Worldwide preliminary studies in large number are advocated to create data base, to identify potential cities / towns that warrant “continuous ambient air quality monitoring and control mechanism” and to evolve priorities for clean air target. The results reported pertain to an eight hour random preliminary air sampling exercise carried out at each of the eight select locations in Chidambaram, a southern semi urban settlement in India. Criteria pollutants SPM, CO, SO2 and NO2 measured are found to have either crossed or on the verge of crossing the limits, necessitating the immediate installation of a continuous monitoring and control mechanism. While transport related emissions are the major sources of air contamination, increasing civil construction activities also contribute to particulates. The exponential rise in volume of vehicles, disadvantageous traffic flow pattern, differing driving cycle pattern and human interceptions deserve due attention. It is concluded that Chidambaram town is a strong case for continuous monitoring of ambient air quality due to alarming and increasing level of pollutants.