Since the early 2000s, clusters of rare acute interstitial pneumonitis of children were noticed every spring in Korea. The prognosis was quite poor and many of them died. In 2011 April, 7 pregnant women were hospitalized for acute severe respiratory disease of similar nature, and half of them died.
The Korean Center for Disease Control (CDC) in its investigation has found the humidifier disinfectant as being responsible for the acute severe lung disease of the victims. Since the start of the investigation, hundreds of cases of similar disease have been reported from all over the country to environmental civic organizations as well as Korean CDC.
An Investigation committee was formed by Korean government which assessed 530 cases including 140 deaths. Shockingly nearly half of the victims are infants and pregnant women and almost 40% of them are family members.