Characterization of indoor and ambient air quality in modern commercial and recreational complex buildings in Hanoi

Abstract

The paper provides new information on the correlation between indoor and ambient air quality in selected commercial and recreational buildings, representing a cross-section of metropolitan building complexes in Hanoi, Vietnam. Air sampling carried out simultaneously at fixed locations within the case study directed the varying behavior across different zones and thus highlighted the relationship between parking basements, commercial floors, and ambient air sites. The fractions of coarse and fine particles were analyzed to identify the associated emission sources on a short-term basis. The elevated 8-h average levels of CO in underground parking zones (11–22 mg/m3) were significantly higher than those measured on commercial floors (0.5–0.9 mg/m3) and relatively ambient air (0.8–1 mg/m3) and exceeded the recommended exposure limit of 10 mg/m3 in the corresponding guidelines. Short-term averages of SO2 mass concentration (112–225 μg/m3) remained below the limits of 500 μg/m3 concerning health exposure in existing standards. The correlation of daily NO2 patterns was analyzed accordingly in relation to the operation of the individual building, the central ventilation mechanism, and the penetration of outside air, which is usually conditioned by traffic emission. The mass concentrations of PM10 and PM2.5 measured outdoors (21–32 μg/m3 and 12–14 μg/m3) and in parking basements (28–67 μg/m3 and 15–27 μg/m3) were generally higher than those recorded indoors at ground levels (1–29 μg/m3 and 1–20 μg/m3), frequently reaching the reference exposure values (15 μg/m3 and 5 μg/m3) for public health concerns. The determined levels and profiles of benzene, toluene, ethylbenzene, (m + p)-xylene, and o-xylene corresponding to the relative ratios of T/B and X/E revealed the responsible emissions from gasoline-fueled vehicles in parking basements and the influence of associated local traffic.