Estimating nitrogen risk to Himalayan forests using thresholds for lichen bioindicators

Himalayan forests are biodiverse and support the cultural and economic livelihoods of their human communities. They are bounded to the south by the Indo-Gangetic Plain, which has among the highest concentrations of atmospheric ammonia globally. This source of excess nitrogen pushes northwards into the Himalaya, generating concern that Himalayan forests will be impacted. To estimate the extent to which atmospheric nitrogen is impacting Himalayan forests we focussed on lichen epiphytes, which are a well-established bioindicator for atmospheric nitrogen pollution. First, we reviewed published literature describing nitrogen thresholds (critical levels and loads) at which lichen epiphytes are affected, identifying a mean and confidence intervals based on previous research conducted across a diverse set of biogeographic and ecological settings. Second, we used estimates from previously published atmospheric chemistry models (EMEP-WRF and UKCA-CLASSIC) projected to the Himalaya with contrasting spatial resolution and timescales to characterise model variability. Comparing the lichen epiphyte critical levels and loads with the atmospheric chemistry model projections, we created preliminary estimates of the extent to which Himalayan forests are impacted by excess nitrogen; this equated to c. 80–85% and c. 95–98% with respect to ammonia and total nitrogen deposition, respectively. Recognising that lichens are one of the most sensitive bioindicators for atmospheric nitrogen pollution, our new synthesis of previous studies on this topic generated concern that most Himalayan forests are at risk from excess nitrogen. This is a desk-based study that now requires verification through biological surveillance, for which we provide key recommendations

Long-term trends of direct nitrous oxide emission from fuel combustion in South Asia

An increasing concentration of nitrous oxide (N2O) in the global atmosphere can perturb the ecological balance, affecting the climate and human life. South Asia, one of the world's most populous regions, is a hotspot for N2O emission. Although agriculture traditionally dominated the region, economic activities are rapidly shifting towards industry and energy services. These activites may become the largest emitters of N2O in future. Yet, few attempts have been made to estimate long-term direct N2O emission from fuel combustion for the different energy-consuming sectors in the South Asian region. Therefore, the present study developed a comprehensive sectoral N2O emission inventory for South Asian countries for the time period of 1990–2017, with projections till 2041. It revealed that the average N2O emission from fuel combustion in the South Asia region is about 40.96 Gg yr−1 with a possible uncertainty of ±12 Gg yr−1, showing an increase of more than 100% from 1990 to 2017. Although India is the major contributor, with an average of 34 Gg yr−1 of N2O emissions, in terms of growth, small countries like Bhutan and Maldives are dominating other South Asian countries. Sector-wise, the residential sector contributed a maximum emission of 14.52 Gg yr−1 of N2O but this is projected to reduce by more than 50% by 2041. This is because of the successful promotion of cleaner fuels like liquefied petroleum gas over more polluting fuelwood. Power generation contributed 9.43 Gg yr−1of N2O emissions, exhibiting a maximum growth of 395%, followed by road transport (289%) and industry (231%). Future N2O emissions from transport, power and industry are projected to rise by 2.8, 3.3, and 23.9 times their 2017 estimates, respectively, due to the incapability of current policies to combat rising fossil fuel consumption. Mitigation options, such as replacing diesel and compressed natural gas vehicles with electricity-driven vehicles, can decelerate N2O emissions to 45% by 2041 for road transport. A 41% reduction is possible by displacing coal with renewables in the power and industry sectors. Overall, the South Asian contribution to global N2O emissions has enlarged from 2.7% in 1990 to 5.7% in 2007–2016, meaning there is an urgent need for N2O emission mitigation in the region

Weed research issues, challenges, and opportunities in Bhutan

Rice, maize and wheat account for 96% of the total food grain production in Bhutan signifying their importance for food security and the socioeconomic value of the Bhutanese agriculture. However, various biotic and abiotic factors impede optimum production of these cereals with weeds as one the main biotic constraints in attaining the full realisation of potential yields. In Bhutan, weeds have the potential to cause rice yield loss up to 50%. Similarly, 50% of the labour in maize production is for hand weeding. Key challenges for weeds management are labour availability, small farm sizes and potential risks of developing herbicide resistance from unsuitable usage patterns. Currently, rice is the only crop which receives herbicide, with long-term usage of a single chemical, butachlor. Manual weeding continues to be the main form of weed management in rice and maize, though the effectiveness of herbicide in maize has been demonstrated. Wheat is currently un-weeded, and no chemicals are used. Developing alternative herbicides to butachlor with different modes of action, and providing training on proper usage are likely to become more important. Considering the existing wide-spread use of low-external-input farming systems in Bhutan, non-chemical tactics will continue to have a key role in weed management. Some of these methods include competitive cultivars, optimum planting configurations, intercropping and strategic agronomic management. Incorporating these into an integrated package that includes herbicides may have long-term benefits for farmers

Factors associated with multidrug-resistant tuberculosis (MDR-TB) in Bhutan: A nationwide case-control study

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is a growing public health concern globally. In Bhutan, the rates of MDR-TB are high. Data on the risk factors of MDR-TB that can help inform policies are limited in Bhutan. This study aimed to determine the risk factors associated with MDR-TB. METHODS: A nationwide unmatched case-control study was conducted that included 79 MDR-TB cases and 118 controls. Data was collected by trained health workers through interviews using a structured questionnaire. Logistic regression analysis was performed to identify the risk factors associated with MDR-TB. RESULTS: The mean age of the participants was 32.4 and 33.7 years among the cases and the controls, respectively. In the multivariate analysis, the odds of having MDR-TB was higher among those who slept for less than 9 hours a day (AOR: 2.77, 95%CI: 1.11-6.92), frequently travelled in public transport (AOR: 2.96, 95% CI: 1.36-6.48), and had previous TB treatment (AOR: 5.90, 95%CI: 2.55-13.64). A greater number of rooms was also marginally associated with odds of having MDR-TB. CONCLUSIONS: The findings suggest previous TB treatment, inadequate sleep duration, and travelling by public transport to be the risk factors associated with having MDR-TB in Bhutan. Intensification of early case detection, strengthening directly observed treatment strategy, improving treatment adherence, and increasing awareness can help control the rising MDR-TB epidemic

Glacier environment and climate change in Bhutan—an overview

Bhutan, a part of the Eastern Himalayas, is a tiny land-locked country hosting rich biodiversity apart from glaciers and snow capped mountains. With similar to 70% of Bhutan under forest cover, this water-rich country promises to maintain at least 60% of the landmass under forest in perpetuity at any given point of time. Yet, climate change hasn't pardoned this carbon-neutral nation. This article conveys a brief idea about the dent that climate change is leaving on the glacier environment in Bhutan. Bhutan is undergoing warming at an unprecedented rate with evidences suggesting higher warming trends during winter months and also at higher altitudes (>4000 m.a.s.l.) (Sharma et al., 2009). With large diversity of glaciers in the region, comprehensive field-based studies have been difficult due to rugged terrain, political issues and limited manpower and financial aid. Yet several remote sensing based have suggested glaciers in Bhutan are melting. Evidences suggest oldest stage of glaciers in Bhutan extended down to 2600 m.a.s.l. (Mool et al., 2001); whereas in the present day, they are found only above 4000 m.a.s.l. Glacial retreat in Bhutan has been extensive (Karma et al., 2003; Rupper et al., 2012; Naito et al., 2012; Bajracharya and Shrestha, 2011; Bajracharya et al., 2014; Veettil et al., 2015) leading to formation of supra-glacial, pro-glacial and moraine dammed lakes. Particularly in Bhutan and Eastern Himalayas, threat from glacial lake outburst floods is high. With 22 potentially dangerous glacial lakes, there is high risk and hazard potential to the regions lying downstream from outburst. In spite of being an environmentally sustainable country with a conservative approach, Bhutan is at the frontline of climate change-related threats. Future water security is not warranted under this scenario. This can have serious implications on water-dependent-economy of Bhutan that thrives on hydropower, agriculture and tourism. Extensive research is called for in Bhutan, apart from efforts to adapt and mitigate climate change

Factors associated with multidrug-resistant tuberculosis (MDR-TB) in Bhutan: A nationwide case-control study.

BackgroundMultidrug-resistant tuberculosis (MDR-TB) is a growing public health concern globally. In Bhutan, the rates of MDR-TB are high. Data on the risk factors of MDR-TB that can help inform policies are limited in Bhutan. This study aimed to determine the risk factors associated with MDR-TB.MethodsA nationwide unmatched case-control study was conducted that included 79 MDR-TB cases and 118 controls. Data was collected by trained health workers through interviews using a structured questionnaire. Logistic regression analysis was performed to identify the risk factors associated with MDR-TB.ResultsThe mean age of the participants was 32.4 and 33.7 years among the cases and the controls, respectively. In the multivariate analysis, the odds of having MDR-TB was higher among those who slept for less than 9 hours a day (AOR: 2.77, 95%CI: 1.11-6.92), frequently travelled in public transport (AOR: 2.96, 95% CI: 1.36-6.48), and had previous TB treatment (AOR: 5.90, 95%CI: 2.55-13.64). A greater number of rooms was also marginally associated with odds of having MDR-TB.ConclusionsThe findings suggest previous TB treatment, inadequate sleep duration, and travelling by public transport to be the risk factors associated with having MDR-TB in Bhutan. Intensification of early case detection, strengthening directly observed treatment strategy, improving treatment adherence, and increasing awareness can help control the rising MDR-TB epidemic

Correlates of sedentary behaviour among Bhutanese adolescents: Findings from the 2016 Global School-based health survey

2020 Elsevier Ltd Background: Sedentary behaviour is shown to be associated with cardiometabolic health including obesity, and mental health. This study examined the factors associated with sedentary behaviour among Bhutanese adolescents. Methods: The nationally-representative dataset of the Bhutan Global School-based Health Survey conducted in 2016 was analysed in this study. Multiple logistic regression using the backward elimination approach was performed to identify the factors associated with sedentariness. The analysis accounted for the complex survey design of the national survey. Results: The weighted prevalence of sedentary behaviour among Bhutanese adolescents was 29.12%. The multivariable analysis showed that higher grades, being a day student, consumption of soft drinks and fast foods, substance use, feeling lonely and suicidal behaviour were associated with higher odds of sedentary behaviour. Short duration of sleep was associated with reduced odds of sedentariness, whereas longer duration with increased odds. In the girls\u27 sample, higher grade, student type, fast food intake, physical activity, longer sleep duration, substance use, and suicidal thought were the factors predicting sedentariness. Among boys, higher grade, soft drink and fast food consumption, physical activity, short sleep duration, smoking and drug use, and loneliness were the significant factors. Conclusions: The results suggest plausible gender differences in the factors influencing sedentariness among adolescents of Bhutan. Gender-specific policies such as those aimed to reduce substance abuse, increase access to mental health services, and promote healthy lifestyles and behaviours are needed to reduce the adverse impacts of sedentary behaviour. Interventions targeting students in higher grades and day students may yield larger gains

Multiple Sexual Partners and Its Associated Factors among Bhutanese Adolescents: Findings from 2016 Global School-Based Student Health Survey

Data on factors influencing multiple sexual partners that can inform cost-effective interventions are limited in Bhutan. This study examined factors associated with multiple sexual partners among adolescents. We analyzed the data of 7437 school-going adolescents from the 2016 Bhutan Global School-based Student Health Survey. Multivariable logistic regression stratified by sex was conducted. The prevalence of sex with multiple partners was 7.39%, with a much higher prevalence among males than females. In the overall sample, males, those &gt;15 years of age, who smoked, consumed alcohol, used drugs, exhibited truancy, and were unmonitored by parents, had higher odds of having sex with multiple partners. In both males and females, being &gt;15 years old, smoking, and drug use were associated with having multiple sexual partners. Alcohol use and truancy were significant only among males, whereas a lack of parental monitoring was significant only among females. The findings suggest that reducing substance use and enhancing parental support, and targeting males and older adolescents may yield larger gains.</jats:p