Temporal variation of atmospheric pollutants a case study of Allahabad city (India)

This paper presents monitoring results of atmospheric concentrations of SO2, NO2, PM10 and SPM of an Indian city, Allahabad at two stations from June 2008 to May 2009. The objective of this work was to estimate seasonal and spatial variations of these pollutants on urban air quality levels using simple statistics. The monitoring sites were selected based on the dominant activities of the area. The correlation between these primary pollutants and some meteorological parameters were also established during the study. The monthly average concentrations of PM10 SPM, SO2 and NO2 were found in the range 87-298 μg/m3, 270-744 μg/m3, 3.64-6.86 μg/m3 and 20.47-73 μg/m3 for mixed station (Katra) whereas, 46-252 μg/m3, 82-404 μg/m3, 1.72-4.82 μg/m3 and 9.87-42.3 μg/m3 for residential station (near Circuit House) respectively. The maximum frequency of PM10 appears in the range of 100-200 μg/m3 for mixed areas whereas 0-150 μg/m for residential area, SPM is higher in the range of 400-500 pg/m: for mixed area and 300- 400 μg/m3 for residential area. The linear regressions between PM10 and SPM for both the area were developed. It has been observed that total SPM concentration has inverse correlation with temperature and humidity. The average concentrations for SO2 and NO2 are lower and PM10 and SPM are higher than the NAAQ guideline values. At residential area 57% PM10 and 66% SPM and at mixed area 60% of PM10 and 44% of SPM exceeded the standards according to NAAQS, 1998 (CPCB, New Delhi) while according to NAAQS, 2009 (CPCB, New Delhi) 57% of PM10 of residential area and 81% of PM10 of mixed area exceeded the standards.