Heavy metals (HMs) and elemental carbon (EC) are important components of atmospheric particulate matter. HMs primarily originate from both anthropogenic and natural sources, including fossil fuel combustion, industrial processes, and dust storms, while EC results mainly from the incomplete combustion of carbonaceous materials.

The unique geographical conditions of the Tibetan Plateau (TP) contribute significantly to the transport, transformation, and accumulation of atmospheric pollutants. Additionally, its proximity to high-emission regions, such as East Asia and South Asia, makes the TP more vulnerable to the influence of HMs and EC.

A new study, led by Prof. ZHU Chongshu from the Institute of Earth Environment of the Chinese Academy of Sciences, reveals health risk assessments for source-specific HMs and EC in the remote TP.

This study highlights that dust contributes significantly to the health risks associated with HMs. Manganese (Mn) is the primary contributor to the non-carcinogenic risks of HMs, while arsenic (As) is the major contributor to the carcinogenic risks in the region. The hazard index for HMs in children has exceeded the safety threshold. Both non-carcinogenic and carcinogenic risks from HMs reached their peak during the winter. Using radiocarbon and stable carbon isotope analyses of EC, the researchers found that the primary contributors to the health risks from EC were biomass burning (30%), coal combustion (28%), and liquid fossil fuel combustion (41%). These findings enhance our understanding of the health effects associated with dust exposure and the source-specific health risks of EC in remote regions.

The study, published in the Journal of Hazardous Materials, was jointly funded by the National Natural Science Foundation of China, the Strategic Priority Research Program of Chinese Academy of Sciences, and the Second Tibetan Plateau Scientific Expedition and Research Program.

Fig.1 Schematic Diagram of Health Risks from Atmospheric Heavy Metals and Elemental Carbon in the Tibetan Plateau (Image by IEECAS)