Xun Wang

Xun Wang
Institute of Geochemistry, Chinese Academy of Sciences · State Key Laboratory of Environmental Geochemistry

Doctor of Philosophy

About

73
Publications
15,424
Reads
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1,713
Citations
Introduction
During last five years, I focused on the mercury (Hg) source-sink relationships in terrestrial ecosystems and utilized regional/global Hg modeling to document the natural Hg inventories, and atmospheric Hg mass balance in East Asia. I also use Hg isotopes to demonstrate influences of climate changes on Hg biogeochemical processes.
Additional affiliations
March 2021 - present
Institute of Geochemistry, Chinese Academy of Sciences
Position
  • Professor
May 2019 - March 2021
Southwest University in Chongqing
Position
  • Professor (Full)
Description
  • Focusing on terrestrial mercury biogeochemical cycling, and on impacts from climate change, landuse change on mercury accumulation, transport, and transformation in glacier regions.
January 2017 - April 2019
Institute of Geochemistry, Chinese Academy of Sciences
Position
  • PostDoc Position
Education
September 2011 - December 2016
University of Chinese Academy of Sciences
Field of study
  • Geochemistry

Publications

Publications (73)
Article
Plant roots are responsible for transporting large quantities of nutrients in forest ecosystems and yet are frequently overlooked in global assessments of Hg cycling budgets. In this study, we systematically determined the distribution of total Hg mass and its stable isotopic signatures in a subtropical evergreen forest to elucidate sources of Hg i...
Article
Full-text available
Significant knowledge gaps in mercury (Hg) cycling challenge our ability to assess the effectiveness of the Minamata Convention on Mercury in reducing human and wildlife Hg exposure due to the complicated impacts of climate change. In this study, we comprehensively quantified the Hg spatial distribution and determined the Hg stable isotopes to unde...
Article
Soils in glacier forefields have a significant capacity for atmospheric CH4 uptake, but this pattern could be changed by high soil water content (SWC). The Hailuogou Glacier in SW China is a typical temperate monsoon glacier on siliceous bedrock, where a forefield soil chronosequence has developed with progressive glacier recession. To understand C...
Article
Rice grain consumption is a primary pathway of human mercury exposure. To trace the source of rice grain mercury in China, we developed a rice paddy mercury transport and transformation model with a grid resolution of 1 km × 1 km by using the unit cell mass conservation method. The simulated total mercury (THg) and methylmercury (MeHg) concentratio...
Article
Source-specific risk apportionment for soil heavy metals (HMs) is crucial for pollution mitigation and risk control in coal-mining areas. The ecological and human health risks resulting from different sources were evaluated through an integrated method that combines risk assessments with positive matrix factorization (PMF) model. Thirty soil sample...
Article
Mercury (Hg) is a toxic metal released into the environment through human activities and natural processes. Human activities have profoundly increased the budget of Hg in the atmosphere and altered...
Article
Understanding atmospheric mercury (Hg) accumulation in remote montane forests is critical to assess the Hg ecological risk to wildlife and human health. To quantify impacts of vegetation, climatic and topographic factors on Hg accumulation in montane forests, we assessed the Hg distribution and stoichiometric relations among Hg, carbon (C), and nit...
Article
Tropical forest contributes to >50% of global litterfall mercury (Hg) inputs and surface soil Hg storage, while with limited understanding of Hg biogeochemical processes. In this study, we displayed the 5−m resolution of Hg spatial distribution in three 1-ha tropical forest plots across the latitudinal gradient in Southwest China, and determined Hg...
Article
Full-text available
As climate change accelerates, extreme weather events become more severe and frequent. We analyzed the datasets of decade-long observation (2005-2020) of mercury (Hg) stored in two subtropical evergreen forests to understand the impacts of extreme weather on the sequestration of atmospheric Hg in forest ecosystems. Results show a weak correlation b...
Article
Manganese (Mn) ores contain substantial concentrations of mercury (Hg), and mining and smelting of Mn ores can bring Hg into the surrounding aquatic environment through atmospheric deposition, leaching of electrolytic Mn residue and Mn gangue dump. However, limited is known that how these processes influence the environmental behaviors of Hg in wat...
Article
Litterfall mercury (Hg) input has been regarded as the dominant Hg source in montane forest floor. To depict combining effects of vegetation, climate and topography on accumulation of Hg in montane forests, we comprehensively quantified litterfall Hg deposition and decomposition in a serial of subtropical forests along an elevation gradient on both...
Article
Forest ecosystem accounts for 31% of global land areas and plays a key role in the global biogeochemical cycling of mercury (Hg). In this critical review, datasets of Hg flux measurements and Hg isotopic compositions in the environmental compartments of forests in the last three decades are synthesized to examine the budgets of Hg mass balance and...
Article
The heavy metal accumulation in the Tibet Plateau (TP) poses a serious ecologic risk to the health of human and the other biota. Given the TP far away from the large anthropogenic emission sources, the rapid development of traffic activities during last several decades possibly leads to the elevated heavy metal concentration in the roadside soils....
Article
In this study, we hypothesized that the distribution patterns of trace metal elements in montane regions would be controlled by the local climate, human activities, vegetation distribution and soil development. Hence, we selected nine forest sites among the elevation of 850 m to 2650 m on the windward (western slope) and leeward (eastern slope) slo...
Article
Full-text available
Land surface emissions are an important source of atmospheric total gaseous mercury (TGM); however, its role on the variations of TGM isotopic compositions and concentrations has not been properly evaluated. In this study, TGM isotope compositions, a powerful tracer for sources and transformation of Hg, were measured at 10 urban sites and one rural...
Article
High geological background levels of trace elements (TEs) and high population density in the karst areas of southwest China have imposed environmental pressure on the fragile ecosystems in this region. Understanding the mass budget of TEs, especially the toxic ones, is of great importance to sustain future developments. This study investigates the...
Article
The effect of long-term applications of fertilizer form and rate on methylmercury concentration in rice grain has been previously reported. However, there remains a large gap in understanding fertilizer treatments affect the transformation of mercury (Hg) in paddy soils and the translocation of Methylmercury (MeHg) in rice plants. Thus, we investig...
Article
The accuracy of mercury (Hg) dendrochemistry has been questioned because significant knowledge gaps exist in understanding the Hg translocation and mobility in tree-ring. In this study, we evaluated Hg concentrations and isotopic profiles in the tree-ring at a Hg artisanal mining site and a control site with the documented local Hg production inven...
Article
Karst regions have long been recognised as landscapes of ecological vulnerability, however the mass balance and fate of mercury (Hg) in karst regions have not been well documented. This study focused on the largest contiguous karst area in China and investigated Hg mass balance in two catchments, one with high geological Hg (Huilong) and the other...
Preprint
Full-text available
Land surface emissions are an important source of atmospheric total gaseous mercury (TGM), however, its role on the variations of TGM isotopic compositions and concentrations has not been properly evaluated. In this study, TGM isotope compositions, a powerful tracer for sources and transformation of Hg, were measured at ten urban sites and one rura...
Article
Litterfall mercury (Hg) deposition is the dominant source of soil Hg in forests. Identifying reduction processes and tracking the fate of legacy Hg on forest floor are challenging tasks. Interplays between isotopes of carbon (C) and nitrogen (N) may shed some lights on Hg biogeochemical processes because their biogeochemical cycling closely links w...
Article
Organic soil is an important transient reservoir of mercury (Hg) in terrestrial ecosystems, but the fate of deposited Hg in organic forest soil is poorly understood. To understand the dynamic changes of deposited Hg on forest floor, the composition of stable Hg and carbon (C) isotopes in decomposing litters and organic soil layer was measured to co...
Article
Mercury (Hg) deposition through litterfall has been regarded as the main input of gaseous elemental mercury (Hg0) into forest ecosystems. We hypothesize that earlier studies largely underestimated this sink because the contribution of Hg0 uptake by moss and the downward transport to wood and throughfall is overlooked. To test the hypothesis, we inv...
Article
In comparison to the extensively documented mercury (Hg) biomagnification in food chains of aquatic/or aquatic-related systems, Hg biomagnification in food chains in strictly terrestrial systems is poorly explored. Here, we report Hg biomagnification through food webs in a monoculture subtropical pine forest in southwest China. A clear pine needle-...
Article
Sediment column and soil samples collected from 12 sampling sites in four regions of the Ruxi River, a typical tributary of the Three Gorges Reservoir, were analyzed for eight selected heavy metals including Cr, Ni, Cu, Mn, Zn, Cd, Pb, and Hg to evaluate their spatial and vertical distribution, source, and biological toxic effects. The results show...
Article
Historical mercury (Hg) mining in the Wanshan Hg mining area in southwest China and other regions worldwide has contaminated soils and left a legacy of health risks for communities consuming crop products harvested from these soils. Agricultural planning strategy is urgently needed in these regions for reducing human exposure to Hg pollution throug...
Article
Significance In this study, we identify a process that recaptures atmospheric Hg in glacier-retreated areas driven by global warming. Melting of glaciers is known to release Hg originally locked in ice into the atmosphere and downstream ecosystems. Recession of glaciers promotes rapid establishment of vegetative ecosystems that capture more atmosph...
Article
Full-text available
China is the largest rice producer and consumer in the world, and mercury (Hg) levels, particularly methylmercury (MeHg), in rice and health exposure risks are public concerns. Total Hg (THg) and MeHg levels in 767 (domestic ¼ 709 and abroad ¼ 58) Chinese commercial rice were investigated to evaluate Hg pollution level, dietary exposures and risks...
Article
A data gap in the evergreen broadleaf (EB) forest ecosystems has resulted in large uncertainties in estimating the quantity of global air–soil exchange of elemental mercury vapor (Hg0). In this study, we systematically measured the soil pore gas Hg0 concentration, air–soil Hg0 exchange flux and associated environmental parameters to elucidate the p...
Article
Soil is the largest Hg reservoir globally. Data of Hg concentration in surface soil are fundamental to understanding environmental Hg cycling. However, present knowledge on the quantity and global distribution of Hg in soil remains deficient. Using stable Hg isotopic analyses and geospatial data, the concentration and global spatial distribution of...
Article
Full-text available
Atmospheric particulate-bound mercury (PBM) plays an important role in the geochemical cycling of mercury (Hg). This study reviewed research progress of the PBM, including the possible emission and deposition pathways, measurement methods and the global distribution. The primary PBM sources are anthropogenic sources, but natural sources could be al...
Article
Full-text available
The original version of this article unfortunately contained a mistake in units.
Article
Full-text available
China took aggressive air pollution control measures from 2013-2017, leading to the mitigation of atmospheric mercury pollution as a co-benefit. This study is the first to systematically evaluate the effect of five major air pollution control measures in reducing mercury emissions, the total gaseous mercury (TGM) concentration and mercury depositio...
Article
Full-text available
Processes facilitated by precipitation play an important role on mercury (Hg) accumulation on forest floor and therefore key to Hg cycling in forest ecosystems. Sites along the windward slope of 1,250 to 2,400 m at Mt. Ailao, Southwestern China, have higher precipitation than the leeward slope sites. In this study, measurements of Hg concentration...
Article
Rice is an important source of selenium (Se) exposure; however, the transformation and translocation of Se in the soil-rice system remain poorly understood. Here, we investigated the speciation of Se in Se-rich soils from Enshi, Central China and assessed which Se species is bioavailable for rice grown in Enshi. Extremely high Se concentrations (0...
Article
Full-text available
Mainland China is the largest emission region of anthropogenic mercury (Hg) in the world. There have been concerns regarding the emission outflow and chemical transport budget of Hg in the region. Earlier assessments of Hg chemical transport are based on relatively outdated emission data. Recent estimates for anthropogenic (Wu et al., 2016, doi: 10...
Article
Rice consumption can be a major pathway for mercury (Hg) exposure, which can cause health hazards to Chinese residents. To accurately assess the potential health risks, the bioaccessibility of Hg in rice samples collected at background and Hg-contamination sites was examined using four in vitro methods. The results showed that < 50% of the total me...
Article
Full-text available
Global forest ecosystems account for 31% of global land areas, and the cycling of materials in the forest has been considered the most complicated among all terrestrial ecosystems also from the perspective of mercury (Hg). Elucidation of the Hg biogeochemical processes in the forest ecosystem yields insights on how atmospheric mercury is evaded and...
Article
Mercury (Hg) accumulation in montane forested areas plays an important role in global Hg cycling. In this study, we used the Hg isotope tracer to understand sources and accumulation processes of Hg in 23 forest sites at the eastern fringe of the Tibetan Plateau (TP). Litter in the TP has a mean total Hg concentration of 32±12 ng g-1, and the 0-60 c...
Article
Full-text available
There exists observational evidence that gaseous elemental mercury (GEM) can be readily removed from the atmosphere via chemical oxidation followed by deposition in the polar and sub-polar regions, free troposphere, lower stratosphere, and marine boundary layer under specific environmental conditions. Here we report GEM depletions in a temperate mi...
Article
Forests play an important role in global mercury (Hg) cycling. To explain the high Hg accumulation in subtropical forest ecosystems, we studied temporal dynamics of Hg, carbon (C), nitrogen (N), and sulfur (S) in forest soil profiles, as well as litterfall flux and precipitation, in an old-growth moist evergreen broadleaf (EB) forest and a mossy co...
Article
Full-text available
Mercury (Hg) emission from natural surfaces plays an important role in global Hg cycling. The present estimate of global natural emission has large uncertainty and remains unverified against field data, particularly for terrestrial surfaces. In this study, a mechanistic model is developed for estimating the emission of elemental mercury vapor (Hg-0...
Code
This code is the for the paper of Wang, X. et, al., ACP 2016 (doi:10.5194/acp-16-1-2016). The development implements recent advancements in the understanding of air–soil and air–foliage exchange of Hg0 and redox chemistry in soil and on surfaces, incorporates the effects of soil characteristics and land use changes by agricultural activities, and i...
Article
Full-text available
The isotopic composition of atmospheric total gaseous mercury (TGM) and particle-bound mercury (PBM) and mercury (Hg) in litterfall samples have been determined at urban/industrialized and rural sites distributed over mainland China for identifying Hg sources and transformation processes. TGM and PBM near anthropogenic emission sources display nega...
Article
There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg0)to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using stat...
Article
Full-text available
There exists observational evidence that GEM can be readily removed from the atmosphere via chemical oxidation followed by deposition in the polar and sub-polar regions, free troposphere, lower stratosphere, and marine boundary layer under specific environmental conditions. Here we report GEM depletions in a temperate mixed forest at Mt. Changbai,...
Article
Full-text available
Forest ecosystems play an important role in the global cycling of mercury (Hg). In this study, we characterized the Hg cycling at a remote evergreen broadleaf (EB) forest site in southwest China (Mt. Ailao). The annual Hg input via litterfall is estimated to be 75.0 ± 24.2 µg m-2 yr-1 at Mt. Ailao. Such a quantity is up to one order of magnitude gr...
Article
Understanding the sources and transformations of mercury (Hg) in the free troposphere is a critical aspect of global Hg research. Here we present one year of observations of atmospheric Hg speciation and gaseous elemental Hg (GEM) isotopic composition at the high-altitude Pic du Midi Observatory (2860 m a.s.l) in France. Bi-weekly integrated GEM fr...
Article
Full-text available
Mercury (Hg) emission from natural surfaces plays an important role in global Hg cycling. The present estimate of global natural emission has large uncertainty and remains unverified against field data, particularly for terrestrial surfaces. In this study, a mechanistic model is developed for estimating the emission of elemental mercury vapor (Hg0)...
Article
Full-text available
Reliable quantification of air–surface fluxes of elemental Hg vapor (Hg0) is crucial for understanding mercury (Hg) global biogeochemical cycles. There have been extensive measurements and modeling efforts devoted to estimating the exchange fluxes between the atmosphere and various surfaces (e.g., soil, canopies, water, snow, etc.) in the past thre...
Article
Biomass burning from the Indo-China Peninsula region is an important source of atmospheric mercury (Hg). We isolated eighteen unique transport events over 2 years using observations of Hg and CO at a high-altitude background site in southwestern China (Mt. Ailao Observatory Station) to assess the transport and impact of Hg emissions from biomass bu...
Article
To evaluate the impact of regional mercury (Hg) emissions and understand possible source regions of atmospheric Hg in eastern China, two-year observation for speciated atmospheric Hg was conducted at the Dameishan Atmospheric Observatory (DAO), a mountain site near the east coast of China. The observed concentration of total gaseous Hg (TGM) was 3....