Abstract

Indoor carbon monoxide (CO) exposure is considered around the world as one of the most important causes of poisoning with fatal outcomes. This study determined indoor CO levels and personal CO exposure and related risk factors during human activities in 96 apartments in a community of Santiago, Chile during the period from September to December of 2003. Indoor levels and personal exposure were determined using fixed, personal, and single-breath CO monitors, respectively. Exposure risk factors and time-activities patterns were evaluated through an ad-hoc exposure assessment questionnaire. Regression models were fitted to evaluate the effects of these risks factors on the personal CO levels. The median indoor CO level was 1 ppm; interquartilic range (IQR): (0-1). The median personal CO level was 1 ppm; IQR: (0-7); CO exhaled was 3.0 ppm; IQR: (1-33). The number of cigarettes smoked and the levels of indoor environmental CO were significant predictors of the concentration of CO exhaled. This study showed that indoor median levels were below the national standard and the most important predictors of CO exposure were tobacco smoke and the smoking habit in apartments.