Concentrations of Carbon Monoxide in Outdoor and Indoor Air of Residential Buildings in Ardabil

Carbon monoxide (CO) is a colorless, odorless, tasteless, and toxic gas. It is one of the important indoor and outdoor air pollutants. This study was aimed to measure CO concentrations in outdoor and indoor air of residential homes in Ardabil city and to compare the results with air quality standards.
For this descriptive-analytical study, concentrations of CO in indoor and outdoor air were measured in 50 dwellings during summer and winter in 2013. Concentrations of CO were measured at breathing zoon using a portable Gas meter for a period of one hour.
CO concentrations in outdoor air (2.18±1.13 ppm) were higher than the indoor air (0.57±0.63 ppm). Also, CO concentrations of indoor air in winter (0.63±0.62 ppm) were slightly higher than the summer amounts (0.51±0.65 ppm). The indoor to outdoor (I/O) ratio of 0.37±0.76 was obtained for CO concentration.
According to the obtained results, CO concentrations are well below the guideline values and, therefore, Ardabil indoor and outdoor air quality is acceptable in terms of CO indicator.