The Source and Distribution of Heavy Metals in the Atmosphere Across Southeast Asia

Atmospheric heavy metal (HMs) pollution that impacts the environment and human health is one of the increasingly concerning problems in developing countries. Southeast Asia (SEA) is now described as a dynamic and rapidly developing region and is facing problems of air pollution, including HMs in the atmosphere. According to the International Cancer Research Institute (IARC), some metals (e.g., Pb, As, Ni, Cd, Hg, Cd, Cr) are particularly harmful to human health. In this chapter, we focus on the knowledge of atmospheric HMs in the SEA region over the last 15 years, in which, the potential sources and spatio temporal distribution of atmospheric HMs in SEA were discussed in detail. Research on atmospheric HMs is unevenly distributed in the SEA region and most of the studies concentrated in countries such as Thailand, Malaysia, and Vietnam. By employing multivariable models, including PCA and PMF, studies show that both anthropogenic sources (e.g., transportation, biomass burning, and industrial processes) and natural sources (e.g., volcanic eruption and dust storms) can contribute to elevated atmospheric HMs. HMs concentrations in industrial areas are often higher than in urban/background locations. On a seasonal basis, HMs concentrations in the dry season are often higher than in the rainy season. Certain knowledge gaps pertaining to atmospheric HMs in the SEA region necessitate comprehensive investigation. Specifically, there is a need for rigorous research focused on elucidating the deposition of atmospheric HMs as well as research regarding atmospheric mercury (Hg). This chapter presents scientific information on atmospheric HMs pollution in SEA from both regulatory and research perspectives. It aims to enhance the understanding of HMs contaminations in the SEA region by providing updated and rigorous scientific analysis.