Assessment of Urban Air Quality for Jodhpur City by the Air Quality Index (AQI) and Exceedance Factor (EF)

Reduction in air quality in urban areas is a concern due to increased emissions from vehicles, and commercial and industrial activities. The high concentration of air pollutants can cause various adverse health effects. This study aims to characterize urban air pollution levels by measuring NO₂, SO₂, and PM₁₀ in Jodhpur city, the Sun City of Rajasthan (India). Air quality index (AQI) and exceedance factors are also calculated to determine the current air quality status and relate possible health impacts associated with air pollutants’ existing levels. Raw data is collected̄ from 10 air quality monitoring stations situated in the critical city’s areas, namely DIC Office, Housing Board, Kudi Woman Police Station, Maha Mandir, RIICO Office Basni Industrial Area, Sangariya Police Sub-station, Shastri Nagar Police Station, Sojati Gate, Soorsagar Police Station, and Collectorate Office for the study period from January 1, 2019, to December 31, 2019. Seasonal and annual variations in the levels of concentration of the three criteria pollutants have been studied along with AQI. The annual average concentrations of gaseous pollutants (SO₂ and NO₂) were 6.76 and 24.82 μg/m³, respectively. The concentration of NO₂ and SO₂ was well under the NAAQS prescribed limits defined by India’s CPCB. PM₁₀ was revealed as the primary pollutant with an annual average concentration of 219.67 μg/m³. The concentration of PM₁₀ was violating the NAAQS in all seasons, making it responsible for the bad air quality of the Jodhpur city during the observation period. The monthly and seasonal data analysis indicates significant variations in the concentration level of all selected parameters for the study. The computed AQI reveals a gradually increasing trend with a range of 71.00–430.0, signifying the prevalence of moderate to heavy pollution levels. Comparing the exceedance factors (EFs) divulges that suspended and respirable particulate matters are the most significant polluting agents, causing maximum deterioration in the ambient air quality. Thus, it can be concluded from the study that significant air pollution in Jodhpur city was due to particulate matters.