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1.
The in vitro study was carried out to examine the toxicity of four commercially used pesticides (phorate, mancozeb, chlorpyrifos, and endosulfan) at the recommended dose (1X) and higher field doses (1.5X, 2X, 2.5X, and 3X) on plant growth-promoting activities of Burkholderia sp. strain L2, isolated from pesticide-treated rhizosphere of Lycopersicon esculentum. At the recommended dose, level of toxicity of all the pesticides to phosphate solubilization activity and indole-3-acetic acid (IAA) production was less detrimental as compared to exceeding doses. At maximum dose rate of each pesticide, the percentage decrease in phosphate solubilization and IAA production over control was found in order of chlorpyrifos < mancozeb < endosulfan < phorate. Present study proves that Burkholderia sp. strain L2 could be used as a potential microbial inoculant in the agricultural soil having persistent pesticide residues. 相似文献
2.
Risk to humans of consuming metals in anchovy (<Emphasis Type="Italic">Coilia</Emphasis> sp.) from the Yangtze River Delta 总被引:1,自引:0,他引:1
Fengyan Liu Jiachun Ge Xin Hu Teng Fei Yuehua Li Yuan Jiang Zhiqiang Xu Shuyan Ding John P. Giesy 《Environmental geochemistry and health》2009,31(6):727-740
Concentrations of metals were determined in four species of anchovy (Coilia sp.) from the Yangtze River, Taihu Lake, and Hongze Lake in Jiangsu Province, China. Concentrations of Cr in anchovy fish
muscle ranged from 2.6 × 10−2 to 5.0 mg/kg ww, and Coilia nasus taihuensis in Jiaoshan, Taihu Lake contained the highest concentrations of Cr, which was almost 111-fold higher than the mean value
at other locations. Concentrations of Pb ranged from 1.5 × 10−2 to 1.3 × 10−1 mg/kg ww. Comparisons of concentrations of lead (Pb) among the four species indicated that anadromous species contained higher
concentrations of Pb than did freshwater species. However, concentrations of Pb in C. nasus from the Nanjing and Haimen locations in the Yangtze River were not significant higher than those of two freshwater species:
C. nasus taihuensis from Taihu Lake and C. brachygnathus from Hongze Lake (Duncan’s test, α = 0.05). While concentrations of Cd and Zn ranged from 7.0 × 10−4 to 3.6 × 10−3 mg/kg ww and 3.4 to 4.8 mg/kg ww, respectively, there were no significant differences in concentrations among the eight locations.
The only concentration of the metals studied that exceeded the Chinese National Standard was Cr in Coilia from Jiaoshan, Taihu Lake, which was 2.5-fold higher than the standard. These results indicate that people who consume the
genus Coilia are not at risk due to concentrations of metals, except Cr in C. nasus taihuensis from Jiaoshan in Taihu Lake. Concentrations of all of the metals studied except for Cr were similar to or less than those
of metals in most other areas in the world. 相似文献
3.
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
4.
Bacterial abundance, production, and extracellular enzyme activity were determined in the shallow water column, in the epiphytic
community of Thalassia
testudinum, and at the sediment surface along with total carbon, nitrogen, and phosphorus in Florida Bay, a subtropical seagrass estuary.
Data were statistically reduced by principle components analysis (PCA) and multidimensional scaling and related to T. testudinum leaf total phosphorus content and phytoplankton biomass. Each zone (i.e., pelagic, epiphytic, and surface sediment community)
was significantly dissimilar to each other (Global R = 0.65). Pelagic aminopeptidase and sum of carbon hydrolytic enzyme (esterase, peptidase, and α- and β-glucosidase) activities
ranged from 8 to 284 mg N m−2 day−1 and 113–1,671 mg C m−2 day−1, respectively, and were 1–3 orders of magnitude higher than epiphytic and sediment surface activities. Due to the phosphorus-limited
nature of Florida Bay, alkaline phosphatase activity was similar between pelagic (51–710 mg P m−2 day−1) and sediment (77–224 mg P m−2 day−1) zones but lower in the epiphytes (1.1–5.2 mg P m−2 day−1). Total (and/or organic) C (111–311 g C m−2), N (9.4–27.2 g N m−2), and P (212–1,623 mg P m−2) content were the highest in the sediment surface and typically the lowest in the seagrass epiphytes, ranging from 0.6 to
8.7 g C m−2, 0.02–0.99 g N m−2, and 0.5–43.5 mg P m−2. Unlike nutrient content and enzyme activities, bacterial production was highest in the epiphytes (8.0–235.1 mg C m−2 day−1) and sediment surface (11.5–233.2 mg C m−2 day−1) and low in the water column (1.6–85.6 mg C m−2 day−1). At an assumed 50% bacterial growth efficiency, for example, extracellular enzyme hydrolysis could supply 1.8 and 69% of
epiphytic and sediment bacteria carbon demand, respectively, while pelagic bacteria could fulfill their carbon demand completely
by enzyme-hydrolyzable organic matter. Similarly, previously measured T. testudinum extracellular photosynthetic carbon exudation rates could not satisfy epiphytic and sediment surface bacterial carbon demand,
suggesting that epiphytic algae and microphytobenthos might provide usable substrates to support high benthic bacterial production
rates. PCA revealed that T. testudinum nutrient content was related positively to epiphytic nutrient content and carbon hydrolase activity in the sediment, but
unrelated to pelagic variables. Phytoplankton biomass correlated positively with all pelagic components and sediment aminopeptidase
activity but negatively with epiphytic alkaline phosphatase activity. In conclusion, seagrass production and nutrient content
was unrelated to pelagic bacteria activity, but did influence extracellular enzyme hydrolysis at the sediment surface and
in the epiphytes. This study suggests that seagrass-derived organic matter is of secondary importance in Florida Bay and that
bacteria rely primarily on algal/cyanobacteria production. Pelagic bacteria seem coupled to phytoplankton, while the benthic
community appears supported by epiphytic and/or microphytobenthos production. 相似文献
5.
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
6.
The transformation of the fungicide carbendazim (methyl-2 benzimidazole carbamate) induced by hydroxyl radical generated by
the UV photolysis of H2O2 has been studied in dilute aqueous solution. The efficient reaction of hydroxyl radicals with carbendazim led to the rapid
degradation of carbendazim. The study of reaction kinetics yielded a second order rate constant of 2.2±0.3 109 M−1 s−1 for HO· radicals with carbendazim. This value is in agreement with a high reactivity of HO· radicals with carbendazim. Most degradation products were identified by high performance liquid chromatography mass spectrometry
(HPLC-MS). In the presence of hydrogenocarbonate and carbonate ions, hydroxyl radicals were quenched and in turn carbonate
radicals CO3
·− were formed. Carbonate radicals are indeed known to react efficiently with compounds containing electron-rich sites such
as nitrogen or sulfur atoms. The use of a kinetic modelling software gave evidence for the occurrence of such reactions with
carbendazim. The second order rate constant of carbonate radical with carbendazim was equal to 6±2 106 M−1 s−1.
Electronic Publication 相似文献
7.
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
8.
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
9.
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
10.
Anthropogenic nitrogen sources and exports in a village-scale catchment
in Southeast China 总被引:6,自引:0,他引:6
An experimental village-scale catchment was selected for investigation of nitrogen (N) sources and exports. The mean N application rate over the catchment was 350.2 kg N ha−1, but this rate varied spatially and temporally. The N leaching loss rate varied from 8.1 to 52.7 kg N ha−1 under different land use regimes. The average N leaching loss rate was 13.4 kg N ha−1 over the whole catchment, representing about 3.8% of the total N inputs. The N export rate through stormflows was 28.8 kg N ha−1, about 8.2% of the total N inputs. Seasonal patterns showed that 95% of N exports through stormflows occurred during July to September in 2002. Overall, the maximum riverine N exports were 12.1% of total N inputs and 15.5% of the inorganic fertilizer N applied. Understanding N sources and exports in a village-scale catchment can provide a knowledge base for amelioration of diffuse agricultural pollution. 相似文献
11.
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
12.
At three coastal dune sites at the island of Hiddensee, north-east Germany, vegetation cover was mapped during 2002 and compared
to vegetation surveys from the late 1980s and 1930s. Abiotic and biotic factors, which have been identified as being critical
for coastal dunes in former studies such as disturbance, salt spray or nutrient availability, were measured. Grazing and land-use
history were reviewed by literature and interviews. Tall graminoid communities, mainly Carex arenaria, are a common vegetation unit today. Development, distribution of these dominances and possible causes for its occurrence
have not been analysed. Generally, older successional vegetation units increased and pioneer stages decreased from the 1930s
until 2002. At the geologically youngest site, the southern dunes, grass encroachment by Carex arenaria was highest (ca. 50% cover in 2002), and age and density of trees lower than at the older, central dunes. Land-use changes
such as decrease in grazing pressure, additional feeding of livestock, increase in coastal protection measures and subsequent
decrease in shifting sands as well as varying availability of groundwater and amount of salt spray are relevant factors for
vegetation changes in coastal dunes over the past 70 years. Site-specific land-use differences such as livestock density and
land-use history have a stronger influence than atmospheric N-pollution on the vegetation composition of these acidic, coastal
dunes under low to moderate N-deposition loads of 6–8 kg N ha−1 yr−1. 相似文献
13.
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
14.
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
15.
The effects of local-scale anthropogenic disturbance from active drilling platforms on epibenthic megafaunal abundance, diversity
and assemblage pattern were examined in two west of Shetland hydrocarbon fields at 420 and 508 m water depth. These areas
were selected to include a range of disturbance regimes and contrasting faunal assemblages associated with different temperature
regimes. Remotely operated vehicle (ROV) video provided high-resolution megafaunal abundance and diversity data, which were
related to the extent of visible disturbance from drilling spoil. These data, in conjunction with a study deeper in the Faroe-Shetland
Channel, have allowed comparison of the effects of disturbance on megabenthos across a range of sites. Disturbance to megafaunal
assemblages was found to be high within 50 m of the source of drill spoil and in areas where spoil was clearly visible on
the seabed, with depressed abundances (Foinaven 1,900 individuals ha−1; Schiehallion 2,178 individuals ha−1) and diversity (H′ = 1.75 Foinaven; 1.12 Schiehallion) as a result of smothering effects. These effects extended to around 100 m from the source
of disturbance, although this was variable, particularly with current regime and nature of drilling activity. Further from
the source of disturbance, megafaunal assemblages became more typical of the background area with increased diversity (H′ = 2.02 Foinaven; 1.77 Schiehallion) and abundance (Foinaven 16,484 individuals ha−1; Schiehallion 5,477 individuals ha−1). Visible effects on megafaunal assemblages as a result of seabed drilling were limited in extent although assemblage responses
were complex, being controlled by differing effects to individual species often based on their motility. 相似文献
16.
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
17.
Parrotfishes can be significant bioeroders and sediment producers on coral reefs. We quantified the bioerosion rates of two
similarly sized Hawaiian parrotfishes with two different feeding modes (Scarus rubroviolaceus—a scraper and Chlorurus perspicillatus—an excavator). The results showed that feeding modes did not affect bioerosion rates but that bioerosion rates were size
dependent, with largest individuals (S. rubroviolaceus 45–54 cm FL) bioeroding up to 380 ± 67 kg ind−1 year−1. The size for onset of bioerosion capabilities for both species was 15 cm. Grazing by the two species consumed 60% of the
carbonate production of the fore reef area, suggesting that large parrotfishes in Hawaii are ecologically important bioeroders.
As individual large S. rubroviolaceus contributed disproportionately more to bioerosion and sediment production than the equivalent biomass of smaller conspecifics,
management strategies designed to retain normal reef bioerosion rates should seek to preserve the historical size structure
of S. rubroviolaceus populations and to especially protect the larger size classes. 相似文献
18.
The influence of naturally occurring uraniferous black shales on cadmium, molybdenum and selenium concentrations in soils
and plants is examined. The possible implications of element concentrations to animal and human health are considered for
the Deog-Pyoung area.
Geochemical surveys have been undertaken within 13 river tributary valleys in the area underlain by uraniferous black shales
and black slates or grey chlorite schists. Sampling of rocks, soils and plants has been carried out along transect lines within
each valley. Samples were analysed for trace elements by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
and for uranium by Neutron Activation Analysis (NAA). Soil pH, cation exchange capacity, loss on ignition and particle size
distribution have been measured for selected samples.
Average trace element concentrations of the Okchon uraniferous black shales were 6.3 μg g−1 Cd, 136 μg g−1 Mo and 8.6 μg g−1 Se. Soils derived from these rocks tend to reflect their extreme geochemical composition. Trace element concentrations in
alluvial soils derived in part from these black shales averaged 1.2 μg g−1 Cd, 20 μg g−1 Mo and 1.5 μg g−1 Se. Trace element concentrations in plants were found to be influenced by those of soils. Cadmium accumulated in tobacco
leaves up to 46 μg g−1 (D.M.) and leafy plants such as lettuce contain up to 0.5 μg g−1 Se (D.M.).
In addition to total concentrations in soils, soil pH is a major factor influencing uptake of Mo into crop plants and soil
texture for Se. Concentrations of trace elements in plants also varied between plant species. The relative concentrations
of Cd were found to vary in the order tobacco > lettuce > red pepper > rice grain.
Elevated concentrations of Cd in crop plants and in tobacco may possibly have deleterious effects on human health in this
area. The low Cu:Mo ratio in rice stalk of 2.65:1 may be associated with disturbed Cu metabolism in ruminant animals which
regularly consume this material. 相似文献
19.
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
20.
Rogan N Serafimovski T Dolenec M Tasev G Dolenec T 《Environmental geochemistry and health》2009,31(4):439-451
This research focuses on the heavy metal contamination of the paddy soils and rice from Kočani Field (eastern Macedonia) resulting
from irrigation by riverine water impacted by past and present base-metal mining activities and acid mine drainage. Very high
concentrations of As, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99, 983 and 1,245 μg g−1) and the rice (0.53, 0.31, 5.8, 0.5 and 67 μg g−1) in the western part of Kočani Field, close to the Zletovska River, which drains the mining facilities of the Pb–Zn mine
in Zletovo. In terms of health risk, the observed highest concentrations of these elements in the rice could have an effect
on human health and should be the subject of further investigations. 相似文献