Characterstics of Polycyclic Aromatic Hydrocarbons (PAHs) in Indoor and outdoor Air in different seasons of Rural India

JAMSON MASIH (1), Ajay Taneja (1,2), Raj Singhvi (3)

(1) ST. JOHN'S COLLEGE, AGRA, (2) IBS KHANDARI, DR. B.R.A.U, AGRA, (3) USEPA, ERT, NJ USA

     Abstract Number: 343
     Last modified: May 9, 2010

Abstract
The concentration of twenty-three Polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in indoor and outdoor environments of rural houses in semiarid region of rural India during three season winter, summer and rainy (November 2006 - September 2007). The gaseous and particulate phase of individual PAHs was identified by using a gas chromatograph with mass spectrometry detector (GC/MS). The results show that average concentration of (gas + particulate) PAHs varied with season. It ranged from (16.7 - 900 ng/m3) in indoors and (21.1 - 1510 ng/m3) in outdoor being the highest in winter, lower in summer (14.1 - 958 ng/m-3) indoors, (14.1 - 1060 ng/m3) outdoors and lowest in the rainy season (12.4 - 760 ng/m3), (9.9 - 823 ng/m3) in indoor and outdoor air respectively. The total PAHs concentrations in outdoor air was 29% and 44% higher in winter season from summer and rainy season and in indoor air it was 12% and 30% higher in winter season than summer and rainy seasons respectively. It was indicated that the two, three and four rings PAHs were predominantly in vapor phase while the five and six rings PAHs were primarily associated with the particulate phase. Among the 23 PAHs, naphthalene was the most abundant PAH found in the indoor and outdoor air. It contributed 29-55% to the sum of PAHs in three different seasons. The trend of the concentrations of the major PAHs found in present study were Nap>2 Methyl Nap>1 Methyl Nap>Biphenyl>Acenapthylene at indoor and outdoor atmosphere of all the selected rural homes. Factor analysis was applied to determine the probable sources of PAHs which reveals that three factor for indoor and two factors for outdoor air were responsible for generating PAHs. The average BaP equivalent exposure calculated by using toxic equivalent factors derived from literature and USEPA was approximately 31.79 ng/m3.