Ramesh P. Singh - Asian Atmospheric Pollution: Sources, Characteristics and Impacts

Crop residue burning; Forest fires; Municipal waste; Biomass burning; South Asia; Southeast Asia; Air quality; AOD; Black carbon; Organic carbon

Atmospheric aerosols form a key research focus in the 21st century due to their wider range of interventions on Earth's energy budget, cloud microphysics, human health, crop productivity, and ecosystem () with ample potentials to affect the air quality and human health, highlighting the need for serious attention.

A comprehensive understanding of aerosol properties from open burning has been a subject of inquisitiveness among both chemistry-climate modeling and policymaking communities due to considerable uncertainties. Such uncertainties are particularly important over the SSEA region because of the high spatiotemporal variabilities, different types of burning, and limited in situ measurements. The Indo-Gangetic Plain (IGP) in South Asia mostly experiences the open burning of crop residues, while forest fires dominate in the Northeastern Indian states and in the Himalayan region (). Besides crop residue burning and forest fires, the open burning of municipal waste is another crucial source injecting huge amounts of aerosols into the atmosphere. Several low-income countries in the region lack a well-managed waste collection system and engineered solid waste management facilities leading to their open burning.

This chapter provides an overview of the atmospheric aerosols from open burning with emphasis on the major classes and spatial distribution of open burning in the SSEA region. Further, the physicochemical properties and size distribution of open burning aerosols are discussed which form the primary basis of their health and climatic impacts. The chapter also presents different measurement and modeling approaches, which are in practice to characterize and simulate the open burning aerosols. The identification of limitations in current measurement approaches and their improvement potentials have been explored for this region.

Open burning is one of the most primitive anthropogenic practices of the world. The magnitude of open burning depends on several factors such as the purpose, the period of burning, topography, type of biomass, and climate and weather conditions. High variabilities in these factors lead to a unique spatialtemporal distribution of open burning globally. Increasing population further induces fluctuations in the land use and resource consumption patterns, leading to more forest clearance, generation of crop residues and municipal waste. SSEA encompasses a large region of strongly heterogenous open burning activities. Crop residue burning, forest fires, and municipal waste burning are the three major classes of open burning in the SSEA region linked closely with the emissions of a variety of trace gases and aerosols.

Agriculture is one of the most important economic activities of this region which results in the generation of huge amounts of biomass waste in the form of postharvest residues. Some fractions of the crop residues are utilized as fodder for cattle, household cooking fuel, and plowed under the field to increase soil fertility ().

Fig. 1 Emissions of carbonaceous aerosols from crop residue burning over the SSEA region.

Punjab, Haryana, and western Uttar Pradesh provinces of India and parts of Pakistan in the South Asian region experience open residue burning during OctoberNovember and AprilMay every year ( enlists the major types of crop residues burned and the typical periods of burning in different regions of the SSEA.

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