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PubMed2001

Study on the kinetics of cerium(III) adsorption-desorption on different soils of China.

The kinetics of Ce(III) adsorption-desorption on four typical soils in China has been studied by using the batch method with the radioactive nuclide 141Ce. Results indicated that Ce(III) adsorption was rapid and nearly finished in less than 0.5 min. Desorption procedure was about completed in 1-30 min in the tested soils. Ce(III) desorption equilibrium times vary with different soils. The amounts of Ce(III) desorption on different soils in the same time were different. The Elovich equation proved to be the best models for fitting the data of Ce(III) desorption reactions in fluvo-aquic soil and black soil; and the parabolic-diffusion equation was the best model in red earth and loess soil.

Adsorption↗
PubMed1991

Lead exposure from conventional and cottage lead smelting in Jamaica.

A survey was conducted to determine the distribution and determinants of environmental and blood lead levels near a conventional and several cottage lead smelters and to assess the relationship between environmental and blood lead levels in a tropical, developing-country setting. Fifty-eight households were studied in the Red Pond community, the site of the established smelter and several backyard smelters, and 21 households were studied in the adjacent, upwind Ebony Vale community in Saint Catherine Parish, Jamaica. Households were investigated, using questionnaires, soil and housedust lead measurements, and blood lead (PbB) measurements from 372 residents. Soil lead levels in Red Pond exceeded 500 parts per million (ppm) at 24% of households (maximum--18,600 ppm), compared to 0% in Ebony Vale (maximum 150 ppm). Geometric mean PbB in Red Pond, where 44% of children less than 6 years of age had PbB levels greater than or equal to 25 micrograms per deciliter (micrograms/dL), was more than twice that Ebony Vale in all age groups (p less than 0.0005). Within Red Pond, proximity to backyard smelters and to the conventional smelter were independent predictors of soil lead (p less than 0.05). Soil lead was the strongest predictor of PbB among Red Pond subjects under 12 years of age. The blood lead--soil lead relationship in children differed from that reported in developed countries; blood lead levels were higher than expected for the household-specific soil lead levels that were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed2004

Effects of crude oil, oil components, and bioremediation on plant growth.

The phytotoxic effects of crude oil and oil components on the growth of red beans (Phaseolus nipponesis OWH1) and corn (Zea mays) was investigated. In addition, the beneficial effects of bioremediation with the oil-degrading microorganism, Nocardia sp. H17-1, on corn and red bean growth in oil-contaminated soil was also determined. It was found that crude oil-contaminated soil (10,000mg/kg) was phytotoxic to corn and red beans. In contrast, obvious phytotoxicity was not observed in soils contaminated with 0-1000 mg/kg of aliphatic hydrocarbons such as decane (C10) and eicosane (C20). Phytotoxicity was observed in soils contaminated with 10-1000mg/kg of the poly aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. It was observed that phytotoxicity increased with the number of aromatic rings, and that corn was more sensitive than red beans to PAH-contaminated soil. Bioremediation with Nocardia sp. H17-1 reduced phytotoxicity more in corn than in red bean, suggesting that this microbial species might degrade PAHs to some degree.

Biodegradation, Environmental↗
PubMed2000

Neutral red retention by earthworm coelomocytes: a biomarker of cadmium contamination in soil.

The earthworm Metaphire posthuma were used as a model to assess the toxic potential of cadmium incorporated into the soil by environmental or human activities. The retention period of neutral red in the lysosomes of the coelomocytes was used as a biomarker. The viability of harvested coelomocytes by a non-invasive extrusion protocol was 93% with no alteration by the dye during experimentation. The control cells retained dye for 119 and 121 min in normal soil and KCl, respectively, whereas a linear decline in the retention time in the treated earthworm coelomocytes was observed. This illustrated that the presence of cadmium caused damage to the lysosomes of the coelomocytes.

Animals↗
PubMed1975

Survival of Poria weirii on paired plots in alder and conifer stands.

Cubes of Douglas-fir wood decayed by Poria weirii (Murr.) Murr. were buried for 12 months on paired plots in red alder and in confier soils on the Cascade Head Experimental Forest. Survival of the fungus was not significantly different in the two soils, although pH was significantly lower and nitrate content significantly higher in alder soils. Even though effects on fungus survival were nil, red alder, for other reasons, might still be used to reduce damage caused by P. weirii root not on areas of heavy infestation.

Basidiomycota↗
PubMedDate not supplied

Hay-scented fern (Dennstaedtia punctilobula (Michx.) Moore) interference with growth of northern red oak (Quercus rubra L.) seedlings.

We assessed the impacts of hay-scented fern (Dennstaedtia punctilobula (Michx.) Moore) and subsoil liming (CaO amendments) on root and shoot growth of greenhouse-grown, first-year, northern red oak (Quercus rubra L.) seedlings. Red oak seedlings and ferns were grown in reconstructed soil profiles of four common Pennsylvanian forest soils. When grown in the presence of hay-scented ferns, with or without subsoil liming, red oak seedlings had significantly reduced height growth, and foliar, stem and total root biomass. Fern foliar biomass was significantly reduced when ferns were grown with red oaks, but there was no significant difference in total belowground biomass of ferns. Belowground fern biomass was concentrated in the upper soil profile, whereas red oak roots showed a variety of distributions. In the presence of ferns, fine root branching in red oak was reduced in the organic horizons of three of the four soils tested. In both the presence and absence of ferns, root branching in red oak was also significantly and negatively correlated with the concentration of 0.01 M SrCl(2)-extractable aluminum in the mineral horizons (r(2) = 0.77). Subsoil liming generally improved root branching in red oaks. The presence of ferns significantly reduced ectomycorrhizal infection frequency in red oak. We conclude that hay-scented fern inhibited root branching and suppressed above- and belowground biomass accumulation of first-year northern red oak seedlings.

Journal Article↗
PubMed2000

Effect of sludge-processing mode, soil texture and soil pH on metal mobility in undisturbed soil columns under accelerated loading.

The effect of sludge processing (digested dewatered, pelletized, alkaline-stabilized, composted, and incinerated), soil type and initial soil pH on trace metal mobility was examined using undisturbed soil columns. Soils tested were Hudson silt loam (Glossaquic Hapludalf) and Arkport fine sandy loam (Lamellic Hapludalf), at initial pH levels of 5 and 7. Sludges were applied during four accelerated cropping cycles (215 tons/ha cumulative application for dewatered sludge; equivalent rates for other sludges), followed by four post-application cycles. Also examined (with no sludge applications) were Hudson soil columns from a field site that received a heavy loading of sludge in 1978. Romaine (Lactuca sativa) and oats (Avena sativa) were planted in alternate cycles, with oats later replaced by red clover (Trifolium pratense). Soil columns were watered with synthetic acid rainwater, and percolates were analyzed for trace metals (ICP spectroscopy), electrical conductivity and pH. Percolate metal concentrations varied with sludge and soil treatments. Composted sludge and ash had the lowest overall metal mobilities. Dewatered and pelletized sludge had notable leaching of Ni, Cd and Zn in Arkport soils, especially at low pH. Alkaline-stabilized sludge had the widest range of percolate metals (relatively insensitive to soils) including Cu, Ni, B and Mo. Old site column percolate concentrations showed good agreement with previous field data. Little leaching of P was observed in all cases. Cumulative percolate metal losses for all treatments were low relative to total applied metals. Leachate and soil pH were substantially depressed in dewatered and pelletized sludge soil columns and increased for alkaline-stabilized and ash treatments.

Journal Article↗
PubMed2005

Selectivity lists of pesticides to beneficial arthropods for IPM programs in carrot--first results.

In order to improve IPM programs in carrot, 7 fungicides, 12 herbicides and 9 insecticides commonly used in Belgium were tested for their toxicity towards five beneficial arthropods representative of most important natural enemies encountered in carrot: parasitic wasps - Aphidius rhopalosiphi (De Stefani-Perez) (Hym., Aphidiidae), ladybirds - Adalia bipunctata (L.) (Col., Coccinellidae), hoverfly - Episyrphus balteatus (Dipt.. Syrphidae), rove beetle - Aleochara bilineata (Col., Staphylinidae) and carabid beetle - Bembidion lampros (Col., Carabidae). Initialy, all plant protection products were tested on inert substrate glass plates or sand according to the insect. Products with a corrected mortality (CM) or a parasitism reduction (PR) lower than 30% were kept for the constitution of positive list (green list). The other compounds were further tested on plant for A. rhopalosiphi, A. bipunctata, E. balteatus and soil for B. lampros and A. bilineata. With these extended laboratory tests results, products were listed in toxicity class: green category [CM or PR < or = 30%], yellow category [30% < CM or PR < or = 60%] and orange category [60% < CM or PR < or = 80%]. Products with toxicity higher than 80% on plants or that reduce parasitism more than 80% on soil were put in red category and are not recommended to Integrated Pest Management programs in carrot. Results showed that all fungicides tested were harmless to beneficials except Tebuconazole, which was slightly harmful for A. bipunctata. Herbicides were also harmless for soil beneficials, except Chlorpropham. This product was very toxic on sand towards A. bilineata and must be tested on soil. All soil insecticides tested were very toxic for ground beneficials and considered as non-selective. Their use in IPM is subject to questioning in view of negative impacts on beneficials. Among foliar insecticides, Dimethoate and Deltamethrin are not recommended for IPM because their high toxicity for all beneficials. The other foliar insecticides were more selective; any of them were harmless for all species tested.

Animals↗
PubMed2003

Linking lysosomal biomarker and population responses in a field population of Aporrectodea caliginosa (Oligochaeta) exposed to the fungicide copper oxychloride.

The effects of the fungicide copper oxychloride on a field population of the earthworm Aporrectodea caliginosa were investigated. Changes were monitored in earthworm numbers and biomass, copper concentrations in soil and earthworms, and neutral red retention times (NRRTs) of coelomocytes. The aim was to establish whether the cellular responses could be linked to changes at the population level. Results indicated that there was a significant (P<0.05) impact on worm density and biomass on the treated plots 6 months after spraying with the fungicide stopped. NRRTs of treated earthworms were significantly lower after one spraying when earthworms had elevated concentrations of copper in their body tissues. Six months after spraying stopped, copper levels in both soil and earthworm tissues declined significantly, but the earthworm numbers and biomass were still significantly lower in the treated plots. This indicated that the effects of the copper oxychloride exposure manifested at a much later stage at the population level, than on NRRT. We conclude that the decrease in NRRTs, which preceded the decrease in both earthworm biomass and numbers, may have predictive value as a biomarker of impending population changes.

Animals↗
PubMed1975

[Supply of trace elements to ruminants in the German Democratic Republic. 3. Supply of zinc].

The supply of zinc to ruminants as influenced by and depending upon the geological origin of soils was investigated using the hair test and the technique of indicator plants. A total of 1276 samples of red meadow clover and 3022 samples of red field clover and 4184 hair specimens from cows were analyzed. The following statistically well-established results were obtained which appear to be generalizable: Red meadow clover contained significantly more Zn than red field clover (48 ppm/38 ppm). Red meadow clover and field clover grown on loamy soils (59%), weathered soils of less (59%), red sandstone (57%) basalt (53%), shell limestone (47%) and Keuper (41%) contained only 59%-41% of the amount of Zn found in indicator plants that were grown in locations were the highest Zn level (weathered soils of porphyry). Zn concentrations in red meadow and field clover grown on soils of the same geological origin correlated with r = 0.87. A positive correlation (B = 0.53) was found to exit between the relative proportions of Zn contained in indicator plants grown on a particular soil and the proportions of Zn contained in hair specimens from Zn-deficient cows (less than 100 ppm of Zn). The largest number of hair specimens containing less than 100 ppm of Zn were found in cows from areas with soils of basalt (17%), and loess (18%), areas with loamy soils (24%), and sandy diluvial soils (25%), or with alluvial pastures (23%), or with soils of Keuper (27%), shell limestone (22%) or red sandstone (29%). Ruminants in these areas are liable to suffer from Zn deficiencies.

Animal Feed↗
PubMedDate not supplied

Chemical changes in agricultural soils of Korea: data review and suggested countermeasures.

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise, 4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, available phosphate and extractable calcium, magnesium and potassium contents, and heavy metal contents such as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The study showed that the average contents of organic matter, available phosphate, and extractable potassium rapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K2O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, and only 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils (0-15 cm depth) were 0.11 mg kg(-1) (ranged from 0 to 1.01), 4.70 mg kg(-1) (0-41.59), 4.84 mg kg(-1) (0-66.44), and 4.47 mg kg(-1) (0-96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn, and As in surface soils (0-15 cm depth) were 0.135 mg kg(-1) (ranged from 0 to 0.660), 2.77 mg kg(-1) (0.07-78.24), 3.47 mg kg(-1) (0-43.00), 10.70 mg kg(-1) (0.30-65.10), and 0.57 mg kg(-1) (0.21-2.90), respectively. In plastic film houses, the average contents of Cd, Cu, Pb, Zn, and As in surface soil were 0.12 mg kg(-1) (ranging from 0 to 1.28), 4.82 mg kg(-1) (0-46.50), 2.68 mg kg(-1) (0-46.50), 31.19 mg kg(-1) (0.19-252.0), and 0.36 mg kg(-1) (0-4.98), respectively. In orchard fields, the average contents of Cd, Cu, Pb, Zn, As, and Hg in surface soils (0-20 cm depth) were 0.11 mg kg(-1) (ranged from 0-0.49), 3.62 mg kg(-1) (0.03-45.30), 2.30 mg kg(-1) (0-27.80), 16.60 mg kg(-1) (0.33-105.50), 0.44 mg kg(-1) (0-4.14), and 0.05 mg kg(-1) (0.01-0.54), respectively. For polluted soils with over the warning content levels of heavy metals, fine red earth application, land reconsolidation and soil amelioration such as lime, phosphate, organic manure, and submerging were recommended. For the countermeasure areas, cultivation of non-edible crops such as garden trees, flowers, and fiber crops; land reformation; and heavy application of fine red earth (up to 30 cm) were strongly recommended. Land use techniques should be changed to be harmonious with the environment to increase yield and income. Soil function characteristics should be taken into account.

Agriculture↗
PubMed2006

Biomarkers responses of the earthworm Eisenia fetida to acetochlor exposure in OECD soil.

To examine the potential of a suite of biomarkers as early warning indicators of environmental pollution, sperm count, neutral red retention time (NRRT) and DNA damage were measured in earthworm Eisenia fetida exposed to increasing concentrations of acetochlor in OECD soil. The neutral red retention time of earthworms coelomocytes was sensitive to acetochlor pollution, and decreased significantly when the concentration was more than 10mgkg(-1) after 30 and 60 days of exposure (P<0.05). The reduced neutral red retention time correlated with the soil acetochlor residual. Sperm count decreased significantly at the concentrations of 40 and 80mgkg(-1) after 15 days of exposure (P<0.05). The DNA damage of earthworms coelomocytes increased significantly after 30 days of exposure at the highest concentration (80mgkg(-1); P<0.05). Earthworms were under physiological stress at field dose of acetochlor (10mgkg(-1)). Higher concentrations of acetochlor caused sperm count decrease and DNA damage of earthworms. Such a suite of biomarkers could serve as indicators of the health of the soil environment and to evaluate the toxicity of acetochlor on earthworms or as a means of monitoring soil acetochlor pollution.

Animals↗
PubMed2004

Thuja plicata exclusion in ectomycorrhiza-dominated forests: testing the role of inoculum potential of arbuscular mycorrhizal fungi.

The ability of trees dependent on arbuscular mycorrhizal (AM) fungi to establish in ectomycorrhizal forests is unknown. On northern Vancouver Island, Canada, there are sharp boundaries between mixed red cedar (Thuja plicata)-hemlock (Tsuga heterophylla) (CH) stands, and stands of hemlock and amabilis fir (Abies amabilis) (HA). We tested differences in AM colonization of red cedar between ectomycorrhiza-dominated (HA) stands and stands containing red cedar (CH), across a range of light levels. We used a soil bioassay approach to determine whether there was sufficient AM fungal inoculum in the HA tree stands to colonize red cedar seedlings. Seeds of hemlock and red cedar were sown in forest floor samples collected from the two types of forests, and shade treatments ranging from < 1 to 53% of full sunlight were imposed. After 6 months, seedling survival and root and shoot biomass were quantified, and red cedar seedlings were sampled for AM fungal colonization. Hemlock survival and growth did not differ between soil types, suggesting there was no substrate-associated limitation to its establishment in either forest type. Red cedar colonization by AM fungi was significantly correlated with light levels in CH soils but arbuscular mycorrhizas were absent in roots of red cedar seedlings grown in HA soil. Red cedar survival and relative growth rate were significantly greater in the CH than in HA soil; higher growth was due primarily to greater shoot growth in CH soils at high light levels. The low soil inoculum potential for red cedar in ectomycorrhiza-dominated stands may account for the virtual exclusion of red cedar seedlings from these forests.

Abies↗
PubMed2000

Root system responses of Japanese red cedar saplings to acidic conditions.

Stemflow from Japanese red cedar (Cryptomeria japonica) enters forest soil at a low pH. We evaluated the responses of the root system of Japanese red cedar saplings to acidic conditions, used to simulate this situation, in two different growth media, a brown forest soil (BS) and a Yahagi sand (YS). Soils were acidified by the addition of solutions at pH 2.0, 3.0 and 5.5 (control). Root morphology, root surface area index, root respiration activity and root biomass were measured. In the pH 3.0 treatment, no significant effects were found on the root systems compared with the controls in either soil, except for a slight difference in root-tip diameter in the Yahagi sand. In the pH 2.0 treatment, the surface area index and dry weight ratios of the whole root in the Yahagi sand were significantly lower than those in the other treatments. No significant effects on the whole root were observed in the brown forest soil. These results suggest that detrimental effects of acidic solutions on the root systems would be less significant in brown forest soil, which contains humus, than in the Yahagi sand, which lacks humus. They also suggest that the threshold pH value causing visible morphological changes on the roots of Japanese red cedar saplings falls in the pH range between 2 and 3. White roots in the pH 2.0 treatment had low respiration activity and showed visible morphological changes in both soils. These responses were presumably related to the effects of excess Al in the soil solution. White roots in the pH 2.0 treatment typically produced exodermis. The results suggest that stemflow with a pH of 3.0 has no effects on the root systems of Japanese red cedar, and that the morphology of white roots was adversely affected not by treatment at pH 2.0 but by excess water-soluble Al in the soil.

Journal Article↗
PubMed2005

Response of Argentine ants and red imported fire ants to permethrin-impregnated plastic strips: foraging rates, colonization of potted soil, and differential mortality.

This study investigated the effects of the permethrin-impregnated plastic on ant mortality and foraging rates, and tested its potential for preventing ants from colonizing potted soil. Direct exposure to the plastic for as short as 1 min caused significant mortality of both red imported fire ants, Solenopsis invicta Buren, and Argentine ants, Linepithema humile (Mayr); however, red imported fire ants were more susceptible than Argentine ants. Knockdown of virtually all ants initially occurred within 15 min after exposure. However, some moribund ants recovered from the effects within 24 h. For example, after 1 min of direct exposure to the permethrin-impregnated plastic, 70% of Argentine ants and 5% of red imported fire ants recovered from the treatment. In established colonies of Argentine ants, significantly fewer ants foraged for food up posts treated with the plastic compared with untreated posts. In addition, colonies responded to introduction of the treatment by significantly reducing their overall foraging rates, even on untreated posts. When pots filled with moistened soil were introduced into established ant colonies, 82% of Argentine ants and 99% of red imported fire ants moved into the soil. In contrast, when a 1-cm-wide coil of the plastic was placed under the pot, no ants moved into the soil. The potential for use of these materials in nursery production is discussed.

Animals↗
PubMed1976

Characterization of a red pigment-antibiotic produced by Streptomyces sp. strain NRC-C7.

The streptomycete strain NRC-C 7 isolated from some Egyptian soil samples, produces a red-coloured pH indicator antibiotic active against gram positive bacteria. The producing organism belongs to the grey series of the genus Streptomyces and has grey coloured aerial mycelium with violet pigmented substrate mycelium, the violet pigment does not diffuse into the agar medium. Glucose sodium nitrate medium proved the most suitable medium for the production of this antibiotic. The pigment was extracted from the broth and purified. The solubility, Rf values, minimal inhibiting concentrations, optical rotation, UV, and IR spectra were studied. Melting point 180, elemental analysis: carbon 51.71%, hydrogen 6.25%, and oxygen 42.04%.

Anti-Bacterial Agents↗
PubMed2004

Differential metallothionein expression in earthworm (Lumbricus rubellus) tissues.

This article describes the immunoperoxidase localization of metallothionein (MT) in the major organs and tissues of the earthworm Lumbricus rubellus sampled from a mine soil heavily polluted with Pb, Zn, and Cd. The polyclonal antiserum used was raised against the MT isoform (wMT2), the molecular characteristics and focal subcellular distribution of which indicate a primary role for it in the sequestration of certain nonessential metals, such as Cd. Intense MT immunostaining was detectable in chloragogenous tissue throughout the body: around the intestine, in the typhlosolar infolding, around blood vessels anterior and posterior to the crop/gizzard, and around the calciferous gland. Electron probe X-ray microanalysis of neutral red-labeled vesicular structures in the chloragogenous tissue indicated that this acidic compartment, probably lysosomal, yielded the strong Cd and S signals associated with Cd-MT. MT expression was also detected in the apical cytoplasm of intestinal epithelial cells; in coelomocytes contiguous with chloragocytes attached to the gut; within the narrow tubular region of nephridia, in the secretory epithelia of the calciferous gland, but not anywhere in the body wall. We concluded that (a) the main route of Cd uptake is probably via absorptive alimentary surfaces, and not across the external epidermal layer; (b) nephridia are involved with Cd excretion and/or are a major target of Cd-induced pathological damage; (c) tentatively, a combination of immunohistochemistry and proton-induced X-ray emission analysis indicated that the calciferous gland is probably not a major "heavy metal" excretory route.

Animals↗
PubMed2002

Electrokinetic ion transport through unsaturated soil: 1. Theory, model development, and testing.

An electromigration transport model for non-reactive ion transport in unsaturated soil was developed and tested against laboratory experiments. This model assumed the electric potential field was constant with respect to time, an assumption valid for highly buffered soil, or when the electrode electrolysis reactions are neutralized. The model also assumed constant moisture contents and temperature with respect to time, and that electroosmotic and hydraulic transport of water through the soil was negligible. A functional relationship between ionic mobility and the electrolyte concentration was estimated using the chemical activity coefficient. Tortuosity was calculated from a mathematical relationship fitted to the electrical conductivity of the bulk pore water and soil moisture data. The functional relationship between ionic mobility, pore-water concentration, and tortuosity as a function of moisture content allowed the model to predict ion transport in heterogeneous unsaturated soils. The model was tested against laboratory measurements assessing anionic electromigration as a function of moisture content. In the test cell, a strip of soil was spiked with red dye No 40 and monitored for a 24-h period while a 10-mA current was maintained between the electrodes. Electromigration velocities predicted by the electromigration transport model were in agreement with laboratory experimental results. Both laboratory-measured and model-predicted dye migration results indicated a maximum transport velocity at moisture contents less than saturation due to competing effects between current density and tortuosity as moisture content decreases.

Coloring Agents↗