Distribution and risk assessment of microplastics in water, sediment and brine shrimps in a remote salt lake on the Tibetan Plateau, China.

Microplastics (MPs) are pervasive environmental contaminants that have infiltrated even the most remote ecosystems. Despite their widespread distribution, the transfer patterns and impacts of MPs in remote lakes remain poorly understood. This study aimed to address the knowledge gap regarding the pathways and consequences of MP pollution in these isolated environments. Focusing on Kyêbxang Co, a remote salt lake in Tibet, this study investigated the transfer patterns, sources and ecological impacts of MPs, providing insights into their mobility and fate in pristine ecosystems. Water, sediment and biota (brine shrimp) samples from Kyêbxang Co, collected during the summer of 2020, were analyzed using µ-Raman spectroscopy to determine MP abundances, polymer types and potential sources. Findings indicated significant MP contamination in all examined media, with concentrations highlighting the role of runoff in transporting MPs to remote locations. The majority of detected MPs were small fragments (<0.5 mm), constituting over 93 %, with polypropylene being the predominant polymer type. The presence of a halocline may slow the descent of MPs, potentially increasing the exposure and ingestion risk to brine shrimp. Despite the currently low ecological risk estimated for MPs, this study underscores the need for long-term monitoring and development of a comprehensive ecological risk assessment model for MPs.

Exploring opportunities to strengthen rural tuberculosis health service delivery: a qualitative study with health workers in Tibet autonomous region, China.

OBJECTIVES: This qualitative study aimed to explore opportunities to strengthen tuberculosis (TB) health service delivery from the perspectives of health workers providing TB care in Shigatse prefecture of Tibet Autonomous Region, China. DESIGN: Qualitative research, semi-structured in-depth interviews. SETTING: The TB care ecosystem in Shigatse, including primary and community care. PARTICIPANTS: Participants: 37 semi-structured interviews were conducted with village doctors (14), township doctors and nurses (14), county hospital doctors (7) and Shigatse Centre for Disease Control staff (2). RESULTS: The three main themes reported include (1) the importance of training primary and community health workers to identify people with symptoms of TB, ensure TB is diagnosed and link people with TB to further care; (2) the need to engage community health workers to ensure retention in care and adherence to TB medications; and (3) the opportunity for innovative technologies to support coordinated care, retention in care and adherence to medication in Shigatse. CONCLUSIONS: The quality of TB care could be improved across the care cascade in Tibet and other high-burden, remote settings by strengthening primary care through ongoing training, greater support and inclusion of community health workers and by leveraging technology to create a circle of care. Future formative and implementation research should include the perspectives of health workers at all levels to improve care organisation and delivery.

Constructing cropland ecological stability assessment method based on disturbance-resistance-response processes and classifying cropland ecological types.

The cropland ecosystem stability (CES) has received increasing attention, especially in ecologically fragile areas, because of its impact on cropland quality, agricultural production and its ability to resist external disturbances. In this study, we first introduced the concepts of resilience and resistance, proposed the ecosystem disturbance-resistance-response process, and established a framework for evaluating the spatial and temporal dynamics of the CES based on RS data, and innovatively combined the RS assessment results of CES with soil field samples data to further classify cropland ecological types (CET) in a key agricultural areas of the Qinghai-Tibetan Plateau, which can effectively identify those croplands in need of priority ecological protection. Results indicate that the combined interactions of disturbance, resistance and response systems affect CES, forming a complex process with significant fluctuations and spatial variations. We also conclude that the disturbance system is positively influenced by topography and precipitation, while slope negatively affects resistance system. Hydrothermal conditions positively influence resistance system, while the response system is influenced by environmental factors at a lower intensity in six periods. It was interesting to note that soil α-biodiversity indicators are significantly and positively correlated with CES at the end of the study period. Therefore, based on the CES assessment results, we further combined the soil α-biodiversity indicators to classify the type of spatial pattern of CET and found that the eastern and northern areas have better quality, which implied an increase in the CES and a higher level of soil biodiversity, which was ideal for cropland expansion. On the contrary, we concluded that the ecosystem maintenance of the Huangshui headwaters and the northern mountainous areas needs to be strengthened in order to reverse the ecological fragility here and safeguard the cropland productive capacity.

Soil quality assessment in low human activity disturbance zones: a study on the Qinghai-Tibet Plateau.

The Qinghai-Tibet Plateau, located at the Third Pole and known as the "Asian water tower," serves as a crucial ecological barrier for China. Grasping the soil quality on the Qinghai-Tibet Plateau holds paramount importance for the rational and scientific exploitation of soil resources within the region and is essential for vegetation restoration and ecological reconstruction. This study, conducted in Maqin County, Qinghai Province, collected 1647 soil samples (0-20 cm) within a study area of 6300 km2. Sixteen soil indicators were selected that were split into beneficial (N, P, S, and B), harmful (Cr, Hg, As, Pb, Ni, and Cd), and essential (Cu, Zn, Se, Ga, K, and Ca) elements. The Soil Quality Index (SQI) was computed to assess soil quality across diverse geological contexts, land cover classifications, and soil profiles. The results indicate that the overall SQI in the study area was comparatively high, with most regions having an SQI between 0.4 and 0.6, categorized as moderately to highly satisfactory. Among the different geological backgrounds, the highest SQI was found in the Quaternary alluvium (0.555) and the lowest in the Precambrian Jinshuikou Formation (0.481). Regarding different land-use types, the highest SQI was observed in glacier- and snow-covered areas (0.582) and the lowest in other types of grassland (0.461). The highest SQI was recorded in typical alpine meadow soil (0.521) and the lowest in leached brown soil (0.460). The evaluation results have significant reference value for the sustainable utilization and management of soil in Maqin County, Qinghai Province, China.

First comprehensive assessment of dietary chlorinated paraffins intake and exposure risk for the rural population of the Tibetan Plateau, China.

Knowledge regarding the occurrence of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) in foodstuffs and their dietary exposure risks for rural Tibetan residents remains largely unknown. Herein, we collected main foodstuffs (including highland barley, vegetables, Tibetan butter, mutton, and yak beef) across the rural Tibetan Plateau and characterized the CP profiles and concentrations. The highest SCCPs concentrations were detected in Tibetan butter (geometric mean (GM): 240.6 ng/g wet weight (ww)), followed by vegetables (59.4 ng/g ww), mutton (51.4 ng/g ww), highland barley (46.3 ng/g ww), and yak beef (31.7 ng/g ww). For MCCPs, the highest concentrations were also detected in Tibetan butter (319.5 ng/g ww), followed by mutton (181.9 ng/g ww), vegetables (127.0 ng/g ww), yak beef (71.2 ng/g ww), and highland barley (30.3 ng/g ww). The predominant congener profiles of SCCPs were C13Cl7-8 in mutton and yak beef, C10Cl7-8 in Tibetan butter, and C10-11Cl6-7 in highland barley and vegetables. The predominant congener profiles of MCCPs were C14Cl7-9 in all sample types. Combined with our previous results of free-range chicken eggs, the median estimated daily intakes (EDIs) of SCCPs and MCCPs via diet for Tibetan rural adults and children was estimated to be 728.8 and 1853.9 ng/kg bw/day and 2565.6 and 5952.8 ng/kg bw/day, respectively. In the worst scenario, MCCPs might induce potential health risks for rural Tibetan population. To our knowledge, this is the first systematic dietary exposure research of SCCPs and MCCPs in the remote rural areas.

Development and testing of a new Tibetan medicine constitutional self-assessment tool.

Previous studies have attempted to develop measurement tools for constitutional identification in Traditional Tibetan Medicine (TTM), but they have limitations. We developed a new constitution self-assessment tool that is more firmly grounded in the Gyüzhi, the foundational text of Tibetan Medicine. This new self-assessment tool takes the form of a questionnaire in which the items represent the diagnostic criteria of the three central elemental dynamics of Tibetan medicine (rLung, Tripa, Béken) and are related to the body, psychology, and diet preferences. We tested versions of the new questionnaire in three samples of Tibetan adults (total n = 973) in Qinghai Province and evaluated its validity in 90 respondents randomly selected from the main samples. These respondents completed the questionnaire and were independently evaluated by Tibetan Medicine experts using traditional methods of constitution identification. A comparison of the results led us to revise the original questionnaire. Based on expert advice, we combined similar and overlapping items to simplify and improve the scale. Cronbach's alpha was used to assess internal consistency and indicated that the final scale is reliable. There was 80-93 % agreement between experts' identifications and self-assessment responses in the survey when both types of data were available. The Traditional Tibetan Medicine (TTM) constitution scale developed in this paper has a strong basis in theory and TTM practice. It can be used by Tibetan medical practitioners, other health care providers, researchers, and the lay public to identify individual constitution and help determine appropriate treatment.

Spatial and temporal evolution of urban resilience in China and analysis of barriers: Based on a sustainable development perspective.

With the increasing uncertainty of urban security, urban resilience construction with risk awareness and bottom-line thinking has become essential for promoting sustainable urban development. This paper measures China's urban resilience development index (CRDI) based on 284 cities in China (except Tibet) using the entropy method from four dimensions: economic, social, environmental, and infrastructure, and analyzes it by combining coupling coordination degree and barrier factor analysis. We find that: (1) At the national level, CRDI and its sub-dimensions show an increasing trend in time, a decreasing spatial layout from coastal to inland, and a "high-high-low-low" clustering feature in space. (2) At the regional level, the CRDI is from high to low in the east, middle, and west order. The sub-dimensions are from high to low in the order of east, middle, and west for economic, social, and infrastructure resilience and from high to low in the order of east, west, and middle for environmental resilience. (3) To coupling coordination degree, the CRDI index coupling coordination is increasing in time trend but is still on the verge of dissonance. (4) Social resilience is the main obstacle factor. In the indicator layer, human resources, innovation, education, security, living, and environmental protection are the areas where CRDI coordinated development is the key to improvement. Based on the above empirical evidence, this paper proposes countermeasures to optimize urban resilience construction from four perspectives: economic, social, environmental, and infrastructure.

Controlling desertification brings positive socioeconomic benefits beyond regional environmental improvement: Evidence from China's Gonghe Basin.

Large-scale desertification combatting programs (DCPs) are crucial tools for addressing climate change and improving the ecological environment. Despite existing research having predominantly focused on assessing the ecological benefits of DCPs, the understanding of their impacts on surrounding socioeconomic aspects remains limited, particularly at the household level. To comprehensively evaluate the returns of DCPs, this study chose the representative desertification control area of the Gonghe Basin on the Qinghai-Tibet Plateau as the research region and identified the dual benefits in terms of ecological environment and socioeconomic gains. Firstly, two essential ecosystem services, carbon sequestration (CS) and wind erosion prevention (WEP), were assessed using the MODIS NPP dataset and the RWEQ model from 2001 to 2021. Household surveys were conducted in 36 villages across 14 townships within the Gonghe Basin to gain a deeper understanding of the residents' socioeconomic conditions. Through regression analysis, the study assessed the impact of DCPs on the regional ecological environment and household socioeconomic status. The research findings revealed significant improvements in CS and WEP across a significant portion of the study area from 2001 to 2021. Upon analyzing data from 401 household questionnaires, it was generally perceived by residents in the Gonghe Basin that the implementation of DCPs led to environmental improvements and increased their income levels. Further regression analysis revealed a significant impact of both natural factors and the extent of resident participation in the projects on the ecological environment surrounding the villages and on household socioeconomic aspects. With increased resident engagement in the projects, the likelihood of increased household income and life satisfaction was higher. The diverse array of DCPs implemented in the Gonghe Basin not only improved the regional ecological environment but also stimulated socioeconomic development. In future projects, it is imperative to consider regional characteristics, align ecological effects, ensure the sustainability of livelihoods, and maximize the role of social capital.

Remarkable Contamination of Short- and Medium-Chain Chlorinated Paraffins in Free-Range Chicken Eggs from Rural Tibetan Plateau.

Rapid social-economic development introduces modern lifestyles into rural areas, not only bringing numerous modern products but also new pollutants, such as chlorinated paraffins (CPs). The rural Tibetan Plateau has limited industrial activities and is a unique place to investigate this issue. Herein we collected 90 free-range chicken egg pool samples across the rural Tibetan Plateau to evaluate the pollution status of CPs. Meanwhile, CPs in related soils, free-range chicken eggs from Jiangxi, and farmed eggs from markets were also analyzed. The median concentrations of SCCPs (159 ng g-1 wet weight (ww)) and MCCPs (1390 ng g-1 ww) in Tibetan free-range chicken eggs were comparable to those from Jiangxi (259 and 938 ng g-1 ww) and significantly higher than those in farmed eggs (22.0 and 81.7 ng g-1 ww). In the rural Tibetan Plateau, the median EDI of CPs via egg consumption by adults and children were estimated to be 81.6 and 220.2 ng kg-1 bw day-1 for SCCPs and 483.4 and 1291 ng kg-1 bw day-1 for MCCPs, respectively. MCCPs might pose potential health risks for both adults and children in the worst scenario. Our study demonstrates that new pollutants should not be ignored and need further attention in remote rural areas.

Assessment of macular choroidal and retinal thickness: a cohort study in Tibetan healthy children.

This research investigates the distribution, progressive changes, and contributing factors of macular choroidal and retinal thickness in Tibetan children utilizing swept-source optical coherence tomography (SS-OCT). The Lhasa childhood study recruited 1632 students from seven primary schools in Lhasa. These participants underwent OCT and ophthalmological evaluations, encompassing retinal and choroidal thickness measurements, refractive error, axial length (AL), and systemic examinations. The median age of the scholars was 8.57 ± 0.50 years with a median spherical equivalent (SE) of 0.19 ± 1.28D. Multivariate regression analysis revealed that thinner macular choroid thickness was correlated with lower value of SE, worse best-corrected visual acuity, higher mean arterial blood pressure (MABP) and boys, while retinal thickness was associated with better image quality and lower value of SE. The choroid and retina were significantly thinner in myopic children. SE was positively related to the thickness of all choroidal and full retinal subregions. In comparison to baseline data from 20 months prior, most regions of the full retina had significantly thinned. Choroidal thickness of Tibetan children is thinner than that of same-age children from other regions. Thinning of retina, the outer-sector GCC and GCIPL may be specified as a follow-up and prognostic indicator for myopia.

Sand fixation and human activities on the Qinghai-Tibet Plateau for ecological conservation and sustainable development.

The sand fixation ecosystem services and human activities on the Qinghai-Tibet Plateau (QTP) play a crucial role in local sustainable development and ecosystem health, with significant implications for surrounding regions and the global ecological environment. We employed an improved integrated wind erosion modeling system (IWEMS) model for the QTP to simulate sand fixation quantities under the unique low temperature and low pressure conditions prevalent on the plateau. Using the human footprint index (HFI), the intensity of human activities on the plateau was quantified. Additionally, an econometric model was constructed to analyze the impacts of the natural factors, the HFI, and policy factors on the sand fixation capacity. The results revealed that the average sand fixation quantity was 1368.0 t/km2/a, with a standard deviation of 1725.4 t/km2/a, and the highest value during the study period occurred in 2003. The average value of the HFI for 2020 was 6.69 with a standard deviation of 6.61, and the HFI exhibited a continuous growth trend from 2000 to 2020. Despite this growth, the average human activity intensity remained at a low level, with over 50 % of the area having an index value of <4.84. Overall, a strong negative correlation was observed between the sand fixation ecological capacity and the HFI on the QTP. However, extensive regions exhibited high values or low values for both indicators. The sand fixation capacity on the QTP is influenced by both natural and human factors. In light of these findings, suggestions are made for optimizing protected area design, rational control of human activity scales, and targeted human activity aggregation within certain regions as part of ecological conservation strategies. This study has implications for assessing sand fixation ecological functions in high-altitude regions and enhancing sand fixation capacity within the region, providing valuable practical guidance.

Grazing exclusion alters denitrification N2O/(N2O + N2) ratio in alpine meadow of Qinghai-Tibet Plateau.

Grazing exclusion has been implemented worldwide as a nature-based solution for restoring degraded grassland ecosystems that arise from overgrazing. However, the effect of grazing exclusion on soil nitrogen cycle processes, subsequent greenhouse gas emissions and underlying mechanisms remain unclear. Here, we investigated the effect of four-year grazing exclusion on plant communities, soil properties, and soil nitrogen cycle-related functional gene abundance in an alpine meadow on the Qinghai-Tibet Plateau. Using an automated continuous-flow incubation system, we performed an incubation experiment and measured soil-borne N2O, N2, and CO2 fluxes to three successive "hot moment" events (precipitation, N deposition, and oxic-to-anoxic transition) between grazing-excluded and grazing soil. Higher soil N contents (total nitrogen, NH4+, NO3-) and extracellular enzyme activities (ß-1,4-glucosidase, ß-1,4-N-acetyl-glucosaminidase, cellobiohydrolase) are observed under grazing exclusion. The aboveground and litter biomass of plant community was significantly increased by grazing exclusion, but grazing exclusion decreased the average number of plant species and microbial diversity. The N2O + N2 fluxes observed under grazing exclusion were higher than those observed under free grazing. The N2 emissions and N2O/(N2O + N2) ratios observed under grazing exclusion were higher than those observed under free grazing in oxic conditions. Instead, higher N2O fluxes and lower denitrification functional gene abundances (nirS, nirK, nosZ, and nirK + nirS) under anoxia were found under grazing exclusion than under free grazing. The N2O site-preference value indicates that under grazing exclusion, bacterial denitrification contributes more to higher N2O production compared with under free grazing (81.6 % vs. 59.9 %). We conclude that grazing exclusion could improve soil fertility and plant biomass, nevertheless it may lower plant and microbial diversity and increase potential N2O emission risk via the alteration of the denitrification end-product ratio. This indicates that not all grassland management options result in a mutually beneficial situation among wider environmental goals such as greenhouse gas mitigation, biodiversity, and social welfare.

Dietary habits of pastoralists on the Tibetan plateau are influenced by remoteness and economic status.

In general, dietary habits of pastoralists are livestock-derived, but are also influenced by external food sources under globalization. We hypothesized that dietary habits of pastoralists would be influenced by their remoteness, and that changes from the traditional diet would result in deviations in the local ecological chain. To test this hypothesis, we determined the δ13C and δ15N values of soil, plants, and hair of animals and pastoralists (n = 885). The δ13C value in human hair reflects the proportions of protein originating from C3 and C4 plants; whereas, the δ15N value reflects the proportions of protein derived from plants and animals, with higher values indicating a greater consumption of meat. The isotopic signatures enabled us to estimate the variation in dietary habits of pastoralists across a socio-economic gradient of easily accessible to remote areas on the Tibetan plateau, and to determine the trophic transfer of the isotopes along an ecological chain. The trophic magnification factor (TMF) evaluated the trophic transfer of δ15N in the soil-plants-animals-pastoralists ecological chain. The high δ15N values in soil and plants were not recovered in animals and pastoralists in easily accessible and developed areas, indicating the use of external feed and food resources, and that they deviated from the ecological chain. The mean δ13C (-22.0 ‰) and δ15N values (6.9 ‰) of pastoralists indicated diets consisting mainly of local C3 plants and animal products. However, pastoralists in remote areas relied more on meat protein and on the local ecological chain than pastoralists in easily accessible areas, as their δ15N values and trophic magnification factor of δ15N in the ecological chain were greater. In addition to remoteness, per capita GDP influenced dietary changes in pastoralists, with richer pastoralists consuming more external food. We concluded that dietary changes of pastoralists in the easily accessible areas were due to external food resources and alterations in the local ecological chain of animals and plant-based foods available to the pastoralists.

[Comparative Analysis of Influencing Factors of Health Service Utilization Among Urban and Rural Residents in Tibet].

Objective: To examine the differences and commonalities of factors influencing the utilization of health services among urban and rural residents in Tibet and to identify vulnerable populations in the utilization of health services, thereby providing references for the formulation of local health policies and the allocation of health resources. Methods: Using the Tibetan area data from the Sixth National Health Service Survey, we conducted statistical analysis of the health service utilization status of 8 297 residents of agro-pastoral areas and 2 179 residents of urban areas with χ 2 test and logistic regression model. Results: The two-week outpatient visit rates of residents in agro-pastoral areas and that of the urban residents were 65.3% and 57.1%, respectively, and the one-year hospitalization rates were 8.3% and 8.9%, respectively. The influencing factors of two-week outpatient visits for rural and pastoral residents included urban and rural health insurance coverage, Three Guarantees in One coverage, distance to medical facilities, chronic disease status, physical examination, family doctor contract status, employment status, and health status self-assessment. The influencing factors of two-week outpatient visit for urban residents included chronic disease status, urban and rural medical insurance coverage, health status self-assessment, health records, and physical examination. The factors influencing hospitalization for agro-pastoral residents were sex, age, marital status, urban and rural medical insurance coverage, Three Guarantees in One coverage, critical illness insurance, health self-assessment, mobility, health records, physical examination, and chronic disease status. The factors influencing the hospitalization of urban residents were sex, marital status, health status self-assessment, health records, urban employee medical insurance coverage, and chronic disease status. The factors influencing the hospitalization of urban residents were sex, marital status, health status self-assessment, health records, urban employee medical insurance coverage, and chronic disease status. Conclusion: The urban and rural residents in Tibet have relatively poor health and their awareness of seeking early medical help after they fall ill is relatively weak. The health institutions concerned should dedicate more attention to the vulnerable populations who have difficulty accessing health services, focus on the commonly shared influencing factors of health service utilization among urban and rural residents, take into account the differences, rationally allocate health resources, and improve the effective utilization rate of health services among residents in Tibet.

Ecological risk assessment and transmission of soil heavy metals in pastoral areas of the Tibetan plateau based on network environment analysis.

The Qinghai-Tibet Plateau is distinguished by its diverse ecosystems and biodiversity, which are highly dependent on their soil. In this study, a comprehensive analysis was conducted to assess the ecological risks in Maqin County, located on the Qinghai-Tibet Plateau, along with the local background values of soil elements, level of element enrichment, and source appointment of soil elements. The findings show that the background soil element levels in Maqin County were greater than the average soil content values in China. The soils in the study area exhibited pollution levels ranging from weak to moderate. The positive matrix factorization (PMF) model was employed to successfully categorized soil elements into four sources: F1 (natural sources), F2 (grazing sources), F3 (volcanic and rock fracture sources), and F4 (intrusive and deep rock source). Based on the characteristics of the ecological communities and the network environmental analysis model, ecological risks were directly introduced through vegetation and soil microorganisms, with subsequent transmission to other components of the ecosystem through the food chain. The integrated risks associated with vegetation, herbivores, soil microorganisms, and carnivores were 0.0106, 0.00193, 0.0282, and 0.00132, respectively. Notably, soil microorganisms were found to be the primary contributors to the total ecological risk in the study area. Furthermore, network environmental analysis and human health risk models revealed that F1, F2, F3, and F4 accounted for 16.85 %, 8.90 %, 21.76 %, and 52.49 % of the input risk of vegetation and soil microorganisms, respectively. Particularly, F4 emerged as the largest contributor to human health risks. This study provides valuable information for the preservation of the ecological environment in pastoral areas, contributing to the global promotion of sustainable ecological practices.

Associations of socioeconomic status and obesity with hypertension in tibetan adults in a Chinese plateau area.

BACKGROUND: Previous studies have identified that socioeconomic status (SES) and obesity are associated with hypertension. However, their interaction on hypertension risk has not yet been assessed. METHODS: The study used data from 6,069 Tibetan residents in Chengguan District in Lhasa, the Chinese Tibetan autonomous region's capital, based on a cohort study conducted from May 2018 to September 2019 in five provinces in southwest China. We used logistic regression models to assess the complex relations of SES and obesity with hypertension. RESULTS: Compared with individuals of high SES, low and moderate SES were positively associated with high risk of hypertension. SES and obesity have significant additive interaction on hypertension (general obesity by BMI: RERI = 1.33, P < 0.001; abdominal obesity by WC: RERI = 0.76, P < 0.001; abdominal obesity by WHtR: RERI = 0.96, P < 0.001). In people from the low and moderate SES segments, obesity was linked to an increased risk of hypertension, but the correlations were stronger in people from the moderate SES category. Compared with people of high SES and non obese, those with moderate SES and obesity had a higher risk of hypertension, and ORs were 4.38 (2.80, 6.84) for general obesity by BMI, 3.38 (2.05, 5.57) for abdominal obesity by WC, and 3.18 (1.57, 6.42) for abdominal obesity by WHtR. CONCLUSION: There is an independent and additive interaction effect of obesity and SES on the risk of hypertension. People with obesity, especially those of moderate and low SES, should reduce weight and waist circumference, and pay more attention to blood pressure. Moreover, the government, health administration departments, and society should prioritize improving the socioeconomic status of the Tibetan population and addressing risk factors like obesity.

Assessment of atmospheric heavy metal pollution in Qinghai-Tibet Plateau: Using mosses as biomonitor.

Atmospheric heavy metal (HM) pollution may pose a significant threat to the fragile ecosystem of Qinghai-Tibet Plateau (QTP). To investigate potential atmospheric HM pollution within the QTP region of China, mosses, along with other higher plants and soil, were collected from 33 sites for heavy metal measurement. The concentration ranges of Zn, Pb, Cd, and Cu in mosses were 6.07-69.9, 5.36-23.9, 0.60-1.05, and 14.4-50.5 mg·kg-1 (dry weight), respectively, significantly higher than those in other higher plants, except for Zn. The spatial distribution of relative concentrations (RCs; moss to top soil) of HMs varied considerably, indicating distinct differences in atmospheric Zn and Cu pollution levels between the northern and southern QTP. This study first reported that moderate regional atmospheric Cu pollution, primarily due to large-scale mining in recent years, had occurred, particularly in southern QTP. Pb also presented slight pollution due to anthropogenic activities. However, Cd showed almost no atmospheric pollution, while Zn concentrations were relatively high in southern QTP. Although less severe than atmospheric pollution levels in Chinese inland or coastal cities, the atmospheric pollution of Pb and Cu in QTP indicated by mosses were far more severe than global background areas, or even worse than most European cities.

Warming and Wetting will continue over the Tibetan Plateau in the Shared Socioeconomic Pathways.

We have used bias-corrected data from CMIP6 models to drive a regional climate model and project climate on the Tibetan Plateau (TP) in the 21st century. Changes in two background fields, namely, 2-meter air temperature and total precipitation, were analyzed. The results show that the WRF simulations capture the terrain effect that cannot be represented in low-resolution models. The simulation of temperature is better in summer than in winter, while the simulated precipitation is the opposite. By the end of the 21st century, the entire TP region experiences significant warming, with an average warming of 3°C and 7°C in the SSP245 and SSP585 scenarios, respectively. The western region shows a greater warming amplitude, with a maximum of more than 10°C in the SSP585 scenario. Most regions of the TP had significant increases in precipitation by the end of the 21st century, with precipitation increasing by 90 mm and 200 mm in the two scenarios, respectively. However, in the low-altitude areas of southeastern TP, total winter precipitation is significantly reduced in the SSP585 scenario. The strengthening of the East Asian summer monsoon and westerly disturbances collectively leads to a significant increase in precipitation within the TP region. By the end of the 21st century, the average annual precipitation in the TP is projected to reach approximately 600 millimeters.

Dietary sources apportionment and health risk assessment for trace elements among residents of the Tethys-Himalayan tectonic domain in Tibet, China.

Dietary intake of toxic elements (TEs) and essential trace elements (ETEs) can significantly impact human health. This study collected 302 samples, including 78 food, 104 drinking water, 73 cultivated topsoil, and 47 sedimentary rock from a typical area of Tethys-Himalaya tectonic domain. These samples were used to calculate the average daily dose of oral intake (ADDoral) and assess the health risks of five TEs and five ETEs. The results indicate that grain and meat are the primary dietary sources of TEs and ETEs for local residents. The intake of manganese (Mn) and copper (Cu) is mainly from local highland barley (66.90% and 60.32%, respectively), iron (Fe) is primarily from local grains (75.51%), and zinc (Zn) is mainly from local yak meat (60.03%). The ADDoral of arsenic (As), Mn, Fe and Zn were found to be higher than the maximum oral reference dose in all townships of study area, indicating non-carcinogenic health risks for local residents. Additionally, lead (Pb) and nickel (Ni) in 36.36% townships, and Cu in 81.82% townships were above the maximum oral reference dose, while As posed a carcinogenic risk throughout the study area. The concentrations of As, mercury (Hg), Pb, Mn, Cu Fe and selenium (Se) in grains were significantly correlated with those in soils. Moreover, the average concentrations of As in Proterozoic, Triassic, Jurassic and Cretaceous was 43.09, 12.41, 15.86 and 6.22 times higher than those in the South Tibet shell, respectively. The high concentrations of TEs and ETEs in the stratum can lead to their enrichment in soils, which, in turn, can result in excessive intake by local residents through the food chain and biogeochemical cycles . To avoid the occurrence of some diseases caused by dietary intake, it is necessary to consume a variety of exotic foods, such as high-selenium foods, foreign rice and flour in order to improve the dietary structure.

Groundwater quality characteristics and health risk assessment in the valley plain area of the western Qinghai-Tibet plateau.

Accurate evaluation of groundwater chemistry, quality, and human health risk could provide detailed and robust evidence of groundwater utilization. Gaer County is an important residential area in western Tibet. A total of 52 samples were collected from the Shiquan River Basin in Gaer County in 2021. Principal component analysis, ratiometric analysis of major ions, and geochemical modeling were conducted to clarify the characteristics of hydrogeochemical compositions and the controlling factors. The groundwater chemistry type is dominated by HCO3-Ca, and its ion concentration from high to low is Ca2+ > Na+ > Mg2+ > K+ and HCO3- > SO42- > Cl- > NO3- > F-. The groundwater compositions were determined by calcite and dolomite dissolution with cation exchange reaction. The human activity causes nitrate contamination, while arsenic contamination is attributed to surface water recharge. According to the Water Quality Index, 99% of the samples meet the requirements of drinking water. Groundwater quality is affected by the arsenic, fluoride, and nitrate concentrations. According to the human health risk assessment model, the cumulative noncarcinogenic risk (HITotal) values for children and the CR values of arsenic (CRArsenic) for adults are higher than 1 and 1E-6, respectively, which are unacceptable risk values. Therefore, appropriate remedial measures are recommended to reduce nitrate and arsenic concentrations in groundwater sources for protecting against further health risks. This study can provide theoretical support and effective groundwater management experience for ensuring groundwater safety in Gaer County and other similar regions around the world.