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551.
Plant uptake factor (PUF), single-variable regression of natural log-transformed concentrations in rice grain/vegetables versus natural
log-transformed concentrations in soil and multiple-variable regression with soil concentrations and pH, was derived, validated and
compared based on the paired crop and soil data collected from studies regarding As, Cd and Pb contaminated croplands in China.
Results showed that the median value of PUF did not present deterministic prediction. But after natural logarithm transformation, the
PUF followed Gaussian distribution which could be useful in risk assessment. The single-variable regression models were significant
for As, Cd and Pb uptake both by rice and vegetables; however, the standard errors of all the regressions were comparatively large.
Soil pH as a variable was generally significant but it only contributed positively to model fit for Cd uptake. After model comparison
and selection, the upper 95% prediction limits of the multiple regression model for Cd uptake by rice was recommended to calculate
screening value of Cd for paddy soil based on the limit for Cd concentration in rice grain. 相似文献
552.
Factors affecting trace element content in periurban market garden subsoil in Yunnan Province, China 总被引:1,自引:0,他引:1
Field investigations were conducted to measure subsoil trace element content and factors influencing content in an intensive periurban market garden in Chenggong County,Yunnan Province,South-West China.The area was divided into three different geomorphological units:specifically,mountain (M),transition (T) and lacustrine (L).Mean trace element content in subsoil were determined for Pb (58.2 mg/kg),Cd (0.89 mg/kg),Cu (129.2 mg/kg),and Zn (97.0 mg/kg).Strong significant relationships between trace element con... 相似文献
553.
南大别山超高压变质杂岩与花岗片麻岩具有不同的变质矿物组合和结构特征,显示它们之间变质作用条件和过程可能存在着差异.超高压榴辉岩峰期变质的温度为754~866℃,压力大于2.7Gpa,退变到榴闪岩和角闪岩的温、压条件分别为0.55~0.69 Gpa和470~570℃.花岗片麻岩中所见到的最高变质作用为角闪岩相,变质的温、压条件分别为450~515℃和0.60~0.75Gpa.花岗片麻岩的变质条件与超高压榴辉岩的退变质条件类似,说明它们之间至少在抬升到约20~25km深的地壳层位后具有共同的抬升和冷却历史.花岗(片麻)岩在超高压环境下处于一种亚稳定状态,尚未来得及发生超高压变质作用就已折返到地壳层位. 相似文献
554.
以研究成果资料为基础 ,探讨了环境地球化学与人体健康的关系 ,试图以医学与环境地球化学相结合和元素地球化学分布与生态学特征相结合的方式进一步阐述这一问题 ,揭示其内在联系和规律。最后从营养角度讨论了强身健体、延年益寿的方法 相似文献
555.
556.
557.
Transportofatmospherictraceelementsanddust-soiltotheWesternPacificOcean¥YangShaojin;ChenBingru;YangYinan(InstituteofHighEnerg... 相似文献
558.
Innocent Chidi Nnorom 《毒物与环境化学》2016,98(2):149-166
Major and trace elements were determined in nzu (calabash clay) from Abia State, Nigeria, by atomic absorption spectrophotometry. Mean calcium content was 1900 ± 100 mg/kg dry weight, followed by Na 1400 ± 96, Fe 1500 ± 480, K 260 ± 150, and Mg 100 ± 48 mg/kg. The mean concentration of Zn was 35 ± 5, Cu 16 ± 2.0, Mn 17 ± 5.0, Cr 10 ± 1.0, Ni 9.0 ± 2.0, Cd 4.3 ± 1.7, Co 3.9 ± 1.1, and Pb 3.0 ± 0.8 mg/kg. The contents of Ba and V were <0.4 mg/kg. The mean Pb content was higher than the WHO safe limit (0.4 mg/kg) and EU (1 mg/kg) limit for food. Estimates of daily intake of Cd, Cr, Fe, and Ni upon consuming 30–80g of nzu were above the recommended daily intake values. The Ba, Ca, Co, K, Mg, Na, and Zn contents should not exceed the recommended daily intake while Cd, Ni, and Pb would pose health risks, especially in pregnancy. The total target hazard quotient indicated potential health risks to consumers. 相似文献
559.
Akira Ohki Tsunenori Nakajima Kentaro Hayashi Haruna Taniguchi Kousei Haraguchi Hirokazu Takanashi 《毒物与环境化学》2016,98(7):778-786
Mt. Sakurajima is a volcanic island in Japan, and a big city, Kagoshima, is quite close to the active volcano. Samples of volcanic ash fall erupted from Mt. Sakurajima were collected at several locations in Kagoshima City and analyzed for Hg and other elements, including major (Mg, Al, Ca, and Fe) and trace elements (V, Cr, Mn, Co, Ni, Zn, As, and Pb). The concentrations of Hg varied from 6.3 to 124 ng g?1, with the amounts of ash varying from 13 to 1230 g m?2 month?1. The Hg concentrations tended to be higher when the monthly amounts of ash fall were lower; other elements did not show such a tendency. 相似文献
560.
The concentration and potential ecological risk of Mn, Zn, Cu, and Cd in the surface soils (0–30?cm) belonging to 12 soil profiles and 4 soil types (Vertisols, Chernozems, Calcisols, and Cambisols) from the cultivated soils and the corresponding uncultivated soils were investigated. Long-term cultivation caused a considerable build-up diethylene-triamine pentaacetic acid (DTPA)-extractable Mn (7–55%), and Cd (12–31%) as well as the total form of Zn (3–14%), Cu (8–25%), and Cd (33–78%) in all soil types. Following long-time cropping, total Zn (mean?=?73?mg?kg?1), Cu (mean?=?33?mg?kg?1), and Cd (mean?=?3.14?mg?kg?1) and DTPA Zn (mean?=?1.2?mg?kg?1) and Cu (mean?=?2.44?mg?kg?1) were below their maximum allowable limits. However, the average amount of DTPA Cd in the tilled soils (min?=?0.4, max?=?0.75, mean?=?0.55?mg?kg?1) was above its maximum permissible limit mainly due to the over application of phosphate fertilisers and the pesticides. Considering the potential ecological risk (RI) assessment of the cultivated soils (min?=?44, max?=?70, mean?=?54), the soil types were categorised as low (RI?≤?50) to moderate (50?相似文献