Extraction Of Soil Samples Research Articles

Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p<0.05), whereas they increased in the RWs with younger age (p<0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth.

Heavy Metals (Cd, Ni and Pb) Contamination of Soils, Plants and Waters in Madina Town of Faisalabad Metropolitan and Preparation of Gis Based Maps

Heavy metal pollution is a great threat to the environment. These metals are enters to the soil-plant environment through anthropogenic sources. A survey study was conducted to assess the heavy metals contamination of soils, plants and waters of Madina town of Faisalabad, Metropolitan area in 2010. Soil, plant and water samples were collected in the vicinity of Faisalabad following 4 × 4 Km grids. Soil samples were taken from 0-15 cm and 15-30 cm depths and prepared for the determination of metals (Cd, Pb and Ni). Plant samples were also taken from the same location and dried and digested in HClO4:HNO3 in the ratio of 1:3. AB-DTPA extract of soil, plants extract and water samples was analyzed on Atomic Absorption Spectrophotometer (Model Thermo S series). The results of the study showed the concentration of metals in Soils ranged from Cd (0.00-0.111 ppm), Pb (0.87-8.97 ppm) and Ni (0.017-1.72 ppm) at 0-15 cm while Cd (0.00-0.88 ppm), Pb (0.43-6.77 ppm) and Ni (0.055-0.852 ppm) at 15-30 cm respectively. Cd, Pb and Ni concentration in the plants ranged from 0.00-2.25 ppm 1.11-5.29 ppm and 1.51-4.96 respectively. Concentration of metal in the ground water ranged from Cd (0.00-0.06 ppm), Pb (0.10-11.10 ppm) and Ni (0.03-0.05). The concentration Pb and Ni was below the permissible limits while concentration of Cd in waters and plants above the permissible limits. Finally it was concluded that soil, plant and water of Madina town were in the safe limits with respect to metals. The use of city effluent is increasing the level of metals into the soils that ultimately contaminate the soils, plants and waters. So, it is suggested that city effluent must be treated for the detoxification of metals before use in irrigation purposes for crops.

Development of a real‐time PCR method for the detection of the dagger nematodes Xiphinema index, X. diversicaudatum, X. vuittenezi and X. italiae, and for the quantification of X. index numbers

The ectoparasitic dagger nematodes Xiphinema index and Xiphinema diversicaudatum, often at low numbers in the soil, are vectors of grapevine nepoviruses, which cause huge agronomical problems for the vineyard industry. This study reports a method, based on real‐time PCR, for the specific detection of these species and of the closely related non‐vector species Xiphinema vuittenezi and Xiphinema italiae. Specific primers and TaqMan probes were designed from the ribosomal DNA internal transcribed spacer 1 (ITS1), enabling the specific detection of single individuals of each of the X. index, X. diversicaudatum, X. italiae and X. vuittenezi species whatever the nematode population. The specificity of detection and absence of false positive reaction were confirmed in samples of each species mixed with the three other Xiphinema species or mixed with nematodes representative from other genera (non‐plant‐parasitic Dorylaimida, Longidorus sp., Meloidogyne spp., Globodera spp. and Pratylenchus sp.). The method was shown to be valid for the relative quantification of X. index numbers through its use, from crude nematode extracts of soil samples, in a greenhouse assay of grapevine accessions ranging from highly susceptible to resistant. As an alternative to time‐consuming microscopic identification and counting, this real‐time PCR method will provide a fast, sensitive and reliable diagnostic and relative quantification technique for X. index nematodes extracted from fields or controlled conditions.

Paddy soil heavy metal contamination and uptake in rice plants from the adjacent area of Barapukuria coal mine, northwest Bangladesh

This study was carried out to estimate the heavy metal contamination in paddy soil and subsoil and uptake by rice plants collected from Barapukuria coal mine area of Bangladesh. The mean contents of As, Cr, Cu, Mn, Ni, Pb, and Zn in paddy soil and subsoil exceed the world averages, and the observed soils are moderately to extremely polluted with inputs from mining activities. Correlation and regression model analyses suggest that pH and TOC have distinct effect on the availability of observed metals in soils. Sequential extraction of paddy soil and subsoil samples demonstrate that the mobility of heavy metals increases in the order of Cu > Zn > Pb > Fe > Cr > Ni > Mn > As. The uptake of metals in rice root is much higher than those in straw and rice grains. Arsenic, Cr, and Pb uptake in rice grains are 6.87-, 1.58-, and 5.26-fold higher than the maximum permissible concentration which shows a tendency of transformation of these elements from contaminated soil to rice plants.

Factors affecting CO2 efflux rates and the stability of soil organic carbon storage in volcanic soils of the Canary Islands

Because volcanic soils store large amounts of soil organic carbon (SOC), they play a far more important role in the carbon (C) cycle than their limited global coverage suggests. We analysed the C released as CO2 from a range of volcanic soils under natural conditions and analysed the influence of environmental variables (moisture and temperature), substrate availability (as assessed from the contents of various SOC fractions and the inputs of plant residues from litterfall), respiratory agents (roots, microorganisms and decomposing enzymes) and other pedological features of the topsoils (0–30 cm depth) on the CO2 efflux rates over a 2-year experimental period. High CO2 efflux rates (419 g C-CO2 m−2 y−1 as the average for Andisols) were obtained that were related to significant decreases in the amount of SOC stored. CO2 release was strongly controlled by soil moisture, although it was inhibited in the Andisols with the highest moisture levels (above 50 kg m−2 in topsoil). It was not responsive to the availability of decomposing microorganisms or enzymes and appeared more related to the inputs of easily decomposable plant residues than to the amount of either labile or recalcitrant SOC. Among the SOC pools, only the water-soluble C in saturated paste extracts (WSCse) of air-dried soil samples was consistently correlated with the CO2 efflux rates. The desiccation of Andisols appeared to induce the release of previously stabilised SOC, which was readily mineralised when the moisture conditions became favourable. The results of this study indicate that SOC storage in Andisols is highly vulnerable to drying-wetting processes even in unmanaged natural ecosystems and that microclimate conditions can be critical for successful C sequestration in these soils.

Effects of zeolite and vermicompost applications on potassium release from calcareous soils

Zeolite and vermicompost applications to soil may improve K fertility of soils. For this purpose, these materials were added to five representative calcareous soils collected from southern Iran. The treatments included (1) control, (2) 20 g/kg zeolite, (3) 20 g/kg vermicompost, and (4) 20 g/kg vermicompost + zeolite (1:1). The samples were incubated for 90 days, and the concentrations of soluble, exchangeable, and non-exchangeable K and K release rate to 0.01M CaCl&lt;sub&gt;2&lt;/sub&gt; during 240 min (16 successive 15 min extractions of soil samples with CaCl&lt;sub&gt;2&lt;/sub&gt; solution) were determined. Results indicated that zeolite application increased significantly the concentration of soluble and exchangeable K. Vermicompost application had a positive effect on all forms of K. Cumulative K release was also affected by vermicompost application. Comparison of experimental data to different kinetic models indicated that Elovich, power function, and parabolic diffusion models described well kinetics of K&amp;nbsp;release from all soil samples to 0.01M CaCl&lt;sub&gt;2&lt;/sub&gt;. The b values of Elovich equation had significant relationships with NH&lt;sub&gt;4&lt;/sub&gt;OAc- and HNO&lt;sub&gt;3&lt;/sub&gt;-extractable K. It is recommended that for K fertility management of calcareous soils, organic and inorganic amendments application to soils should be taken into consideration.

No bottom-up effects of food addition on predators in a tropical forest

Several studies in temperate forests have demonstrated effects of litter addition on decomposers and predators. However, adding litter does not allow separating the effects of food availability and habitat space. We investigated the response of decomposers and predators to increased food resources and space in forests of the southern Mata Atlântica of Brazil. In two forest ecosystems representing an early successional stage of secondary forests and old-growth forest, we added nutrient-rich organic material, artificial litter of no nutritional value, or a combination of both to the soil surface of 120 plots to separate the effects of habitat space and food on soil food webs. We sampled litter- and soil-dwelling arthropods after three months using pitfall traps, soil sample extraction, and sticky traps just above the soil. Adding artificial litter had no positive effect on any of the 17 analyzed arthropod groups. Combining all sampled arthropods the effect was even significantly negative. Adding food had a positive effect on the abundance of decomposers, but not predators. We found no interactions between added artificial litter and added organic material. Our results suggest that the soil fauna in tropical forests is food limited. The lack of a bottom-up effect on predators suggests that they are not predominantly regulated by the abundance of epigeic prey but rather by competition or predation.

The geographic distribution of Sr isotopes from surface waters and soil extracts over the island of Bornholm (Denmark) – A base for provenance studies in archaeology and agriculture

In this paper we report the Sr isotope signatures, and Sr, Al and Na concentrations of 30 surface waters (lakes/ponds and rivers/creeks) and 19 soil sample extracts from the island of Bornholm (Denmark) and present a categorized 87Sr/86Sr value distribution map that may serve as a base for provenance studies, including archaeological migration and authenticity proof for particular food products. The Sr isotopic compositions of surface waters range from 87Sr/86Sr=0.7097–0.7281 (average 0.7175±0.0049; 1σ), whereas 0.1M HNO3, 0.05M HNO3, and 0.01M CaCl2 soil extracts range from 87Sr/86Sr=0.7095–0.7197 and define somewhat lower but statistically indistinguishable averages of 0.7125±0.003 (1s). These compositions are lower than the values expected from the Precambrian granitoid basement (87Sr/86Sr=0.758–0.944), and from the overlying, mainly clastic Paleozoic sediments. Combined Sr isotope composition vs. Sr, Na and Al concentration relationships of soil extracts imply that lowering of the isotopic composition of leachable Sr on Bornholm results as a consequence of significant admixture to this fraction of Sr deposited as marine salts (aerosols), and that rainwater only has a minor influence on the Sr budget of the surface waters. Positively correlated Al/Na and [1/Sr] vs. 87Sr/86Sr relationships in soil extracts and surface waters indicate that the surface run-off on Bornholm is characterized by two predominant sources, namely marine aerosols (sea salts) with high Sr and low 87Sr/86Sr values, and a source with lower [Sr] delivering radiogenic Sr to the surface waters, which we equate with Sr leached from the products of mineral weathering (soils).A feasibility study for using Sr isotopic compositions of surface waters and soil extracts as a proxy for bioavailable Sr signatures was performed with a few samples collected in the vicinity of the eleventh century AD Ndr. Grødbygård cemetery site in SW Bornholm, from where Sr isotope compositions of modern fauna samples and tooth enamel of humans buried in the cemetery have been reported. Waters and soil extracts studied herein from around this site range from 87Sr/86Sr=0.7104–0.7166 and correspond to Sr compositions extracted from snail shells in this area which span a range of 87Sr/86Sr=0.7095–0.7160. Some human tooth enamel is characterized by more radiogenic values (87Sr/86Sr up to 0.718) which points to a possible provenance of these humans from the granite–gneiss terrain in the north of the island and/or to immigration of these humans in their childhood from other places (for example from mainland Sweden) to Bornholm. If the total compositional range of 87Sr/86Sr=0.709–0.718 (n=44) recorded in human enamel from the Ndr. Grødbygård site is considered representative for the variation of bioavailable Sr on Bornholm, then our soil leachate and surface water data entirely covers this range. We therefore propose that the combination of Sr isotope analyses of surface waters and soil leachates are an easy, fast and relatively cost efficient way to characterize a local bioavailable 87Sr/86Sr signature, and consequently propose that the overall average of 87Sr/86Sr=0.7153±0.0048 (1σ; n=50) can be taken as a band for bioavailable Sr fractions suitable to discriminate between local and non-local signatures in provenance studies in the field of archaeology and for food and plant authenticity control in agricultural applications.

REY and Sr-Nd isotopic ratios of aqua regia extracts to assess pedogenic processes and pollution in soils from Ravenna (north Italy)

Sr, Ca and REY (REE+Y) concentrations along with Sr-Nd isotopic ratios have been determined in 17 aqua regia extracts from three soils of different land use, located in the area near the industrial town of Ravenna, in northern Italy, to test what information can be obtained about the pedogenesis, Sr and REY provenance and soil pollution. 6 samples of selected parts of horticultural plants from the agricultural soil, have also been analyzed for Sr isotopic composition. The Sr and Ca concentrations in the extracts generally increase with depth in each soil profile, reflecting selective mineral weathering in upper horizons and removal of the two elements by the soil solution. In this context, the decrease of the Sr/Ca ratios with depth in each profile suggests preferential removal of Ca, due to resistance of non-carbonate Sr-bearing minerals to weathering and preferential Ca uptake by plants as a nutrient. The PAAS-normalized REY patterns of the extracts from two out of the three studied soils, are similar, displaying middle REE enrichment with a Gd peak and, generally, a positive Y anomaly. These characteristics suggest the contribution of marine carbonates and phosphates. The aqua regia extracts of the two soils perturbated by plowing and gardening practices, exhibit narrower ranges of δ 87 Sr (from -0.49 to -0.97) than the natural soil (from -1.03 to +0.37). However, excluding decarbonated upper horizons, the natural soil displays a δ 87 Sr range (from -0.47 to -1.03) similar to the other two soils. These overlapping ranges indicate that labile Sr mainly derives from a common source, represented by marine carbonates and phosphates of the bedrocks. In the geological context of the study area, Miocene sedimentary formations of Romagna’s Apennines may be the likely sources of those phases. In contrast, the more positive δ 87 Sr (from -0.21 to +0.37) of decarbonated upper horizons of the natural soil, likely reflect the contribution of radiogenic Sr from silicates of old crustal rocks from either the bedrock and/or atmospheric deposition (Saharan dust). The three soils display overlapping and relatively narrow ranges of e Nd (from -6.5 to -9.4), indicating a common source of Nd, mainly represented by phosphates. The contribution from silicates of old crustal rocks appears to be very subordinate. The Sr-Nd isotopic overlap of the soil extracts with the corresponding ranges of anthropogenic (i.e. industry, traffic) sources, prevents from ascertaining potential pollution from the study area. Compared with the isotopic values of the soil extracts, the higher δ 87 Sr (from -0.32 to -0.07) of selected parts of horticultural plants grown on the agricultural soil, indicate the soil solution from which the plants uptake Sr, contains more radiogenic Sr. The comparison with the δ 87 Sr of the ammonium acetate extracts from the same soil samples, indicates that the milder extraction than that carried out with aqua regia, leaves non-radiogenic Sr-bearing phosphates undissolved and, thus, more radiogenic Sr in the solution. As a whole, the aqua regia extraction of soil samples can provide significant information on the behavior of Sr and REY in the pedogenesis as well as in recognizing the sources of these elements with respect to the soluble soil phases and their possible references in the geological context of the study area. In contrast, the aqua regia extraction is not a suitable procedure for studying the soil-plant relationship, providing less information than the ammonium acetate extraction.

Biases in community structures of ammonia/ammonium-oxidizing microorganisms caused by insufficient DNA extractions from Baijiang soil revealed by comparative analysis of coastal wetland sediment and rice paddy soil

Repetitive extraction of DNAs from surface sediments of a coastal wetland in Mai Po Nature Reserve (MP) of Hong Kong and surface Baijiang soils from a rice paddy (RP) in Northeast China was conducted to compare the microbial diversity in this study. Community structures of ammonia/ammonium-oxidizing microorganisms in these samples were analyzed by PCR-DGGE technique. The diversity and abundance of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and anaerobic ammonium-oxidizing (anammox) bacteria were also analyzed based on archaeal and bacterial ammonia monooxygenase subunit A encoding (amoA) and anammox bacterial 16S rRNA genes, respectively. DGGE profiles of archaeal and bacterial amoA and anammox bacterial 16S rRNA genes showed a similar pattern among all five repetitively extracted DNA fractions from both MP and RP, except the anammox bacteria in RP, indicating a more diverse anammox community retrieved in the second to the fifth fractions than the first one. Both soil and marine group AOA were detected while soil and coastal group AOB and Scalindua-anammox bacteria were dominant in MP. Soil group AOA and marine group AOB were dominant in RP, while both Scalindua and Kuenenia species were detected in RP. Pearson correlation analysis showed that the abundance of archaeal and bacterial amoA and anammox bacterial 16S rRNA genes was significantly correlated with the DNA concentrations of the five DNA fractions from MP, but not from RP (except the archaeal amoA gene). Results suggest that anammox bacteria diversity may be biased by insufficient DNA extraction of rice paddy soil samples.

탄성파 속도를 이용한 간극비 산출 식의 고찰

Abstract The void ratio is an important parameter for reflecting the soil behavior including physical property, compressibility, and relative density. The void ratio can be obtained by laboratory test with extracted soil samples. However, the specimen has a possibility to be easily disturbed due to the stress relief when extracting, vibration during transportation, and error in experimental process. Thus, the theoretical equations have been suggested for obtaing the void ratio based on the elastic wave velocities. The objective of this paper is to verify the accuracy of the proposed analytical solution through the error norm. The paper covers the theoretical methods of Wood, Gassmann and Foti. The elastic wave velocity is determined by the Field Velocity Probe in the southern part of Korean Peninsular. And the rest parameters are assumed based on the reference values. The Gassmann method shows the high reliability on determining the void ratio. The error norm is also analyzed as substitution of every parameter. The results show every equation has various characteristics. Thus, this paper may be widely applied for obtaining the void ratio according to the field condition.

The tandem analytical method of flow injection diode array spectrophotometry and flame atomic absorption spectrometry (FI-DAD(vis)-FAAS) in iron speciation studies using 1,10-phenanthroline complexes

The article presents the new analytical method of determination of the content of selected iron forms in soil and sediment extracts. The presented tandem analytical system uses the molecular and atomic absorption and works in the flow injection mode. The system is equipped with two detectors: the spectrophotometric detector of diode array and the atomic absorption spectrometer. The new analytical system allows for the determinations of the content of ionic iron forms: Fe(II) and Fe(III), as well as the content of non-ionic forms complexed in the extracts of soil and sediment solid samples. The determination limits of 0.2, 0.9 and 0.9μgmL−1 were obtained, for Fe(II), Fe(III) and for iron in acid leachable fraction in solid sample extracts respectively, and the precision of determinations fell within the range of 1.8% - 2.4%. The developed and optimised analytical method was applied in the studies of iron speciation in the acid leachable fraction of sediments and soils of different origin.

Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions

Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101–107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14–46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent.Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π–π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples.

Validation Testing of a Soil Macronutrient Sensing System

Rapid on-site measurements of soil macronutrients, i.e., nitrogen (N), phosphorus (P), and potassium (K), are needed for site-specific crop management, where fertilizer nutrient application rates are adjusted spatially based on local requirements. This study reports on validation testing of a previously developed ion-selective electrode (ISE) based soil macronutrient sensing system using 36 soil samples from a single site, the Northern Illinois Agronomy Research Center (NIARC), and previously developed calibration models. Objectives were to (1) validate calibration models with a new array of membranes and electrodes, and (2) evaluate the ability of the system to estimate variations in soil NO3-N, P, and K within a single test site. Soil extract samples were obtained using the Kelowna extractant. Electrode responses were measured with five ISEs for each of NO3-N, P, and K and were normalized using the baseline correction and two-point normalization methods developed in our previous work. The array of ISEs fabricated with new membranes and cobalt rod, in conjunction with the previously developed normalization methods and calibration models, accurately estimated NO3-N, P, and K in solution without need to recalibrate the ISE system through standard laboratory analysis of soil samples from the new test site. ISE-measured NO3-N, P, and K concentrations in Kelowna-based soil extracts were similar to those determined by standard instruments, validating the ability of the system to identify within-field macronutrient differences. The use of a calibration factor to adjust ISE measurements for the difference in extraction efficiency between Kelowna and standard extractants resulted in a slope near unity between soil NO3-N, P, and K concentrations determined by ISEs and standard methods. However, a relatively large offset in soil P concentration between calibrated ISEs and standard methods will require further investigation to identify the cause. This study showed that it was possible to transfer existing calibration equations to new membranes and electrodes through application of the baseline correction and two-point normalization methods and an adjustment for differences in extraction efficiency. This finding enhances the applicability of the ISE-based soil macronutrient sensing system and methodology for rapid soil analysis.

Determination of Inorganic Antimony Species Conversions during Its Speciation Analysis in Soil Using Isotope Dilution Techniques

A new method was developed in this work to account for inorganic Sb species interconversion during soil sample preparation and subsequent separation steps. The Sb(III) and Sb(V) concentrations at each investigated step in the analytical procedure were determined using species specific spikes (121Sb(III) with 81.18% and 123Sb(V) with 74.04% enrichment). The spiking of these enriched isotopes species solutions was done separately before soil sample extraction and before HPLC separation. Simply by subtracting the final concentration of each species done by on-line isotope dilution (ID) from its concentration at different stages of the analytical procedure done by species specific ID, the influence of each step on species transformation can be estimated. After optimization, the extraction procedure for inorganic Sb species 6% Sb(III) (1.3 RSD, n = 3) and 43.2% Sb(V) (2.9% RSD, n = 3) as percent of total Sb were detected in the examined soil sample using online ID. Using the above described methodology we found that there was no reduction of Sb(V) to Sb(III) during sample preparation or species separation. While about 9.3% of extractable Sb (4.6% of total) was converted from Sb(III) to Sb(V) during the extraction step, no conversion during HPLC separation step was observed. By compensating for Sb(III) transformation during the sample preparation step; the extractable Sb(III) and Sb(V) as percent of total Sb yielded 10.6% and 38.7%, respectively.

Commentary on: a review on delayed toxic effects of sulfur mustard in Iranian veterans

Dear Editor-in-Chief I read with interest the recent nice article published by Dr Razavi titled “A review on delayed toxic effects of sulfur mustard in Iranian veterans” [1]. Sulfur mustards (SM), commonly known as mustard gas are alkylating agents capable of causing short and long term morbidity [2]. The author stated in Table three that ophthalmic complications in Khateri et al. studies are 93.3% but there is a typesetting problem over there and the correct number is 39.3% [3]. The eyes are the most sensitive organ to SM exposure. Nearly 90% of eye injuries after SM exposure may cause later some kind of ocular disorders [4]. Also, in the paper of Razavi et al. [1], they have highlighted that SM can remain in the battlefields (for example beside the moats in World War I) and can be found in the amount of 1–25 mg/m3 in 6–12 inch depth of the soil. In moderate temperatures with mild winds, SM can remain stable for more than a week but some forms of SM can be stored in the soil for up to 10 years [1]. Natural degradation of SM in soil is a result of chemical hydrolysis and biodegradation. The major product of chemical hydrolysis is thiodiglycol. Chemical hydrolysis of SM and its chlorine derivatives in soil depends on soil type and moisture content, degree of contamination, and temperature. If the moisture content of soil is lower than 50% of its moisture capacity, then chemical hydrolysis in soil does not occur [5]. With higher temperatures and moisture content, the extent of hydrolysis of SM increases, but never to 100% completion. The SM is known to degrade faster in alkaline soils. If SM droplets are considerably below the soil surface, then SM can persist for several years [6,7]. The process of biodegradation of thiodiglycol is still longer [8]. Elimination, hydrolysis and sulfoxide products were also detected in extracts of soil samples from the Iran–Iraq war [9]. SM can be absorbed following inhalation [10] and dermal [10,11] exposure from air and soil. Therefore, although SM is a very reactive substance which hydrolyzing rapidly on contact with water, it may persist in the environment for many years, even decades, longer than expected [12]. Considering all the above facts, the correct assessment of the amount of agent in the air, in nearby water, on equipment, and on the ground (substrates such as soil, grass, concrete and asphalt) is critical to making correct decisions about the need for decontamination. Therefore, testing methods that detect both the SM and its degradation products, some of which may be toxic, since the war zones in our country now are major tourist areas where every year a large number of people travel there, are essential. Again, I would like to thank authors for collecting those valuable data using mostly domestic data and writhing such a nice review.

High performance liquid chromatography–tandem mass spectrometry method for quantifying phenylurea herbicides and their main metabolites in amended and unamended soils

A sensitive multiresidue method for the simultaneous determination of sixteen phenylurea herbicides and their main metabolites in amended soils has been developed. Liquid chromatography tandem–mass spectrometry (LC–MS2) in electrospray ionization positive mode was used for the separation, identification and quantification of these compounds. The procedure involves initial single phase extraction of soil sample with acetonitrile by sonication, followed by liquid–liquid partitioning formed by addition of NaCl. The average recovery by the LC–MS2 method obtained for these compounds varied from 76.2 to 107.9% with a relative standard deviation ranging from 2.1 to 5.8%. The method presents good linearity (R2>0.99) over the range assayed 10–1000μgL−1 (except N-phenylurea 50–1000μgL−1). The detection limits for the compounds studied varied from 0.1 to 9.0ngg−1.

Assessment of wastewater-irrigated soil containing heavy metals and establishment of specific biomarkers

Irrigation with treated wastewater (TWW) is a vital alternative for arid and semi-arid lands but it poses pollution-risk to soil, vegetation and groundwater. Therefore, in the present study, in vitro bioassays were used to evaluate the adverse effects of TWW and irrigated-soil extract sample, on mammalian cells, with respect to heavy metal—Ni, Cd, Pb, Fe, Al-content. The heat shock protein (HSP) 47, E-screen, and transepithelial electrical resistance (TEER) assays served to investigate the stress response of treated-HSP47-transfected Chinese hamster ovary (CHO) cells, the estrogenic activity of the samples in MCF-7 breast cancer cells, and the barrier function (BF) of Caco-2 cells. Furthermore, proteomics analyses were performed to shed light on involved mechanisms and to establish pollution biomarkers. Results showed that the TWW elicited a stress response on HSP cells from 0.1% concentration while soil extract samples exhibited a stress at 1%. TWW induced an estrogenic activity at 10%; up-regulating cell proliferation and tumor-related proteins. Soil extract triggered the enhanced expression of HSP70 family proteins as survival mechanisms against their cytotoxicity toward MCF-7 cells. Moreover, depending on the concentration, 1% of soil extract from 20cm depth (T20) resulted in a disruption of BF in Caco-2 cells involving cell metabolism, protein synthesis and tumor marker proteins, whereas, 5% of T20 induced the expression of BF-related proteins associated to heat shock, oxidative stress, cell proliferation and glycolytic metabolic pathway. These biological techniques were found to be extremely useful to evaluate the impact of wastewater reuse and to establish specific biomarkers that are common proteins for humans, other mammals and plants. Future studies should focus on exposure quantifications.

Quantification of vertical water fluxes in the vadose zone using particle-size distribution and pedology-based approaches to model soil heterogeneities

One-dimensional flow simulations were conducted at four locations of the shallow alluvial aquifer of the upper Rhine River (at the Erstein polder) to quantify the time-dependent moisture distribution, the water flux and the water volume infiltrated in the unsaturated zone as a function of soil heterogeneities during a five-day-long flooding event. Three methods of estimating the hydraulic parameters of soil in the vadose zone were tested. They are based on the following: (1) experimental data, (2) soil particle-size distribution and (3) pedology information on soils. Water fluxes calculated from modelling approaches 2 and 3 were compared with those of the experiment-based values and the effect of these differences on the arrival time and velocity of water at the water table were analysed. Major differences in water fluxes were found among the methods of estimating the hydrodynamic parameters. At the Terrace location, the groundwater recharge predicted using soil data from methods 1 and 2 are approximately 4500 and 2400 mm, respectively. Flow simulations using soil data and the experiment-based method show the highest velocities of infiltrating water at the soil surface and largest volume of groundwater infiltration but result in the lowest centres of the moisture content mass. The results obtained using soil data based on the pedological method are similar to those calculated using soil parameters based on the particle-size distribution of extracted soil samples. Water pressure profiles calculated on Terrace and Channel location, 3 and 7 days after the inundation event agreed reasonably well with those observed when using hydrodynamic parameters from the experiment-based method. However, the flow model using the pedology-based parameters largely underestimates the time needed to achieve hydrostatic conditions of the soil water profile once water flooding at the soil surface stops. This can be mainly attributed to the low values of estimated van Genuchten parameter α. Copyright © 2012 John Wiley & Sons, Ltd.

Effect of olive-mill waste addition to soil on sorption, persistence, and mobility of herbicides used in Mediterranean olive groves

Laboratory and field experiments were conducted to evaluate the effect of olive-mill waste (OMW) addition to a Mediterranean olive grove soil on sorption, persistence, and mobility of two herbicides which are simultaneously applied for weed control in olive groves: terbuthylazine (TA) and fluometuron (FM). Laboratory batch sorption experiments showed that OMW addition to the soil at rates of 5 and 10% (w/w) greatly enhanced the sorption of both herbicides, thus suggesting that amendment with OMW could be useful to enhance the retention and reduce the mobility of FM and TA in the soil. Incubation experiments showed that OMW increased the persistence of FM and had little effect on the long persistence of TA in the soil studied. A demonstration field experiment was also conducted in field plots with a slope of about 5%, either unamended or amended with OMW at a rate of 10kgm−2, and then treated with a commercial formulation containing a mixture of TA and FM. Extraction of field soil samples, taken from different soil depths (0–5, 5–10, 10–20, and 20–30cm) at different times after herbicide application, showed that both TA and FM moved deeper in unamended soil than in OMW-amended soil, and that OMW addition affected the persistence of FM in the toplayer, increasing its half-life from 24 to 58days, while having little effect on the persistence of TA. Thus, data obtained under real field conditions were consistent with those obtained under controlled laboratory conditions. Preliminary herbicide runoff data indicated that the total herbicide runoff losses were also reduced upon OMW addition. Addition of OMW could be beneficial in reducing the mobility of TA and FM in olive grove soils, and also in increasing the persistence of FM in soils where this herbicide could be rapidly degraded.