Spatio-temporal variation in chemical characteristics of PM sub(10) over Indo Gangetic Plain of India

• Published in: Environmental science and pollution research international 2016-09, Vol.23 (18), p.18809-18822
• Main Authors: Sharma, S K, Mandal, T K, Srivastava, M K, Chatterjee, A, Jain, Srishti, Saxena, M, Singh, B P, Saraswati, Saraswati, Sharma, A, Adak, A, K.Ghosh, S
• Format: Article
• Language: English
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-7025-2

The paper presents the spatio-temporal variation of chemical compositions (organic carbon (OC), elemental carbon (EC), and water-soluble inorganic ionic components (WSIC)) of particulate matter (PM sub(10)) over three locations (Delhi, Varanasi, and Kolkata) of Indo Gangetic Plain (IGP) of India for the year 2011. The observational sites are chosen to represent the characteristics of upper (Delhi), middle (Varanasi), and lower (Kolkata) IGP regions as converse to earlier single-station observation. Average mass concentration of PM sub(10) was observed higher in the middle IGP (Varanasi 206.2 plus or minus 77.4 mu g m super(-3)) as compared to upper IGP (Delhi 202.3 plus or minus 74.3 mu g m super(-3)) and lower IGP (Kolkata 171.5 plus or minus 38.5 mu g m super(-3)). Large variation in OC values from 23.57 mu g m super(-3) (Delhi) to 12.74 mu g m super(-3) (Kolkata) indicating role of formation of secondary aerosols, whereas EC have not shown much variation with maximum concentration over Delhi (10.07 mu g m super(-3)) and minimum over Varanasi (7.72 mu g m super(-3) ). As expected, a strong seasonal variation was observed in the mass concentration of PM sub(10) as well as in its chemical composition over the three locations. Principal component analysis (PCA) identifies the contribution of secondary aerosol, biomass burning, fossil fuel combustion, vehicular emission, and sea salt to PM sub(10) mass concentration at the observational sites of IGP, India. Backward trajectory analysis indicated the influence of continental type aerosols being transported from the Bay of Bengal, Pakistan, Afghanistan, Rajasthan, Gujarat, and surrounding areas to IGP region.