Investigation of PM_2.5 and carbon dioxide levels in urban homes

Abstract

PM 2.5 (particulate matter with an aerodynamic diameter <2.5 μm) samples were collected in the indoor environments of 15 urban homes and their adjacent outdoor environments in Alexandria, Egypt, during the spring time. Indoor and outdoor carbon dioxide (CO 2 ) levels were also measured concurrently. The results showed that indoor and outdoor PM 2.5 concentrations in the 15 sites, with daily averages of 45.5 ± 11.1 and 47.3 ± 12.9 µg/m 3 , respectively, were significantly higher than the ambient 24-hr PM 2.5 standard of 35 µg/m 3 recommended by the U.S. Environmental Protection Agency (EPA). The indoor PM 2.5 and CO 2 levels were correlated with the corresponding outdoor levels, demonstrating that outdoor convection and infiltration could lead to direct transportation indoors. Ventilation rates were also measured in the selected residences and ranged from 1.6 to 4.5 hr −1 with median value of 3.3 hr −1 . The indoor/outdoor (I/O) ratios of the monitored homes varied from 0.73 to 1.65 with average value of 0.99 ± 0.26 for PM 2.5 , whereas those for CO 2 ranged from 1.13 to 1.66 with average value of 1.41 ± 0.15. Indoor sources and personal activities, including smoking and cooking, were found to significantly influence indoor levels.Implications: Few studies on indoor air quality were carried out in Egypt, and the scarce data resulted from such studies do not allow accurate assessment of the current situation to take necessary preventive actions. The current research investigates indoor levels of PM 2.5 and CO 2 in a number of homes located in the city of Alexandria as well as the potential contribution from both indoor and outdoor sources. The study draws attention of policymakers to the importance of the establishment of national indoor air quality standards to protect human health and control air pollution in different indoor environments.

Impact of Outdoor Air Pollution on Indoor Air Quality in Low-Income Homes during Wildfire Seasons

“…High indoor concentration spikes of pollutants associated with indoor sources like cooking are difficult to avoid in real-life, thus to reduce exposure better strategies can be implemented to ensure protection from outdoor air pollution in low-income homes, such as installing cooling devices so that windows can remain closed during pollution episodes and distributing air cleaners on especially polluted days. As seen from Tables S3 and S4, I/O ratios for PN 0.5–2.5 were highest for homes without kitchen stove hoods, followed by homes with recirculating stove hoods when compared to exhaust-type stove hoods, a finding in agreement with another study [79]. Indoor source-related emissions should still be addressed with engineering approaches such as source control (stove exhaust hoods) or other strategies to reduce air pollutant exposure.…”

Controlling Indoor Air Pollution from Moxibustion

“…CO 2 is a natural air component whose source is usually due to the occupants’ exhalation. CO 2 is a proper indicator of adequate and efficiency ventilation and is related to indoor air pollutants’ accumulation [ 12 ]. However, the variance of CO 2 is not similar to that of other pollutants in our study.…”

The effects of carbon dioxide exposure concentrations on human vigilance and sentiment in an enclosed workplace environment

“…The atmospheric CO 2 concentration is approximately 400 ppm and may increase to 670 or 936 ppm by the end of the century 1 . The average indoor CO 2 concentration in offices, schools, and homes typically ranges from 600 to 1000 ppm, 2‐5 but can exceed 2000 ppm with the increased room occupancy and the restricted building ventilation 6,7 . The indoor CO 2 concentration depends on the outdoor air supply rate and the source strength that generally refers to the production rate of metabolic CO 2 .…”