Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from <0.005 to 1.014 mg L(-1) where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg(-1). The arsenic content in different parts of plants are found in the order of roots>shoots>leaves>edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg(-1))>onion bulb (0.45 mg As kg(-1))>cauliflower (0.33 mg As kg(-1))>rice (0.18 mg As kg(-1))>brinjal (0.09 mg As kg(-1))>potato (<0.01 mg As kg(-1)).     

Evolving policies for conservation: An Historical Profile of the Protected Area System of Nepal

Nepal has instituted progressive conservation programmes since the 1970s. This move was in reaction to very rapid rates of land clearance in the lowland areas of the country and an opening up to the world that led to nature-based tourism as a major economic enterprise. Formal conservation began with the passage of national legislation in 1973 offering strong protection for national parks and wildlife reserves, but denied usufruct rights to rural communities. From the late 1970s to the 1990s, the legislation was amended several times. Each case was, in several fundamental ways, a loosening of control by government authorities. Nepal now has buffer zone legislation and allows for the designation of conservation areas in addition to the more-strictly defined categories. Beginning in the 1990s, both government and foreign-backed projects have been implementing landscape level conservation approaches; a number of initiatives in trans-boundary protected area management with India and China have also begun and non-governmental organizations have taken an increasingly active role. This paper considers the expansion of the protected areas network in light of historical, cultural and economic factors and concludes that Nepal has been reactive in adopting conservation programmes. Both outside and inside influences have strongly affected the development of conservation programmes and there are several areas in which more work needs to be done. This includes the need for implementing both national and international conservation law and adopting social and biological monitoring programmes in and around protected areas. In addition, factors outside the control of conservation officials (i.e. a Maoist insurgency) have indirectly hindered conservation programmes in recent years and have greatly complicated prospects for further success.     

Attribution of aerosol light absorption to black carbon and volatile aerosols

We investigated the contribution of volatile aerosols in light-absorption measurement by three filter-based optical instruments [aethalometer, continuous light-absorption photometer (CLAP), and continuous soot monitoring system (COSMOS)] at Gosan Climate Observatory (GCO) from February to June 2012. The aerosol absorption coefficient (σ _abs) and the equivalent black carbon (BC) mass concentration (M _BC) measured by the aethalometer and CLAP showed good agreement with a difference of 9 %, which is likely due to the instrumental uncertainty. However, σ _abs and M _BC measured by the COSMOS with a heated inlet were found to be approximately 44 and 49 % lower than those measured by the aethalometer and CLAP under ambient conditions, respectively. This difference can be attributed to the light absorption by the volatile aerosols coexisting with the BC. Even considering inherent observational uncertainty, it suggests that approximately 35–40 % difference in the σ _abs and M _BC can be contributed by volatile aerosols. Increase in the difference of M _BC measured by the aethalometer and COSMOS with the increasing thermal organic carbon (OC) measured by Sunset OC/EC analyzer further suggests that the filter-based optical instruments without the use of a heater are likely to enhance the value of σ _abs and M _BC, because this sample air may contain both BC and volatile aerosols.     

A conceptual framework for understanding illegal killing of large carnivores

The growing complexity and global nature of wildlife poaching threaten the survival of many species worldwide and are outpacing conservation efforts. Here, we reviewed proximal and distal factors, both social and ecological, driving illegal killing or poaching of large carnivores at sites where it can potentially occur. Through this review, we developed a conceptual social–ecological system framework that ties together many of the factors influencing large carnivore poaching. Unlike most conservation action models, an important attribute of our framework is the integration of multiple factors related to both human motivations and animal vulnerability into feedbacks. We apply our framework to two case studies, tigers in Laos and wolverines in northern Sweden, to demonstrate its utility in disentangling some of the complex features of carnivore poaching that may have hindered effective responses to the current poaching crisis. Our framework offers a common platform to help guide future research on wildlife poaching feedbacks, which has hitherto been lacking, in order to effectively inform policy making and enforcement.     

Constructions of Climate Change on the Radio and in Nepalese Lay Focus Groups

To date analyses of media climate change constructions have mostly focused on coverage in western newspapers. Consideration of coverage in developing countries, and analyses of media constructions alongside local understandings of climate change are comparatively rare. This article provides an analysis of the construction of climate change on Nepalese radio and lay constructions of environment and climate change within the country. Data from a radio program and six focus groups are analyzed. Analysis of the radio program indicated that climate change was portrayed as a certain reality with national impacts caused by the actions of the West. While climate change dominated the radio headlines, in focus groups local environmental problems received far more attention. The paper aims to both inform directions for future climate change communication in Nepal and the wider research agenda.     

Seasonal variations of natural ventilation and radon-222 exhalation in a slightly rising dead-end tunnel

The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.     

Co-benefits of a carbon tax in Nepal

This paper analyzes the co-benefits of introducing a time variant carbon (C) tax scheme in Nepal, a hydropower resourceful country, by using a bottom up integrated energy system model based on the MARKet ALlocation (MARKAL) framework with time horizon of 2005–2050. It discusses the effects of C tax on energy mix, environmental emissions, energy supply security, energy efficiency, energy system cost, and employment benefit. The study shows that the C tax (that gradually increases from US13/tCO < sub > 2 < /sub > e in 2015 to US 13/tCO₂e in 2015 to US 200/tCO₂e by 2050) results in a reduction of the cumulative emission of greenhouse gases by 83.9 million tons CO₂e (12%) as compared to that in the base case. With the introduction of the C tax, there would be a need for additional hydropower capacity of 945 MW by 2050 as compared to the capacity in the base case. The emission of local pollutants consisting of sulphur dioxide (SO₂), nitrogen oxides (NO_x) and non-methane volatile organic compound (NMVOC) in 2050 would be reduced by 12%, 7% and 1% respectively under the C tax scenario. Total amount of imported energy would decrease by 13%, which corresponds to a reduction in discounted net fuel import cost by 5% during the study period. Furthermore, the C tax would result in new employment generation of 151 thousand man-years associated with the additional hydropower capacity requirement.     

Developing indicators for assessing land-use sustainability in a tropical agro-ecosystem: The case of Sakaekrang watershed,Thailand

While the concept of sustainable land management is now widely accepted, there remains considerable scope for developing location-specific land-use indicators for sustainability evaluation. A study was conducted to investigate the indicators of land-use sustainability in the context of tropical agro-ecosystems using the case of Sakaekrang watershed, Thailand. The biophysical data were generated from Geographic Information Systems (GIs) and the socioeconomic data were collected through a field survey. In the light of sustainable land management objectives, a total of 32 criteria were considered in the analysis to determine land-use sustainability and identify indicators that best explain the sustainability level. About one quarter of the agricultural area in the watershed meets the sustainability threshold, indicating a substantial unstable area in the watershed. Among 11 indicators that showed a significant relationship with the computed land-use sustainability, land quality, source of farm income, and evapo transpiration were the most important.     

Effect of acute concentration of zinc on the biochemical contents of brain of Labeo rohita: an FT-IR study

Heavy metal discharges to aquatic environment are of great concern due to their toxicity and accumulative behavior. Zinc is an essential trace element required for different physiological functions and plays important role in cellular metabolism. However, it becomes toxic when elevated concentrations are introduced into the environment. The aim of this work is to analyze zinc induced biochemical changes in the brain tissues of Labeo rohita fingerlings using Fourier Transformation Infrared Spectroscopy. Several important features have been observed in the zinc intoxicated brain tissues, namely, altered membrane lipid, altered protein profile and decreased glycogen content, indicating an alteration in the lipid and protein profiles leading to modification in membrane composition. Further, it is observed that the acute exposure to zinc causes some alteration in protein profile with a decrease in α-helix and an increase in random coil structures.     

Performance Evaluation of Human-Specific Viral Markers and Application of Pepper Mild Mottle Virus and CrAssphage to Environmental Water Samples as Fecal Pollution Markers in the Kathmandu Valley,Nepal

Monitoring of environmental water is crucial to protecting humans and animals from possible health risks. Although numerous human-specific viral markers have been designed to track the presence of human fecal contamination in water, they lack adequate sensitivity and specificity in different geographical regions. We evaluated the performances of six human-specific viral markers [Aichi virus 1 (AiV-1), human adenoviruses (HAdVs), BK and JC polyomaviruses (BKPyVs and JCPyVs), pepper mild mottle virus (PMMoV), and crAssphage] using 122 fecal-source samples collected from humans and five animal hosts in the Kathmandu Valley, Nepal. PMMoV and crAssphage showed high sensitivity (90–100%) with concentrations of 4.5–9.1 and 6.2–7.0 log₁₀ copies/g wet feces (n = 10), respectively, whereas BKPyVs, JCPyVs, HAdVs, and AiV-1 showed poor performances with sensitivities of 30–40%. PMMoV and crAssphage were detected in 40–100% and 8–90%, respectively, of all types of animal fecal sources and showed no significantly different concentrations among most of the fecal sources (Kruskal–Wallis test, P > 0.05), suggesting their applicability as general fecal pollution markers. Furthermore, a total of 115 environmental water samples were tested for PMMoV and crAssphage to identify fecal pollution. PMMoV and crAssphage were successfully detected in 62% (71/115) and 73% (84/115) of water samples, respectively. The greater abundance and higher mean concentration of crAssphage (4.1 ± 0.9 log₁₀ copies/L) compared with PMMoV (3.3 ± 1.4 log₁₀ copies/L) indicated greater chance of detection of crAssphage in water samples, suggesting that crAssphage could be preferred to PMMoV as a marker of fecal pollution.