Comparing the environmental exposures between the cases and controls.

<p>Comparing the environmental exposures between the cases and controls.</p

Number of cases with lung injury from one hospital in Seoul.

<p>Number of cases with lung injury from one hospital in Seoul.</p

Socio-demographic and clinical characteristics of the study participants.

<p>Socio-demographic and clinical characteristics of the study participants.</p

Exposure-response relationship between humidifier disinfectants containing polyhexamethyleneguanidine phosphate and lung injury.

<p>Exposure-response relationship between humidifier disinfectants containing polyhexamethyleneguanidine phosphate and lung injury.</p

Case ascertainment criteria.

<p>(A) Chest radiography showing diffuse, ill-defined ground-glass opacities and several ill-defined small nodular opacities in both lungs (in the 4 weeks after respiratory symptoms started). (B) Chest computed tomography showing diffuse centrilobular nodules in both lungs, with ground-glass opacities suggestive of peribronchiolar fibrosis (in the 4 weeks after respiratory symptoms started). (C) The most striking histological feature, interstitial thickening and fibrosis with a centrilobular distribution and relative sparing of the subpleural parenchyma (upper one-third). Original magnification ×40. (D) Interstitial fibroblasts proliferating in a pale myxoid stroma (arrows) and collapsed alveolar spaces lined by activated pneumocytes (arrowhead). Original magnification ×200.</p

Comparison of indoor environmental factors between the16 children with children’s interstitial lung diseases and their 47 matched control.

a<p>Variables in the previous 1 year.</p>*<p><i>P</i><0.05.</p

Comparison of outdoor environmental factors between the16 children with children’s interstitial lung diseases and their 47 matched controls.

a<p>Variables in the previous 1 year.</p

Univariate analysis of the association between the use of a humidifier disinfectant and the risk of children’s interstitial lung diseases in 1∶3 matched case and control.

a<p>Variables in the previous 1 year.</p>b<p>Univariate analysis; conditional logistic regression analysis.</p>c<p>Immune-suppressive therapy, general anaesthesia, transfusion, admission within 6 months, and prior use of antibiotics within 1 month.</p>d<p>The occurrence of any of the following in the previous 6 months: autoimmune disease, chronic liver disease, chronic renal insufficiency, neurologic diseases with immobility, congenital heart disease, chronic lung disease, diabetes.</p>e<p>Garbage incinerator, sewage treatment plants, factory, chemical treatment area, plants, farm/orchard, cattle shed/pigsty, and power station.</p