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1.
Ryan R. P. Noble Robert M. Hough Ronald T. Watkins 《Environmental geochemistry and health》2010,32(3):193-205
Stawell Gold Mine in NW Victoria, Australia, mines ores that contain large concentrations of As and significant quantities of the metals Pb and Cr. The aim of this research was to understand the dispersion, enrichment and probable exposure of these potentially hazardous elements around the mine site. Fifty-five surface soil samples were collected near the mine (<15 km) and analysed by ICP-MS/OES following bioavailable and four-acid extractions. Soils near the mine show greater concentrations of As, Cr and Pb than those near a regionally determined background. This is attributed to the combination of a natural geochemical halo around mineralization and anthropogenic dispersion due to mining and urbanization. Total As concentrations were between 16 and 946 mg kg−1 near the mine in a regional background of 1–16 mg kg−1. Total Cr concentrations were between 18 and 740 mg kg−1 near the mine in a regional background of 26–143 mg kg−1. Total Pb concentrations were between 12 and 430 mg kg−1 near the mine in a regional background of 9–23 mg kg−1. Dispersion of contaminant elements from the present ore processing is <500 m. The most enriched soils occur close to the town and are unrelated to present mining practices. The bioavailable As, Cr and Pb, soil ingestion rates and Risk Reference Doses were used to estimate health risks. An average toddler (12 kg) would need to consume at least 1.5 g, and most likely 12 g, of soil per day to show some symptoms of As toxicity. The maximum measured bioavailable As would pose a risk at average ingestion rates of 200 mg per day. Individuals with soil-eating disorders would exceed the safe daily consumption limits for As, and potentially Cr and Pb. Small children are not typically exposed to soil everyday, very few have soil eating disorders, and, therefore, the health risk from the soils around the mine is minimal. 相似文献
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
Moreno Rodriguez MJ Cala Rivero V Jiménez Ballesta R 《Environmental geochemistry and health》2005,27(5-6):513-519
Selenium was determined from 25 topsoils and 25 plants in the semi-arid Central Spain where large extents of soils are developed
on evaporitic materials. Some species of vegetation associated with them are of the genera Astragalus, Salsola, Mercurialis, Phlomis, Thymus and Atriplex. Total selenium in soils was determined and its bioavailability assessed by chemical sequential fractionation. Se content
in soils was adequate (in the range 0.17–0.39 mg kg−1) or large (in the range 0.50–4.38 mg kg−1) and appeared in highly and/or potentially available forms. Several plant species showed high Se levels (in the range 5–14.3 mg kg−1), which can be a potential risk of toxicity to animals. Data obtained from the study area can be used as a guide to the range
of values in soils and plants of the European Mediterranean area that are relatively unpolluted from industrial sources, allowing
comparison with more polluted areas. 相似文献
13.
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
14.
The ecological toxicity of cadmium (Cd, 10 mg kg−1 of dry weight soil) and butachlor (10, 50 and100 mg kg−1 of dry weight soil) in both their single and combined effects on soil urease and phosphatase was studied after 1, 3, 7, 14,
21 and 28 days exposure under controlled conditions in paddy and phaeozem soils. The results showed that Cd reduced the activities
of urease and phosphatase at early incubation time (1–7 days), while the reduction almost disappeared at the end of the incubation.
The effect of Cd on phosphatase was more pronounced than that on urease. The activities of urease and phosphatase were reduced
by butachlor, while urease activity was significantly (P < 0.05 or P < 0.01) improved when the concentrations of butachlor were 10 and 50 mg kg−1 at the end of the incubation. When Cd (10 mg kg−1) was combined with butachlor (50 and 100 mg kg−1), the activities of urease and phosphatase became lower than without combination at early incubation time, which indicated
that the toxicity of Cd significantly increased (P < 0.05 or P < 0.01). However, when Cd (10 mg kg−1) was combined with butachlor (10 mg kg−1), the activities of urease and phosphatase became higher than those without combination at the end of the incubation, which
indicated that the toxicity of Cd decreased. It was indicated that the combined effects depended largely on the incubation
time and the concentration ratio of Cd and butachlor. In addition, it was showed that the combined effects of butachlor and
Cd appeared different in paddy from phaeozem, which may be related to the different properties of these soils. 相似文献
15.
Palumbo-Roe B Cave MR Klinck BA Wragg J Taylor H O'Donnell KE Shaw RA 《Environmental geochemistry and health》2005,27(2):121-130
Jurassic ironstones outcropping over parts of eastern England give rise to soils with arsenic concentrations in excess of
the UK soil guideline value of 20 mg kg−1 for residential areas. Total arsenic concentrations were determined for 73 ironstone derived soils and bioaccessible arsenic
determined using an in vitro physiologically based extraction test. The bioaccessible arsenic concentration for these soils was found to be well below
the soil guideline value with a mean concentration of 4 mg kg−1 and a range of 2–17 mg kg−1. The bioaccessible fraction ranges from 1.2 to 33%. Data from a sequential extraction test based on the use of aqua regia
as the main extractant is presented for a subset of 20 of the soils. Chemometric data reduction is used to demonstrate that
the bioaccessible arsenic is mainly contained within calcium iron carbonate (sideritic) assemblages and only partially iron
aluminosilicates, probably berthierine, and iron oxyhydroxide phases, probably goethite. It is suggested that the bulk of
the non-bioaccessible arsenic is bound up with less reactive iron oxide phases. 相似文献
16.
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
17.
Andrew McMinn Andrew Pankowskii Chris Ashworth Ranjeet Bhagooli Peter Ralph Ken Ryan 《Marine Biology》2010,157(6):1345-1356
Primary production at Antarctic coastal sites is contributed from sea ice algae, phytoplankton and benthic algae. Oxygen microelectrodes
were used to estimate sea ice and benthic primary production at several sites around Casey, a coastal area in eastern Antarctica.
Maximum oxygen export from sea ice was 0.95 mmol O2 m−2 h−1 (~11.7 mg C m−2 h−1) while from the sediment it was 6.08 mmol O2 m−2 h−1 (~70.8 mg C m−2 h−1). When the ice was present O2 export from the benthos was either low or negative. Sea ice algae assimilation rates were up to 3.77 mg C (mg Chl-a)−1 h−1 while those from the benthos were up to 1.53 mg C (mg Chl-a)−1 h−1. The contribution of the major components of primary productivity was assessed using fluorometric techniques. When the ice
was present approximately 55–65% of total daily primary production occurred in the sea ice with the remainder unequally partitioned
between the sediment and the water column. When the ice was absent, the benthos contributed nearly 90% of the primary production. 相似文献
18.
Srinivasulu M Jaffer Mohiddin G Subramanyam K Rangaswamy V 《Environmental geochemistry and health》2012,34(3):365-374
The effect of selected pesticides, monocrotophos, chlorpyrifos alone and in combination with mancozeb and carbendazim, respectively,
was tested on nitrification and phosphatase activity in two groundnut (Arachis hypogeae L.) soils. The oxidation of ammonical nitrogen was significantly enhanced under the impact of selected pesticides alone and
in combinations at 2.5 kg ha−1 in black soil, and furthermore, increase in concentration of pesticides decreased the rate of nitrification, whereas in the
case of red soil, the nitrification was increased up to 5.0 kg ha−1 after 4 weeks, and then decline phase was started gradually from 6 to 8 weeks of incubation. The activity of phosphatase
was increased in soils, which received the monocrotophos alone and in combination with mancozeb up to 2.5 and 5.0 kg ha−1, whereas the application of chlorpyrifos singly and in combination with carbendazim at 2.5 kg ha−1 profoundly increased the phosphatase activity after 20 days of incubation, in both soils. But higher concentrations of pesticides
were either innocuous or inhibitory to the phosphatase activity. 相似文献
19.
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
20.
Róza Uminska 《Environmental geochemistry and health》1993,15(1):15-19
Cadmium was measured in soils limed with industrial solid wastes, in cultivated lands located near waste yards and in soils of allotment gardens exposed to contamination. The median level and range of cadmium in soils of varying exposure to contamination was respectively: 0.3 mg kg–1 and 0.01–107 mg kg–1, 0.2 mg kg–1 and 0.02–2,198 mg kg–1, 0.4 mg kg–1 and 0.05–161 mg kg –1. Cadmium levels exceeded the value of 3 mg kg–1 considered permissible for arable soils in the samples of soils limed with wastes from the chemical industry (2.4%), the mining industry and metallurgy sites (2.1 %), in 12.4% samples of soils located in the neighbourhood of industrial waste storage yards and in 17.2% samples of soils from allotment gardens located on lands formerly used for waste storage. 相似文献