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PubMed2001

Comparative soil sampling in the Dornach site (Switzerland) for soil three-dimensional pollution description.

Fifteen institutions from 13 European countries and Switzerland participated in a comparative test sampling at the Dornach site, near Basel in Switzerland. They received the site description and were asked to develop their own sampling plans, based on their national guidelines for a three-dimensional description of the Pb, Zn, Cu and Cd pollution, with a maximum of 15 samples. The comparative sampling test took place in late August 1997. The sampling plans and records, provided by the participants, were compared and evaluated in terms of sampling strategy throughout the site, the sampling strategy inside the sampling unit, strategy at the sampling point and last minute alteration of the sampling plans in the field. The object of this was to define the similarities and the differences in the sampling plans and identify the crucial steps inducing error or uncertainty which should be harmonized throughout Europe. The number of the total composite samples varied from 4 to 16, while the number of sampling points varied from 4 to 224 and the sampling density varied from 0.25 to 16 single samples per 100 m2. The number of 10 x 10 m2 quadrats from which samples were taken varied from 3 to 56, out of the total 61. The number of sampling units varied between 3 and 12. The criteria in descending order of frequency were: both land use and pedology, land use, pedology. The majority of the national participants divided the sampling units into two or three sub-units, while seven participants collected replicate composite samples from the same sampling unit. Only one sampled from the existing profiles, eight national representatives ignored the plough depth. The sampling pattern inside the sampling unit was in descending order of frequency: random, point sampling, regular, 'W' and 'X' shaped sampling. The number of single samples in the composite varied from 1 to 20. Most of the national participants sampled to pre-defined (ad-hoc) sampling depths, while others sampled soil horizons and others both. The maximum soil depth sampled also varied from 20 to 117 cm. Most participants mixed in the top organic matter horizon while others sampled it separately. Most sampled separately the top Ah horizon in the forest while the rest mixed it with the underlying soil horizon. The last-minute sampling plan alterations were in: the sampling depth (nine), the movement of sampling points (five), the reduction of sub-samples in the composite sample (four), changes in the number of sampling units (three), ignoring the bottom sample (three), not sampling the L/H layer (three) although this was planned, unplanned sampling of the L/H layer (two) and changing the number of planned samples (two). This study has highlighted the need for soil sampling harmonization throughout Europe for pollution and soil quality determination.

Environmental Monitoring↗
PubMed2001

Harmonisation and quality assurance in pre-analytical steps of soil contamination studies--conclusions and recommendations of the CEEM Soil project.

The paper summarises the project's results and consequences including expert's statements. Based on sampling strategies and methodological details which have been recognised to be critical for the comparability of the results of soil contamination studies, recommendations are given towards harmonisation of soil sampling guidelines, improvement of quality assurance of pre-analytical steps and inclusion of soil sampling into accreditation systems. Recommended approaches to improve QA and QC in soil sampling are: harmonised guidelines; specified SOPs; written sampling (strategy) plans; defined qualification and experience of sampling personnel; sampling records; regular interlaboratory comparisons (proficency tests) for sampling; and inclusion of sampling and sample preparation into accreditation procedures. Needs for further research in the field of pre-analytical phases of soil contamination studies are outlined and further R&D projects are encouraged.

Accreditation↗
PubMed1985

The distribution of the infective larvae of sheep gastro-intestinal nematodes in soil and on herbage and the vertical migration of Trichostrongylus vitrinus larvae through the soil.

From May 1982 until September 1983 samples of soil and herbage were collected from a paddock grazed from May to October 1982, and for two short periods between May and July 1983, by sheep infected with gastro-intestinal nematodes. Few infective larvae were recovered from the soil although appreciable numbers of larvae were recovered from the herbage. Infective larvae of Trichostrongylus vitrinus in faeces buried in the soil of grass plots, at a depth of 10 cm, each month from April 1982 until March 1983, migrated on to the herbage at all times of the year, few remaining in the soil. The significance of the soil as a reservoir of infective larvae is discussed.

Animals↗
PubMed1998

Simultaneous determination of imidazolinone herbicides from soil and natural waters using soil column extraction and off-line solid-phase extraction followed by liquid chromatography with UV detection or liquid chromatography/electrospray mass spectroscopy.

This paper describes the simultaneous quantification of the imidazolinone herbicides (IMIs) imazapyr, m-imazamethabenz, p-imazamethabenz, m,p-imazamethabenz-methyl, imazethapyr, and imazaquin in two types of samples. (a) Groundwater, lake water, and river water samples were enriched by off-line solid-phase extraction with a Carbograph-1 cartridge and analyzed by reversed-phase liquid chromatography using a UV detector (lambda = 240 nm). The overall recoveries of IMIs extracted from 1 L of groundwater (fortified with 500-100 ng/L), 0.5 L of lake water (fortified with 500-100 ng/L), and 0.5 L of river water (fortified with 1000-200 ng/L) samples were not lower than 89%. The mean relative standard deviation (RSD) was 5.1% (ranging from 4.1% to 6.8%) in natural water. The detection limits were 30-39 ng/L in groundwater, 43-51 ng/L in lake water, and 55-67 ng/L in river water. The method involves confirmatory analysis by LC/ES-MS in full-scan mode. The dependence of the ion signal intensities on proton concentration in the mobile phase was investigated with a view to optimizing the sensitivity of the ES-MS detector. When LC/ES-MS was used, the limit of detection, calculated from extracted-ion current profiles (EICPs), was 4-7 ng/L for ground-water and 9-13 ng/L for river water. (b) Soil sample analysis utilized combined soil column extraction (SCE) and off-line solid phase extraction (SPE) for sample preparation, analyzing with LC/ES-MS under selected ion monitoring (SIM). Several different extractants were evaluated for the purpose of SCE optimization. The system that best optimizes the extractability IMIs from the soil was found to be the mixture CH3OH/(NH4)2CO3 (0.1 M, 50:50 v/v). The effect of IMI concentration in the matrix on recovery was evaluated. The total recovery of each IMI from soil at each of the two levels investigated ranged from 87% to 95%. Under three ion SIM conditions, the limit of detection (S/N = 3) was 0.1-0.05 ng/g in soil samples.

Chromatography, High Pressure Liquid↗
PubMed2003

Molecular-scale speciation of Zn and Ni in soil ferromanganese nodules from loess soils of the Mississippi Basin.

Determining how environmentally important trace metals are sequestered in soils at the molecular scale is critical to developing a solid scientific basis for maintaining soil quality and formulating effective remediation strategies. The speciation of Zn and Ni in ferromanganese nodules from loess soils of the Mississippi Basin was determined by a synergistic use of three noninvasive synchrotron-based techniques: X-ray microfluorescence (microXRF), X-ray microdiffraction (microXRD), and extended X-ray absorption fine structure spectroscopy (EXAFS). We show that Ni is distributed between goethite (alpha-FeOOH) and the manganese oxide lithiophorite, whereas Zn is bound to goethite, lithiophorite, phyllosilicates, and the manganese oxide birnessite. The selective association of Ni with only iron and manganese oxides is an explanation for its higher partitioning in nodules over the soil clay matrix reported from soils worldwide. This could also explain the observed enrichment of Ni in oceanic manganese nodules. The combination of these three techniques provides a new method for determining trace metal speciation in both natural and contaminated environmental materials.

Environmental Monitoring↗
PubMed2000

Natural soil colloids To retard simazine and 2,4-D leaching in soil.

Natural or synthetic sorbents for pesticides can be used to reduce contamination of soils and natural waters. The sorption of simazine and 2,4-D on montmorillonite minerals has been studied and their potential use to retard pesticide leaching in soil evaluated. Simazine and 2,4-D did not sorb on high-layer charge montmorillonite, whereas sorption on the lower layer charge montmorillonite SWy varied depending on the saturating cation. Simazine sorption increased in the order Ca(2+)SWy << K(+)SWy < Fe(3+)SWy. Simazine molecules sorb on hydrophobic microsites of the montmorillonite. Once protonated, further sorption through cation exchange takes place in the interlamellar space of the montmorillonite, as corroborated by X-ray diffraction and FT-IR studies. 2,4-D does not sorb on K(+)SWy or Ca(2+)SWy, but does sorb on Fe(3+)SWy, because the acidic character of this sorbent allows the molecular form of 2, 4-D to sorb by hydrogen bonding and/or by hydrophobic interactions. Leaching experiments in hand-packed soil columns indicate that simazine and 2,4-D application as a complex with FeSWy renders later breakthrough and lower maximum concentration peaks, and the total herbicide leached is lower than when applied as the pure analytical grade compound. These results suggest the possible use of natural soil colloids as sorbents for herbicides such as simazine and 2,4-D to retard pesticide leaching in soil, thus reducing their ground water contamination potential.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2001

Bioremediation of DDT in soil by genetically improved strains of soil fungus Fusarium solani.

Bioremediation of DDT in soil by genetically improved recombinants of the soil fungus Fusarium solani was studied. The parent strains were isolated from soil enriched with DDD or DDE (immediate anaerobic and aerobic degradation products of DDT), as further degradation of these products are slow processes compared to the parent compound. These naturally occurring strains isolated from soil, however, are poor degraders of DDT and differed in their capability to degrade its metabolites such as DDD, DDE, DDOH and DBP and other organochlorine pesticides viz. kelthane and lindane. Synergistic effect was shown by some of these strains, when grown together in the medium containing DDD and kelthane under mixed culture condition. No synergism in DDE degradation was observed with the strains isolated from enriched soil. DDD-induced proteins extracted from individual culture filtrate (exo-enzyme) when subjected to SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) showed complementary polypeptide bands in these strains i.e., each strain produced distinct DDD degrading polypeptide bands and the recombinant or hybrid strains produced all of the bands of the two parents and degraded DDD better than the parental strains. Recombinant hybrid strains with improved dehalogenase activity were raised by parasexual hybridisation of two such complementary isolates viz. isolate 1(P-1) and 4(P-2) showing highest complementation and are compatible for hyphal fusion inducing heterokaryosis. These strains are genetically characterised as Kel+Ben(R)DBP-Lin- and Kel-Ben(r)DBP+Lin+ respectively. Recombinants with mixed genotype, i.e., Kel+Ben(R)DBP+Lin+ showing superior degradation quality for DDT were selected for bioremediation study. Recombination was confirmed by polypeptide band analysis of DDD induced exo-proteins from culture filtrate using SDS-Polyacrylamide Gel Electrophoresis (PAGE) and RAPD (Random Amplified Polymorphic DNA) of genomic DNA using PCR (Polymerase Chain Reaction) technique. SDS-PAGE showed combination of DDD induced polypeptide bands characteristic of both the parents in the recombinants or the hybrids. PCR study showed the parent specific bands in the recombinant strains confirming gene transformation.

Biodegradation, Environmental↗
PubMedDate not supplied

Soil quality evolution after land use change from paddy soil to vegetable land.

A survey was done in 15 typical villages, 150 soil and 86 vegetable plant samples were taken in Jiaxin prefecture of the Taihu Lake region, northern Zhejian province. Results indicate that after 15-20 years land use changed from the paddy rice-wheat (or oilseed rape) double cropping system, to a continuous vegetable land has caused soil quality dramatic change. (1) Acidification: average soil pH was 5.4; about 61% of total samples were pH < 5.5. It was 0.9 units lower than 10 years ago with same upland vegetable cultivation and was 1.2 units lower than soil pH of paddy rice-wheat (or oilseed rape) rotation. (2) Fertilizer salt accumulation: the average salt content was 0.28%, among these about 36.2% of the total samples contained more than 0.3%. (3) Nitrate N and available phosphorus (P) over accumulation: on average it was 279 mg NO3-N/kg, and 45-115 mg P/kg. Nitrate N four times higher and available P 4-10 times more than it is in present paddy rice-wheat rotation soils respectively. This has caused wide concern because of possible groundwater and well drinking water pollution by leached nitrate N and the P losses to water by runoff from vegetable lands induce surface water eutrophication.

Agriculture↗
PubMedDate not supplied

Estimating soil ingestion: the use of tracer elements in estimating the amount of soil ingested by young children.

In this pilot study, we modified methods used in estimating the amount of soil ingested by ruminants to measure soil ingested by children. Using aluminum, silicon, and titanium as tracers, we estimated soil ingestion for 59 children aged 1-3 yr from East Helena, Montana. Estimated daily soil ingestion based on aluminum and silicon concentrations were 181 and 184 mg/day, respectively, whereas the estimate based on the titanium concentration was about 10 times higher, 1,834 mg/day. Although we do not consider these estimates accurate measures of soil ingestion, the method we used is a reasonable approach that, to our knowledge, has not been used before in humans. However, our estimates will be revised as refinement of this method and better understanding of the metabolism of aluminum, silicon, and titanium lead to more accurate data for analysis.

Aluminum↗
PubMed1978

Survey of keratinophilic fungi in Alpine marmot (Marmota marmota) burrow soil and in adjoining soils.

Soil samples from 127 marmot (Marmota marmota) burrows were examined for keratinophilic fungi along with 48 soil samples from adjoining areas. The occurrence of keratinophilic fungi (especially Microsporum gypseum) was significantly higher in burrow soil. A review of the literature and our results support the hypothesis that the "animalization" (i.e. the enrichment of soil with hairs, crusts and other organic matters) of the environment may create conditions suitable for the growth of keratinophilic fungi. The presence of keratinophilic fungi in alpine mountain soil was noted for the first time.

Animals↗
PubMed2000

Near surface soil vapor clusters for monitoring emissions of volatile organic compounds from soils.

The overall objective of this research was to develop and test a method of determining emission rates of volatile organic compounds (VOCs) and other gases from soil surfaces. Soil vapor clusters (SVCs) were designed as a low dead volume, robust sampling system to obtain vertically resolved profiles of soil gas contaminant concentrations in the near surface zone. The concentration profiles, when combined with a mathematical model of porous media mass transport, were used to calculate the contaminant flux from the soil surface. Initial experiments were conducted using a mesoscale soil remediation system under a range of experimental conditions. Helium was used as a tracer and trichloroethene was used as a model VOC. Flux estimations using the SVCs were within 25% of independent surface flux estimates and were comparable to measurements made using a surface isolation flux chamber (SIFC). In addition, method detection limits for the SVC were an order of magnitude lower than detection limits with the SIFC. Field trials, conducted with the SVCs at a bioventing site, indicated that the SVC method could be easily used in the field to estimate fugitive VOC emission rates. Major advantages of the SVC method were its low detection limits, lack of required auxiliary equipment, and ability to obtain real-time estimates of fugitive VOC emission rates.

Air Pollutants↗
PubMed2003

Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites.

Biodegradation, Environmental↗
PubMed2002

Diurnal radon variations in the upper soil layers and at the soil-air interface related to meteorological parameters.

Measurements of the radon concentration in a column (1 m2 x 2 m) consisting of a homogeneous mixture of dry sand and uranium tailings have been performed to obtain information on the radon transport under well defined conditions. The dependence of the radon concentration has been exclusively studied on the soil/air temperature gradient and on the wind speed. The soil moisture content has been kept constant. Significant diurnal variations of the radon concentration were detected in the uppermost soil layer and at the soil/air interface. Such a behavior was not found in 30 cm and deeper soil layers. It is argued that the diurnal radon variation in the uppermost soil layer is mainly associated with the diurnal inversion of the soil/air temperature gradient giving rise to a convective soil gas migration additional to the common upward diffusion processes, whereas the diurnal variation of the radon concentration at the soil/air interface is caused by the interplay of the temperature gradient and the wind speed. No impact of atmospheric pressure variations on the radon migration has been observed.

Air↗
PubMedDate not supplied

[Ultraviolet irradiation of soil samples as a model of the effect of stress factors on bacterial diversity in soil ecosystem].

UV irradiation is proposed for use in studying the effect of radioactive irradiation, since radioresistant bacteria are, as a rule, resistant to UV, and the mechanisms of repair of cell damage induced by UV and ionizing radiation are similar. It was found that the total number of bacteria and the number of dominant species in soil samples exposed to UV radiation decreased, indicating the unfavorable effect of UV radiation on bacterial diversity in soil ecosystems. The percentage of cells of bacteria belonging to dominant species varied significantly depending on the intensity of UV irradiation. It can be inferred that long-term irradiation of soils must impair the stability of soil ecosystems, a phenomenon that was indeed observed in the zone around the Chernobyl Nuclear Power Plant. At the same time, the UV irradiation of soil samples made it possible to reveal minor species, primarily UV-resistant pigmented bacteria. UV irradiation can probably be used as a selective factor for the isolation of radioresistant species.

Bacteria↗
PubMed2000

Soil pollution and soil limit values.

One of the tools for preventing soil pollution and thus protection of public health is the application of appropriate limit values. Policies on soil protection in relation to soil pollution include two basic strategies: a preventive approach and a remediation or cleanup approach. Preventive, multifunctional limit values are independent from present or future land use. Remediation limit values are connected with land use--these are functional limit values. Both types of limit values are applied in Hungary. Determination of soil limit values demands long-term field investigations, but to estimate allowable concentration for a given site reverse risk assessment methods are well applicable. A comparison and evaluation of the calculated data and the measurement results obtained at the use of the area is indispensable. Further investigations are needed for establishment of combined limit values when more polluting components are present simultaneously in the soil.

Environmental Monitoring↗
PubMed2001

[Effect of soil moisture and wetting-drying on Mn release in Ca(NO3)2-amended soils].

A study on the effects of two moisture levels (200 and 400 g.kg-1) and wetting-drying on the solubility of Mn in Ca(NO3)2-amended soils showed that water regime was a factor affecting Mn availability. Easily reducible Mn was transformed into soluble and exchangeable Mn, when soil water content was high. Salt had a definite effect on the transformation of easily reducible Mn. NO3- could decrease soil redox potential, and inhibit the transformation of easily reducible Mn. Wetting-drying significantly(alpha < 0.05) decreased the content of soil water-soluble and exchangeable Mn, while Ca(NO3)2 increased the insolubility of Mn, which might eventually lead to the deficiency of soil Mn.

Calcium Compounds↗
PubMed2002

[Effects of maize stubble remaining in field on dynamics of soil microbial biomass C and soil enzyme activities].

This study dealt with the effects of maize stubble remaining in field on dynamics of soil microbial biomass C and soil enzyme activities. The results showed that maize stubble remaining in field could raise soil microbial biomass C and the activities of urease, phosphatase, cellulase, and invertase in soil remarkably. According to the dynamics of soil microbial biomass C and activities of the four enzymes, the five characters reached their maximum values about 60 days after sowing, and the crops were in bloom of growth. The results also showed that maize stubble remaining in field had positive effects on improving fertility and keeping high and steady yield of maize.

Biodegradation, Environmental↗
PubMed2003

Effect of soil moisture on seed germination, plant growth and root rot severity of navy bean in Fusarium solani infested soil.

The development of root rot and its severity were affected by numerous factors which through their interaction could distort results. In this study, a single factor, soil moisture was considered. Using Fusarium solani infested root rot soil we investigated the effect of three available soil moisture (ASM) levels (i.e. 100%, 70% and 25%) on seed rot, germination, plant growth and root rot severity of navy bean in the greenhouse. Percent germination differed strikingly averaging of 58.5, 89.5 and 87.0% respectively to ASM levels. Apparently, high soil moisture promoted seed rot and impeded seed germination. Root rot incidence and severity were examined two months later. Percent plant with root rot averaged 89.5, 89.0 and 69.8% while root rot severity was 3.01, 2.3 and 1.1 (on a 0-9 scale), respectively to ASM levels. Plant growth was moderate, good and poor with respect to ASM levels. It was apparent that the final plant growth was a sum of seed rot, root rot incidence, disease severity and soil moisture adequacy. However, seed rot appeared to be the largest contributing factor to final plant yield.

Crops, Agricultural↗