Variation in the Chemistry of Aerosols in Two Different Winter Seasons at Pune and Sinhagad, India

Samples of Total Suspended Particulates (TSP) were collected at Pashan, Pune (semi-urban) and Sinhagad (rural) locations in India, during the winter season of 2003/4, using a high volume air sampler and were analyzed for major water-soluble chemical components using Ion Chromatograph and Atomic Absorption Spectrophotometer. Results of the study were compared with those reported for the same locations in winter season, about two decades back. It was observed that TSP and all of its chemical components showed marked increase in concentrations after the period of two decades at both Pune and Sinhagad. Especially, for NH sub(4) super(+), SO sub(4) super(2-), NO sub(3) super(-) and Ca super(2+), the concentrations increased by about 9, 7,7 and 4 times at Pune and about 23,10,10 and 6 times at Sinhagad, respectively. This feature shows the significant impact of anthropogenic activities at both the locations. SO sub(4) super(2-) is still the main acidifying component of aerosols and NH sub(4) super(+) dominates over Ca super(2+) in the neutralization of acidity in 2003/4 whereas earlier two decades back, Ca super(2+) was the major neutralizer.