Environmental Soil Samples Research Articles

A simple and rapid spectrophotometric method for the determination of iron in environmental, biological, pharmaceutical, food and soil samples using 1,2-dihydroxybenzene-3,5-disulfonic acid

An ultra-sensitive and highly selective non-extractive spectrophotometric method is presented for the rapid determination of iron (III) at trace levels using 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron) as a new spectrophotometric reagent (l max = 665 nm) in slightly acidic aqueous (2×10 -6 - 2×10 -5 mol/L H 2 SO 4 ) solution. The reaction is instantaneous and absorbance remains stable for over 24 h. The average molar absorption coefficient and Sandell’s sensitivity and detection limit were found to be 6.0×10 5 L/mol.cm, 10 ng/cm 2 , and 1 µg/L, respectively. Linear calibration graphs were obtained for 0.02-70.00 mg/L of Fe(III). The stoichiometric composition of the chelate is 2:3 (Fe(III):Tiron). Large excesses of over 50 cations, anions and complexing agents (e.g. Tartrate, oxalate, citrate, phosphate, thiourea, and thiocyanate) do not interfere in the determination. The method was successfully used in the determination of iron in several standard reference materials (Alloys and steels) as well as in some environmental waters (portable and polluted), biological samples (Human blood and urine), food, pharmaceutical and soil samples, solution containing iron (II) and iron (III) and some complex synthetic mixtures. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).

Abundance of Mycobacterium avium ssp. hominissuis in soil and dust in Germany - implications for the infection route

The nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria found in soil, water and dust. The spread of NTM infection depends on the exposure to reservoirs with high proportions of mycobacteria, the virulence of the NTM strains, the enhanced sensitivity to infections such as those of immune-compromised hosts and patient risk factors such as Cystic Fibrosis. Since several decades, NTM lung disease has been increasingly observed in slender postmenopausal women. The most important NTM in Germany is Mycobacterium avium ssp. hominissuis (MAH). The routes of MAH infection are in almost all cases unknown, but water is often suspected as source of infection. We wanted to examine this hypothesis by determining the frequency of MAH in environmental samples of water, biofilms, soil and dust originating from Germany. We found MAH in 33% of the dust samples and 20% of the soil samples. No MAH could be isolated from water and biofilm. Dust and soil clearly presented more abundance of MAH in comparison with water and biofilms. Therefore, more attention should be paid to soil and dust in Germany as an important source of Myco. avium infections. This study was conducted to investigate the ecological abundance of the most prominent clinical nontuberculous mycobacteria (NTM) in Germany, the Mycobacterium avium ssp. hominissuis (MAH). Examination of soil, water, dust and biofilm samples revealed that MAH in Germany was predominant in soil and dust. No MAH was identified in water and biofilms. Our finding contributes to the identification of the environmental niche of this opportunistic pathogen and proposes soil and dust as sources of MAH infection in Germany.

A Simple Spectrophotometric Method for the Determination of Trace Level of Cadmium in Real, Environmental, Biological, Tobacco, Fertilizer and Soil Samples Using 2⁄, 3, 4⁄, 5, 7 Pentahydroxyflavone

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of cadmium using 2, 3, 4, 5, 7pentahydroxyflavone (morin) has been developed. Morin reacts in a slightly acidic (0.000001-0.000012M H2SO4) in 50% ethanolic solution with cadmium to give a deep greenishyellow chelate which has an absorption maximum at 422 nm. The reaction is instantaneous and the absorbance remains stable for over 24 h. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 4.09 × 10 L molcm and 4.0 ng cm of cadmium, respectively. Linear calibration graphs were obtained for 0.01 25 mg L of cadmium with a correlation co-efficient value 0.9996 for Cd-morin complex. The stoichiometric composition of the chelate is 1:2 (Cd:morin). The detection limit and quantification limit of the reaction system were found 1μg L and 10μg L, respectively. A large excess of over 50 cations, anions and complexing agents (like, chloride, tartrate, azide, citrate, EDTA, SCN etc.) do not interfere in the determination. The developed method was successfully used in the determination of cadmium in several Standard Original Research Article American Chemical Science Journal, 4(4): 481-503, 2014 482 Reference Materials (alloys and steels) as well as in some environmental waters (inland and surface), biological samples (human blood, urine and hair), tobacco, fertilizer, soil samples and complex synthetic mixtures. The results of the proposed method for biological samples were comparable with AAS and were found to be in good agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg L).

Improved group-specific primers based on the full SILVA 16S rRNA gene reference database.

Quantitative PCR (qPCR) and community fingerprinting methods, such as the Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis,are well-suited techniques for the examination of microbial community structures. The use of phylum and class-specific primers can provide enhanced sensitivity and phylogenetic resolution as compared with domain-specific primers. To date, several phylum- and class-specific primers targeting the 16S ribosomal RNA gene have been published. However, many of these primers exhibit low discriminatory power against non-target bacteria in PCR. In this study, we evaluated the precision of certain published primers in silico and via specific PCR. We designed new qPCR and T-RFLP primer pairs (for the classes Alphaproteobacteria and Betaproteobacteria, and the phyla Bacteroidetes, Firmicutes and Actinobacteria) by combining the sequence information from a public dataset (SILVA SSU Ref 102 NR) with manual primer design. We evaluated the primer pairs via PCR using isolates of the above-mentioned groups and via screening of clone libraries from environmental soil samples and human faecal samples. As observed through theoretical and practical evaluation, the primers developed in this study showed a higher level of precision than previously published primers, thus allowing a deeper insight into microbial community dynamics.

Kläui Ligand Thin Films for Rapid Plutonium Analysis by Alpha Spectrometry

As part of a nuclear forensics capability, rapid and effective methods to analyze for plutonium and other actinide metals are needed. A key requirement of these methods is that they afford a high chemical yield while still providing isotopic information necessary for forensic evaluation. Toward this objective, a new method for binding plutonium for analysis by alpha spectrometry has been developed. Thin films of Kläui-type tripodal oxygen donor ligands were prepared by spin-casting solutions onto glass substrates. Three different ligands were evaluated for plutonium binding, and the best results were obtained using the ethyl-substituted complex Na[Cp*Co(P(O)(OEt)2)3], which bound 80-88% of the dissolved Pu under equilibrium conditions. The thin films are simple and inexpensive to prepare and exhibit excellent alpha spectral resolution, having line widths of ~33 keV. The method has been successfully applied to analyze for plutonium in both an archived nuclear debris sample and a certified environmental soil sample. The results obtained from the soil analysis are in good agreement with the certified values, demonstrating the effectiveness of the method for rapid plutonium analysis.

Longitudinal Study of Distributions of Similar Antimicrobial-Resistant Salmonella Serovars in Pigs and Their Environment in Two Distinct Swine Production Systems

The aim of this longitudinal study was to determine and compare the prevalences and genotypic profiles of antimicrobial-resistant (AR) Salmonella isolates from pigs reared in antimicrobial-free (ABF) and conventional production systems at farm, at slaughter, and in their environment. We collected 2,889 pig fecal and 2,122 environmental (feed, water, soil, lagoon, truck, and floor swabs) samples from 10 conventional and eight ABF longitudinal cohorts at different stages of production (farrowing, nursery, finishing) and slaughter (postevisceration, postchill, and mesenteric lymph nodes [MLN]). In addition, we collected 1,363 carcass swabs and 205 lairage and truck samples at slaughter. A total of 1,090 Salmonella isolates were recovered from the samples; these were isolated with a significantly higher prevalence in conventionally reared pigs (4.0%; n = 66) and their environment (11.7%; n = 156) than in ABF pigs (0.2%; n = 2) and their environment (0.6%; n = 5) (P < 0.001). Salmonella was isolated from all stages at slaughter, including the postchill step, in the two production systems. Salmonella prevalence was significantly higher in MLN extracted from conventional carcasses than those extracted from ABF carcasses (P < 0.001). We identified a total of 24 different serotypes, with Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Anatum, Salmonella enterica serovar Infantis, and Salmonella enterica serovar Derby being predominant. The highest frequencies of antimicrobial resistance (AR) were exhibited to tetracycline (71%), sulfisoxazole (42%), and streptomycin (17%). Multidrug resistance (resistance to ≥ 3 antimicrobials; MDR) was detected in 27% (n = 254) of the Salmonella isolates from the conventional system. Our study reports a low prevalence of Salmonella in both production systems in pigs on farms, while a higher prevalence was detected among the carcasses at slaughter. The dynamics of Salmonella prevalence in pigs and carcasses were reciprocated in the farm and slaughter environment, clearly indicating an exchange of this pathogen between the pigs and their surroundings. Furthermore, the phenotypic and genotypic fingerprint profile results underscore the potential role played by environmental factors in dissemination of AR Salmonella to pigs.

A study on lead (210Pb) and polonium (210Po) contamination from phosphogypsum in the environment of Wiślinka (northern Poland)

The results of polonium ((210)Po) and lead ((210)Pb) determination in different environmental soil samples collected in the vicinity of the phosphogypsum stack in Wiślinka (northern Poland) are presented and discussed in this paper. The (210)Po and (210)Pb concentrations in soil samples from the phosphogypsum stack recorded in this study are significantly higher only in areas that are close to the heap. The relationship between atmospheric deposition and elevated analyzed radionuclides concentrations in top soil layers, especially in the vicinity of the phosphogypsum stack, was showed in this study. (210)Po and (210)Pb radionuclides were detected in concentrations which could have harmful effects on human health or the environment. The considerably high concentrations of (210)Po and (210)Pb in soil samples collected from the vicinity of the phosphogypsum stack obtained in this study can lead to the conclusion that the presently undertaken recultivation process is successful and the 300 m(2) protection zone around the phosphogypsum stack seems to be able to offset the negative influence of the phosphogypsum stack on the surrounding environment.

Amino modified multi-walled carbon nanotubes/polydimethylsiloxane coated stir bar sorptive extraction coupled to high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental samples

In this work, amino modified multi-walled carbon nanotubes/polydimethylsiloxane (multi-walled carbon nanotubes-4,4′-diaminodiphenylmethane/polydimethylsiloxane, MWCNTs-DDM/PDMS) was synthesized, and utilized as a novel coating for stir bar sorptive extraction (SBSE) of seven phenols (phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-choro-m-cresol and 2,4,6-trichlorphenol) in environmental water and soil samples, followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The prepared MWCNTs-DDM/PDMS coated stir bar was characterized and good preparation reproducibility was obtained with the relative standard deviations (RSDs) ranging from 4.7% to 11.3% (n=9) in one batch, and from 4.8% to 13.9% (n=8) among different batches. Several parameters affecting the extraction of seven target phenols by MWCNTs-DDM/PDMS-SBSE including extraction time, stirring rate, pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.14μg/L (2-nitrophenol) to 1.76μg/L (phenol) and the limits of quantification (LOQs, S/N=10) were found to be in the range of 0.46μg/L (2-nitrophenol) to 5.8μg/L (phenol). The linear range was 5–1000μg/L for phenol and 4-nitrophenol, 1–1000μg/L for 2-nitrophenol and 2–1000μg/L for other phenols, respectively. The RSDs of the developed method were in the range of 6.2–11.6% (n=8, c=10μg/L) and the enrichment factors were from 6.5 to 62.8-fold (theoretical enrichment factor was 100-fold). The proposed method was successfully applied to the analysis of phenols in environmental water and soil samples, and good recoveries were obtained for the spiked samples. The proposed method is simple, highly sensitive and suitable for the analysis of trace phenols in environmental samples with complex matrix.

Pyrosequencing of environmental soil samples reveals biodiversity of thePhytophthoraresident community in chestnut forests

Pyrosequencing analysis was performed on soils from Italian chestnut groves to evaluate the diversity of the resident Phytophthora community. Sequences analysed with a custom database discriminated 15 pathogenic Phytophthoras including species common to chestnut soils, while a total of nine species were detected with baiting. The two sites studied differed in Phytophthora diversity and the presence of specific taxa responded to specific ecological traits of the sites. Furthermore, some species not previously recorded were represented by a discrete number of reads; among these species, Phytophthora ramorum was detected at both sites. Pyrosequencing was demonstrated to be a very sensitive technique to describe the Phytophthora community in soil and was able to detect species not easy to be isolated from soil with standard baiting techniques. In particular, pyrosequencing is an highly efficient tool for investigating the colonization of new environments by alien species, and for ecological and adaptive studies coupled with biological detection methods. This study represents the first application of pyrosequencing for describing Phytophthoras in environmental soil samples.

Simultaneous analysis of endosulfan, chlorpyrifos, and their metabolites in natural soil and water samples using gas chromatography-tandem mass spectrometry

Analysis of endosulfan, chlorpyrifos, and their nonpolar metabolites in extracts from environmental aqueous and soil samples was performed using a gas chromatography-tandem mass spectrometry (GC-MS/MS) technique. Full-scan GC-MS analysis showed poor sensitivity for some of the metabolites (endodiol and endosulfan ether). A multisegment MS/MS method was developed and MS/MS parameter isolation time, excitation time, excitation voltage, and maximum excitation energy were optimized for chosen precursor ions to enhance selectivity and sensitivity of the analysis. The use of MS/MS with optimized parameters quantified analytes with significantly higher accuracy, and detection limits were lowered to ~1/6th compared with the full-scan method. Co-eluting compounds, chlorpyrifos and chlorpyrifos oxon, were also analyzed successfully in the MS/MS mode by choosing exclusive precursor ions. Analysis of soil and water phase samples from contaminated soil slurry bioreactors showed that the MS/MS method could provide more reliable estimates of these pesticide and metabolites (especially those present in low concentrations) by annulling interferences from soil organic matter.

Microwave assisted extraction combined with solvent bar microextraction for one-step solvent-minimized extraction, cleanup and preconcentration of polycyclic aromatic hydrocarbons in soil samples

For the first time, a novel one-step sample preparation method that combines microwave assisted extraction and solvent bar microextraction (MAE–SBME) with analysis by gas chromatography–mass spectrometry (GC–MS), was developed for the fast and efficient determination of polycyclic aromatic hydrocarbons (PAHs) in environmental soil samples. An interesting feature of the new procedure is that SBME was conducted simultaneously with MAE. Thus, the extract from the SBME could be directly and immediately analyzed by GC–MS. A separate clean up and/or preconcentration process, such as time-consuming and tedious gel permeation chromatography, solid-phase extraction, filtration, or adsorption chromatography, normally associated with conventional MAE, was not necessary. It is also notable that the procedure was environmentally benign since water was used as the extraction solvent in MAE, and only several microliters of organic solvent were used in SBME. Some factors affecting the extraction were studied and optimized. Under the most favorable conditions, the method showed good linearities (between 0.2 and 500, 0.5 and 500, 1 and 500, and 2 and 500ng/g, depending on the analytes), low limits of detection (from 0.03 to 0.25ng/g), and satisfactory precision (with relative standard deviations below 9.8%). The MAE–SBME procedure provides a fast and simple sample preparation approach for the processing of environmental soil samples.

A new approach to studying ion uptake by actinomycetes

A streptomycete that had the ability to avidly sequester iron via siderophores was previously isolated from environmental soil samples. The chelating agent expressed by this organism is confirmed by HPLC as desferrioxamine E. Although the traditional chromo azuerol sulphate (CAS) assay for detection of siderophores is based upon the chelation of iron we were interested to examine the relationship of these iron-capturing molecules with other ions. Consequently, a new approach was employed that enabled the assessment of the affinity of the siderophore moieties for other ions by adapting the CAS assay. The present study reveals that the isolate produced a siderophore that was capable of sequestering a range of ions including Mn, Co, Cd, Ni, Al, Li, Cu, Zn and Mg. On the basis of the assay described it would appear that the organism sequesters copper more readily than iron. This raises an age-old debate surrounding the replacement of copper as a fundamentally essential element with iron as a consequence of the evolution of the di-oxygen environment.

Emergence of Antibiotic-Producing Microorganisms in Residential Versus Recreational Microenvironments.

AimsTo identify novel antibiotic-producing microbial strains with unprecedented pertinence. We hypothesize that site-specific soil samples will contain a variety of antibiotic-producing species (APS) with diverse specificity of molecular elements.Place and Duration of StudyLaboratory of Microbiology, Division of Biological and Health Sciences, University of Pittsburgh, Bradford, PA-16701, USA, between August 2010 and May 2011.MethodologyThe environmental soil samples were collected from residential and recreational sites in Southern, PA, USA at longitude: −76 42 21.7116, latitude: 39 56 35.7252; approximately 201 meters above sea level. Over 70 natural antibiotic-producing soil bacteria were screened against 19 pathogenic microorganisms. Agar-plug assay was established to identify the antibiotics’ potency and pathogenic inhibitory index calculations were employed to measure the inhibitory potential of each isolate; 16S rRNA sequencing was used for microbial classification.ResultsA total of 71 microorganisms from residential soil demonstrated zones of inhibition (ZOI), followed by 9 organisms from recreational soil sample. A total of 15 bioactive strains demonstrated convincing growth inhibitory properties against 16 clinically relevant pathogens; 40% revealed pDNA presence, of which 67% exhibited stringent potencies against S. aureus. We observed a highly bioactive residential soil microbiota compared to recreational soil.Conclusion16S rRNA sequence analysis corroborated several of the species belonging to Enterobacteriaceae, Xanthomonadaceae, and Bacillaceae. These findings may indicate a co-evolutionary biosynthesis of novel antibiotics driven by the increase of bioactive microbiota in residential environments.

An enzyme-linked immunosorbent assay for the determination of tribenuron-methyl in water and soil using a molecularly imprinted film as an artificial antibody

This paper describes the development of a direct competitive enzyme-linked immunosorbent assay with a molecularly imprinted film as an artificial antibody to measure trace tribenuron-methyl (TBM) in environmental water and soil samples. The molecularly imprinted film was directly synthesized on the well surface of a MaxiSorp polystyrene 96-well plate by a non-covalent approach, and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and static and kinetic adsorption experiments. Under optimum conditions, the IC50 and IC15 of the established method are 19.73 μg L−1 and 0.30 μg L−1, respectively, and its cross-reactivity with three sulfonylurea herbicides is in the range of 3.17–13.10%. The method was successfully applied to the determination of TBM in spiked environmental water and soil samples with recoveries from 93.6 to 96.8% and 87.5 to 97.5%, respectively. The results are in good agreement with those obtained by high performance liquid chromatography.

Detection of Polycyclic Aromatic Hydrocarbons in a Soil Sample with Photon Ionization Technique

An electron beam pumped rare gas excimer lamp (EBEL) was utilized to emit the intensive vacuum ultraviolet (VUV) radiation at 126 nm for soft single photon ionization (SPI) of polycyclic aromatic hydrocarbons (PAHs) in a soil sample. The VUV light source was coupled to a compact and mobile time-of-flight mass spectrometer (TOFMS) for the on-line measurement of PAHs. The moderate desorption temperature was set at 300 °C to guarantee the rapid evaporation of the PAHs in the soil sample and without decomposition from the larger molecules. With the thermal treatment, sample extraction and cleanup steps were not needed. The system developed herein was found to perform sufficiently well to evaluate the PAHs in the environmental soil sample at ppm level.

Presence of tetracycline resistant bacteria and genes in grassland-based animal production systems

L. Lopez, J. Santamaria, A. Sanchez, L. Castro, and J.L. Moreno. 2012. Presence of tetracycline resistant bacteria and genes in grassland-based animal production systems. Cien. Inv. Agr. 39(3): 411-423. This study assessed the presence of tetracycline-resistant bacteria in five different grassland-based production systems dedicated to raising dairy cattle located in the Colombian Andes. Animal (ruminal fluid and feces) and environmental (soil and water) samples were evaluated, and resistant heterotrophic bacteria were found in rumen fluid, feces, soil, and runoff water samples. The resistant bacteria were isolated and identified based on the 16S rDNA region. Subsequently, they were evaluated for the presence of tet genes, which encode ribosomal protection proteins and membrane efflux pumps. The most frequent phyla detected were Firmicutes and Proteobacteria. The most common resistance genes found were tet(W), tet(Q), and tet(M). The nucleotide sequences of the genes showed no differences in bacteria isolated from environmental samples versus ruminal fluid and feces. This result suggests that the observed environmental resistance in the evaluated grasslands is the result of horizontal gene transfer from animals to the environment.

Spectrophotometric measurement of Cu(DDTC)2 for the simultaneous determination of zinc and copper

A spectrophotometric procedure for the simultaneous determination of zinc(II) and copper(II) in a mixture using diethyldithiocarbamate (DDTC) as ligand has been described. Complexes formed with DDTC was extracted with CHCl3/CCl4 and the absorbance was measured at 435nm which is equivalent of Cu(II) in sample only as Zn(DDTC)2 has no absorption. Zinc measurement is based on the quantitative displacement of zinc from Zn(DDTC)2 by Cu(II) with the addition of excess copper(II) to the extract. The absorbance is measured again where additional absorbance is equivalent to zinc. The molar absorptivity and sandall’s sensitivity at this wavelength are 2.86×105mol−1Lcm−1 and 3.076ngcm−2, respectively. Reproducibility with in 4% and detection limits of 0.29μgmL−1 was obtained. Linear calibration range was 0.2–14μgmL−1 for zinc and 0.2–12μgmL−1 for copper with the regression coefficient (r2) 0.998 for each. In the presence of a suitable masking agent (EDTA) very good selectivity was achieved. The method was extended to the determination of zinc and copper in a number of environmental water and soil samples, biological, pharmaceutical, fertilizer and food samples.

Determination of pyrethroid pesticides in environmental samples using ionic liquid dispersive liquid-liquid microextraction

Dispersive liquid-liquid microextraction (DLLME) using ionic liquid (IL) as extraction solvent was developed as a new approach for the determination of four pyrethroid pesticides in environmental water and soil samples. High-performance liquid chromatography with ultraviolet detection (HPLC-UV) was employed on chromatographic analysis. The method is rapid, easy to operate and enviromentally-friendly. The highly toxic chlorinated solvent was replaced by the IL 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]), in which high extraction recovery and enrichment factors were obtained. The effects of IL volume, type and volume of disperser solvent, salt addition, pH and extraction time were investigated and optimized. Under optimum conditions, the method showed good linear response with correlation coefficient (R²) values in the range of 0.9943 to 0.9986. Relative standard deviation (RSD) varied from 3.9 to 10.1%. Enrichment factor, limit of detection and recovery ranged from 260 to 319, 0.94 to 1.97 µg L-1 and 89 to 98%, respectively. For real water samples, RSD ranged from 3.8 to 10.8%, and recovery from 83 to 99%. For soil sample analysis, RSD and recovery ranged from 3.7 to 8.9% and 88 to 98, respectively.

Natural Radioactivity Levels and Estimation of Radiation Exposure in Environmental Soil Samples from Tulkarem Province-Palestine

The activity concentrations of the natural radionuclides namely 238U, 232Th, 40K and 137Cs are measured for soil samples collected from different locations of Tulkarem district in West Back-Palestine. High-resolution gamma spectrometry (HPGe detector) was used to determine the activity concentration of these radionuclides in 72 surface soil samples taken from areas in and surrounding Tulkarem city. The concentration of 238U varied in the range 9.7 - 83.5 Bq kg–1 with an average value of 34.5 Bq kg–1, 232Th in the range 5.3 - 44.8 Bq kg–1 with an average value of 23.8 Bq kg–1, 40K in the range 10.2 - 404.0 Bq kg–1 with an average value of 120.0 Bq kg–1 and 137Cs in the range 1.0 - 24.5 Bq kg–1 with an average value of 7.8 Bq kg–1. The results have been compared with those of different countries of the world and Palestine. To assess the radiological hazard of the natural radioactivity, the absorbed dose rate (Dr), the radium equivalent activity (Raeq), the effective dose rate (Eeff), the annual effective dose equivalent (AEDE), Excess Lifetime Cancer Risk (ELCR), the radioactivity level index (Iγ), and the external (Hex) and internal (Hin) hazard indices were calculated .It can be concluded that no risk may threat the residents around and center of Tulkarem city except some areas which activity due to fallout 137Cs were high concentration levels. Hence the probability of occurrence of any of the health effects of radiation is low. Hence, measurements have been taken as representing baseline values of these radionuclides in the soil in studying area.

Functional environmental genomics of a municipal landfill soil.

We investigated the toxicity of soil samples derived from a former municipal landfill site in the South of the Netherlands, where a bioremediation project is running aiming at reusing the site for recreation. Both an organic soil extract and the original soil sample was investigated using the ISO standardized Folsomia soil ecotoxicological testing and gene expression analysis. The 28 day survival/reproduction test revealed that the ecologically more relevant original soil sample was more toxic than the organic soil extract. Microarray analysis showed that the more toxic soil samples induced gene regulatory changes in twice as less genes compared to the soil extract. Consequently gene regulatory changes were highly dependent on sample type, and were to a lesser extent caused by exposure level. An important biological process shared among the two sample types was the detoxification pathway for xenobiotics (biotransformation I, II, and III) suggesting a link between compound type and observed adverse effects. Finally, we were able to retrieve a selected group of genes that show highly significant dose-dependent gene expression and thus were tightly linked with adverse effects on reproduction. Expression of four cytochrome P450 genes showed highest correlation values with reproduction, and maybe promising genetic markers for soil quality. However, a more elaborate set of environmental soil samples is needed to validate the correlation between gene expression induction and adverse phenotypic effects.