Air Quality Assessment with Human Health Effects for Kota Metropolis, Rajasthan (India) Current World Environment

Bad air quality is the number one environmental concern globally due to its severe impact on animals, plant life, humans and property. This study has assessed air quality and health impact on humans in Kota metropolis, Rajasthan (India), to increase the understanding of the relation between health and pollutant sources, emission characteristics, topography, and meteorological conditions. AQI and EFare also calculated to determine the pollution category and critical level of pollutants, respectively. The health effects of particulate matter on inhabitants are estimated with the AirQ+ software. The annual concentration of PM 10 and PM 2.5 were more than prescribed limits by CPCB, while SO 2 and NO 2 are well below the prescribed limits. The maximum concentrations of pollutants were detected in Winter, followed by Summer and Rainy seasons. AQI varies from satisfactory to inferior category. EF was more than 1 for all monitoring stations for PM 10 and PM 2.5 exhibiting High pollution, 0.5-.09 indicates Moderate pollution for NO 2 , while less than .5 for SO 2 shows Low pollution. Particulate matter is the primary cause of air pollution. The PM 2.5 induced ENACs (Estimated Number of Attributable Cases) for all causes of mortality, COPD, ALRI, LC, IHD, and stroke were 4546, 435, 255, 806,1958, and 1772, respectively. The ENACs for post neonatal infant mortality, the prevalence of bronchitis, and chronic bronchitis due to PM 10 increased by 326006, 716, and 13700, respectively. This study carries useful findings and suggestions for stakeholders and policymakers to control and mitigate the decrement in air quality.


Introduction
Air pollution kills about 6.9 million people worldwide, as per the World Health Organisation (WHO). 1 Particulate matter (PM) is the 4 th leading cause of 85 risk factors as per the Global Burden of Disease study, leading to more than 5 million deaths in 2017. 1,2 46 Indian cities are among the 100 most polluted cities globally, attributed to the high concentration of air pollutants. 3 In 2019, more than 1.13 lakh deaths in Rajasthan were due to air pollution. 4 According to the literature, the primary air pollutants in the Indian scenario are Particulate matter (PM 2.5 and PM 10 ), Sulphur dioxide(SO 2 ), Nitrogen dioxide (NO 2 ), Ozone (O 3 ), Carbon monoxide (CO), Lead(Pb), and (NH 3 ). [5][6][7] Atmospheric particulate matter (PM) is one of the key contributorsto urban and rural air pollution. 8 PM 2.5 (aerodynamic diameter ≤ 2.5 μm) 9 and PM 10 (aerodynamic diameter ≤ 10 μm) 10 with significant health problems, including chronic respiratory disease, 11 premature mortality, 12 aggravated asthma, 13 acute respiratory, 14 emergency visits, and hospital admissions symptoms, 15,16 and decrease in lung function. 17 Other air pollutants include Sulphur dioxide (SO 2 ), which adversely affects the mucous upper respiratory tract and nose membranes. 17, 18 10-minute exposures at 4000 ppbreduce mean lung function values among groups of healthy individuals. It is among the most significant contributors to acid rain, which has several adverse effects on soil, water, property, and materials. 19,20 Nitrogen dioxide (NO 2 ) concentrations in Indian cities due to increased vehicles show an alarmingly high increasing trend. 7,21,22 Continuous exposure to NO 2 with as little concentration (0.1 ppm) for 1-3 years increases the incidence of emphysema and bronchitis and affects lung performance. Further NO 2 concentration exceeding 1 ppm leads to decreased lung function and increased airway responsiveness to broncho-constrictions in healthy subjects. It also contributes to acid rains. 23 The parameters to be selected for assessing air quality in Kota metropolis, Rajasthan (India), is PM 2.5 , PM 10 , SO 2 , and NO 2 . The data is collected for all air quality monitoring stations from January 2018 to December 2021 for 4 years. This study also estimates the AQI and EF to determine the pollution category and critical level of pollutants.Very few studies have estimated human health risks due to air pollutants in Kota city. Hence, AirQ+ software is employed to assess the effect of particulate matter on human beings.

Study Area & Observation Period
The study area selected for assessing air quality is Kota metropolis, Rajasthan (India). Kota comes under the category of smart cities in India, consisting of 512 square meters of the geographical area in a dumber-like shape. The topmost length and width of the Kota district are 153 kilometres from north to south and 84 kilometres from east to west, respectively. The longitude and latitude of the district lie between 75º 37' to 77º 26' and 24º 25' to 25º 51', respectively. 24,25 Figure 1 and Table 1.The observation period for the study is four years, from 1st January 2018, to 31st December 2021. The data is collected from Regional Office, Rajasthan State Pollution Control Board (RSPCB), Kota.
The data are collected for PM 10 , PM 2.5 , SO 2 , and NO 2 and then segregated for seasonal and annual analysis. The segregated data were then compared with Indian National Ambient Air Quality Standards (NAAQS), as mentioned in Table 2, to determine the pollution. The effect of the meteorological parameters such as Temperature and Rainfall is also taken into account to determine pollution. Health impacts are evaluated with the help of AirQ+ Software. The overall research methodology followed in this research work is graphically present in Figure 2.

Air Quality Index
The weighted values of each air pollutant are converted into a single number by the air quality index (AQI).The CPCB method to calculate AQI in India is a two-step process, (i) Calculation of subindex for each air pollutant, and (ii) Maximum operator system to define AQI. 18,29 AQI range with respective category and colour code is tabulated in Table 3. AQI range with respective category and colour code is mentioned in Table 3

Health Effects of Particulate Matter
An assessment of human health risk due to long-term exposure to a particular air pollutant is estimated  Figure 7.    It is clear from Table 6 that the AS-4 (Regional Office, RSPCB) air quality monitoring station is in the top most position in the Winter season among all stations. It is observed from the analysis of monitored data that the air quality of this area is continuously deteriorating. Particulate matter is the leading cause of the worst air quality in this area. This area's PM 2.5 and PM 10  The CPCB permissible limits of PM10 and PM 2.5 are 100 and 60 micrograms per meter cube, respectively. Not a single location follows the CPCB standards for PM 10 providing significant evidence of being an air pollutant. A similar scenario is observed for PM 2.5 except for two stations (AS-1 and AS-3) in 2020. It has been observed that the station with a high PM 2.5 concentration also has a higher concentration of PM 10 and vice versa in the Winter season.
Shreenathpuram stadium (AS-7) always has a high concentration of SO 2 , but the concentrations were almost seven times lower than the prescribed It is clear from Table 7 that the AS-4 (Regional Office, RSPCB) air quality monitoring station is again in the topmost position in the Summer season among all stations. It is observed from the analysis of monitored data that the air quality of this area is continuously deteriorating. Particulate matter is the leading cause of the worst air quality in this area. This area's PM 2.5 and PM 10   It is clear from Table 8 that the AS-4 (Regional Office, RSPCB) air quality monitoring station is in the top most position during the Rainy season among all stations. It is observed from the analysis of monitored data that the air quality of this area is continuously deteriorating. Particulate matter is the leading cause of the worst air quality in this area. This area's PM 2.5 and PM 10  The CPCB standards for PM 10 and PM 2.5 are 100 and 60 micrograms per meter cube, respectively.
All monitoring location follows the CPCB standards for PM 10 except for the 2018 Rainy season, providing significant improvement in the air quality. A different scenario is observed for PM 2.5 . All monitoring location follows the CPCB standards for PM 2.5 . It has been observed that the station with a high PM 2.5 concentration also has a higher concentration of PM 10 and vice versa in the Rainy season.
Shreenathpuram stadium (AS-7) always has a high concentration of SO 2 , but the concentrations were almost seven times lower than the prescribed limit of 80 µg/m 3   It is clear from Table 9 that the AS-4 (Regional Office, RSPCB) air quality monitoring station is in the topmost position annual basis among all stations. It is observed from the analysis of monitored data that the air quality of this area is continuously deteriorating. Particulate matter is the leading cause of the worst air quality in this area. This area's PM 2.5 and PM 10  The CPCB standards for annual PM 10 and PM 2.5 are 60 and 40 micrograms per meter cube, respectively. Not a single location follows standards for PM 10 and PM 2 .5 , providing significant evidence of being air pollutants. It has been observed that the station with a high PM 2.5 concentration also has a higher concentration of PM 10 and vice versa in the Winter season.
Shreenathpuram stadium (AS-7) always has a high concentration of SO 2 , but the concentrations were almost four times lower than the prescribed limit of 50 µg/m 3 mentioned in Indian NAAQS.  Figure 7.

Exceedance Factor
EF was more than 1 for all monitoring stations for PM10 and PM 2.5 , exhibiting High pollution (H), 0.5-.09 indicates Moderate pollution (M) for NO 2 , while less than. 5 for SO 2 exhibits Low pollution (L). The exceedance Factor (EF) for air quality parameters at each monitoring station is shown in Figure 8 and tabulated in Table 10. The ENACs (long-term) for postneonatal infant mortality, the prevalence of bronchitis, and chronic bronchitis due to PM 10 increased by 326006, 716, and 13700, respectively, Whereas the ENAC (short-term) for asthma symptoms in kids, was 322. The estimated LTEs and STEs of current PM 10 concentration on human health are shown in Table 13.
Long-term effects of PM10 and PM 2.5 are compared with National Capital Territory (NCT) Delhi (India), 14 Alwar (India), 32 and Tehran (Iran), 33 The maximum number of cases was for NCT Delhi, followed by Different studies suggest that as the concentration of particulate matter increases, disease cases also increase. A comparison of Long-term effects among different cities is tabulated in Table 14.

Discussion
The main reasons behind low concentrations of SO 2 and NO 2 are the absence of a source of their primary production, such as burning fossil fuels, and other reduction initiatives taken by the Government. 18,20,34,35 The leading causes of higher PM 10 and PM 2.5 are natural dunes, 36 cement plants, 37 stone cutting industries, 37 crushing industries, 38 municipal incineration, power plants, chemical plants, 39 diesel and petrol stations, 19 natural dust, 9 stuble burning, 40 vehicular population, 36 etc.
Air quality varies enormously from day to day at a particular location due to the dynamics of the atmosphere, even though emissions may remain relatively constant. The factors affecting the atmosphere's dynamics are temperature, pressure, wind, moisture, and relative humidity 18 The maximum concentration of air pollutants was observed in the Winter season, followed by the Summer and Rainy seasons of the observation period except the year 2020. High-pressure systems are generally encountered during Winter. High-pressure systems are related to clear sky, light winds, and atmospheric stability. When such a system becomes stagnant over an area for several days, air contaminants can cause air pollution problems.
While low-pressure systems (usually associated with cloudy skies, gusty winds, atmosphere instability, and the formation of fronts) and other meteorological parameters significantly contribute to the lower concentration of pollutants in the Summer and Rainy seasons.
The minimum concentration was detected during the Rainy season. The main reason behind it is that the precipitation occurred due to the study area's southwest monsoon and a low-pressure system. Rain always serves as a cleaning agent for the atmosphere, removing soluble gases and particulate matter in a washout process. 41 The Summer season in 2020 has the lowest concentrations of air pollutants compared to the Rainy season. It may be because India was affected by the outbreak of Coronavirus Disease of 2019 (Covid-19), the global-level infectious disease declared as a pandemic by WHO (World Health Organization). 7 Many countries had started imposing complete lockdown across the globe resulting in full closure of business, trade, cultural, tourist, educational, and socio-economic activities. India went for a complete lockdown starting from 25th March 2020, which continued till 17th May 2020, as imposed by the Government of India. 42,43 This lockdown resulted in the complete halting of transportation, business activities, shops and malls, tourist and recreational centres, and other economic activities. This resulted in a significant decrease in fuel demand by almost 70% due to the non-movement of transport and domestic vehicles, regularly used for movement. 44 There are varied reasons which may be attributed to improvement in air quality in lockdown. Closure of industrial and transportation activities, reduced mining, and lesser economic activities have significantly reduced particulate matter concentrations. This also concurs that traffic pollution and industrial activities which are major point source contributors to deteriorating air quality. Sustainable remedial measures are to be considered as a major step towards reducing air pollution and having a proper balance with economic activities. However, it is noteworty that the lockdown was also forced in 2021, but it had less impact on air quality improvement compared to the lockdown in 2020 in India.

Conclusion
This study concludes that Kota metropolis is subjected to particulate matter pollution and inhabitants of the city are extremely susceptible to the adverse effects of PM 10 and PM 2.5. Urbanised areas are the prime hotspots that contribute significantly toward particulate matter concentrations. Lifestyle patterns, culture, land use patterns, and the presence of heavy industries are other socio-cultural factors contributing to air quality.
The absence of primary production sources of NO 2 and SO 2 , such as burning fossil fuels, and other reduction initiatives taken by the Government, have a very significant impact on maintaining low levels of these pollutants.
Temperature and rainfall have significant impacts on the air quality of the Kota metropolis. Minimum concentration of pollutants was observed in the Rainy followed by Summer and Winter seasons. The range of AQI varies between the satisfactory to very poor category. EF was more than 1 for all monitoring stations for PM 10 and PM 2.5 , exhibiting High pollution (H), 0.5-.09 exhibiting Moderate pollution (M) for NO 2 , while less than 0.5 for SO 2 exhibits Low pollution (L).Human health risk assessment results reveal that cardiovascular and respiratory disease principally contributes to total mortality caused by particulate matter pollution.
Therefore, particulate matter pollution is a critical factor to be considered by the policymakers to ensure sustainability coupled with environmental concerns. Improving solid waste management, increasing green beltway, restricting open burning, planting some new species of plants in internal sources, prohibiting old vehicles, and shifting vehicles towards clean energy would be adequate to mitigate the effect of particulate matter on inhabitants.