Occurrence and Source of Microplastics in the Sagarmatha National Park, Nepal

Microplastics pollution is an emerging concern to the environment and public health, and has been found in the high Himalayan mountains. However, the abundance and sources of microplastics in the area have not been well understood, partly due to the difficulties of sample collection in the remote areas and the lack of standard testing procedures. Water samples were collected from streams and tributaries in the Sagarmatha National Park in May 2022. The samples are being analyzed in the laboratory for the microplastics abundance and types. The study also establishes a streamlined procedure for researchers to adopt to better identify the quantities and types of microplastics in water samples while saving labor cost and analysis time. Specifically, microplastics were collected via a net sieve attached to the end of a flow meter. This approach ensures that a large volume of water flux is filtered so that microplastics are collected while eliminates the burden of bringing a large volume of water to the lab. Major analysis steps include density separation with a centrifuge, coloration with Rose-Bengal solutions, and identification with a dissect microscope with further validation from FT-IR analysis.

The results will reveal the abundance and categories of microplastics in the Sagarmatha National Park, Nepal, and indicate the potential sources of this emerging contaminant. The methodology developed will benefit researchers in the microplastics field and has broader impacts to the general public.