Spatial-Temporal Re-Analysis of Seasonal Air Quality Data in Karachi City for Future Prospects

Abstract

Air quality in Karachi, Pakistan appears to be deteriorating in the world due to rapid increase in population, economic growth and subsequent increase in urbanization and energy demand. This study Re-is about the cumulative effects of anthropogenic activities on air chemistry of the study area atmosphere with ground base concentration measurements of gaseous air pollutants (SO2, NO2, CO, CO2 and O3), particulates (PM10 and TSP), Methane, Lead and Noise with temperature and seasonal influences on Karachi city. The primary goal of this study was to define spatial and temporal distribution of air pollutants with ArcGIS, seasonal behavior of airborne contaminants, convert the five major pollutants termed as criteria pollutants into Air Quality Index (AQI) and their temperature association for future prospects. The maximum average values of four seasons concentrations of air pollutants were found SO2=64.5 ug/m3 (GR), NO2=55.5 ug/m3 (FB), CO= 8.00 mg/m3 (CC), CO2=645 ug/m3 (NZ), O3=56.7 ug/m3 (ST), PM10=225 μg/m3 (CC), TSP=402 ug/m3 (CC), Methane=1.65 m/gm3 (CC), Lead=5.1 ug/m3 (ST), and Noise=85 dB (GR). The minimum four seasons average concentration values with monitoring location as {SO2=48.2 ug/m3 (FB), NO2=44.6 ug/m3 (NZ), CO=4.1 mg/m3 (BC), CO2=601 ug/m3 (JH), O3=42.4 ug/m3 (GR), PM10=150 ug/m3 (BC), TSP=226 ug/m3 (JH), Methane=0.68 mg/m3 (BC), Lead=32 ug/m3 (GZ), and Noise=81 dB (BC). The spatial-temporal analysis of air quality revealed that the pollutants in the summer are higher in industrial and high-density traffic junctions. In this study, temperature and air quality are significantly associated, while rainfall and relatively high humidity days are negatively correlated. High temperature months have highest air pollution values, whereas the washout impact of precipitation and relative humidity have the lowest levels. The analysis of air quality index parameters demonstrated a high coherence among NO2, CO and O3 with variation in