Assessing exposure of young children to air pollutants in urban homes in Alexandria, Egypt

Sensitive groups, including infants and children, spend much or even all of their time at home and are more exposed to household air pollutants at higher concentrations. Due to behavioral and physiological reasons, young children under the age of 5 are at higher risk when compared to adults from exposure to indoor air pollution. Indoor and outdoor monitoring of particulate matter (PM₁₀ and PM_2.5) and gaseous pollutants (CO and CO₂) were performed in 45 urban homes in Alexandria city, Egypt during the winter season. Occupants were requested to complete a questionnaire and time activity diary to collect information on building characteristics (home area, home age, floor level, etc.), indoor activities (smoking, cooking, and cleaning), and time spent by young children in different microenvironments. Results indicated that young children spent 97.5% of time indoors (49.8% in bedrooms and 47.7% in living rooms). Living rooms showed the largest contribution to the daily average exposure of young children to PM_2.5, PM₁₀, and CO with average values of 59.7%, 59.3%, and 63.9%, respectively. For CO₂, bedrooms showed the highest contribution to the daily average exposure of young children with an average value of 53.2%. Daily average children's exposures to PM₁₀ (96.1 ± 21.3 μg/m³) and PM_2.5 (65.5 ± 17.0 μg/m³) exceeded the WHO guidelines which is of high risk for their health. Daily average children's exposures to CO (0.8 ± 0.5 ppm) and CO₂ (772.7 ± 74.7 ppm) were below the WHO guideline and the ASHRAE Standard 62.1, respectively. Factors that are most likely to lead to high children's exposures to PM₁₀ and PM_2.5 in homes are outdoor sources (e.g. traffic emissions) and indoor human activities (e.g. smoking, cooking, and cleaning). Specific mitigation measures at the household level associated with policies and regulation for outdoor air pollution can have considerable impact on reducing children's exposure and protect their health.