Spatial distribution of mercury deposition fluxes in Wanshan Hg mining area, Guizhou province, China

Abstract. The legacy of long-term mining activities in Wanshan mercury (Hg) mining area (WMMA), Guizhou, China including a series of environmental issues related to Hg pollution. The spatial distribution of gaseous elemental mercury (Hg0) concentrations in ambient air were monitored using a mobile RA-915+ Zeeman Mercury Analyzer during daytime and night time in May 2010. The data imply that calcines and mine wastes piles located at Dashuixi and on-going artisanal Hg mining activities at Supeng were major sources of atmospheric mercury in WMMA. For a full year (May 2010 to May 2011), sampling of precipitation and throughfall were conducted on a weekly basis at three sites (Shenchong, Dashuixi, and Supeng) within WMMA. Hg in deposition was characterized by analysis of total Hg (THg) and dissolved Hg (DHg) concentrations. The corresponding data exhibit a high degree of variability, both temporarily and spatially. The volume-weighted mean THg concentrations in precipitation and throughfall samples were 502.6 ng l−1 and 977.8 ng l−1 at Shenchong, 814.1 ng l−1and 3392.1 ng l−1 at Dashuixi, 7490.1 ng l−1and 9641.5 ng l−1 at Supeng, respectively. THg was enhanced in throughfall compared to wet deposition samples by up to a factor of 7. The annual wet Hg deposition fluxes were 29.1, 68.8 and 593.1 μg m−2 yr−1 at Shenchong, Dashuixi and Supeng, respectively, while the annual dry Hg deposition fluxes were estimated to be 378.9, 2613.6 and 6178 μg m−2 yr−1 at these sites, respectively. Dry deposition played a dominant role in total atmospheric Hg deposition in WMMA since the dry deposition fluxes were 10.4–37.9 times higher than the wet deposition fluxes during the whole sample period. Our data showed that air deposition was still an important pathway of Hg contamination to the local environment in WMMA.

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Spatial distribution of mercury deposition fluxes in Wanshan Hg mining area, Guizhou, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-5739-2012 ◽

2012 ◽

Vol 12 (2) ◽

pp. 5739-5769 ◽

Cited By ~ 2

Author(s):

Z. H. Dai ◽

X. B. Feng ◽

X. W. Fu ◽

P. Li

Keyword(s):

Spatial Distribution ◽

Dry Deposition ◽

Dominant Role ◽

Ambient Air ◽

Mining Area ◽

Atmospheric Mercury ◽

Mercury Deposition ◽

Night Time ◽

Deposition Fluxes ◽

Hg Mining

Abstract. A long-term mining history introduced a series of environmental problems in Wanshan Hg mining area, Guizhou, China. The spatial distribution of gaseous elemental Hg (Hg0) concentrations in ambient air were investigated using RA-915+ Zeeman Mercury Analyzer during day time and night time in May 2010, which showed that calcines and mine wastes piles located at Dashuixi and on-going artisanal Hg mining activities at Supeng were major sources of atmospheric mercury in Wanshan Hg mining area. Meanwhile, both precipitation and throughfall samples were collected weekly at Shenchong, Dashuixi, and Supeng from May 2010 to May 2011, respectively. Our data showed that the concentrations of different Hg species varied with a large range, and the annual volume-weighted mean total mercury (THg) concentrations in precipitation and throughfall samples were 502.6 ng L−1 and 977.8 ng L−1 at Shenchong, 814.1 ng L−1and 3392.1 ng L−1 at Dashuixi, 7490.1 ng L−1 and 9641.5 ng L−1 at Supeng, respectively. Besides, THg concentrations in all throughfall samples were 1–7 folds higher than those in precipitation samples. The annual wet Hg deposition fluxes were 29.1, 68.8 and 593.1 μg m−2 yr−1 at Shenchong, Dashuixi and Supeng, respectively, while the annual dry Hg deposition fluxes were estimated to be 378.9, 2613.6 and 6178 μg m−2 yr−1 at these sites, respectively. Dry deposition played a dominant role in total atmospheric Hg deposition in Wanshan Hg mining area since the dry deposition fluxes were 10.4–37.9 times higher than the wet deposition fluxes during the whole sample period. Our data showed that air deposition was still an important pathway of Hg contamination to the local environment in Wanshan Hg mining area.

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Atmospheric total gaseous mercury (TGM) concentrations and wet and dry deposition of mercury at a high-altitude mountain peak in south China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-23465-2009 ◽

2009 ◽

Vol 9 (6) ◽

pp. 23465-23504 ◽

Cited By ~ 11

Author(s):

X. W. Fu ◽

X. Feng ◽

Z. Q. Dong ◽

R. S. Yin ◽

J. X. Wang ◽

...

Keyword(s):

South China ◽

Dry Deposition ◽

Urban Areas ◽

Wet Deposition ◽

Ambient Air ◽

Total Gaseous Mercury ◽

Deposition Fluxes ◽

Wet And Dry Deposition ◽

Gaseous Mercury ◽

Seasonal And Diurnal Variations

Abstract. China is regarded as the largest contributor of mercury (Hg) to the global atmospheric Hg budget. However, concentration levels and depositions of atmospheric Hg in China are poorly known. Continuous measurements of atmospheric total gaseous mercury (TGM) were carried out from May 2008 to May 2009 at the summit of Mt. Leigong in south China. Wet and dry deposition fluxes of Hg were also calculated following collection of precipitation, throughfall and litterfall. Atmospheric TGM concentrations averaged 2.80±1.51 ng m−3, which was highly elevated compared to global background values but much lower than semi-rural and industrial/urban areas in China, indicating great emissions of Hg in central, south and southwest China. Seasonal and diurnal variations of TGM were observed, which reflected variations in source intensity, deposition processes and meteorological factors. Wet deposition of Hg was quite low, while its dry deposition of Hg (litterfall + throughfall-direct wet deposition) constituted a major portion of total deposition (~88% for total mercury (THg) and 84% for methyl mercury (MeHg)). This highlights the importance of vegetation to Hg atmospheric cycling. In a remote forest ecosystem of China, dry deposition of TGM, especially gaseous elemental mercury (GEM), was very important for the depletion of atmospheric Hg. Elevated TGM level in ambient air may accelerate the foliar uptake of Hg through air which may partly explain the elevated Hg dry deposition fluxes observed in Mt. Leigong.

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Total atmospheric mercury deposition in forested areas in South Korea

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-7653-2016 ◽

2016 ◽

Vol 16 (12) ◽

pp. 7653-7662 ◽

Cited By ~ 12

Author(s):

Jin-Su Han ◽

Yong-Seok Seo ◽

Moon-Kyung Kim ◽

Thomas M. Holsen ◽

Seung-Muk Yi

Keyword(s):

South Korea ◽

Dry Deposition ◽

Wet Deposition ◽

Deciduous Forest ◽

Atmospheric Mercury ◽

Deposition Flux ◽

Mercury Deposition ◽

Temperate Deciduous Forest ◽

Deposition Fluxes ◽

Forested Areas

Abstract. In this study, mercury (Hg) was sampled weekly in dry and wet deposition and throughfall and monthly in litterfall, and as it was volatilized from soil from August 2008 to February 2010 to identify the factors influencing the amount of atmospheric Hg deposited to forested areas in a temperate deciduous forest in South Korea. For this location there was no significant correlation between the estimated monthly dry deposition flux (litterfall + throughfall – wet deposition) (6.7 µg m−2 yr−1) and directly measured dry deposition (9.9 µg m−2 yr−1) likely due primarily to Hg losses from the litterfall collector. Dry deposition fluxes in cold seasons (fall and winter) were lower than in warmer seasons (spring and summer). The volume-weighted mean (VWM) Hg concentrations in both precipitation and throughfall were highest in winter, likely due to increased scavenging by snow events. Since South Korea experiences abundant rainfall in summer, VWM Hg concentrations in summer were lower than in other seasons. Litterfall fluxes were highest in the late fall to early winter, when leaves were dropped from the trees (September to November). The cumulative annual Hg emission flux from soil was 6.8 µg m−2 yr−1. Based on these data, the yearly deposition fluxes of Hg calculated using two input approaches (wet deposition + dry deposition or throughfall + litterfall) were 6.8 and 3.6 µg m−2 yr−1, respectively. This is the first reported study which measured the amount of atmospheric Hg deposited to forested areas in South Korea, and thus our results provide useful information to compare against data related to Hg fate and transport in this part of the world.

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Total Atmospheric Mercury Deposition in Forest Areas in Korea

10.5194/acp-2016-7 ◽

2016 ◽

Author(s):

Jin-Su Han ◽

Yong-Seok Seo ◽

Moon-Kyung Kim ◽

Thomas M. Holsen ◽

Seung-Muk Yi

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Deciduous Forest ◽

Atmospheric Mercury ◽

Litter Production ◽

Mercury Deposition ◽

Temperate Deciduous Forest ◽

Deposition Fluxes ◽

Mercury Volatilization ◽

High Precipitation

Abstract. Atmospheric mercury dry and wet deposition, mercury in throughfall and litterfall, and mercury volatilization from soil were measured during August 2008 to February 2010 in a temperate deciduous forest in Korea. The yearly estimated mercury budget was calculated using two input approaches. For this location the annual mercury accumulation was estimated to be 6.8 μg m-2 yr-1 or 3.9 μg m-2 yr-1 depending on the approach used. Cumulative wet and throughfall fluxes were 4.3 and 6.7 μg m-2 yr-1, respectively. The annual litterfall flux was 4.6 μg m-2 yr-1 and was highest from October to December due to the increased litter production during that period. The annual Hg emission flux from soil was 6.8 μg m-2 yr-1. The overall ratio of wet deposition, throughfall, and litterfall was 1 : 1.6 : 1.1. Cumulative dry deposition fluxes of gaseous oxidized mercury (GOM) were highest in spring 2009 (10.0 ± 2.0 μg m-2 yr-1), followed by summer 2009 (5.8 ± 4.2μg m-2 yr-1), winter 2008 (5.1 ± 5.0 μg m-2 yr-1), winter 2009 (4.6 ± 5.7 μg m-2 yr-1), fall 2008 (1.9 ± 1.0 μg m-2 yr-1) and fall 2009 (1.2 ± 1.4 μg m-2 yr-1) while dry deposition fluxes for particulate bound mercury (PBM) were highest in summer 2009 (9.6 ± 9.0 μg m-2 yr-1), followed by winter 2009 (5.3 ± 5.9 μg m-2 yr-1), winter 2008 (3.8 ± 2.0 μg m-2 yr-1), spring 2009 (3.3 ± 2.6 μg m-2 yr-1), fall 2008 (3.0 ± 1.7 μg m-2 yr-1) and fall 2009 (1.2 ± 0.4 μg m-2 yr-1). The VWM TM concentration in throughfall (14.4 ± 7.1 ng L-1) was about two times higher than that in wet deposition (5.9 ± 3.8 ng L-1). Wet deposition and throughfall fluxes were higher in summer than those in other seasons possibly due to a high precipitation depth.

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Methylmercury in rice (Oryza sativa L.) grown from the Xunyang Hg mining area, Shaanxi province, northwestern China

Pure and Applied Chemistry ◽

10.1351/pac-con-11-09-16 ◽

2011 ◽

Vol 84 (2) ◽

pp. 281-289 ◽

Cited By ~ 19

Author(s):

Guangle Qiu ◽

Xinbin Feng ◽

Bo Meng ◽

Xun Wang

Keyword(s):

Oryza Sativa ◽

Oryza Sativa L ◽

Ambient Air ◽

Mining Area ◽

Northwestern China ◽

Guizhou Province ◽

Shaanxi Province ◽

Mass Balance Calculation ◽

Polished Rice ◽

Hg Mining

Mercury (Hg) is a global pollutant and can transform into methylmercury (MeHg), a highly toxic and bioaccumulative organic form. Recent surveys showed that rice (Oryza sativa L.) rather than fish is the main source of human MeHg exposure in Hg mining and retorting regions in Guizhou province, southwestern China, where rice is a traditional staple food. Here we report that MeHg in rice grown at an active Hg mining and retorting region in Shaanxi province, northwestern China, characterized with different climate compared to Guizhou, contained levels up to 240 μg kg–1 MeHg in bran, 78 μg kg–1 MeHg in polished rice, and 30 μg kg–1 MeHg in hull, respectively. Although the polishing process may reduce MeHg content, the mass balance calculation showed that greater than 50 % of total MeHg mass can be observed in white rice (polished rice). The ongoing Hg retorting activities, which account for the high levels of ambient air Hg, result in high levels of MeHg in rice grains. Our results further demonstrate that the accumulation of MeHg is a common feature of rice.

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Mercury methylation in paddy soil: source and distribution of mercury species at a Hg mining area, Guizhou Province, China

Biogeosciences ◽

10.5194/bg-13-2429-2016 ◽

2016 ◽

Vol 13 (8) ◽

pp. 2429-2440 ◽

Cited By ~ 34

Author(s):

Lei Zhao ◽

Christopher W. N Anderson ◽

Guangle Qiu ◽

Bo Meng ◽

Dingyong Wang ◽

...

Keyword(s):

Paddy Soil ◽

Surface Soil ◽

Ambient Air ◽

Rice Paddy ◽

Guizhou Province ◽

Mercury Species ◽

Low Concentration ◽

Paddy Water ◽

Hg Mining

Abstract. Rice paddy plantation is the dominant agricultural land use throughout Asia. Rice paddy fields have been identified as important sites for methylmercury (MeHg) production in the terrestrial ecosystem and a primary pathway of MeHg exposure to humans in mercury (Hg) mining areas. We compared the source and distribution of Hg species in different compartments of the rice paddy during a complete rice-growing season at two different typical Hg-contaminated mining sites in Guizhou province, China: an abandoned site with a high Hg concentration in soil but a low concentration in the atmosphere and a current-day artisanal site with a low concentration in soil but a high concentration in the atmosphere. Our results showed that the flux of new Hg to the ecosystem from irrigation and atmospheric deposition was insignificant relative to the pool of old Hg in soil; the dominant source of MeHg to paddy soil is in situ methylation of inorganic Hg (IHg). Elevated MeHg concentrations and the high proportion of Hg as MeHg in paddy water and the surface soil layer at the artisanal site demonstrated active Hg methylation at this site only. We propose that the in situ production of MeHg in paddy water and surface soil is dependent on elevated Hg in the atmosphere and the consequential deposition of new Hg into a low-pH anoxic geochemical system. The absence of depth-dependent variability in the MeHg concentration in soil cores collected from the abandoned Hg mining site, consistent with the low concentration of Hg in the atmosphere and high pH of the paddy water and irrigation water, suggested that net production of MeHg at this site was limited. We propose that the concentration of Hg in ambient air is an indicator for the risk of MeHg accumulation in paddy rice.

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Characteristics of atmospheric mercury deposition and size-fractionated particulate mercury in urban Nanjing, China

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-2233-2014 ◽

2014 ◽

Vol 14 (5) ◽

pp. 2233-2244 ◽

Cited By ~ 42

Author(s):

J. Zhu ◽

T. Wang ◽

R. Talbot ◽

H. Mao ◽

X. Yang ◽

...

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Fine Particles ◽

Unit Area ◽

Atmospheric Mercury ◽

Anthropogenic Sources ◽

Deposition Flux ◽

Coarse Particles ◽

Mercury Deposition ◽

Particulate Mercury

Abstract. A comprehensive measurement study of mercury wet deposition and size-fractionated particulate mercury (HgP) concurrent with meteorological variables was conducted from June 2011 to February 2012 to evaluate the characteristics of mercury deposition and particulate mercury in urban Nanjing, China. The volume-weighted mean (VWM) concentration of mercury in rainwater was 52.9 ng L−1 with a range of 46.3–63.6 ng L−1. The wet deposition per unit area was averaged 56.5 μg m−2 over 9 months, which was lower than that in most Chinese cities, but much higher than annual deposition in urban North America and Japan. The wet deposition flux exhibited obvious seasonal variation strongly linked with the amount of precipitation. Wet deposition in summer contributed more than 80% to the total amount. A part of contribution to wet deposition of mercury from anthropogenic sources was evidenced by the association between wet deposition and sulfates, as well as nitrates in rainwater. The ions correlated most significantly with mercury were formate, calcium, and potassium, which suggested that natural sources including vegetation and resuspended soil should be considered as an important factor to affect the wet deposition of mercury in Nanjing. The average HgP concentration was 1.10 ± 0.57 ng m−3. A distinct seasonal distribution of HgP concentrations was found to be higher in winter as a result of an increase in the PM10 concentration. Overall, more than half of the HgP existed in the particle size range less than 2.1 μm. The highest concentration of HgP in coarse particles was observed in summer, while HgP in fine particles dominated in fall and winter. The size distribution of averaged mercury content in particulates was bimodal, with two peaks in the bins of < 0.7 μm and 4.7–5.8 μm. Dry deposition per unit area of HgP was estimated to be 47.2 μg m−2 using meteorological conditions and a size-resolved particle dry deposition model. This was 16.5% less than mercury wet deposition. Compared to HgP in fine particles, HgP in coarse particles contributed more to the total dry deposition due to higher deposition velocities. Negative correlation between precipitation and the HgP concentration reflected the effect of scavenging of HgP by precipitation.

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Wet and dry deposition of mineral dust particles in Japan: factors related to temporal variation and spatial distribution

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-21801-2013 ◽

2013 ◽

Vol 13 (8) ◽

pp. 21801-21835

Author(s):

K. Osada ◽

S. Ura ◽

M. Kagawa ◽

M. Mikami ◽

T. Y. Tanaka ◽

...

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Mineral Dust ◽

Temporal Variations ◽

Dust Particles ◽

Insoluble Residue ◽

Spatial Distributions ◽

Dust Deposition ◽

Deposition Fluxes ◽

Deposition Amount

Abstract. Data of temporal variations and spatial distributions of mineral dust deposition fluxes are very limited in terms of duration, location, and processes of deposition. To ascertain temporal variations and spatial distributions of mineral dust deposition by wet and dry processes, weekly deposition samples were obtained at Sapporo, Toyama, Nagoya, Tottori, Fukuoka, and Cape Hedo (Okinawa) in Japan during October 2008–December 2010 using automatic wet and dry separating samplers. Mineral dust weights in water-insoluble residue were estimated from Fe contents measured using an X-ray fluorescence analyzer. For wet deposition, highest and lowest annual dust fluxes were found at Toyama (9.6 g m−2 yr−1) and at Cape Hedo (1.7 g m−2 yr−1) as average values in 2009 and 2010. Higher wet deposition fluxes were observed at Toyama and Tottori, where frequent precipitation (>60% days per month) was observed during dusty seasons. For dry deposition among Toyama, Tottori, Fukuoka, and Cape Hedo, the highest and lowest annual dust fluxes were found respectively at Fukuoka (5.2 g m−2 yr−1) and at Cape Hedo (2.0 g m−2 yr−1) as average values in 2009 and 2010. Although the seasonal tendency of the monthly dry deposition amount roughly resembled that of monthly days of Kosa dust events, the monthly amount of dry deposition was not proportional to monthly days of the events. Comparison of dry deposition fluxes with vertical distribution of dust particles deduced from Lidar data and coarse particle concentrations suggested that the maximum dust layer height or thickness is an important factor for controlling the dry deposition amount after long-range transport of dust particles. Size distributions of refractory dust particles were obtained using four-stage filtration: >20, >10, >5, and >1 μm diameter. Weight fractions of the sum of >20 μm and 10–20 μm (giant fraction) were higher than 50% for most of the event samples. Irrespective of the deposition type, the giant dust fractions were decreasing generally with increasing distance from the source area, suggesting the selective depletion of larger giant particles during atmospheric transport. Because giant dust particles are an important mass fraction of dust accumulation, especially in the north Pacific where is known as a high-nutrient, low-chlorophyll (HNLC) region, the transport height of giant dust particles is an important factor for studying dust budgets in the atmosphere and their role in biogeochemical cycles.

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Measurement of Ambient Air Arsenic (As) Pollutant Concentration and Dry Deposition Fluxes in Central Taiwan

Aerosol and Air Quality Research ◽

10.4209/aaqr.2010.09.0075 ◽

2011 ◽

Vol 11 (3) ◽

pp. 218-229 ◽

Cited By ~ 9

Author(s):

Guor-Cheng Fang ◽

Chia-Ching Lin ◽

Jun-Han Huang ◽

Yi-Liang Huang

Keyword(s):

Dry Deposition ◽

Ambient Air ◽

Pollutant Concentration ◽

Deposition Fluxes ◽

Central Taiwan

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Atmospheric mercury deposition over the land surfaces and the associated uncertainties in observations and simulations: a critical review

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-15587-2019 ◽

2019 ◽

Vol 19 (24) ◽

pp. 15587-15608 ◽

Cited By ~ 4

Author(s):

Lei Zhang ◽

Peisheng Zhou ◽

Shuzhen Cao ◽

Yu Zhao

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Quantitative Methods ◽

Experimental System ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Future Research ◽

Observation Data ◽

Mercury Deposition ◽

Land Surfaces

Abstract. One of the most important processes in the global mercury (Hg) biogeochemical cycling is the deposition of atmospheric Hg, including gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM), to the land surfaces. Results of wet, dry, and forest Hg deposition from global observation networks, individual monitoring studies, and observation-based simulations have been reviewed in this study. Uncertainties in the observation and simulation of global speciated atmospheric Hg deposition to the land surfaces have been systemically estimated based on assessment of commonly used observation methods, campaign results for comparison of different methods, model evaluation with observation data, and sensitivity analysis for model parameterization. The uncertainties of GOM and PBM dry deposition measurements come from the interference of unwanted Hg forms or incomplete capture of targeted Hg forms, while that of GEM dry deposition observation originates from the lack of a standardized experimental system and operating procedure. The large biases in the measurements of GOM and PBM concentrations and the high sensitivities of key parameters in resistance models lead to high uncertainties in GOM and PBM dry deposition simulation. Non-precipitation Hg wet deposition could play a crucial role in alpine and coastal regions, and its high uncertainties in both observation and simulation affect the overall uncertainties of Hg wet deposition. The overall uncertainties in the observation and simulation of the total global Hg deposition were estimated to be ± (25–50) % and ± (45–70) %, respectively, with the largest contributions from dry deposition. According to the results from uncertainty analysis, future research needs were recommended, among which a global Hg dry deposition network, unified methods for GOM and PBM dry deposition measurements, quantitative methods for GOM speciation, campaigns for comprehensive forest Hg behavior, and more efforts in long-term Hg deposition monitoring in Asia are the top priorities.

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