Characteristics of polycyclic aromatic hydrocarbons in indoor and outdoor atmosphere in the North central part of India

Twenty-three polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in indoor and outdoor environment of ten homes at urban and roadside sites in the north central part of India during winter season (November 2006 to February 2007). The average concentration of total PAH (TPAH) was 1946.84 ng/m3 in kitchen, 1666.78 ng/m3 in living room and 1212.57 ng/m3 in outdoors at urban site, whereas at roadside site it was 2824.87 ng/m3, 2161.26 ng/m3, and 3294.28 ng/m3 in kitchen, living room and outdoors respectively. The two, three and four ring PAHs were predominant in vapour phase, while the five, six ring PAHs were primarily associated with the particulate phase. The concentration trends of the PAHs in present study were naphthalene > 2-methylnaphthalene > 1-methylnaphthalene > biphenyl > acenaphthylene in indoor and outdoor environment of both the sites. The spatial trend of total PAHs concentrations in the house located at urban sites, was kitchen > living room > outdoors whereas at roadside site, the trend was outdoors > kitchen > living room. Correlation analysis has been used to identify the sources of PAHs. The correlation between CO2 and ratio of living room/outdoors (L/O) and kitchen/outdoor (K/O) of total PAHs concentration for two sites was found to be significant.