Indoor-Outdoor Volatile Organic Compounds (VOCs) levels: The Case of Dhaka Urban and Industrial Area

Mitali Parvin, Herman Van Langenhove, Christophe Walgraeve and Do Hoai Duc

Volatile organic compounds (VOCs) are of concern both as indoor and outdoor air pollutants for their potential adverse impact on health of people who are exposed and ability to create photochemical smog under certain conditions. Although VOCs are expected to be an important environmental and health risk factor for the rapidly industrializing countries like Bangladesh but there are limited studies on the outdoor and indoor air levels of VOCs in different environments such as industrial and urban areas. On the other hand, there is no known published data yet to assess the indoor VOCs of residential houses in Bangladesh. Therefore, the presence and concentration levels of VOCs were investigated for urban (Mirpur) and industrial (Tejgaon) areas of Dhaka city, Bangladesh in this study. For this purpose six places were selected in two areas (urban and industrial area) for sampling campaigns from 30 of August 2013 to 11 September 2013. Outdoor and indoor samples from both areas were obtained by means of active sampling using Tenax TA tubes as sorbent material during the sampling time. Analysis and quantification were done by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and internal standard calibration. A total set of 44 VOCs consisting of (cyclo)-alkanes, aromatic compounds, halogenated compounds, oxygenated compounds and terpenes were identified from the six sampling sites. Considering safe sampling volume (SSV) 5 VOCs excluded from the data interpretation. Data were interpreted in terms of total volatile organic compounds(TVOCs) which is the sum of 39 VOCs, individual groups and subgroups of TVOCs. The highest mean of TVOCs was measured in the roadside of the industrial street (mean: 96μg/m3; maximum: around 151μg/m3). The lowest mean of TVOCs was measured in the park of the urban area (mean: 28μg/m3; minimum: around 14μg/m3). Although this work has brought forward new data on VOCs concentrations level on wide range of VOCs, further studies concerning more sites and seasonal variations are recommended.