Author
Rahul Kisan Sawalkar
MMS-FY-A-44
1. Evaluation on Risk Assessment on Indoor Air Pollution: A Case Study of Delhi-NCR Region
This research article by (Singh, et al , 2021 )says that air pollution is a major public health threat, contributing to respiratory and cardiovascular diseases through pollutants such as PM₂.₅, PM₁₀, NO₂, SO₂, CO, O₃, NH₃, and Pb. In India, rapid urbanization, industrial growth, traffic, construction, and biomass burning have worsened air quality. To simplify pollution reporting, the government introduced the National Air Quality Index (AQI) in 2014, categorizing air quality from “Good” to “Severe.”Since people spend nearly 90% of their time indoors, indoor air pollution—caused by poor ventilation and solid fuel use—poses significant health risks, including asthma, COPD, and lung cancer. This study uses data from the Central Pollution Control Board to calculate AQI through standard formulas using a Java-based program, translating pollutant levels into clear health risk categories. It also recommends practical measures such as source control, better ventilation, and HEPA air purifiers to reduce indoor exposure and protect public health.
2. The Attractiveness of Urban Complexes: Economic Aspect and Risks of Environmental Pollution
( Milan, et al, 2021) Cities have long been magnets for opportunity, offering better jobs, education, healthcare, and infrastructure that promise an improved quality of life. However, the same economic growth and industrial activity that make urban areas attractive can also worsen environmental pollution—especially air pollution—which directly affects public health. This study explores this delicate balance by introducing a simple idea of “economic attractiveness,” measured as the ratio between GDP per capita (a sign of prosperity) and the Air Quality Index (a measure of environmental risk). By comparing major global cities such as Boston, New York, Washington, London, Milan, Brussels, and Shanghai, the findings show that wealthier cities often tend to have better air quality, though this is not guaranteed. The results make it clear that economic success alone does not determine how desirable a city truly is—clean air and a healthy environment matter just as much. Even when income levels rise, poor air quality can reduce a city’s overall appeal. Ultimately, the study emphasizes that for cities to remain attractive and sustainable in the long term, economic development must go hand in hand with strong environmental protection and public health priorities.
3. Air Quality Index Prediction
(Avvari, et al, 2023) Air pollution continues to threaten public health worldwide, affecting the lungs and heart and increasing the risk of serious illness and premature death. Because air quality can change quickly, being able to predict the Air Quality Index (AQI) in advance is extremely important—it helps authorities issue warnings, plan interventions, and protect vulnerable populations. In this study, we explore how machine learning can be used to forecast AQI more accurately. Using daily pollution data from India’s Open Government Data (OGD) Platform, the raw information was carefully cleaned and prepared to ensure reliable analysis. We reviewed traditional prediction methods such as regression models and neural networks, recognizing both their strengths and limitations. Building on this, we developed two advanced models—Support Vector Machine (SVM) and Random Forest (RF)—implemented in Python with modern tools like Keras and TensorFlow. By comparing their performance using standard statistical measures, we identified the model that produced the most accurate predictions. Overall, the findings show that intelligent, data-driven techniques can play a powerful role in anticipating pollution levels and supporting better environmental and public health decision-making.
4. Festive Pollution: A Global Concern—A Comparative Study of Diwali in India and New Year’s Eve in Poland
This study(Anamika, et al,2025) examines the environmental impact of firecracker celebrations during Diwali in Malda (2023–2024) and New Year’s Eve in Warsaw (2024), revealing sharp short-term spikes in particulate matter (PM₁, PM₂.₅, PM₁₀), especially around midnight. While gaseous pollutants largely remained within limits, fine particles—often containing metals such as iron, magnesium, strontium, zinc, arsenic, and cadmium—rose far above safety standards, posing serious respiratory and cancer-related health risks. The smallest particles (PM₁) were particularly dangerous due to their ability to penetrate deep into the lungs and bloodstream, with children identified as more vulnerable. Noise pollution also exceeded permissible levels. Meteorological conditions like low temperatures and weak winds further trapped pollutants near the ground. Overall, the findings show that festive fireworks can temporarily but significantly degrade air quality, emphasizing the need for stricter regulation and eco-friendly celebration practices
5. Strengths and Weaknesses of the WHO Global Ambient Air Quality Database
This paper (Schwela, et al, 2020) evaluates the World Health Organization Global Ambient Air Quality Databases (2016, 2018), which compile PM₂.₅ and PM₁₀ data from thousands of cities worldwide to assess urban air pollution. While the databases are valuable for raising awareness about particulate pollution and its health impacts, the study identifies key limitations that hinder direct city comparisons and “most polluted” rankings. These include inconsistent QA/QC standards, gaps in spatial and temporal coverage, varying monitoring methods, meteorological influences, reliance on estimated conversion factors, and incomplete national datasets. Important pollutants like NO₂ and O₃ are not consistently included. The authors warn that media-driven rankings can be misleading and politically sensitive. They recommend stricter quality controls, broader pollutant inclusion, improved transparency, and caution against simplistic comparisons to ensure accurate, credible, and policy-relevant air quality reporting.
6. The role of atmospheric feedback and groundwater conservation policies in degrading air quality in Delhi
This study by (Ghude,et al,2025)says that post-harvest stubble burning in Punjab and Haryana significantly worsens air pollution in Delhi-NCR, a problem unintentionally intensified by the 2009 Groundwater Conservation Policy, which delayed crop cycles and shifted peak burning to early November—when cooler temperatures, weak winds, and low boundary layer height trap pollutants. WRF-Chem simulations (2017–2021) show this shift increased Delhi’s PM₂.₅ levels by about 36% (~60 µg/m³) and tripled severe AQI episodes, with aerosol-radiative feedback further amplifying pollution and contributing to measurable excess health burdens. In parallel, researchers developed a Cumulative Index (CI) combining SO₂, NO₂, PM₂.₅, and PM₁₀ into a single indicator for clearer pollution classification. An optimized Support Vector Machine (SVM), tuned using the Grey Wolf Optimizer, effectively distinguished between good and harmful air quality levels. Together, these findings highlight the need for integrated emission control policies and advanced analytical tools to better manage and mitigate severe pollution episodes.
7. Investigating the geographic linkage between airborne pollutants and tuberculosis rates in India.
This research article (Kumar, et al, 2025)highlights that recent satellite and public health analyses reveal a strong link between air pollution and tuberculosis (TB) burden in India. Using 2022 Sentinel-5P and MODIS data alongside records from the Ministry of Health and Family Welfare, the study found that states such as Uttar Pradesh, Madhya Pradesh, and Bihar show high TB incidence and mortality, coinciding with severe pollution, dense populations, and low vegetation cover. TB rates were positively associated with pollutants including PM₁₀, NO₂, SO₂, O₃, and HCHO, as well as higher land surface temperatures, while greener areas showed protective effects. Population density strongly predicted TB mortality, with major vulnerability clusters identified across the Indo-Gangetic Plain. The findings suggest that integrating air pollution control, urban greening, and sustainable planning with biomedical TB programs is essential to reduce disease burden, though more detailed longitudinal research is needed to clarify causal relationships.
8. Large gaps in monitoring urban air pollution in low- and middle- income countries associated with economic conditions and political institutions
This study by (Schoch,et al,2026) analyzes air quality monitoring (AQM) in over 7,000 cities across low- and middle-income countries, finding that nearly 90% lack adequate monitoring while the rest have inconsistent coverage. Using data from OpenAQ, WAQI, and PurpleAir combined with socio-political indicators, the research shows that wealthier and more democratic cities are more likely to monitor air pollution—especially in highly polluted areas—whereas less democratic cities often monitor cleaner areas, possibly for political reasons. Reference-grade monitors are concentrated in China and India, while low-cost sensors are more common in democratic nations. Corruption negatively affects monitoring coverage. The findings highlight major global inequalities in AQM and emphasize that political and economic factors strongly shape monitoring systems. Expanding reliable air quality monitoring in underrepresented cities is crucial for improving transparency, public awareness, accountability, and effective environmental policymaking worldwide.
9. Transported dust modulates aerosol pollution domes over rapidly urbanizing Indian cities
This study by (Sethi,et al,2025) says that a detailed satellite-based analysis of aerosol optical depth (AOD) from 2003 to 2020 across 141 cities in India reveals the existence of distinct “urban aerosol islands,” or pollution domes, showing a pronounced north–south divide. In southern and southeastern cities, aerosol concentrations are generally higher over urban centers, forming classic urban aerosol pollution islands, whereas many northern and northwestern cities—particularly across the Indo-Gangetic Plain—exhibit lower aerosol levels within cities compared to their surrounding areas, creating what can be described as urban aerosol clean islands. This seemingly counterintuitive pattern is largely influenced by elevated regional background pollution, especially dust transported from arid regions like the Thar Desert, which weakens or “punctures” northern pollution domes by raising aerosol concentrations more in non-urban areas than within the cities themselves. The study identifies a significant negative correlation between dust loading and the intensity of urban aerosol islands, highlighting the major role that large-scale atmospheric circulation and long-range transport play in shaping urban air quality. While pollution domes in India are generally weaker compared to those in some other global cities, the findings clearly demonstrate that both urban and rural regions experience considerable aerosol burdens. This underscores the urgent need for coordinated mitigation strategies at both regional and local levels to effectively reduce pollution, protect public health, and promote sustainable urban development across the country.
10. ASSESSMENT OF IMPACT OF COVID-19 LOCKDOWN ON AIR QUALITY IN NATIONAL CAPITAL REGION OF NEW DELHI, INDIA
This research article by (Anitil,et al ,2022)says that following the World Health Organization declaration of COVID-19 as a pandemic on 11 March 2020, India imposed a phased nationwide lockdown (23 March–31 May 2020), halting most transport, industrial, and commercial activities. This study assessed its impact on PM₂.₅, PM₁₀, SO₂, NO₂, and O₃ at Jahangirpuri (Delhi), Sonipat, and Panipat. During Lockdown Phase 1, major pollutants declined significantly: PM₂.₅ fell by 28.1% (Jahangirpuri), 33.5% (Sonipat), and 40.8% (Panipat), while NO₂ and SO₂ also decreased. However, PM₁₀ often remained near or above standards due to wind-blown dust. Ozone showed a paradoxical rise despite reduced NO₂, likely due to enhanced photochemical reactions under clearer skies and meteorological influences. Pollution levels rose slightly in later phases as restrictions eased. Industrial sources and thermal power plants influenced trends in Sonipat and Panipat, while vehicular reductions improved air quality in Delhi. Overall, lockdown significantly improved air quality, highlighting the roles of emission control and meteorology, though such measures carry economic and social costs.
Conclusion
The collective findings of these studies present a comprehensive and multidimensional understanding of air pollution as a complex environmental, public health, economic, and governance challenge. From indoor exposure risk assessments in Delhi-NCR to global evaluations of monitoring systems, the research demonstrates that air pollution is influenced by interconnected factors including urbanization, economic development, festive emissions, agricultural practices, transported dust, atmospheric feedback mechanisms, and political institutions. Advanced analytical approaches—such as AQI modeling, cumulative pollution indices, machine learning prediction (SVM, Random Forest, GWO-optimized models), satellite-based aerosol analysis, and socio-economic correlation frameworks—highlight the importance of data-driven decision-making in air quality management. The studies further reveal that policy interventions, such as groundwater conservation measures or urban economic strategies, can produce unintended environmental consequences if not integrated with atmospheric and public health considerations. Additionally, global disparities in air quality monitoring, particularly across low- and middle-income countries, underscore the role of economic capacity and democratic governance in ensuring environmental accountability. The observed linkages between pollution exposure and health burdens—including respiratory diseases and tuberculosis—reinforce the urgent need for coordinated, multi-sectoral strategies. Overall, the research emphasizes that effective air quality management requires an integrated framework combining scientific modeling, reliable monitoring systems, socio-economic evaluation, technological innovation, and evidence-based policy interventions to safeguard public health and promote sustainable urban development.
Reference
Abera, A., Friberg, J., Isaxon, C., Jerrett, M., Malmqvist, E., Sjöström, C., et al. (2021). Air quality in Africa: Public health implications. Annual Review of Public Health, 42, 193–210.
Akinfolarin, O. M., Boisa, N., & Obunwo, C. C. (2017). Assessment of particulate matter-based air quality index in Port Harcourt, Nigeria. Journal of Environmental & Analytical Chemistry, 4, 224.
Burnett, R., et al. (2018). Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter. Proceedings of the National Academy of Sciences of the United States of America, 115, 9592–9597.
Gorai, A. K., & Goyal, P. (2015). A review on air quality indexing system. Asian Journal of Atmospheric Environment, 9(2), 101–113. https://doi.org/10.5572/ajae.2015.9.2.101
Guttikunda, S. K., et al. (2023). What is polluting Delhi’s air? A review from 1990 to 2022. Sustainability.
Laumbach, R., Meng, Q., & Kipen, H. (2015). [Article title not fully provided]. Environmental and Occupational Health Sciences Institute, Rutgers University.
Liang, L., Gong, P., Cong, N., et al. (2019, June 7). Assessment of personal exposure to particulate air pollution.
Pratap, V., Saha, U., Kumar, A., & Singh, A. (Year not provided). [Article title not fully provided]. Advances in Space Research, 68.
Shi, Y., Zhai, G., Xu, L., Zhou, S., Lu, Y., Liu, H., & Huang, W. (2021). [Article title not fully provided]. Volume 112, 103141.
World Health Organization. (2019). WHO guidelines on tuberculosis infection prevention and control.
Yuan, Y., Mu, X., Shao, X., Ren, J., Zhao, Y., & Wang, Z. (Year not provided). [Article title not fully provided]. Applied Soft Computing, 123.