injury was considered to have occurred or been exacerbated entirely due to other factors.

• Journal of Environmental Health Sciences
• /
• v.47 no.6
• /
• pp.513-520
• /
• 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
• /
• v.42 no.3
• /
• pp.141-146
• /
• 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.

• Clinical and Experimental Pediatrics
• /
• v.63 no.7
• /
• pp.251-258
• /
• 2020

Exposure to environmental factors can cause interstitial lung diseases (ILDs); however, such types of ILDs are rare. From 2007 to 2011, an ILD epidemic occurred in South Korea owing to inhalational exposure to toxic chemicals in humidifier disinfectants (HDs). HD-associated ILDs (HD-ILDs) are characterized by rapidly progressing respiratory failure with pulmonary fibrosis and a high mortality rate of 43.8%-58.0%. Although 18.1%-31.1% of the general population used HDs, only a small proportion of HD users were diagnosed with HD-ILDs. This finding suggests that investigation of the pathophysiologies underlying HD-ILDs is needed in addition to the identification of susceptibility to HD-ILDs. Further, there have been several concerns regarding the diverse health effects of exposure to toxic chemicals in HDs, including those that have not been identified, and long-term prognoses in terms of pulmonary function and residual pulmonary lesions observed on follow-up chest images. In this review, we summarize the clinical features, pathologic findings, and changes in radiologic findings over time in patients with HD-ILDs and the results of previous experimental research on the mechanisms underlying the effects of toxic chemicals in HDs. Studies are currently underway to identify the pathophysiologies of HD-ILDs and possible health effects of exposure to HDs along with the development of targeted therapeutic strategies. The experience of identification of HD-ILDs has encouraged stricter control of safe chemicals in everyday life.

• Environmental Analysis Health and Toxicology
• /
• v.31
• /
• pp.25.1-25.9
• /
• 2016

Objectives After the initial investigations by the Korea Centers for Disease Control in 2011, over 1000 suspicious cases of humidifier disinfectant (HD) victims were subsequently reported by 2015, and numbers are still increasing dramatically in 2016 in the midst of the prosecutors' office investigation. This study attempts to summarize the current understandings of the related health effects of HD based upon a systemic review of published epidemiologic studies and toxicology investigations. Methods Published studies of HDs were searched through PubMed and TOXLINE under the search words 'humidifier disinfectant,' and related reports were identified from the references and published report list of regulatory agencies including the Korean National Institute of Environmental Research, US Environmental Protection Agency, and EU European Chemicals Agency. Results Case reports and epidemiologic studies have reported the clinical features of severe forms of HD lung damage, together with epidemiologic findings of seasonal occurrence and demographic variations, including the heightened susceptibility of young children. Toxicological studies have reported inhalation toxicities together with positive findings of in vitro genotoxicity studies. Conclusions This study examined unsolved issues based on cases of upper respiratory diseases and diseases of other organs, including cancers, among suspected victims of HDs. These issues should be clarified in future research for the management and prevention of health effects from HDs and chemicals of other related household products.