Trends and source attribution of PAHs in fine particulate matter at an urban and a rural site in Indo-Gangetic plain

Abstract

Abstract PM2.5 samples were collected on day time and night-time basis at an urban and a rural site in Delhi region. A total of 11 Polycyclic Aromatic Hydrocarbons (PAHs) were identified and analyzed for urban and rural sites on day time and night time basis respectively. The mean concentrations of total PAHs during day time were 96 and 123.1\u202fng/m3 for urban and rural sites respectively. For the night-time, the mean concentrations were 98.1 and 113.1\u202fng/m3 for urban and rural sites respectively. The highest levels of PAHs were observed during winter at both the sites. However, the least concentrations were observed during monsoon at the urban site while during summer at the rural site. The diagnostic ratios indicated vehicular emissions, coal, wood burning and fuel combustion as major sources of PAHs. The coefficient of divergence indicated statistically significant inter-site differences of all PAHs.