Seasonal variation in airborne endotoxin levels in indoor environments with different micro-environmental factors in Seoul, South Korea.

Abstract This study evaluated the variation over a year in airborne endotoxin levels in the indoor environment of five university laboratories in Seoul, South Korea, and examined the micro-environmental factors that influenced endotoxin levels. These included temperature, relative humidity, CO 2 , CO, illumination, and wind velocity. A total of 174 air samples were collected and analyzed using the kinetic limulus amebocyte lysate assay. Endotoxin levels ranged from 3 , with an overall geometric mean of 0.240 EU/m 3 . Endotoxin levels showed significantly negative correlation with temperature ( r =−0.529, p 2 ( r =−0.213, p r =−0.538, p p p