Skip to main content
Log in

Sources and environmental processes of polycyclic aromatic hydrocarbons and mercury along a southern slope of the Central Himalayas, Nepal

  • Research Article
  • Published:
Environmental Science and Pollution Research Aims and scope Submit manuscript


Semi-volatile pollutants can undergo long-range atmospheric transport from low-altitude source regions to high-altitude regions and then accumulate in surface matrices (soil and plants). The Himalayas is the highest mountain range worldwide, but there have been limited studies on the source, transport, and deposition of polycyclic aromatic hydrocarbons (PAHs) and mercury (Hg) in the region. In this study, atmospheric PAHs, and the PAHs and Hg in soil and foliage were determined along a transect on a southern slope of the Himalayas, Nepal. The study showed anthropogenic emissions of PAHs and Hg occurred in the lowland areas of Nepal, and upslope transport to the high-altitude regions happened for both pollutants. During the upslope transport, forest filter effect and snow scavenging may be the important factors that enhance the deposition of PAHs, contributing to the negative pattern between concentrations of PAHs and altitudes. On the contrary, more Hg accumulated in the high Himalayas, relating to the enhanced deposition in the high altitude caused by the higher input from upper atmosphere.

Distribution and environmental processes of PAHs and Hg along the southern slope of Himalayan mountain

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others


Download references


This work was supported by the National Natural Science Foundation of China (41571463, 41222010, and 41201489) and the Third Pole Environment (TPE) Program. We would like to thank the Kathmandu Center for Research and Education, Chinese Academy of Sciences and Tribhuvan University (KCRE, CAS & TU) for their help with the fieldwork. We also thank Lei Wang, who was at China University of Mining and Technology, Beijing, for analyzing the Hg concentrations in the samples. In addition, B.P. would like to thank Dr. Krishna Prasad Pokhrel for his assistance in preparing the map and other suggestions.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Xiaoping Wang.

Additional information

Responsible editor: Hongwen Sun

Electronic supplementary material

Below is the link to the electronic supplementary material.


(DOCX 958 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Pokhrel, B., Gong, P., Wang, X. et al. Sources and environmental processes of polycyclic aromatic hydrocarbons and mercury along a southern slope of the Central Himalayas, Nepal. Environ Sci Pollut Res 23, 13843–13852 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: