Abstract ID: 3.5536 | Reviewing | Talk | TBA | TBA

Microplastics (MPs) and nanoplastics (NPs) have been extensively studied in marine environments, yet there lies a significant gap in assessing their occurrence and impacts in glacier environments. This study investigated (i) the occurrence, abundance, and characterization of MPs and NPs in four major glaciers (Kolahai, Thajwas, Harmukh, and Pir Panjal range) of northwestern Himalayas, and (ii) the sources and pathways of MPs transport to the Himalayan region using HYSPLIT trajectory model. Glacier ice and snow samples were collected in duplicates with bare hands to avoid any plastic contamination from different glacier sites. MPs and NPs were isolated in a biosafety cabinet following standard methodology. An InVia Raman microscope was used to characterize the polymer composition of MPs, while SEM-EDS provided morphological and elemental composition. MPs concentration ranged from 1000 particles m^-3 in Kolahai glacier to 151000 particles m^-3 in Thajwas glacier. In suspended air, MPs occurred at 5 particles m^-3, while dry deposition samples showed a concentration of 1-13 particles m^-2 d^-1. Dynamic light scattering (DLS) confirmed the presence of NPs in all glaciers, with sizes varying between 31-689 nm in Thajwas glacier and 360-953 nm in Harmukh glacier. The majority of the MPs particles included fibres (62.1%), followed by fragments (23.2%), beads (7.9%), films (4.5%), and pellets (2.3%). HYSPLIT model revealed that air masses reaching Himalayan glaciers predominantly originate from global sources (75%), followed by followed by followed by regional (16.7%), and local (8.3%) sources. The pollution load index (PLI) ranged from 3.9 (hazard category I) to 40 (hazard category IV) indicating moderate to excessive pollution of glaciers. While as polymer hazard index (PHI) ranged from 10 (hazard category II) to 1987 (hazard category V) indicating medium to extreme danger due to presence of polyvinyl chloride (PVC) and polyacrylonitrile (PAN). The findings highlight the vulnerability of Himalayan glaciers to MP and NP pollution, exacerbated by their light-absorbing properties that may accelerate warming and melting. Further research is essential to understand the implications of MPs and NPs on glacier health and climate change.

Acknowledgments
Shahid Ahmad Dar acknowledges the National Post-Doctoral Fellowship (NPDF) (Grant No. PDF/2023/000935) provided by the Anusandhan National Research Foundation (ANRF) formerly Science & Engineering Research Board (SERB), India for carrying out this work.