Air Pollution Episodes: Brief History, Mechanisms and Outlook

Ojha, Narendra; Soni, Meghna; Kumar, Manish; Girach, Imran A.; Sharma, Som; Gunthe, Sachin S.

doi:10.1007/978-981-16-7727-4_12

Cited by 1 publication

(2 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, due to the aforementioned roles of chemistry and atmospheric dynamics, air pollution is no longer confined to highly urbanised regions but is being experienced in rural and remote locations as well [23,24]. Higher PM 2.5 levels are seen in parts of South Asia, East Asia, the Middle East, Southeast Asia, and Africa regions throughout the year [25]. However, the widespread enhancements are most pronounced typically during winter over the Indo-Gangetic Plain (IGP) and the North-China Plain (NCP) [21] The studies show higher NO 2 levels (≥ 16 ppbv) generally near the source regions, i.e.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanisms and Pathways for Coordinated Control of Fine Particulate Matter and Ozone

et al. 2022

Self Cite

View full text Add to dashboard Cite

Purpose of Review Fine particulate matter (PM 2.5 ) and ground-level ozone (O 3 ) pose a significant risk to human health. The World Health Organization (WHO) has recently revised healthy thresholds for both pollutants. The formation and evolution of PM 2.5 and O 3 are however governed by complex physical and multiphase chemical processes, and therefore, it is extremely challenging to mitigate both pollutants simultaneously. Here, we review mechanisms and discuss the science-informed pathways for effective and simultaneous mitigation of PM 2.5 and O 3 . Recent Findings Global warming has led to a general increase in biogenic emissions, which can enhance the formation of O 3 and secondary organic aerosols. Reductions in anthropogenic emissions during the COVID-19 lockdown reduced PM 2.5 ; however, O 3 was enhanced in several polluted regions. This was attributed to more intense sunlight due to low aerosol loading and non-linear response of O 3 to NO x . Such contrasting physical and chemical interactions hinder the formulation of a clear roadmap for clean air over such regions. Summary Atmospheric chemistry including the role of biogenic emissions, aerosol-radiation interactions, boundary layer, and regional-scale transport are the key aspects that need to be carefully considered in the formulation of mitigation pathways. Therefore, a thorough understanding of the chemical effects of the emission reductions, changes in photolytic rates and boundary layer due to perturbation of solar radiation, and the effect of meteorological/seasonal changes are needed on a regional basis. Statistical emulators and machine learning approaches can aid the cumbersome process of multi-sector multi-species source attribution.

show abstract

Section: Introductionmentioning

confidence: 99%

“…For example, substantial build-up in PM 2.5 levels corresponding to reduced BLH due to synoptic forcing is seen in several megacities in NCP, Sichuan Basin, and Central China [35]. On a seasonal basis, severe PM 2.5 pollution is evident during winters when the average PBLH is lowest [25,36].…”

Section: Introductionmentioning

confidence: 99%