It took Ryu Jae-wook several years to bring himself to apply to the government for a health probe over the death of his father who had regularly used a toxic humidifier disinfectant.

Although the government accepted such applications from product users over four separate occasions since 2011, with the latest one currently underway, Ryu deliberately ignored such information, telling himself that his father died of old age not from using the disinfectant.

His father passed away in June 2006, and he had shown symptoms of pneumonia since 2003. He was exposed to Oxy Reckitt Benckiser’s product Oxy Ssak Ssak from 2001, which was most used by victims recognized by the government.

“I was the one who poured the toxic chemical into the humidifier in my father’s room every day. I didn’t want to admit that I killed my father. I kept telling myself that he didn’t die because of the disinfectant,” Ryu told The Korea Herald.

Every winter, Ryu had put more than the recommended amount of the chemical into his father’s humidifier, believing that the cleaner the humidifier, the better it would be. Even when his father was hospitalized for pneumonia, the son never forgot to put Oxy Ssak Ssak into the humidifier next to his bed.

For years, he had kept the nagging secret that he believed was the cause of his father’s death, even from his sisters. However, the 53-year-old teacher at a private education institute, finally decided to come forward to apply for the fourth round of the health probe after witnessing Oxy’s apology.

“Seeing the head of Oxy superficially apologizing right before the prosecutorial probe, I thought that it was not right. I decided to check whether my dad died of old age or not,” he added.

“I confessed to my sisters that I had used the disinfectant for our father. They didn’t know anything about the disinfectant use. After telling the truth, I felt much more at ease.”

He also joined the class-action lawsuit against the disinfectant manufacturers and the government, along with other victims and their families.

“There must have been many elderly disinfectant users who didn’t realize its impact on their health and just died,” Ryu added.

While infants and their mothers are known to have been the most vulnerable victims to the toxic humidifier disinfectants, the health damages suffered by elderly victims is relatively overlooked, with many having died.

Since 2011 when the toxic impact of the disinfectant was first revealed, a total of 530 users, including 146 who have died, applied for the first two rounds of the public health probe that checks the causality between health damages and disinfectant use.

According to the Environment Ministry, 221 of them were classified in the top two categories which officially recognize the disinfectants’ impact on lung health, with only three elderly aged 60 or above included. Most of them were infants or women.

The government is conducting the third-round probe on 752 additional users while receiving the fourth round of health probe requests from other potential victims. A total of 1,057 users have applied, as of Wednesday. The number of elderly among them has not been disclosed.

Only recognizing the health damages of three senior patients does not mean that the elderly were not affected by the toxic chemicals, experts said.

The immune system of the elderly is much weaker than adults in general, which suggests that they are as vulnerable to chemicals as infants, according to Leem Jong-han, an occupation and environment medicine professor from Inha University.

“Considering that the disinfectants were used in many sanatoriums, a large number of the elderly could have been exposed. Yet, in many cases, the sanatorium patients would have just suffered from their underlying diseases and passed away, without realizing the disinfectant’s impact,” added Leem, who also heads the Korean Society of Toxicology. “The damage scale of the elderly may be much larger than infants. It’s just that many cases are not revealed or detected.” 

Since 2004 when the humidifier disinfectant was first developed by a local company, about 600,000 products were sold every year for seven years until they were withdrawn from the market in 2011.

Considering that the number of disinfectant users is estimated to be around 9 million, the potential victims could reach up to 2.7 million, said civic group Asian Citizen’s Center for Environment and Health. As of Wednesday, 2,339 users have reported their health symptoms to the civic group, with 464 dead. This includes the number reported to the government.

Seoul Asan Medical Center’s survey also showed that, 31.3 percent of the entire Korean population could have been exposed to the disinfectant chemicals. 

“As the disinfectant tragedy tends to focus on infants or females, the concern for elderly victims is relatively lower. Although they are physically vulnerable to toxic chemicals as much as infants or pregnant women, there is prevalent social prejudice that the elderly group is not as important as others as they are considered to have lived enough. That’s why many elderly victims are not reported,” said Choi Ye-yong, head of the Asian Citizen’s Center for Environment and Health.

Yoo Yeong-seok, 71, is one of the disinfectant users who participated in the first round of the health probe. Having used Oxy’s product from 2004 to 2009, he started to have difficulties breathing and doing vigorous activities starting a year later.

Despite these sudden symptoms, he was classified into category 4, the group that is considered to have suffered little health impact, due to the strict classification criteria.

What stresses him out the most, apart from his current health, is the sense of guilt that he feels about his 97-year-old mother who passed away in 2010.

“I used to place a humidifier in her room and put the disinfectant into it every day. She soon started to complain about itchy skin. Thinking that it was caused by dry skin, I moved the humidifier right next to her head, and injected more disinfectant,” he said.

While others speculated that she died of old age, the son stressed that the disinfectant was the culprit, citing the longevity of his family members.

“Although she was in her 90s, she was so healthy that she enjoyed hiking. There was no reason for her to suddenly suffer a lung problem.”

He has not filed his mother’s case to the government, citing issues with preparing the documents. 

“I’m a son who killed his mother. How could this happen? I still pray every night that she forgives me,” Yoo said.

Experts highlight that more attention should be paid to grown-up children who have lost their parents due to disinfectant use, as many of them tend to keep their sorrow to themselves and live with the guilt.

“Aside from financial support or compensation, various measures are necessary to console and support them so that they can at least have mental and psychological compensation. Many are likely to feel reluctant to express their emotions, thinking that the deaths were their fault,” said psychologist Kwak Keum-joo from Seoul National University.

By Lee Hyun-jeong (rene@heraldcorp.com)