采用原子吸收光谱仪,对小兴安岭汤洪岭雨养型泥炭中的铅进行了测定,结合前人的定年工作,获得了小兴安岭地区近5000 a来大气铅沉降及与气候变化的响应关系.研究结果表明,小兴安岭雨养型泥炭剖面中大气铅的沉降通量与区域气候变化有着良...采用原子吸收光谱仪,对小兴安岭汤洪岭雨养型泥炭中的铅进行了测定,结合前人的定年工作,获得了小兴安岭地区近5000 a来大气铅沉降及与气候变化的响应关系.研究结果表明,小兴安岭雨养型泥炭剖面中大气铅的沉降通量与区域气候变化有着良好的响应关系.5200-2800 a BP的铅沉降通量较大,这与全新世大暖期后的气候温暖湿润有利于大气铅的沉降密切相关,该时期大气铅沉降清晰地显示了2次强降温事件.2800—350 a BP的铅沉降通量较低,且波动起伏较大,与中国大暖期结束,气候转变为冷湿,不利于大气铅的沉降密切相关.距今350 a以来的大气铅沉降通量较大,与近代工业革命和该区域金属冶炼等关系密切.展开更多
Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years ...Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn （508 mg kg^-1）, Pb （95.6 mg kg^-1）, and Cd （5.98 mg kg^-1） with low ratios of Zn/Cd （59.1-115） and Pb/Cd （12.4-23.4）. Composite pollution indices （CPIs） of surface soils （2.52-15.2） were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals （SDM） in soils within 1.5 km of the smelter （averaging 1.25） was six times higher than that of the reference soils （0.209）. A smaller soil microbial biomass was found more frequently in metal accumulated soils （85.1-438 μg C g^-1） than in reference soils （497 μg C g^-1）, and a negative correlation （P 〈 0.01） of soil microbial biomass carbon to organic carbon ratio （Cmic/Corg） with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM （R = -0.773, P 〈 0.01）. Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass .展开更多
Ombrotrophic bogs are faithful archive of atmospheric metal deposition, but the potential for fens to reconstruct environmental change is often underestimated. In this study, some new data on the Pb depositional histo...Ombrotrophic bogs are faithful archive of atmospheric metal deposition, but the potential for fens to reconstruct environmental change is often underestimated. In this study, some new data on the Pb depositional history in northeast China were provided using two ^210Pb-dated peat sequences from a poor fen in the Fenghuang Mountain of Heilongjiang province. Anthropogenic, detritic and atmospheric soil sources were discriminated using a two-step sequential digestion （weak acid leaching to liberate mobile Pb which is often regarded as anthropogenic Pb, especially for recent samples） and a ratio of unsupported ^210Pb and supported ^210Pb with the logic of that the ^214Pb mainly represents the residual detritus （constant throughout the core） and the unsupported ^210Pb arises from atmospheric fallout. A higher ^210Pb/^214Pb suggests more contributions from atmospheric deposition to the Pb content in the peat, and a ratio of 10 was defined to indicate the boundary between detrific input and atmospheric deposition. The detritic Pb was estimated to be 10-13 mg·kg^-1, the anthropogenic Pb ranged from 10-80 mg·kg^-1, and the atmospheric soil-derived Pb ranged from 〈 5 mg·kg^-1 to 30 mg·kg^-1. The history of anthropogenic Pb pollution over the last 150 years was reconstructed, and the calculated Pb deposition rate （AR Pb） ranged from 5 to 56 mg·m^-2·yr^-1. Using Ti as a reliable reference, the enrichment factor of Pb （EF Pb） relative to the upper continental crust was calculated. Both AR Pb and EF Pb increased with time, especially after the foundation of the People＇s Republic of China. This is consistent with increasing industrialization and coal burning in the last 60 years in northeast China. The present record of anthropogenic Pb deposition was consistent with the previous reports and an increasing trend of environmental pollution due to anthropogenic activities, in contrasts to Europe and North America which have experienced a major environmental cleanup. For the first time, this work estimates atmospheric Pb deposition via a minerotrophic peat core in China. This will enhance the use of peat archives for studies of environmental change.展开更多
Atmospheric lead （Pb） and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collecte...Atmospheric lead （Pb） and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collected on Ao Mountain, Central China, to obtain the spatial distributions of Pb in these materials, decipher the possible factors controlling the distribution, and quantitatively distinguish the natural versus anthropogenic sources of Pb through the Pb isotopic tracing and biomonitoring. The results show that soil Pb concentrations （mg/kg） decreased significantly with depth, and they were markedly higher in the 0 （42.6 ＋ 2.7） and A （36.4 ＋ 2.2） horizons than in the litter （7.20 ~ 1.9） and mosses （28.o ~ 3-9）- The Pb enrichment in the surface soils （0 and A horizons）, litter and mosses existed in the relatively high altitudes, which was attributed to the influences from atmospheric wet deposition, plants, soil Dhvsicochemical DroDerties and human activitv. ThePb isotopic ratios identified the Pb sources as originating mainly from Chinese coal combustion, mining and smelting. Atmospheric Pb from southeastern, southwestern and northwestern regions could be deposited in the alpine ecosystem by long distance atmospheric transport. The anthropogenic Pb reached over 50% in the 0 and A horizons, and over 70% in the litter and mosses, which corresponded to the concentrations of 26.9, 17.7, 5.92 and 21.2 mg/kg, respectively. The results indicate that the mutual effects of climate and regional human activity could increase the Pb accumulation in remote alpine ecosystems.展开更多
文摘采用原子吸收光谱仪,对小兴安岭汤洪岭雨养型泥炭中的铅进行了测定,结合前人的定年工作,获得了小兴安岭地区近5000 a来大气铅沉降及与气候变化的响应关系.研究结果表明,小兴安岭雨养型泥炭剖面中大气铅的沉降通量与区域气候变化有着良好的响应关系.5200-2800 a BP的铅沉降通量较大,这与全新世大暖期后的气候温暖湿润有利于大气铅的沉降密切相关,该时期大气铅沉降清晰地显示了2次强降温事件.2800—350 a BP的铅沉降通量较低,且波动起伏较大,与中国大暖期结束,气候转变为冷湿,不利于大气铅的沉降密切相关.距今350 a以来的大气铅沉降通量较大,与近代工业革命和该区域金属冶炼等关系密切.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KZCX2-105)the "Light in Western China" Program of the Chinese Academy of Sciences and Guizhou Province, and the National Natural Science Foundation of China (No.40473049)
文摘Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn （508 mg kg^-1）, Pb （95.6 mg kg^-1）, and Cd （5.98 mg kg^-1） with low ratios of Zn/Cd （59.1-115） and Pb/Cd （12.4-23.4）. Composite pollution indices （CPIs） of surface soils （2.52-15.2） were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals （SDM） in soils within 1.5 km of the smelter （averaging 1.25） was six times higher than that of the reference soils （0.209）. A smaller soil microbial biomass was found more frequently in metal accumulated soils （85.1-438 μg C g^-1） than in reference soils （497 μg C g^-1）, and a negative correlation （P 〈 0.01） of soil microbial biomass carbon to organic carbon ratio （Cmic/Corg） with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM （R = -0.773, P 〈 0.01）. Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass .
基金supported by the National Natural Science Foundation of China (Grant No.41301215)the Natural Science Foundation of Jiangsu Province,China (Grant No.BK20131058)+1 种基金the National Basic Research Program of China(Grant No.2012CB956100)the International Atomic Energy Agency (RC-19018)
文摘Ombrotrophic bogs are faithful archive of atmospheric metal deposition, but the potential for fens to reconstruct environmental change is often underestimated. In this study, some new data on the Pb depositional history in northeast China were provided using two ^210Pb-dated peat sequences from a poor fen in the Fenghuang Mountain of Heilongjiang province. Anthropogenic, detritic and atmospheric soil sources were discriminated using a two-step sequential digestion （weak acid leaching to liberate mobile Pb which is often regarded as anthropogenic Pb, especially for recent samples） and a ratio of unsupported ^210Pb and supported ^210Pb with the logic of that the ^214Pb mainly represents the residual detritus （constant throughout the core） and the unsupported ^210Pb arises from atmospheric fallout. A higher ^210Pb/^214Pb suggests more contributions from atmospheric deposition to the Pb content in the peat, and a ratio of 10 was defined to indicate the boundary between detrific input and atmospheric deposition. The detritic Pb was estimated to be 10-13 mg·kg^-1, the anthropogenic Pb ranged from 10-80 mg·kg^-1, and the atmospheric soil-derived Pb ranged from 〈 5 mg·kg^-1 to 30 mg·kg^-1. The history of anthropogenic Pb pollution over the last 150 years was reconstructed, and the calculated Pb deposition rate （AR Pb） ranged from 5 to 56 mg·m^-2·yr^-1. Using Ti as a reliable reference, the enrichment factor of Pb （EF Pb） relative to the upper continental crust was calculated. Both AR Pb and EF Pb increased with time, especially after the foundation of the People＇s Republic of China. This is consistent with increasing industrialization and coal burning in the last 60 years in northeast China. The present record of anthropogenic Pb deposition was consistent with the previous reports and an increasing trend of environmental pollution due to anthropogenic activities, in contrasts to Europe and North America which have experienced a major environmental cleanup. For the first time, this work estimates atmospheric Pb deposition via a minerotrophic peat core in China. This will enhance the use of peat archives for studies of environmental change.
基金supported by National Natural Science Foundation of China(41402313)Key Laboratory of Mountain Surface Processes and Ecological Regulation,Chinese Academy of SciencesYouth Innovation Promotion Association,Chinese Academy of Sciences
文摘Atmospheric lead （Pb） and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collected on Ao Mountain, Central China, to obtain the spatial distributions of Pb in these materials, decipher the possible factors controlling the distribution, and quantitatively distinguish the natural versus anthropogenic sources of Pb through the Pb isotopic tracing and biomonitoring. The results show that soil Pb concentrations （mg/kg） decreased significantly with depth, and they were markedly higher in the 0 （42.6 ＋ 2.7） and A （36.4 ＋ 2.2） horizons than in the litter （7.20 ~ 1.9） and mosses （28.o ~ 3-9）- The Pb enrichment in the surface soils （0 and A horizons）, litter and mosses existed in the relatively high altitudes, which was attributed to the influences from atmospheric wet deposition, plants, soil Dhvsicochemical DroDerties and human activitv. ThePb isotopic ratios identified the Pb sources as originating mainly from Chinese coal combustion, mining and smelting. Atmospheric Pb from southeastern, southwestern and northwestern regions could be deposited in the alpine ecosystem by long distance atmospheric transport. The anthropogenic Pb reached over 50% in the 0 and A horizons, and over 70% in the litter and mosses, which corresponded to the concentrations of 26.9, 17.7, 5.92 and 21.2 mg/kg, respectively. The results indicate that the mutual effects of climate and regional human activity could increase the Pb accumulation in remote alpine ecosystems.
