• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.107-114
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• 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
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• v.42 no.6
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• pp.365-374
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• 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
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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.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.349-359
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• 2017

The objective of this study is to review the safety and health information displayed on containers of humidifier disinfectants (HD). We summarized not only general characteristics related to the marketing and manufacturing of HD, such as the duration sold and the name of the company, but also the safety and health information, such as identification of disinfectants, recommended use volume, and precautions. All of this information was reviewed by HD brand. We collected safety and health information from 31 HD brands. We found that companies that sold and manufactured HD brands differ. Two companies were found to sell their HD without permission after 2011 when the health effects caused by HD were widely known. The name of the disinfectants were not identified on the container of HD. The recommended volumes were found not to be based on toxicological evidence and set without consideration of the level of susceptibility of users. Most companies displayed phrases such "this HD is safe for humans, even children" on the front of the container. No inhalation and skin toxicity precautions were provided. In conclusion, most HD did not properly display information related to safety and health to protect the health of HD users. There has been no official investigation to evaluate the risks posed by HD, such as the sales volume by HD, identification of chemical disinfectants, or their concentration, nor have there been actions to control the chemical quality of HD. In addition, government actions to punish the malicious practices of companies that manufactured and sold HD were found to inappropriate.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.128-135
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• 2020

Objective: The objectives of this study are to report the number of humidifier disinfectant (HD) associated health problems, including HD associated lung injury (HDLI), by year. This data was analyzed by the type of HD and HD brand. Methods: A total of 530 patients registered with the national program on HD through its third round were distributed based on the year when they developed their first health problem including HDLI (N=221). The distribution of health problems at diagnosis was clinically evaluated in order to examine the association between their lung injury and the use of HD. Results: The number of HD associated victims and HDLI patients was found to rise sharply from 2008 to 2011, with a peak in 2011. This trend was found not only for HD brands containing polyhexamethylene guanidine phosphate (PHMG), but also chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT). The number of patients who responded as developing health problems in the specific year was 35 for 2008, 51 for 2009, 108 for 2010 and 182 for 2011. Other types of HD brands and HD chemicals did not follow the trend of abrupt increase in HD associated patients since 2008. Conclusion: This study found the number of HD associated victims and HDLI patients who used HD brands containing PHMG sharply increased starting in 2008. A significant change in the process of manufacturing PHMG can be suspected with the abrupt rise in HD associated patients in specific years.

• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.312-323
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• 2020

Objective: This study aimed to summarize the physiochemical properties, toxicity, and legal regulation of chloromethylisothiazolinone (CMIT) and/or methylisothiazolinone (MIT), review the health effects caused by exposure to CMIT/MIT, and evaluate the individual association of lung injury with the use of humidifier disinfectants (HD) containing a mixture of CMIT and MIT. Method: A literature review was conducted by searching keywords such as CMIT, MIT, health effect, dermatitis, asthma, and lung injury, either singly or combined. Results: Both CMIT and/or MIT were found to be associated with the development of several types of adverse health effects. In particular, respiratory diseases including asthma, nasal symptoms, cough, and rhinitis were caused by the use of products including CMIT or/and MIT. The mixture of CMIT/MIT has been banned in cosmetics. As of the end of 2017, nine patients who were confirmed to have HD associated lung injury (HDLI) were found to have used only an HD brand containing CMIT and MIT. Their responses regarding the name of the HD used could be trustworthy based on the short duration of HD use (less than six months) before the onset of HDLI and frequent use of HD per day. Conclusion: According to the toxicity and HDLI cases, the use of HD containing CMIT and /or MIT can cause fatal lung injury. Further study with manufacturers' assistance is necessary in order to obtain more clear evidence on the causal relationship since HDLI cases are being reported continuously.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.224-231
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• 2020

Objective: The objectives of this study are to update the information on the characteristics of humidifier disinfectant (HD) usage with HD associated health problems and to discuss the role of HD exposure assessment in the national program to monitor health problems in patients with HD associated diseases. Method: A total of 201 HD associated patients who registered to undergo clinical examination at Kangbuk Samsung Hospital was interviewed to acquire their responses regarding several HD use characteristics, including type of HD brands used, HD use duration, average daily HD use hours, and the volume of the room in which HD was used. The responses of the HD associated patients to HD use-related questions were compared between responses in the lung injury investigation and this study. Results: The responses of HD associated patients in this study were found to be different from those in the lunginjury investigation. In particular, some of the patients who had not answered in the lung-injury investigation were able to answer thanks to assistance from the investigator in this study. For their responses regarding the name of the most commonly used HD brand, the number of patients who did not answer (N=11) was reduced to eight in this study. Significant changes in the responses of study subjects to questions related to HD use were achieved through the interview in this study. Conclusion: This study found significant changes in the responses regarding HD use characteristics. HD exposure assessment should be included in the program in order to allow surveillance of HD associated health problems.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.147-159
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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 objective of this study is to characterize exposure to HD among a total of 221 HDLI patients who used HD. Information and data on the HDs used were collected through a structured questionnaire and home environmental investigations. The conditions of these 221 HDLI patients were clinically confirmed to be caused by the use of HD. Children aged under 5 years old made up the highest proportion of HDLI cases (n=125, 56.6 %), followed by pregnant women (n=35, 15.8%). Forty-three percent (n=95) of the victims died. There were three cases of fetuses and 35 pregnant women among the victims. The number of HDLI patients who used only the Oxy Saksak brand of HD was found to be 85 (38.5%), followed by the HD brands Cefu (n=24, 10.9%), Lottemart Wiselect (n=9, 4.1%) and Aekyung (n=3). Patients who exclusively used HD brands containing polyhexamethylene guanidine phosphate (PHMG) (n=13, 55.7%) as an active ingredient made up the largest share, followed by those who exclusively used HD containing only oligo(2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and by those who only used a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). HD products containing PHMG were found to be the most commonly used among the confirmed HDLI patients. Three exposed fetuses who never used HD after birth developed lung injuries, indicating a probability of exposure to HD during gestation. All HDLI patients responded that they used HD while sleeping and for longer than 10 hours per day. In conclusion, the development of HDLI was clinically found to be associated with the use of several HD products containing PHMG, PGH and CMIT/MIT.