Assessment of Ambient Air Quality at Gajuwaka Industrial Hub in Visakhapatnam using IND-AQI method

S. Srinivasa Rao, N. Srinivasa Rajamani, E.U.B. Reddi

Air pollution is projected as one of the major environmental issues as it risks the health of humans by spoiling air quality.  Hence, air quality indices have been considered by many researchers as a simple and understandable way to measure the air quality with respect to its effects on human health.  In this context, we collected a total of 168 ambient air samples in winter and summer seasons at seven points in selected residential areas of the Gajuwaka industrial hub. The measured data of six criteria air pollutants such as RSPM, TSPM, SO₂, NO_x, NH₃ and Pb were converted into an Indian air quality index (IND-AQI) recently developed by CPCB, New Delhi to study the status and seasonal variation of the air quality.  The results revealed that the seasonal mean of air quality index values was varied from 60.2 to 143.3 and 82.8 to 226.5 in winter and summer seasons respectively. Gaseous pollutants and RSPM values were found to be higher in winter compared to summer season whereas TSPM values are high in summer with respect to winter season. It has been observed that on the basis of IND-AQI scale, the study area has fallen under ‘moderate’ category with the annual mean value of 118.4 The study indicated that total suspended particulate matter (TSPM) was mainly responsible for air pollution (92.9%) in this area during the study period and became a critical pollutant in the majority of the sampling points followed by RSPM.  Further, the calculated Exceedence factors were also confirmed the deterioration of air quality in the study area as moderate to high pollution category with TSPM as a critical pollutant. Increasing trends of air pollution were observed consistently during the study period at all the locations.