Fig. 3: Diurnal variation in household CO across all household-days.
From: Chronic household air pollution and exposure patterns among Himalayan nomads

Five-minute boxplots of continuous CO across all household-days show the emergence of a diurnal trend with peaks corresponding to meal times. Black line represents median. Green represents the interquartile range. Measurements beyond the 90th percentile of 5-minute measurements reached above 700 ppm CO but were excluded here in order to provide more detail in the lower measurement range. Median and interquartile range are skewed low due to imperfect overlap of cooking times in study homes. Red horizontal line represents average heating signature (13 ppm CO).