Investigations on air quality of a critically polluted industrial city using multivariate statistical methods: Way...

Industrially developed cities affect public health, and can directly cause inconvenience to the nearby societies especially due to their associated air pollution. In this context, the present study was conducted in Jharsuguda district of Odisha state (India), which is a well-known worldwide hub of industrial clusters. The study area is having mainly medium to large scale industries which makes it prone to poor air quality. A total of twelve air pollutants, namely, PM₁₀, PM_2.5, SO₂, NO₂, CO, O₃, NH₃, and heavy metals (Cu, Mn, Ni, Pb, Zn) were monitored during winter season, at the 16 locations of study area. The air quality data was further assessed using multivariate analysis, and the obtained information was presented using histogram plots, box plots, cluster analysis, principal component analysis (PCA), analysis of variance (ANOVA) analysis, and air quality index (AQI). The statistical analysis results revealed that PM₁₀ and PM_2.5 levels exceeded the permissible limits of study area, ∼40 and 30% of sampling times, respectively. Contrary, values of other pollution parameters were observed to be well within the permissible limits. The cluster analysis distinguishingly summarized the monitoring data into four clusters types, named as severely polluted, moderately polluted, satisfactory, and fine. The PCA analysis of monitored data resulted in identification of prominent emission sources of analyzed pollutants. These sources were mainly found to be associated with coal burning in power plants, agricultural activities, vehicular emissions, and mining activities. The minimum AQI was observed as 87 at Orient (mine no. 4) and Kinjirma which is under satisfactory category, whereas maximum AQI was observed at Bhedabahal with a value of 132 which is under moderate category. Overall, the results of this study indicated that the air pollution of industrial areas must be evaluated thoroughly on regular basis, considering the sustainability of societies and expanding industries.