Benzene was used as cancer risk maker, whereas toluene and xylene were used as non-cancer risk marker. Among BTEX compounds, xylene showed the most notable hazard quotient and was the main pollutants responsible for high risk for the toddlers. Benzene showed an upper-bound life time cancer risk that exceeds the benmark, presenting moderate risk for the toddlers. | Vietnam Journal of Science and Technology 55 (4C) (2017) 78-84 PRELIMINARY ASSESSMENT OF BTEX CONCENTRATIONS INDOOR AND OUTDOOR AIR IN RESIDENTIAL HOMES IN HANOI, VIETNAM Vo Thi Le Ha1, Nguyen Thi Thu Hien1, Nghiem Trung Dung1, Minoru Yoneda2, Thai Ha Vinh3 1 School for Environmental Science and Technology (INEST), Hanoi Univesity of Sience and Technology (HUST), 1, Dai Co Viet road, Ha Noi, Viet Nam 2 Dept. of Environmental Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8540, Japan 3 Viet Nam National Institute of Occupational Safety and Health, 99 Tran Quoc Toan, Hoan Kiem Dist, Ha Noi, Viet Nam * Email: Received: 7 September 2017; Accepted forpublication: 17 October 2017 ABSTRACT Indoor air quality is considered to be of great concern due to its adverse impact on the human health nowadays. BTEX concentrations in 29 residential homes including (new/renovated and old) were studied in Hanoi Metropolis and influencing parameters such as smoke habit, cooking appliances, solvent consumption, and ventilation system were considered in this study. Samples were conducted using active diffusion monitors and analyzed by GC/FID. Concentrations of BTEX indoor and outdoor in new/innovated homes were significantly higher than those in old homes. Benzene was used as cancer risk maker, whereas toluene and xylene were used as non-cancer risk marker. Among BTEX compounds, xylene showed the most notable hazard quotient and was the main pollutants responsible for high risk for the toddlers. Benzene showed an upper-bound life time cancer risk that exceeds the benmark, presenting moderate risk for the toddlers. Keywords: indoor air, outdoor air, VOCs, benzene, hazard quotient. 1. INTRODUCTION countries worldwide people spend more than 80 % of their time indoor [1]. Indoor air quality and its potential health consequences are much less investigated in comparison to ambient air quality. The volatile organic .
