Dust Storms Can Travel Hundreds of Kilometres to the Himalayas

A new study has identified airborne pathogens carried by elevated desert dust plumes originating in Western India and reaching the top of the Eastern Himalayas, which are associated with respiratory and skin diseases.

The Himalayan hill-top atmosphere is widely considered beneficial for human health. Vulnerability in these regions has been found to be intensified by cold climatic conditions and hypoxia.

There is limited evidence connecting airborne microbial exposure to respiratory disease outcomes in high-altitude Himalayan populations, and the microbiological dimension of transboundary dust transport remains poorly understood. This knowledge gap prompted researchers to undertake the present study.

Through over two years of continuous monitoring of dust storms rising from the arid regions of western India, Researchers from Bose Institute, an autonomous institute of the Department of Science and Technology (DST), found that powerful dust storms can travel hundreds of kilometres, crossing densely populated and polluted Indo-Gangetic Plain before finally settling over the Himalayan hilltops.

Fig: Schematic illustrating the Himalayan hill-top atmospheric bacterial community influenced by horizontally transported desert dust–associated pathogens and vertically uplifted polluted air carrying airborne pathogens from the Himalayan foothills, collectively contributing to human health impacts over the Eastern Himalayas.

They carry airborne bacteria, including pathogens that can affect human health.

In addition to respiratory and skin diseases caused by transported pathogens, vertical uplift injects locally sourced pathogens into the high-altitude atmosphere, where they mix with long-range travellers arriving from afar.

Together, they reshape the bacterial community floating above the Himalayas and contribute to gastrointestinal infections.

The results of this first-of-its-kind study, published in the Journal” Science of the Total Environment”, quantitatively demonstrate the perturbation of the atmospheric bacterial community over the Himalayas due to horizontal long-range dust transport and vertical uplifting of foothill air pollution, which has direct implications on public health.

This research provides critical insights to strengthen national action plans for human health and to develop health forecasting systems.