Seasonal Variations in Chemical Composition and Source Apportionment of Fine Particulate Matter (PM1) in an Urban Site of Jaipur City,Rajasthan

Abstract

The present study was conducted with an aim to investigate the seasonal variation in mass concentration of fine particulate matter (PM₁), their chemical composition, (water and soluble and non-soluble ions and other elements) and gaseous pollutants (SO₂, NO₂, CO and O₃) at an urban site of Jaipur city in India. During summers, pollutants showed a reduction of 18.97%, 41.95%, 32.32% and 20.56% for PM₁, NO₂, SO₂ and CO, respectively. In contrast, O₃ showed an increase of 27%. The substantial reduction was also observed in the levels of secondary aerosols SO₄ ^2- (71.15%), NO₃^-(21.86%), Cl^- (65.63%) and K⁺ (8.16%). The elemental components Al, B, Be, Ca, Cu, Fe, Mn, Ni, and Pb showed a reduction in the range of 15.13 % (Al) to 71% (Cu). On the contrary, an increment was found in the levels of Ag (21.95%), Cd (62.5%), Cr (89.74%), Mg (10.43%) and Na (25.32%). Four factors were extracted by principal component analysis (PCA). In addition to the local sources, three stationary sources have been identified as contributing to the pollution load located in the WNW, NE and ENE direction of the site. It can be concluded that pollutant concentration and chemical composition of any area not only depend on the local emission, but nearby stationary sources and meteorology are significant contributors.