Himalayan Environment Research Institute HERI

Kathmandu, Nepal

Himalayan Environment Research Institute HERI

Kathmandu, Nepal
Time filter
Source Type

Li X.,Chinese Academy of Sciences | Li X.,University of Chinese Academy of Sciences | Kang S.,Chinese Academy of Sciences | Kang S.,University of Chinese Academy of Sciences | And 15 more authors.
Science of the Total Environment | Year: 2017

Light-absorbing impurities (LAIs), such as organic carbon (OC), black carbon (BC), and mineral dust (MD) deposited on the glacier surface can reduce albedo, thus accelerating the glacier melt. Surface fresh snow, aged snow, granular ice, and snowpits samples were collected between August 2014 and October 2015 on the Xiao Dongkemadi (XDKMD) glacier (33°04'N, 92°04'E) in the central Tibetan Plateau (TP). The spatiotemporal variations of LAIs concentrations in the surface snow/ice were observed to be consistent, differing mainly in magnitudes. LAIs concentrations were found to be in the order: granular ice > snowpit > aged snow > fresh snow, which must be because of post-depositional effects and enrichment. In addition, more intense melting led to higher LAIs concentrations exposed to the surface at a lower elevation, suggesting a strong negative relationship between LAIs concentrations and elevation. The scavenging efficiencies of OC and BC were same (0.07 ± 0.02 for OC, 0.07 ± 0.01 for BC), and the highest enrichments was observed in late September and August for surface snow and granular ice, respectively. Meanwhile, as revealed by the changes in the OC/BC ratios, intense glacier melt mainly occurred between August and October. Based on the SNow ICe Aerosol Radiative (SNICAR) model simulations, BC and MD in the surface snow/ice were responsible for about 52% ± 19% and 25% ± 14% of the albedo reduction, while the radiative forcing (RF) were estimated to be 42.74 ± 40.96 W m− 2 and 21.23 ± 22.08 W m− 2, respectively. Meanwhile, the highest RF was observed in the granular ice, suggesting that the exposed glaciers melt and retreat more easily than the snow distributed glaciers. Furthermore, our results suggest that BC was the main forcing factor compared with MD in accelerating glacier melt during the melt season in the Central TP. © 2017 Elsevier B.V.

Rupakheti D.,CAS Institute of Tibetan Plateau Research | Rupakheti D.,University of Chinese Academy of Sciences | Tripathee L.,Chinese Academy of Sciences | Tripathee L.,Lappeenranta University of Technology | And 9 more authors.
Human and Ecological Risk Assessment | Year: 2017

The concentration of 13 metals (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, and Hg) and their associated health risk assessment was performed for two Himalayan lakes, urban Phewa and remote Gosainkunda, from Nepal. Water Quality Index (WQI), Metal Index (MI), Hazard Quotient (HQ), Hazard Index, and Cancer Risk were calculated in order to evaluate the water quality of these lakes. Correlation analysis revealed that Mn and Fe were derived from natural geological weathering processes and Pb, V, Cr, Co, Ni, Cu, Zn, and Cd might have originated from anthropogenic sources. The results revealed that WQI of the remote lake fell into excellent water quality and urban lake fell into poor water quality, which is also supported by the MI calculation. Moreover, the HQ of Mn in urban lake showed values greater than unity suggesting its health risk to the local inhabitants. The cancer index values indicated “high” risk due to Cr, whereas Cd possesses “very low” cancer risk on local population residing nearby areas. This study provides the useful database and suggests for the regular assessment and policy formulation for safeguarding the natural water bodies in the region. © 2017 Taylor & Francis Group, LLC

Sharma Ghimire P.,CAS Institute of Microbiology | Sharma Ghimire P.,University of Chinese Academy of Sciences | Sharma Ghimire P.,Himalayan Environment Research Institute HERI | Jin C.,CAS Institute of Microbiology | Jin C.,University of Chinese Academy of Sciences
Current Microbiology | Year: 2017

Filamentous fungi play a dynamic role in health and the environment. In addition, their unique and complex hyphal structures are involved in their morphogenesis, integrity, synthesis, and degradation, according to environmental and physiological conditions and resource availability. However, in biotechnology, it has a great value in the production of enzymes, pharmaceuticals, and food ingredients. The beginning of nomenclature of overall fungi started in early 1990 after which the categorization, interior and exterior mechanism, function, molecular and genetics study took pace. This mini-review has emphasized some of the important aspects of filamentous fungi, their pattern of life cycle, history, and development of different strategic methods applied to exploit this unique organism. New trends and concepts that have been applied to overcome obstacle because of their basic structure related to genomics and systems biology has been presented. Furthermore, the future aspects and challenges that need to be deciphered to get a bigger and better picture of filamentous fungi have been discussed. © 2017 Springer Science+Business Media, LLC

Paudyal R.,Chinese Academy of Sciences | Paudyal R.,Himalayan Environment Research Institute HERI | Paudyal R.,University of Chinese Academy of Sciences | Kang S.,Chinese Academy of Sciences | And 15 more authors.
Science of the Total Environment | Year: 2017

Long-term monitoring of global pollutant such as Mercury (Hg) in the cryosphere is very essential for understanding its bio-geochemical cycling and impacts in the pristine environment with limited emission sources. Therefore, from May 2015 to Oct 2015, surface snow and snow-pits from Xiao Dongkemadi Glacier and glacier melt water were sampled along an elevation transect from 5410 to 5678 m a.s.l. in the central Tibetan Plateau (TP). The concentration of Hg in surface snow was observed to be higher than that from other parts of the TP. Unlike the southern parts of the TP, no clear altitudinal variation was observed in the central TP. The peak Total Hg (HgT) concentration over the vertical profile on the snow pits corresponded with a distinct yellowish-brown dust layer supporting the fact that most of the Hg was associated with particulate matter. It was observed that only 34% of Hg in snow was lost when the surface snow was exposed to sunlight indicating that the surface snow is less influenced by the post-depositional process. Significant diurnal variation of HgT concentration was observed in the river water, with highest concentration observed at 7 pm when the discharge was highest and lowest concentration during 7–8 am when the discharge was lowest. Such results suggest that the rate of discharge was influential in the concentration of HgT in the glacier fed rivers of the TP. The estimated export of HgT from Dongkemadi river basin is 747.43 g yr− 1, which is quite high compared to other glaciers in the TP. Therefore, the export of global contaminant Hg might play enhanced role in the Alpine regions as these glaciers are retreating at an alarming rate under global warming which may have adverse impact on the ecosystem and the human health of the region. © 2017 Elsevier B.V.

Raut R.,Kathmandu University | Bajracharya R.M.,Kathmandu University | Sharma S.,Kathmandu University | Sharma C.M.,Kathmandu University | And 10 more authors.
Water, Air, and Soil Pollution | Year: 2017

This study assessed the level of potentially toxic trace metals (PTMs), seasonal variations, and their possible sources from the surface water and lake-bed sediment of Panchpokhari lake series, an alpine and glacial lake at 4160 m a.s.l. in Central Nepal. The lake series have five lakes, with Lake-1 larger than others. So, Lake-1 was investigated thoroughly during pre-monsoon and post-monsoon seasons. Sediment core was collected from the deepest basin of the Lake-1 during pre-monsoon. Most of the PTM concentrations were higher in the pre-monsoon season; however, Sc, Cr, Cu, Zn, As, and Ag were higher in the post-monsoon. This is an indication that the lake has been impacted either by natural or long-range transported atmospheric pollutants. Ti, Sb, and Ag had extremely high enrichment factor (EF) in waters, whereas Cd, Zn, and As had high EF in sediments indicating that these metals originated from anthropogenic sources. Furthermore, PTM concentrations in the sediment were in the increasing order of Hg < Cd < Ag < Mo < Sb < Sn < As < U < Sc < Co < Cs < Cu < Pb < Ni < Cr < V < Zn < Rb < Mn < Ti < Fe and showed that the upper layer (top 10 cm) of lake sediment has been receiving a higher load of PTMs in the recent period. he observed EF values also suggested that major sources of PTMs in the sediment were from crustal origin except for a few metals (Ti, V, Sb, and Ag) which were enriched anthropogenically due to long-range transport of atmospheric pollutants, deposited at the higher elevations. Nevertheless, the level of pollution in sediments was low as indicated both by EF and geo-accumulation index. © 2017, Springer International Publishing AG.

Tripathee L.,Chinese Academy of Sciences | Tripathee L.,Lappeenranta University of Technology | Tripathee L.,Himalayan Environment Research Institute HERI | Kang S.,Chinese Academy of Sciences | And 5 more authors.
Atmosphere | Year: 2016

The total suspended particulate (TSP) samples were collected from April 2013 to April 2014 at the urban location of Pokhara valley in western Nepal. The major aims were to study, quantify, and understand the concentrations and variations of TSP and major water-soluble inorganic ions (WSIIs) in the valley with limited data. The annual average TSP mass concentration was 135.50 ± 62.91 μg/m3. The average analyzed total WSIIs accounted for 14.4% of total TSP mass. Major anions and cations in TSP samples were SO4 2- and Ca2+, respectively. Seasonal differences in atmospheric conditions explain the clear seasonal variations of ions, with higher concentrations during pre-monsoon and winter and lower concentrations during the monsoon period. Neutralization factor calculations suggested that Ca2+ in the Pokhara valley mostly neutralizes the acidity in the atmosphere. Principle component analysis, NO3 -/SO4 2- ratio, and non-sea salt fraction calculations suggested that the WSIIs in the valley were mostly derived from anthropogenic activities and crustal mineral dust, which was also supported by the results from precipitation chemistry over the central Himalayas, Nepal. In addition, back trajectories analysis has suggested that the air pollution transported from and through Indo-Gangetic Plains (IGP) during the dry periods, which has resulted in high ionic loadings during this period. Average NO3 -/SO4 2- ratio was found to be 0.69, indicating the dominance of stationary sources of TSP in Pokhara valley. Secondary inorganic aerosols can have an adverse health impact on the human population in the valley. The data set from this one-year study provides new insights into the composition of WSIIs in the foothills of the Himalayas, which can be of great importance for understanding the atmospheric environment in the region.

Tripathee L.,Chinese Academy of Sciences | Tripathee L.,Himalayan Environment Research Institute HERI | Tripathee L.,Lappeenranta University of Technology | Kang S.,Chinese Academy of Sciences | And 13 more authors.
Environmental Earth Sciences | Year: 2016

Soils in the fragile Himalayan region could be affected by the transport and deposition of potentially toxic trace metals (PTEs) from urban and industrialized areas of South Asia. The transported pollutants could pose a serious threat to the soil quality in the pristine regions at high elevations having minimal direct human influence. Therefore, it is important to understand the geochemical and physical characteristics of soils in this region and determine the extent of their chemical pollution. In order to achieve these objectives, soil samples were collected from different elevation transects of the Langtang Himalaya in Nepal. The samples were analyzed for PTEs and rare earth elements for the purpose of identifying their possible sources and to evaluate their environmental risk in the region. The PTEs and REEs concentrations were measured by ICP-MS (X-7; Thermo-elemental, USA) and total organic carbon (TOC) by TOC analyzer. The results of this study were comparable to those of the world average background soil as well as the Tibetan plateau surface soil. TOC revealed a decreasing trend with increasing elevation. Correlation analysis and principle component analysis (PCA) indicated that most of the elements were highly associated with major crustal elements, suggesting that their primary sources were of natural origin. Furthermore, the geo-accumulation index (Igeo), enrichment factor (EF) and pollution index (PI) analyses indicated that the Himalayan soils represent minimal pollution and the data from this study may be used as background values for the Himalayan region in the future studies. REEs in the soil samples were found to be consistent with an order of average abundance of the Earth’s crust. In addition, the chondrite-normalized REE distribution of the light REE suggested enrichment of LREE and Eu depletion. Moreover, this study emphasized that soils of the Himalayan region could, in future, be under threat of elemental pollution from long-range transport via atmospheric circulation and deposition. © 2016, Springer-Verlag Berlin Heidelberg.

Sharma C.M.,Kathmandu University | Sharma C.M.,CAS Institute of Tibetan Plateau Research | Sharma C.M.,Lappeenranta University of Technology | Kang S.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | And 11 more authors.
Water, Air, and Soil Pollution | Year: 2015

Two lakes, one from the remote high altitude on the southern slope of the Himalaya (Lake Gosainkunda) and another from the urban mid-hill area (Lake Phewa) were studied for evaluating anthropogenic inputs of the pollutants, particularly mercury (Hg) and other trace elements (TEs) (such as Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb). A total of 77 water samples, 24 from Lake Gosainkunda and 53 from Lake Phewa were collected from different depth profiles during October/November 2010. Concentrations of Hg were significantly higher in Lake Gosainkunda compared to Lake Phewa probably due to long-range transport of Hg and its deposition on high altitudes of the Himalayas, in addition to the probable natural geological sources. Some of the TEs (such as Al, V, Cr, Mn, Fe, and Co) show crustal origin in Lake Gosainkunda, whereas others such as Ni, Cu, Zn, Cd, and Pb indicate possible anthropogenic origin (enrichment factor (EF)∈>∈4). On the other hand, Al, V, Cr, Ni, and Cu show crustal origin in Lake Phewa and the remaining TEs (Mn, Fe, Co, Zn, Cd, and Pb) showed high EF values relative to the crustal elements suggesting potential anthropogenic inputs of the pollutants. The study further indicates that two studied lakes have different potential sources for Mn, Fe, Co, Ni, and Cu regarding TE pollution. A high enrichment of Cd and Pb in high-altitude lake (with less anthropogenic activities) compared to the low-altitude lake (with high anthropogenic activities) indicates atmospheric long-range transportation of the pollutants in remote areas of the Himalayas which might be possible as air masses pass through the industrial areas and deposit in the high altitudes. © 2015 Springer International Publishing Switzerland.

Paudyal R.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Paudyal R.,University of Chinese Academy of Sciences | Paudyal R.,Himalayan Environment Research Institute HERI | Paudyal R.,Lappeenranta University of Technology | And 11 more authors.
Environmental Earth Sciences | Year: 2016

During pre-monsoon of 2013, water samples were collected from 30 sites of two major rivers, viz. Dudh Koshi and Indrawati to assess the river water quality on the southern side of the Nepalese Himalayas. The physical parameters such as pH, EC, turbidity and water temperature were measured in the field and major ions (Na+, NH4 +, K+, Ca2+, Mg2+, Cl−, SO4 2−, and NO3 −) and element concentrations (Li, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Cs, Ba, Pb, U, Y, Zr, Nb and Cd) in the water samples were analyzed in the laboratory. The result indicated river waters were neutral to mostly alkaline with pH ranging from 6.57 to 8.81 and EC ranging from 10.5 to 321 μS/cm. The lower values of turbidity were recorded in the pristine tributaries of Dudh Koshi, whereas the main rivers had the higher values with a range of 0.51–515 NTU. Bicarbonate (HCO3 −) showed a significant correlation with Ca2+ and Mg2+, suggesting carbonate weathering as the dominant geochemical process in the region. Furthermore, the Gibbs plot also suggested the dominance of rock weathering. Very low concentration of trace elements was found in most of the samples which were within the WHO guidelines. In addition, the concentrations of toxic elements such as As and Pb were below the detectable limits in most of the samples. Furthermore, the analysis of PCA suggests that most of the elements originated from natural weathering; however, there were some evidences of anthropogenic effect on water quality which may not be critical issue at present but can be of concern in future. © 2015, Springer-Verlag Berlin Heidelberg.

Tripathee L.,Chinese Academy of Sciences | Tripathee L.,Lappeenranta University of Technology | Tripathee L.,Himalayan Environment Research Institute HERI | Kang S.,Chinese Academy of Sciences | And 9 more authors.
Bulletin of Environmental Contamination and Toxicology | Year: 2016

This study investigates the contamination levels and risk assessments of 14 elements (Ba, Cd, Co, Cr, Cu, Pb, Li, Mn, Mo, Ni, Sb, Sr, V and Zn) in three sub-basins of Himalayan rivers. Water samples were collected and the hazard quotient (HQ), hazard index (HI), and water quality index (WQI) were calculated. Total average concentrations of the metals were 135.03, 80.10 and 98.34 µg/L in Gandaki, Indrawati and Dudh Koshi rivers, respectively. The results of HQ and HI were less than unity, suggesting a low risk of metals in the region. However, HQ for antimony (Sb) was found to be 4.4 × 10−1, 2.1 × 10−1 and 5.4 × 10−1 in three river basins and HI near unity, suggesting its potential risk. Additionally, HI for Cd in Indrawati was 5.4 × 10−1 also close to unity, suggesting that Cd could have a potential risk to the local residents and aquatic ecosystems. Further, WQI suggested that the rivers Gandaki and Indrawati fell into the excellent water quality and river Dudh Koshi fell into good water quality. © 2016 Springer Science+Business Media New York

Loading Himalayan Environment Research Institute HERI collaborators
Loading Himalayan Environment Research Institute HERI collaborators