| Elevated levels of heavy metals in environments are a result of modern industrial activities, especially mining and smelting, and the land application of sewage sludge and industrial by-products, in general. In contrast to interests in the ecological impacts of modern industrial activities, comparatively little research has focused on the environmental impacts of the ancient metal mining and smelting in areas where these activities took place. On the other hand, investigations of heavy metal tolerance and accumulation in plants naturally grown in ancient mining and smelting sites are significant for identifying heavy metal accumulating or hyperaccumulating plants. Based on the textual research of the records about ancient mining and smelting activities, heavy metal pollution in soils and its environmental risk in selected ancient mining and smelting sites in Zhejiang Province were studied with field survey, leaching experiments and fractionation. By a hydroponic experiment, cadmium tolerance and accumulation in two ecotypes of Sedum sarmentosum collected from ancient mining sites in Chun'an and Sanman were also investigated. The important results were summarized as follows:1. The ancient records about copper and silver mining and smelting from the Spring and Autumn and the Warring States Period (770 B.C) to Republic of China (1948 A.D) in Zhejiang Province, China were collected and summarized through the textual research. There were 9 sites of ancient copper mining or smelting distributed in Shaoxing, Huzhou, Hangzhou, Quzhou, Dongyangand, Jinhua and Lishui cities and 22 sites of ancient silver mining or smelting distributed in Shaoxing, Huzhou, Hangzhou, Quzhou, Jinhua, Lishui and Wenzhou cities.2. The results of field surveys showed that Cd, Cu, Ni, Pb and Zn concentrations in soils collected from ancient silver/lead-zinc mining and smelting sites were 4.51-74.96 mgCd/kg (average 29.51 mg Cd/kg), 40.00-248.68 mg Cu/kg (average 105.89 mg Cu/kg), 9.35-186.50 mg Ni/kg (average 39.17 mg Ni/kg), 380.3-5382.4 mg Pb/kg (average 3010.8 mg Pb/kg), 389.7.3-3981.4 mg Zn/kg (average 2633.6 mg Zn/kg), respectively. Cd, Cu, Ni, Pb and Zn concentrations in soils collected from ancient copper mining and smelting sites were 0.12-11.56 mg Cd/kg (average 2.89 mg Cd/kg), 75.16-3440.00 mg Cu/kg (average 1341.89 mg Cu/kg), 1.10-30.40 mg Ni/kg(average 8.11 mg Ni/kg), 1.20-392.4 mg Pb/kg (average 96.32 mg Pb/kg), 33.3-1493.4 mg Zn/kg (average 389.87 mg Zn/kg), respectively. The results of the assessment by using the single pollution index (SPI) methods indicated that heavy metal pollution in soils was in a order as Cd (SPI 249.9) ? Zn (SPI 19.7) > Pb (SPI 11.4) > Ni (SPI 4.7) > Cu (SPI 2.5) for ancient silver/lead-zinc sites, and Cu (SPI 41.0) > Cd (SPI 11.6) > Pb (SPI 3.4) > Ni (SPI 0.8) for copper mining and smelting sites. The results of the assessment by using the comprehensive pollution index (CPI) methods indicated that soils in the ancient silver/lead-zinc ming and smelting site in Quzhou with CPI 177.1 were most seriously polluted with heavy metals, followed by soils in the ancient copper mining and smelting site in Songyang with CPI 29.3), soils in the ancient silver/lead-zinc ming and smelting site in Sanmen with CPI 19.6, and soils in the ancient copper mining and smelting site in Chun'an with CPI 4.6.3. It was obtained with the field survey that Cd, Cu, Ni, Pb and Zn concentrations in shoots were 0.16-892.6 mg Cd/kg, 1.74-10.81 mg Cu/kg, 0.09-1.96 mg Ni/kg, 0.15-270.7 mg Pb/kg, and 43.7-3069.7 mg Zn/kg for plants grown in ancient silver mining and smelt sites, and 0.01-15.27 mg Cd/kg, 4.15-1394.4 mg Cu/kg, 0.29-52.29 mg Ni/kg, 0.54-24.93 mg Pb/kg, and 3.6-1224.0 mg Zn/kg for plants grown in ancient copper mining and smelt sites. Cd concentration (231.9-892.6 mg/kg, average 412.2 mg/kg) in shoots of Sedum alfredii Hance collected from Quzhou was much higher than that of other collected plants. Cd concentrations in shoots of Sedum sarmentosum (15.27 mg/kg) collected from Sanmen and Artemisia apiacea Hance (10.02 mg/kg) collected from Quzhou were quite high. Cu concentration (206.6-1349.43 mg/kg, average 778.0 mg/kg) in shoot of Rumex acetosa collected from Chun'an was much higher than that of other collected plants, and followed by Elsholtzia splendens (144.9-894.3 mg/kg, average 519.6 mg/kg). Pb concentration in shoot of Sedum alfredii Hance collected from Quzhou was as high as 14.92-270.7 mg Pb/kg (average 96.7 mg Pb/kg). Zn concentrations in shoot of Artemisia apiacea Hance and Sedum alfredii Hance, and Macleaya cordata collected from Quzhou were as high as 3012.6 mg/kg, 2507.1-3069.7 mg/kg (average 2751.9 mg/kg) and 1991.0 mg/kg in order. Cd bioaccumulating factor of Sedum alfredii Hance grown on the soils at the ancient silvermining and smelting site in Quzhou was the largest, followed by that of Sedum sarmentosum and Artemisia apiacea Hance. Cu bioaccumulating factor of Rumex acetosa grown on soils at the ancient copper mining and smelting site in Chun'an was the largest, followed by that of Elsholtzia splendens. Pb bioaccumulating factor of Sedum alfredii Hance grown on the soils at the ancient silver mining and smelting site in Quzhou was the largest. Zn bioaccumulating factors of Artemisia apiacea Hance and Sedum alfredii Hance, and Macleaya cordata grown on soils at the ancient silver mining and smelting site in Quzhou were larger than that of other plants grown on soils at the ancient silver or copper mining and smelting sites. It could be concluded that Sedum alfredii Hance naturally grown in ancient silver mining site could hyperaccumulate Cd, Rumex acetosa naturally grown in ancient copper mining site could hyperaccumulate Cu. Cd accumulation in Sedum sarmentosum and Artemisia apiacea Hance, Cu accumulation in Elsholtzia splendens, Pb and Zn accumulation in Sedum alfredii Hance, and Zn accumulation in Artemisia apiacea Hance and Macleaya cordata were also evident.4. The results of the fractionation experiments showed that percentage of acid extractable heavy metal to total heavy metal in soils were as follows: Cd 29.2%-66.2% (average 41.4%), Cu 1.7%-46.9% (average 18.7%), Ni 3.6%-21.2% (average 12.6%), Pb 0%-21.6% (average 5.6%), and Zn 23.0%-34.8% (average 29.8%), implying that Cd in soils of ancient mining and smelting sites was most available.5. It was found that the relationships of leaching capacity of Cd and Ni in soils collected from ancient mining and smelting sites and amount leaching solution (0.005 mol/L CaCb) could be illustrated with the first-order kinetics equation with coefficients as 0.977-0.985** for Cd and 0.889-0.950**, for Ni, and that of Cu, Pb and Zn in soils collected from ancient mining and smelting sites could be illustrated with Logistic equation with coefficients as 0.879-0.999** for Cu, 0.951-0.999** for Pb and 0.979-0.996** for Zn. Thus, the regression equations can be used to estimate the maximum leaching capacity of metals. The estimated results indicated that the maximum leaching capacity of Cd, Cu, Ni, Zn in soils collected from ancient silver mining and smelting site, Quzhou were larger than other soils, implying that the higher risk of heavy metal translation and pollution in this area existed. The risk of Pb translation and pollution in the ancient copper mining and smelting site, Chun'an was also existed.6. Cd tolerance and hyperaccumulation of two ecotypes of Sedum sarmentosum (collected from Sanmen and Chun'an, respectively) were compared with a hydroponic experiment. The results indicated that the criteria of Cd concentration in nutrient solution fornormal growth were 50 umol/L for Sanmen ecotype and 10 umol/L for Chun'an ecotype. It was also obtained that both of two ecotypes Sedum sarmentosum (collected from Sanmen and Chun'an) were with the character of Cd accumulation as Cd concentrations in shoots were as high as 98.71 mg/kg (Sanmen ecotype) and 73.41 mg/kg (Chun'an ecotype).
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