A study on the levels of indoor air pollutants in Ha Noi was conducted. Three offices in Ha Noi were selected for this purpose. Selected indoor air pollutants including SO2, NO2 and respirable particulate matter (PM10) were monitored in the wet and dry seasons of 2015. Air conditioners were turned on for the whole time, while air purifiers were turned on for haft of the time in each sampling site. | Vietnam Journal of Science and Technology 56 (2C) (2018) 148-156 LEVELS OF SELECTED INDOOR AIR POLLUTANTS IN THREE HA NOI OFFICES Bich-Thuy Ly1, Hien Thi Thu Nguyen1, Minh-Thang Nguyen1, Mitsuru Matsui2, Trang Thi Phuong Ly3, Trung-Dung Nghiem1, * 1 2 School of Environmental Science and Technology, Hanoi University of Science and Technology, 1 Dai Co Viet, Ha Noi, Viet Nam Daikin Industries, Ltd., Umeda Center Building, 2- 4- 12, Nakazaki-Nishi, Kita-ku, Osaka, 530-8323, Japan 3 Daikin Vietnam, 201-203 Cach Mang Thang Tam street, Ward 4, District 3, Ho Chi Minh City, Viet Nam * Email: Received: 10 May 2018; Accepted for publication: 22 August 2018 ABSTRACT A study on the levels of indoor air pollutants in Ha Noi was conducted. Three offices in Ha Noi were selected for this purpose. Selected indoor air pollutants including SO2, NO2 and respirable particulate matter (PM10) were monitored in the wet and dry seasons of 2015. Air conditioners were turned on for the whole time, while air purifiers were turned on for haft of the time in each sampling site. An hourly measurement of outdoor levels was also conducted before indoor measurement. Levels of outdoor PM10 varied in the range of µg/m3. The level of indoor PM10 varied in the range of µg/m3. The average levels of indoor PM10 were lower than that of outdoor one in all cases. High time resolution data showed that indoor PM10 levels temporarily increased sharply by activities (walking and room sweeping) and high frequency of opening the doors. Concentrations of outdoor/indoor SO2 varied in the range of . Table 2. Average level of PM10 (µg/m3). Wet season Site Air purifier Date Outdoor 3 (µg/m ) Dry season Indoor 3 (µg/m ) Date Outdoor 3 (µg/m ) Indoor (µg/m3) 23-Jul ± ± 10-Nov ± ± 24-Jul ± ± 11-Nov ± ± 27-Jul ± ± 12-Nov ± ± .
