共查询到20条相似文献,搜索用时 453 毫秒
1.
Fernández-Caliani JC 《Environmental geochemistry and health》2012,34(1):123-139
The peri-urban soils of Huelva, one of the first industrial cities in Spain, are subject to severe pollution problems primarily
due to past poor management of industrial wastes and effluents. In this study, soil cores were collected in seven sites potentially
contaminated with toxic chemicals arising from multiple anthropogenic sources, in order to identify trace elements of concern
and to assess human health risks associated with them. In most soil core samples, total concentrations of As (up to 4,390 mg kg−1), Cd (up to 12.9 mg kg−1), Cu (up to 3,162 mg kg−1), Pb (up to 6,385 mg kg−1), Sb (up to 589 mg kg−1) and Zn (up to 4,874 mg kg−1) were by more than one order of magnitude greater than the site-specific reference levels calculated on the basis of regional
soil geochemical baselines. These chemicals are transferred from the hazardous wastes, mainly crude pyrite and roasted pyrite
cinders, to the surrounding soils by acid drainage and atmospheric deposition of wind-blown dust. Locally, elevated concentrations
of U (up to 96.3 mg kg−1) were detected in soils affected by releases of radionuclides from phosphogypsum wastes. The results of the human health
risk-based assessment for the hypothetical exposure of an industrial worker to the surface soils indicate that, in four of
the seven sites monitored, cancer risk due to As (up to 4.4 × 10−5) is slightly above the target health risk limit adopted by the Spanish legislation (1 × 10−5). The cumulative non-carcinogenic hazard index ranged from 2.0 to 12.2 indicating that there is also a concern for chronic
toxic effects from dermal contact with soil. 相似文献
2.
Bioavailability and accumulation of trace elements in soils and plants of a highly contaminated estuary (Domingo Rubio tidal channel,SW Spain) 总被引:1,自引:0,他引:1
Madejón P Burgos P Murillo JM Cabrera F Madejón E 《Environmental geochemistry and health》2009,31(6):629-642
The Domingo Rubio tidal channel (Palos de la Frontera, Huelva, Spain) is an estuary located in the mouth of the Tinto River.
The estuary is affected by different sources of pollution (waters of the Tinto River, contaminated with trace elements from
the Iberian Pyrite belt, and effluent from the Huelva chemical industrial area). Soil and the most frequent plant species
were collected in 2004 and 2006 at six different locations on the estuary. In general, N-Kjedahl, Total Organic Carbon values,
salinity and contamination (total trace elements up to 1,000 mg kg−1 As, 6 mg kg−1 Cd, 2,500 mg kg−1 Cu, 1,900 mg kg−1 Pb and 1,300 mg kg−1 Zn) tended to increase downstream of the tidal channel. Soil biochemical properties were not negatively affected either by
the high salinity or by trace element contamination. Despite the high values of the trace elements, analysed plant samples
showed that Cu was the only metal that could be a serious risk for the food chain. 相似文献
3.
Lead (Pb) contents and partition in soils collected from eleven vegetable-growing lands in Fujian Province, China, were investigated
using a modification of the BCR (Community Bureau of Reference) sequential extraction procedure coupled with the Pb isotope
ratio technique. Pb contents in Chinese white cabbage (B. Chinensis L.) grown on the lands for this study were also measured. Results showed that Pb concentrations in fifty samples of topsoil
ranged from 456 to 21.5 mg kg−1, with each mean concentration of six sampling lands exceeding the national standard (50 mg kg−1); while Pb concentrations in edible portions of thirty-two vegetable samples ranged from 0.009 to 2.20 mg kg−1, with four sampling sites exceeding the national sanitary standard (0.2 mg kg−1). A significant correlation (r = 0.971, P < 0.01) of Pb contents in the acid-extractable fractions by BCR approach and the vegetables was observed, which indicates
that the acid-extractable Pb is useful for evaluating the metal bioavailability for plants and potential risk for human health
in soils. The determination of lead isotope ratios in different chemical forms of soils by BCR sequential extraction procedures
provides useful information on the Pb isotopic composition associated with different soil fractions (especially in the acid-extractable
fractions), and the result is helpful for the further study on controlling and reducing Pb contamination in vegetable-growing
soils. 相似文献
4.
We investigated the spatial distribution of Pb in soil and dust samples collected from 54 sites in Shenyang city, Liaoning province, Northeast China. Soil background Pb concentration was 22 mg kg−1 and control values from non-industrial areas were 33 mg kg−1 for soil and 38 mg kg−1 for dust. Soil Pb concentrations varied widely, ranging from 26 to 2911 mg kg−1, with a mean concentration of 200 mg kg−1, 9 times the background value and 6 times the control value. There was great variation in soil Pb, with a coefficient of variation (CV) of 1.06 and a standard deviation (SD) of 212 mg kg−1. Dust Pb concentrations fluctuated from 20 to 2810 mg kg−1, with a mean value of 220 mg kg−1, almost 6 times the control value. No significant differences in distribution were observed between soil Pb and dust Pb. The highest Pb concentration was observed in Tiexi district in an industrial area. Soil Pb concentration decreased with depth and with distance from the pollution source. Lead concentrations initially changed little but then decreased with distance from the roadside, and were generally higher on the east side of roads than on the west. Lead contents in different categories of urban area differed substantially with dust and soil Pb concentrations decreasing in the sequence: industrial >business >mixed (residential, culture and education)> reference areas. 相似文献
5.
Heavy metal contamination in soils and food crops around Dabaoshan mine in Guangdong,China: implication for human health 总被引:12,自引:0,他引:12
This study was designed to investigate heavy metal (Cu, Zn, Pb, and Cd) contamination levels of soils, vegetables, and rice
grown in the vicinity of the Dabaoshan mine, south China. The concentration of Cu, Zn, Pb, and Cd in paddy soil exceeded the
maximum allowable concentrations for Chinese agricultural soil. The heavy metal concentrations (mg kg−1, dry weight basis) in vegetables ranged from 5.0 to 14.3 for Cu, 34.7 to 170 for Zn, 0.90 to 2.23 for Pb, and 0.45 to 4.1
for Cd. The concentrations of Pb and Cd in rice grain exceeded the maximum permissible limits in China. Dietary intake of
Pb and Cd through the consumption of rice and certain vegetable exceeded the recommended dietary allowance levels. The status
of heavy metal concentrations of food crops grown in the vicinity of Dabaoshan mine and their implications for human health
should be further investigated. 相似文献
6.
Ravi Naidu Euan Smith S. M. Imamul Huq Gary Owens 《Environmental geochemistry and health》2009,31(Z1):61-68
The bioavailability of arsenic (As) in the soil environment is largely governed by its adsorption–desorption reactions with
soil constituents. We have investigated the sorption–desorption behaviour of As in four typical Bangladeshi soils subjected
to irrigation with As-contaminated groundwater. The total As content of soils (160 samples) from the Laksham district ranged
from <0.03 to approximately 43 mg kg−1. Despite the low total soil As content, the concentration of As in the pore water of soils freshly irrigated with As-contaminated
groundwater ranged from 0.01 to 0.1 mg l−1. However, when these soils were allowed to dry, the concentration of As released in the pore water decreased to undetectable
levels. Remoistening of soils to field moisture over a 10-day period resulted in a significant (up to 0.06 mg l−1) release of As in the pore water of soils containing >10 mg As kg−1 soil, indicating the potential availability of As. In soils containing <5 mg As kg−1, As was not detected in the pore water. A comparison of Bangladeshi soils with strongly weathered long-term As-contaminated
soils from Queensland, Australia showed a much greater release of As in water extracts from the Australian soils. However,
this was attributed to the much higher loading of As in these Australian soils. The correlation of pore water As with other
inorganic ions (P, S) showed a strongly significant (P < 0.001) relationship with P, although there was no significant relationship between As and other inorganic cations, such
as Fe and Mn. Batch sorption studies showed an appreciable capacity for both AsV and AsIII sorption, with AsV being retained in much greater concentrations than AsIII. 相似文献
7.
Assessment of bioaccessibility and exposure risk of arsenic and lead in urban soils of Guangzhou City,China 总被引:5,自引:0,他引:5
Ying Lu Wei Yin Longbin Huang Ganlin Zhang Yuguo Zhao 《Environmental geochemistry and health》2011,33(2):93-102
Soil ingestion is an important human exposure pathway of heavy metals in urban environments with heavy metal contaminated
soils. This study aims to assess potential health risks of heavy metals in soils sampled from an urban environment where high
frequency of human exposure may be present. A bioaccessibility test is used, which is an in vitro gastrointestinal (IVG) test
of soluble metals under simulated physiological conditions of the human digestion system. Soil samples for assessing the oral
bioaccessibility of arsenic (As) and lead (Pb) were collected from a diverse range of different land uses, including urban
parks, roadsides, industrial sites and residential areas in Guangzhou City, China. The soil samples contained a wide range
of total As (10.2 to 61.0 mg kg−1) and Pb (38.4 to 348 mg kg−1) concentrations. The bioaccessibility of As and Pb in the soil samples were 11.3 and 39.1% in the stomach phase, and 1.9
and 6.9% in the intestinal phase, respectively. The As and Pb bioaccessibility in the small intestinal phase was significantly
lower than those in the gastric phase. Arsenic bioaccessibility was closely influenced by soil pH and organic matter content
(r
2 = 0.451, p < 0.01) in the stomach phase, and by organic matter, silt and total As contents (r
2 = 0.604, p < 0.001) in the intestinal phase. The general risk of As and Pb intake for children from incidental ingestion of soils is
low, compared to their maximum doses, without causing negative human health effects. The exposure risk of Pb in the soils
ranked in the order of: industrial area/urban parks > residential area/road side. Although the risk of heavy metal exposure
from direct ingestion of urban soils is relatively low, the risk of inhalation of fine soil particulates in the air remains
to be evaluated. 相似文献
8.
Genotypic variation in element concentrations in brown rice from Yunnan landraces in China 总被引:3,自引:0,他引:3
Yawen Zeng Hongliang Zhang Luxiang Wang Xiaoying Pu Juan Du Shuming Yang Jiafu Liu 《Environmental geochemistry and health》2010,32(3):165-177
The mineral elements present in brown rice play an important physiological role in global human health. We investigated genotypic
variation of eight of these elements (P, K, Ca, Mg, Fe, Zn, Cu, and Mn) in 11 different grades of brown rice on the basis
of the number and distance coefficients of 282 alleles for 20 simple sequence repeat (SSR) markers. Six-hundred and twenty-eight
landraces from the same field in Yunnan Province, one of the largest centers of genetic diversity of rice (Oryza sativa L.) in the world, formed our core collection. The mean concentrations (mg kg−1) of the eight elements in brown rice for these landraces were P (3,480) > K (2,540) > Mg (1,480) > Ca (157) > Zn (32.8) > Fe
(32.0) > Cu (13.6) > Mn (13.2). Mean P concentrations in brown rice were 6.56 times total soil P, so the grains are important
in tissue storage of P, but total soil K is 7.82 times mean K concentrations in brown rice. The concentrations of the eight
elements in some grades of brown rice, on the basis of the number and distance coefficients of alleles for 20 SSR markers
for the landraces, were significantly different (P < 0.05), and further understanding of the relationship between mineral elements and gene diversity is needed. There was large
variation in element concentrations in brown rice, ranging from 2,160 to 5,500 mg P kg−1, from 1,130 to 3,830 mg K kg−1, from 61.8 to 488 mg Ca kg−1, from 864 to 2,020 mg Mg kg−1, from 0.40 to 147 mg Fe kg−1, from 15.1 to 124 mg Zn kg−1, from 0.10 to 59.1 mg Cu kg−1, and from 6.7 to 26.6 mg Mn kg−1. Therefore, germplasm evaluations for Ca, Fe, and Zn concentrations in rice grains have detected up to sevenfold genotypic
differences, suggesting that selection for high levels of Ca, Fe, and Zn in breeding for mass production is a feasible approach.
Increasing the concentrations of Ca, Fe, and Zn in rice grains will help alleviate chronic Ca, Zn, and Fe deficiencies in
many areas of the world. 相似文献
9.
During combustion, most of the inorganic nutrients and trace elements in the fuel are retained and enriched in the ash. However,
here we show that, due to the low total heavy metal concentrations, the flue gas cleaning residue (i.e. the fly ash) originating
from the wet scrubber device at a medium-sized (32 MW) municipal district heating plant, is a potential forest fertilizer.
Furthermore, the easily soluble calcium (1,980 mg kg−1; d.w.) and phosphorus (50 mg kg−1; d.w.) concentrations indicate that the flue gas cleaning residue is a potential agent for soil remediation and for improving
soil fertility. 相似文献
10.
Assessment of toxicity of heavy metal contaminated soils by the toxicity characteristic leaching procedure 总被引:5,自引:0,他引:5
The concentrations of Cu, Zn, Pb and Cd in soils near a lead–zinc mine located in Shangyu, Zhejiang Province, China, were determined and their toxicity was assessed using the toxicity characteristic leaching procedure (TCLP) developed by the United States Environmental Protection Agency. The TCLP method is a currently recognized international method for evaluation of heavy metal pollution in soils. The available levels of Cu, Zn, Pb and Cd were 8.2–36, 23–143, 6.4–1367 and 0.41–2.2 mg kg−1, respectively, while the international standards were 15, 25, 5 and 0.5 mg kg−1, respectively. Soils around the mine were more polluted with Zn and Pb, followed by Cd and Cu. Moreover, the levels of heavy metals in the soils extracted by TCLP indicated that extraction fluid 2 was more effective than extraction fluid 1 in extracting the heavy metals from the polluted soils and there was a positive correlation between fluids 1 and 2. Available heavy metal contents determined by TCLP were correlated with soil total heavy metal contents. 相似文献
11.
Trace element concentration in wheat grain: results from the Swedish long-term soil fertility experiments and national monitoring program 总被引:4,自引:1,他引:3
Holger Kirchmann Lennart Mattsson Jan Eriksson 《Environmental geochemistry and health》2009,31(5):561-571
Concentrations of trace elements in wheat grain sampled between 1967 and 2003 from the Swedish long-term soil fertility experiments
were analyzed using ICP-MS. The long-term effect of inorganic and organic fertilization on trace metal concentrations was
investigated including the impact of atmospheric deposition and myccorhiza, whereas other factors such as soil conditions,
crop cultivar, etc. are not discussed in this paper. Mean values derived from 10 experimental sites were reported. Significantly
declining Pb and Cd concentrations in wheat grain could be explained by lower atmospheric deposition. Mean Se contents in
all samples were 0.031 mg kg−1 grain dry weight. No samples had sufficiently high Se concentrations for human (0.05 mg Se kg−1) or animal demand (0.1 mg Se kg−1). Concentrations of Co in wheat grain were extremely low, 0.002–0.005 mg Co kg−1 grain dry weight, and far below the minimum levels required by animals, which applied to all fertilizer treatments. A doubling
of Mo concentrations in grain since 1975 resulted in Cu/Mo ratios often below one, which may cause molybdenosis in ruminants.
The increase in Mo concentrations in crops correlated with the decline in sulfur deposition. Concentrations of Cu and Fe declined
in NPK-fertilized wheat as compared to unfertilized or manure-treated wheat. Very low concentrations of Se and Co and low
concentrations of Fe and Cu require attention to counteract risks for deficiencies. The main characteristic of the study is
that there are few significant changes over time between different fertilizer treatments, but throughout there are low concentrations
of most trace elements in all treatments. In general, good agreement between concentrations in wheat from the long-term fertility
experiments and the national monitoring program indicate that values are representative. 相似文献
12.
Hg transfer from contaminated soils to plants and animals 总被引:1,自引:0,他引:1
S. M. Rodrigues B. Henriques A. T. Reis A. C. Duarte E. Pereira P. F. A. M. R?mkens 《Environmental Chemistry Letters》2012,10(1):61-67
Understanding the transfer of mercury (Hg) from soil to crops is crucial due to Hg toxicity and Hg occurrence in terrestrial
systems. Previous research has shown that available Hg in soils contributes to plant Hg levels. Plant Hg concentrations are
related to soil conditions and plant characteristics. Mechanistic models describing such soil–plant interactions are however
difficult to quantify. Here we performed a field study in agricultural, mining and industrial areas in Portugal to evaluate
potential food chain risks. The uptake of Hg by Italian ryegrass, ryegrass, orchard grass, collard greens and rye was measured
to calculate daily intakes (DI) of Hg for cows and sheep grazing. A total of 136 soil samples and 129 plant samples were analysed.
Results show that total Hg concentrations ranged from 0.01 to 98 mg kg−1 in soils; 0.01–5.4 mg kg−1 in shoots and 0.01–42 mg kg−1 in roots. Calculated DI ranged from 0.18 to 132 mg d−1 for cows, and from 0.028 to 23 mg d−1 for sheep. In 27 grassland sites, daily intakes exceeded the acceptable daily intake of both cows and sheep in view of food
safety considering Hg in animal kidneys evidencing potential risks to human health. The transfer of Hg from soil to crops
was described using empirical Freundlich-type functions. For ryegrass, orchard grass and collard greens, the soil-to-root
or soil-to-shoot transfer of Hg appeared to be controlled by the total soil Hg concentration and levels of Alox and Feox. Empirical functions allowed us to obtain realistic estimates of Hg levels in crops and can be used as an alternative to
mechanistic models when evaluating food chain risks of Hg contamination in agricultural soils. 相似文献
13.
Distribution and phytoavailability of antimony at an antimony mining and smelting area,Hunan, China 总被引:9,自引:0,他引:9
He M 《Environmental geochemistry and health》2007,29(3):209-219
An investigation of the distribution, fractionation and phytoavailability of antimony (Sb) and other heavy metals in soil
sampled at various locations in the vicinity of a Sb mine revealed elevated levels of Sb, most certainly due to the mining
activities. The concentration of Sb in the soil samples was 100.6–5045 mg kg−1; in comparison, the maximum permissible concentration for Sb in soil in The Netherlands is 3.5 mg kg−1, and the maximum permissible concentration of pollutant Sb in receiving soils recommended by the World Health Organization
is 36 mg kg−1. The soil sampled near the Sb mine areas had also contained high concentrations of As and Hg. Root and leaf samples from
plants growing in the Sb mine area contained high concentrations of Sb, with the concentration of Sb in the leaves of radish
positively correlating with Sb concentrations in soil. The distribution of Sb in the soil showed the following order: strongly
bound to the crystalline matrix > adsorbed on Fe/Mn hydrous oxides, complexed to organic/sulfides, bound to carbonates > weakly
bound and soluble. Solvents showed varying levels of effectiveness in extracting Sb (based on concentration) from the soil,
with
, in decreasing order. The concentration of easily phytoavailable Sb was high and varied from 2.5 to 13.2 mg kg−1, the percentage of moderately phytoavailable Sb ranged from 1.62 to 8.26%, and the not phytoavailable fraction represented
88.2–97.9% of total Sb in soils. 相似文献
14.
Patel KS Shrivas K Brandt R Jakubowski N Corns W Hoffmann P 《Environmental geochemistry and health》2005,27(2):131-145
Arsenic contamination in the environment (i.e. surface, well and tube-well water, soil, sediment and rice samples) of central
India (i.e. Ambagarh Chauki, Chhattisgarh) is reported. The concentration of the total arsenic in the samples i.e. water (n=64), soil (n=30), sediment (n=27) and rice grain (n=10) were ranged from 15 to 825 μg L−1, 9 to 390 mg kg−1, 19 to 489 mg kg−1 and 0.018 to 0.446 mg kg−1, respectively. In all type of waters, the arsenic levels exceeded the permissible limit, 10 μg L−1. The most toxic and mobile inorganic species i.e. As(III) and As(V) are predominantly present in water of this region. The
soils have relatively higher contents of arsenic and other elements i.e. Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, As, Ga, Zr, Sn, Sb, Pb and U. The mean arsenic contents in soil of this region are much higher than in arsenic soil of
West Bengal and Bangladesh. The lowest level of arsenic in the soil of this region is 3.7 mg kg−1 with median value of 9.5 mg kg−1. The arsenic contents in the sediments are at least 2-folds higher than in the soil. The sources of arsenic contamination
in the soil of this region are expected from the rock weathering as well as the atmospheric deposition. The environmental
samples i.e. water, soil dust, food, etc. are expected the major exposure for the arsenic contamination. The most of people
living in this region are suffering with arsenic borne diseases (i.e. melanosis, keratosis, skin cancer, etc.). 相似文献
15.
Tarek G. Ammari Yasin Al-Zu’bi Samih Abu-Baker Basem Dababneh Wafa’ Gnemat Alaeddin Tahboub 《Environmental geochemistry and health》2011,33(5):427-437
Lithium is found in trace amounts in all soils. It is also found in plants and in nearly all the organs of the human body.
Low Li intake can cause behavioral defects. Thus, this study was conducted to investigate the concentration and distribution
of water-soluble Li in soils of the Jordan Valley and its concentration in citrus trees and some important food crops in view
of the significant implications of Li for human health. The concentration of soluble Li was measured in 180 soil samples collected
at two depths (0–20 and 20–40 cm) whereas its content was determined in fully expanded leaves collected from citrus and different
vegetable crops. Concentrations of soluble Li in soils vary from 0.95 to 1.04 mg l−1 in topsoil and from 1.06 to 2.68 mg l−1 in subsoil, while Li concentration in leaves ranged from 2 to 27 mg kg−1 DM. Lithium concentrations in leaves of crops of the same family or different families vary with location in the valley;
i.e., they decreased from north to south. It is concluded that soluble Li in soils and the plant family did not solely affect
Li transfer in the food chain. In addition, soil EC, Ca, Mg, and Cl, which increased from north to south, might adversely
affect plant Li uptake. The current study also showed that consuming 250–300 g FW of spinach day−1 per person is recommended to provide consumers with their daily Li requirement necessary for significant health and societal
benefits. 相似文献
16.
Alžbeta Jarošová Jiří Harazim Lenka Krátká Doubravka Kolenčíková 《Environmental Chemistry Letters》2010,8(4):387-391
Phthalates are animal carcinogens and may cause death or tissue deformities. Samples of feedstuffs collected in 2005 and 2006
from industrial feed manufacturers in the Czech Republic were analysed for contamination with phthalic acid esters (PAEs),
specifically di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP). Samples of feed additives, premixes and raw materials were collected (year 2005, n = 26). For soybean oil, the total volume of phthalates measured (DBP + DEHP) reached a level of 131.42 mg kg−1; for rapeseed oil, fish meal and animal fats, the levels measured were 15.00, 7.96 and 58.87 mg kg−1, respectively. The lowest level of DBP + DEHP was found in corn (2.03 mg kg−1). Since phthalates were detected, samples of feed additives (n = 28) and raw materials (n = 28) were collected again in 2006. The highest levels of DBP + DEHP were found in raw materials containing fat. Phthalate
levels in rapeseed oil samples ranged from 1.38 to 32.40 mg kg−1 DBP + DEHP. For feed additives, contamination levels in vitamins and amino acids ranged from 0.06 to 3.15 and 1.76 to 4.52 mg kg−1 DBP + DEHP, respectively. Here, we show that the levels of PAEs found in cereals such as wheat, barley and corn may be regarded
as being alarmingly high, because cereals make up the largest proportion of compound feed of farm animals. 相似文献
17.
The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters
of the abandoned Songcheon Au–Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils
were 230, 2.5, 120, 160, and 164 mg kg−1, respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 μg
L−1, 161 μg L−1 and 3899 μg L−1, respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by
Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were
summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water
were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals.
(2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable
risk of 1 in 10,000 set for regulatory purposes. 相似文献
18.
Sequential extraction of cadmium in different soil phases and plant parts from a former industrialized area 总被引:2,自引:1,他引:1
Cd concentrations in mobile phases of soil are more representative than total Cd concentration for estimating Cd bioavailability,
physicochemical reactivity and mobility. In this study, selective sequential extraction procedures were used to determine
Cd in different soil phases. Soil samples and plants grown in these soils were collected from a serpentine and copper-mining
area in Maden-Elazig-Turkey. The extracted fractions were exchangeable/carbonate, reducible-iron/manganese oxides, oxidizable-organic
matter and sulfides, and residual phases except silicates. Concentrations of Cd in soils and plant samples were determined
by flame atomic absorption spectrometry and inductively coupled plasma-mass spectrometry. We found that Cd concentrations
in the EDTA and NH2OH·HCl extracts are higher in most soil samples compared to the other extracts. We conclude that Cd levels in mobile phases
are unexpectedly high. The observed Cd concentrations are in ranges of 0.03–3.4 mg kg−1 for soil and 0.02–2.5 mg kg−1 for plant parts. The percentages of cadmium up to 56% in exchangeable and carbonates fractions were observed to be significantly
higher than in those values less than 2% reported in literature. This study has shown that the modified extraction method
can be usefully applied to determine Cd concentrations in potentially mobile phase of soil. Furthermore, it was concluded
that Brassicasea and Rumex leaves can be used as hyperaccumulator plants because their translocation factor and/or enrichment coefficient values were
found to be higher than 1.0. 相似文献
19.
Element analysis of the annual increments in a longitudinal section from the tusk of a female dugong Dugong dugon (Müller) from Exmouth, Western Australia, was carried out by X-ray fluorescence-imaging, inductively coupled plasma-atomic
emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). Nine elements (Ba, Ca, Fe, Li,
Mg, Na, P, Sr and Zn) were present in concentrations amenable to determination by these techniques. Most elements revealed
both long-term trends and shorter, year-to-year, variations. For example, sodium concentrations increased from 0.55 to 0.72%
with the age of the dugong. Strontium concentrations (mean 0.17%) were closely correlated (r = 0.86) with those of barium (mean 4.5 mg kg−1). Zinc concentrations increased from ∼70 to 170 mg kg−1 with dugong age, but also showed shorter-term fluctuations of ∼30 mg kg−1 that were correlated (r = 0.41) with mean annual Fremantle sea level (a measure of the Southern Oscillation Index and strength of the Leeuwin Current).
The concentrations of the elements and correlations with year and between pairs of elements are discussed.
Received: 10 January 1997 / Accepted: 21 April 1997 相似文献
20.
The use of higher plants to remediate contaminated land is known as phytoremediation, a term coined 15 years ago. Among green technologies addressed to metal pollution, phytoextraction has received increasing
attention starting from the discovery of hyperaccumulator plants, which are able to concentrate high levels of specific metals
in the above-ground harvestable biomass. The small shoot and root growth of these plants and the absence of their commercially
available seeds have stimulated study on biomass species, including herbaceous field crops. We review here the results of
a bibliographical survey from 1995 to 2009 in CAB abstracts on phytoremediation and heavy metals for crop species, citations of which have greatly increased, especially after 2001. Apart from the most frequently cited
Brassica juncea (L.) Czern., which is often referred to as an hyperaccumulator of various metals, studies mainly focus on Helianthus annuus L., Zea mays L. and Brassica napus L., the last also having the greatest annual increase in number of citations. Field crops may compensate their low metal
concentration by a greater biomass yield, but available data from in situ experiments are currently very few. The use of amendments
or chelators is often tested in the field to improve metal recovery, allowing above-normal concentrations to be reached. Values
for Zn exceeding 1,000 mg kg−1 are found in Brassica spp., Phaseolus vulgaris L. and Zea mays, and Cu higher than 500 mg kg−1 in Zea mays, Phaseolus vulgaris and Sorghum bicolor (L.) Moench. Lead greater than 1,000 mg kg−1 is measured in Festuca spp. and various Fabaceae. Arsenic has values higher than 200 mg kg−1 in sorghum and soybean, whereas Cd concentrations are generally lower than 50 mg kg−1. Assisted phytoextraction is currently facilitated by the availability of low-toxic and highly degradable chelators, such
as EDDS and nitrilotriacetate. Currently, several experimental attempts are being made to improve plant growth and metal uptake,
and results are being achieved from the application of organic acids, auxins, humic acids and mycorrhization. The phytoremediation
efficiency of field crops is rarely high, but their greater growth potential compared with hyperaccumulators should be considered
positively, in that they can establish a dense green canopy in polluted soil, improving the landscape and reducing the mobility
of pollutants through water, wind erosion and water percolation. 相似文献