This paper deals with spatial classification and their respective sources of pollutants within the selected TNPCB and CPCB monitoring station based on a Eleven year Database (2005 â€“2015). HACA grouped the eight monitoring stations into three different clusters, bases on concentration of air pollutants. HACA results also speculate that a methodological difference lies in the stations operated by CPCB and TNPCB. PCA was performed individually on each cluster to determine the source of pollutant. PCA analysis showed production of wax, fuel, petrochemical feedstock and lube by petrochemical and manufacturing industries, soil dust emission due to construction activities and vehicular movement form the foundation of the pollution base for the first cluster, whereas abundant increase in vehicular fumes which had resulted from drastic increase in personal vehicle trips and decline of public ridership in buses and trains leading to detour was the source for pollutant concentration in second cluster. Illegal commercialization of residential plots, construction of restaurants and complexes, heavy traffic movement explains the result of the third cluster.