首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 156 毫秒
1.
Effects of mercury on ecosystems and human health are well documented. Human activities have significant impacts on transport, transformation, and fate of mercury in the natural environment. In this study, a gold mining area （Tongchuan）, an urban area （Xi＇an）, and a historical site （Qinshihuan Tomb） in Shaanxi Province, China, was chosen to study the effects of human activities on the transport, transformation, and fate of mercury in the area. Samples of atmospheric precipitate, soil, sediment, pomegranate, corn and those from wells and the rivers that flow through or flow by the city and from the mining area were collected. The EPA methods were used for sample preparation and analysis of these samples. These methods combine acid digestion, chemical reduction, purge and trap with Cold Vapor Atomic Fluorescence Spectrometry （CVAFS）. Preliminary results showed high total mercury concentrations in the water samples collected from a river in Tongguan County. The total mercury concentrations ranged from 133 to 188 ng/L in the water samples collected from the rivers flowing through Xi＇an City. The amount of total mercury in the soil/sediment samples which were collected in the vicinity of Xi＇an ranged from 31.8 to 83.2 ng/g. The total mercury concentrations in the samples of atmospheric precipitate （including rain and snow collected from Sep. 2005 to Jan. 2006） ranged from 106-298 ng/L.  相似文献   

2.
Effects of mercury on ecosystems and human health are well documented. Human activities have significant impacts on transport, transformation, and fate of mercury in the natural environment. In this study, a gold mining area (Tongchuan), an urban area (Xi…  相似文献   

3.
The Podljubelj mercury mine lies in the NW part of Slovenia. The ore is of hydrothermal-vein type. The ore deposit was exploited between the years 1557 and 1902. Total production of the mine was 110000 tons of ore （360 tons of Hg）. A smelter located close to the mine had been in operation since 1855. The waste material from the mine and the smelter was dumped in close vicinity of the mine. Total quantity of the waste has been estimated at 170000 tons. In order to establish environmental impacts, soil and stream sediment samples were investigated. Soil samples were collected at two different depths （horizons A and B） in a 100 m grid within an 88 ha area. In the vast area also 11 samples of stream sediments were considered. Heavy metals were determined by means of cold vapor atomic absorption spectrometry CV-AAS after aqua regia digestion. Based on the chemical analyses of samples, the estimated mercury mean for soils is 3.67 mg/kg （0.35-244 mg/kg） for horizon A and 1.39 mg/kg （0.17-71.7 mg/kg） for horizon B. The estimated mercury mean for stream sediments is 0.64 mg/kg （0.065-1.36 mg/kg）. The concentrations of mercury in soils generally decrease with depth and distance from the mine. The highest content of Hg was determined in a sample taken in the immediate vicinity of the smelter （719 mg/kg）. The results have shown that on the 9 ha of the study area, the contents of Hg in soils exceeded the officially set limit value for soils （10 mg/kg）. High contents of Hg in soil around the abandoned smelter are a consequence of former atmospheric emissions and technological losses. High contents of Hg were also found in the mine and smelter waste dump. At the edges of the study area and in the samples of stream sediments, Hg concentrations are low.  相似文献   

4.
《中国地球化学学报》2006,25(B08):240-241
  相似文献   

5.
Caohai Lake which is situated in Guizhou Province, has suffered drain project many times since 1958.The main mercury contamination includes industry waste water, litter and waste residue from refine zinc furnace and so on. The water and sediment samples which were collected from Caohai Lake in different seasons using metal clean protocols. Study sites were selected at the upper and down reaches and the tributaries of this lake, respectively. Total mercury （THg）, reactive mercury （RHg） and dissolved mercury （DHg） concentrations were measured by trap pre-concentration and CVAFS detection methods, and the concentrations of particulate mercury （PHg） are equal to difference of THg and DHg. Total methylmercury （MeH） and dissolved methylmercury （DMeHg） concentrations were measured by GC-CVAFS detection method. Mercury in sediment was measured by AAS method. The results in autumn were obtained as follows： the average concentrations of total mercury, reactive mercury,  相似文献   

6.
Mercury is a pollutant of concern due to its toxic and bioaccumulative properties. Studies on the distribution and hazard of mercury in the environment are mainly focused on its forms, toxicity and the environment standard, and progresses and results have been achieved. But these studies in the past were concentrated on the scales of laboratory or smaller districts merely, such as a small unit of mineral area, vegetable base, paddy field, lake, etc. Multi-target regional geochemical survey carried out by China Geological Survey from the 1990s to now is a fundamental and commonweal geological survey, large-scale and systematical inquisition and research were conducted in 19 provinces （or municipalities directly under the Central Government） in the eastern overlay region of China, and the purpose is to provide the basic geochemical data for national economic construction, adjustment of industrial and agricultural structures and sustainable social development. Geochemical studies aim at investigating soils in these regions and 52 elements have been tested, producing a great amount of data at the same time. Methods： based on the data from 3061 samples of surface soil and 832 samples of deep soil from the project of multi-purpose geochemical survey in the Chengdu Basin, Sichuan, China, this paper describes the correlation relationship between Hg and other 48 elements and their spatial distribution in surface and deep soils of these areas by applying the method of linear regression and factor analysis.  相似文献   

7.
The Takab area in NW of Iran is an important gold mineralized region with a long history of gold mining. In this study ASTER data is used to evaluate environmental effects of gold mining. The results show that mining activities have resulted in release of…  相似文献   

8.
Mercury as a toxic element poses environmental concerns, especially in historically Hg-mined districts. The Wanshan Hg mine located in the eastern part of Guizhou Province, southwestern China, ranks the largest Hg-producing district in China. Mining at Wanshan was initiated in 221 B.C., but ceased in 2001. Approximately 22000 tons of Hg, 6000 tons of cinnabar and large quantities of mine-wastes had been produced at Wanshan. Significant quantities of calcines, which were piled irregularly near the old mine processing sites and retorts, continue to impact the local environments in the Wanshan area. In this study, a regional contamination of mercury in surface waters collected from the Meizixi, Dashuixi, Huandao and Gaolouping rivers, whose upstreams or branches originate from the hilly karstic area and receive drainage arising from the calcines, was investigated by determining all Hg species in a base-flow and a flood-flow season. Reactive, dissolved, particulate, and total Hg concentrations in surface water varied from 0.60 to 400 ng/L, 11 to 430 ng/L, 1.4 to 9210 ng/L, and 15 to 9260 ng/L, respectively. Total methylmercury in water samples ranges from 0.31 to 25 ng/L. The concentrations of total Hg and particulate Hg in water samples collected during the flood season are higher than those in the base-flow season, whereas, the concentrations of dissolved and reactive Hg are lower with the peak values observed in water samples collected in the base-flow season. A strong positive correlation between total Hg and particulate Hg is noticed in the water samples collected from Hg-mined areas with the proportion higher than 80%.  相似文献   

9.
Small-scale mercury smelting activities with indigenous method are always extensive in the Wuchuan area, northeastern Guizhou Province, China. Because of the simple processes without any environmental protection, a large amount of mercury vapor released to the ambient air during the processing of cinnabar roasting. So the health of the workers may be negatively affected through inhalation of the mercury-polluted air. Mercury, creatinine and β2-MG contents in urine among the workers in the study areas and the residents in the control site （Changshun County） were determined to discuss the health impact of mercury vapor exposure to the workers in the study areas. Health examinations also were carded out to identify clinical symptoms of mercury poisoning for the smelting workers. Results indicated that the geometric mean value of urinary mercury for the smelting workers was g/g Cr μg/g Cr （N=22）, significantly higher than 1.24 μg/g （N=54） for residents in the control site. β2-MG as a renal biomarker can be used to study human nephrotoxicity at an early stage and it is most useful to define effects for assessing re-absorption function to indicate tubular injury. The results showed a serious adverse effect on renal system for the smelting workers due to mercury exposure. Several workers have already manifested some clinical symptoms of lightly chronic mercury poisoning and the symptoms include finger and eyelid lightly tremor, gingivitis and blue mercury line in mouth. The study illuminated that the workers in gaged in indigenous mercury smelting in the Wuchuan area were seriously exposed to mercury vapor,  相似文献   

10.
Environmental pollution is one of several essential problems of concern global. Although total mercury concentration in the lake is at trace or even ultra-trace level, it is greatly harmful to human health through food chain by the enrichment in fish, etc…  相似文献   

11.
The concentrations of total mercury and methylmercury in sediments were determined at the dam of the Wujiangdu Reservoir in different seasons. Total mercury (HgT) levels in the whole sediment profile were 254.2±47.0 ng/g in winter, 254.2±31.6 ng/g in spring, and 256.7±60.8 ng/g in summer, without significant variations in different seasons or at different depths. In contrast, the methylmercury (MeHg) compounds were most abundant at the sediment-water interface and decreased progressively with depth. MeHg contents of the sediments during different seasons are highly dependent on microbial activity, and seem to be higher when Hg (II)-methylating microorganisms are active. Thus, MeHg levels tend to rise in the loci where nutrient supplies and biological productivity are favorable. The percentage of HgT that is present as MeHg in the sediments increased gradually from December 2003 to April 2004 and to July 2004.  相似文献   

12.
The dental and skeletal fluorosis is highly prevalent in Zhijin, Guizhou, especially at Hualuo Village, Hehua Village and Majiazhuang Village. The contents of fluorine in coal, clay used for coal combustion, mixed fuel of coal and clay, corn, and chili from households of the three villages were determined by the pyrohydrolysis-fluorine ion-selective electrode method. The average contents of fluorine in the above samples respectively are 237 mg/g, 2262 mg/g, 828 mg/g, 1419 mg/g, and 110 mg/g. The clay used for coal combustions is the main fluorine source of endemic fluorosis and the inferior coal and weathered coal are the secondary source of fluorine. During the combustion of mixed fuel of coal and clay, about eighty percent of fluorine was volatilized, approximately two thirds of which was from the clay and the other one third from the coal. The occurrence of fluorine in clay used for coal combustion is closely related to apatite and hornblende. The contents of fluorine in corn and chili, dried by coal-clay mixed fuel are about 1400 and 73 times higher than the permitted level of fluorine in foods according to the Chinese Standard. It is worth paying attention to the high-fluorine indoor surroundings, such as coal, clay, corn, and chili, particularly ash from boiler bottom with the fluorine content of 15738 μg/g. Besides the technologies of fluorine fixation during the combustion,  相似文献   

13.
The water system in a rural area of Lanmuchang in Southwest Guizhou is facing a risk of thallium (Tl) contamination due to Tl mineralization around the area. The major trace elements and Tl in the water system are studied to understand the hydrogeochemical processes of Tl constrained by Tl mineralization. The results showed that the dispersion pattern of Tl follows a descending order in concentration from mine groundwater (deep groundwater) →stream water→shallow groundwater→background water, reflecting the impact of Tl mineralization on the hydrogeochemical composition. Tl concentrations in stream water in both regimes are remarkably higher (2-30 fold) downstream than up- and mid-streams, probably caused by the unidentified discharge of deep groundwater. Low Tl levels are detected in the current drinking water, however, the highly elevated Tl in stream water and ground water may pose a potential environmental risk through daily washing and agricultural irrigation. This study suggests that human activities, such as agricultural irrigation, could intensify the environmental risk of Tl.  相似文献   

14.
Many kinds of pollutants such as suspended solid, oil and grease and heavy metals were enriched in urban road runoff, they can significantly degrade quality of the receiving water and affect hydro-ecosystem. Road runoff water quality was investigated in a typical city of South China-Guangzhou and it was found that road runoff from this city was seriously polluted than the investigation results carried out in other countries, water quality of them was assigned to V type according to Chinese surface water quality criteria. Some water quality parameters COD, SS, TP, Cu, Cr and Zn were highly correlated, indicating that these pollutants have the same sources or attached themselves to the others. In the six monitored heavy metals, Cr, Ni and Zn were mainly of particulate-bounded phase;  相似文献   

15.
《中国地球化学学报》2006,25(B08):237-238
  相似文献   

16.
Mercury smelting is one of the important anthropogenic atmospheric mercury emission sources. Small-scale mercury smelting activities with indigenous method which is considered illegal and forbidden by local government always extensively existed in the Wuchuan area, northeastern Guizhou Province, China. Because of the simple processes without any environmental protection, a large amount of mercury vapor released to the ambient air during the processing of cinnabar roasting. By determining mercury concentrations in mercury ore and smelting slag samples, a mass balance method was used to calculate mercury emission factors and annual mercury emission from indigenous mercury smelting in Wuchuan mercury mining areas, Guizhou Province, China. The mercury emission factors ranged from 6.9% to 32.1% with the recovery from 78.4% to 93.6% and the annual mercury emission was up to 3.7-9.6 metric tons. The results highlighted that the indigenous mercury smelting was one of the most important anthropogenic atmospheric mercury emission sources in this region.  相似文献   

17.
Mercury is an important pollutant in lakes. Methylmercury （MeHg）, the most toxic mercury species, which can be formed from inorganic mercury in lakes, can be bioaccumulated into high concentration in food chain and result in a potential threat to human beings. Sediments play an important role for the Hg biogeochemistry in the aquatic systems： Mercury methylation has been shown to be fastest in the surfacial sediments, where the microbial activity is highest. The formation of MeHg in lakes suggests that sediments and/or near-shore wetlands can be the sources of MeHg in aquatic environments. The Baihua Reservoir, located in the suburb of Guiyang, was impounded in 1966. From the 1970s to the 1990s, Guizhou Organic Chemical Plant which used inorganic mercury as catalyst to produce acetic acid, was responsible for the discharge of waste water with high mercury content.  相似文献   

18.
Damming effect on the distribution of mercury in Wujiang River   总被引：2，自引：0，他引：2  
Seasonal changes in total mercury concentrations in surface water were observed for the Wujiang River, with higher values at the time of greater flow. The total mercury in this river was mostly associated with suspended particles, particulate mercury accounting for 84% of the total mercury flux on average during the high flow period, and 52% of the total mercury flux on average in the low flow period. Significant losses of Hg from the water were observed in the downstreams of the reservoir. In addition, the concentrations of particulate mercury in the downstreams of reservoir appeared to have been enhanced by sediment re-suspension and shoreline erosion caused by flood discharge, while the filtered portion decreased. These observations suggested that reservoirs played an important role in controlling the transport and fate of mercury in the Wujiang River.  相似文献   

19.
This preliminary work reported here dealt with potential impacts of wastewater irrigation on soils and crops sampled along the Koshk River canal in the suburban area of Shiraz City, Iran. It also attempts to assess the extent of heavy metal contamination in soils and crops and human exposure risk. For this purpose, samples including soils and plants were collected from two wastewater irrigated sites and a tubewell-irrigated site （marked by A, B and C）. Concentrations of the six heavy metals Ni, Pb, Cd, Zn, Cr and Cu were determined by AAS. Physical and chemical properties of soil samples were also determined. The PLIs and CF for soils and HQ （Hazard quotient） for some vegetables were calculated. The results showed that organic matter content increased from 22% to 30 % in wastewater-irrigated soils as compared to tubewell water irrigated and admixture water irrigated ones. The soil pH was raised by 2 units as a result of wastewater irrigation at site A compared to sites B and C. Wastewater irrigation also result in relatively high concentrations of Ni, Pb and Zn （275.5, 441.3 and 177 mg/kg, respectively） in wastewater irrigated soils over tubewell water irrigated soils. These levels are higher than the maximum permissible limits in unpolluted soils, indicating that a degree of contamination has occurred. This was confirmed by calculated PLIs and contamination factors in soil samples, The results also showed some crops cultivated at sites A and B contained high levels of Ni and Cd beyond the maximum permissible concentrations and those cultivated at site C. The concentrations of these heavy metals are within or very close to the critical levels. HQ indices and daily intake calculated in respect of metal contents in some vegetables （spinach, lettuce and celery） showed that toxic risk due to Cd in these vegetables and crops was greater than one. This study generally concludes that although the content of heavy metals did not reach toxic level, extensive use of untreated wastewater drawn from the Koshk River has obviously increased the contamination of Ni and Pb in soils and Cd in some vegetables cultivated along the canal, causing potential health risk in the long-term scense for consumers or local residents.  相似文献   

20.
1Introduction Thebiogeochemicalcycleofmercuryinaqueous systemisthekeyfactorleadingtotheexpansionof mercurypollutiononaglobalscaleandthesafetyof fishconsumers.Dissolvedgaseousmercury(DGM)e vasionisconsideredasoneofthemostimportantmer curysourcesforatmosphere.Atthesametime,this procedurewillreducetheHgburdeninthewatercol umnandmaythusdecreasemethylmercuryproduction andaccumulationinfish(Nriagu,1994).TheBaihua ReservoirissituatedinGuizhouProvince,andithas sufferedseriousmercurycontaminationfr…  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号