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Balkan endemic nephropathy (BEN) is an irreversible, lethal kidney disease that occurs in regions of the Balkans where residents drink untreated well water. A key factor contributing to the development of BEN may be consumption of dissolved organic matter leached from low-rank coal called lignite. This hypothesis—known as lignite-water hypothesis—was first posed for areas of the Balkans. It is possible that a BEN-like condition exists in the United States (US) Gulf Coast region in parts of the Mississippi Embayment and the Texas Coastal Uplands aquifers —Arkansas, Louisiana, and Texas, for instance—that rely heavily on groundwater from aquifers that contain lignite. This study utilizes a geographic information system (GIS) to map the distributions of end-stage renal disease (ESRD) in relation to water from lignite-containing aquifers in the tri-state region. Regional patterns emerged from geospatial analysis, suggesting that counties that relied on lignite-containing aquifers for their main water source had higher rates of ESRD in comparison to other populations in the region that rely on other water sources, including surface water and groundwater from aquifers not associated with lignite seams. Statewide rates of ESRD and diabetes associated ESRD (ESRD-DM) showed strong correlations to the percent of families at or below poverty level and the percentage of African Americans. These confounding factors somewhat mitigate the association seen between ESRD and lignite-containing regions at the state level. However, at the larger tri-state view, there is a significant (p = 0.002) increase in incidence rates where groundwater is connected to lignite-containing aquifers when considering both race and poverty. Additionally, no relationship was observed between the rate of public water supply withdrawal from lignite-bearing aquifers and rates of ESRD or ESRD-DM at the state or tri-state regions, supporting the observation that the risk associated with water from lignite-containing aquifers is limited to water from untreated domestic supply.

International audience; Sewage impacted soil, sludge and water samples were studied to understand the occurrence and formation of thiosteranes and to determine the relevance of these compounds as tracers for sewage input into the environment. Soils were collected from wastewater irrigation fields (Wroclaw, Poland), water from the Nexapa River Basin (Mexico), which also received wastewater and wastewater treatment plant (WWTP) effluent, and water and sludge from the Norman WWTP (USA) at different treatment stages. Thiosteranes represented a high proportion of the steroid fraction in the Wroclaw irrigation field and the Nexapa River Basin samples. Small amounts of thiosteranes were found in anaerobically digested sludge from the Norman WWTP. A good correlation between coprostanone and thiosterane concentrations suggests thiosteranes were produced by stanone sulphurization under anoxic conditions. Thiosterane stability under anoxic and suboxic conditions indicates their potential use as tracers for environmental input of sewage products or land application of sewage sludge.

The sterol distributions of 9 sediment samples from the Illinois River Basin (OK and AR, USA) were examined in order to identify the source of fecal contamination. The samples were extracted with organic solvent using sonication and the fractions containing the sterols were isolated and analyzed by gas chromatography-mass spectrometry. The sterol distributions of the Illinois River samples were dominated by phytosterols. They were compared to those of different animal feces and manures using a principal component analysis and correspondence appeared between the sediments and one group of chicken feces samples. Gas chromatography-isotope ratio mass spectrometry analyses were also performed to determine the δ(13)C values for the phytosterols and to get an indication of their origin based on the C(3)/C(4) plant signatures. The δ(13)C values obtained ranged from -30.6 ‰ to -17.4 ‰ (VPDB) corresponding to a mixed signature between C(3) and C(4) plants, indicating a C(4) plant contribution to the C(3) plant natural background. These observations indicate that a proportion of the phytosterols originated from chicken feces.

We evaluated the ability of the native microbiota in a low-temperature, sulfidic natural hydrocarbon seep (Zodletone) to metabolize short-chain hydrocarbons. n-Propane and n-pentane were metabolized under sulfate-reducing conditions in initial enrichments and in sediment-free subcultures. Carbon isotope analysis of residual propane in active enrichments showed that propane became enriched in (13)C by 6.7 (+/-2.0) per thousand, indicating a biological mechanism for propane loss. The detection of n-propylsuccinic and isopropylsuccinic acids in active propane-degrading enrichments provided evidence for anaerobic biodegradation via a fumarate addition pathway. A eubacterial 16S rRNA gene survey of sediment-free enrichments showed that the majority of the sequenced clones were phylogenetically affiliated within the Deltaproteobacteria. Such sequences were most closely affiliated with clones retrieved from hydrocarbon-impacted marine ecosystems, volatile fatty acid metabolizers, hydrogen users, and with a novel Deltaproteobacterial lineage. Other cloned sequences were affiliated with the Firmicutes and Chloroflexi phyla. The sequenced clones were only distantly (

High-temperature gas chromatography (HTGC) has enhanced our ability to characterize hydrocarbons extending to C120 in crude oils. As a result, hydrocarbons in waxes (> C20) have been observed to vary significantly between crude oils, even those presumed to originate from the same source. Prior to this development, microcrystalline waxes containing hydrocarbons above C40 were not characterized on a molecular level due to the analytical limitations of conventional gas chromatography. Routine screenings of high pour-point crude oils by high-temperature gas chromatography has revealed that high molecular weight hydrocarbons (> C40) are very common in most oils and may represent 2% of the crude oil. Precise structures, origins, and significance of these high molecular weight compounds remain elusive. As a preliminary step to expand our knowledge of these compounds their general molecular structures and formulas have been investigated in this study. Initial results suggest that the major high molecular weight compounds include a homologous series of n-alkanes, methylbranched alkanes, alkylcyclopentanes, alkylcyclohexanes, alkylbenzenes and alkylcycloalkanes. # 2000 Elsevier Science Ltd. All rights reserved.

The occurrence of high molecular weight hydrocarbons in a selected solid bitumen (ozocerite) and a waxy yellow crude oil from the Uinta Basin (Utah) have been studied by field ionization-mass spectrometry (FIMS). The FIMS spectra consisted predominantly of molecular ions ranging up to near mass 2000, and correspond to several series of hydrocarbons ranging up to C110. The use of FIMS permits the range of hydrocarbons identified in geological materials to be extended far beyond that identified by the usual chromatographic techniques. Moreover, from the FIMS spectra it was possible to extract the molecular ions corresponding to series of hydrocarbons with different degree of unsaturation or ring closures (different Z-numbers). The ozocerite solid bitumen consisted mainly of series of branched alkanes (CnH2n+2) and cyclic alkanes (CnH2n and CnH2n−2) up to C110 with a predominance of monocyclic alkanes in the high molecular weight region (above C40). The waxy yellow crude oil, on the other hand, contained only acyclic compounds, mainly n-alkanes, ranging up to C100.

In order to investigate the formation of organosulphur compounds during the very early stage of diagenesis, experiments were designed to simulate sulphur incorporation from H2S, or elemental sulphur, into recently deposited natural sedimentary organic matter (cyanobacterial mats from salt ponds in Baja California) and performed under relatively mild reaction conditions (40°C, 2 to 30 days, hydrous and anhydrous). The sulphur-containing moieties in the reaction products were examined by pyrolysis-gas chromatography (GC) using a GC equipped with a flame photometric detector (FPD) and a flame ionization detector (FID), and pyrolysis-gas chromatography/mass spectrometry (GC/MS). Sulphur incorporation from H2S into recently deposited cyanobacterial mats occurred fairly readily, but elemental sulphur does not react as readily with the cyanobacterial mats. Sulphur incorporation into humic acids occurred more rapidly than into proto-kerogens. Sulphur incorporation into lipid fractions was not observed. Two major sulphur incorporation stages are proposed, with the formation of thiols by reaction between H2S and active carbonyl groups considered to be the most likely mechanism of sulphur incorporation in the first stage. The second stage of sulphur incorporation is proposed to be related to the reaction between H2S and proteinaceous organic matter.

Bitumens collected in the east zone of the Cigar Lake deposit have been analyzed by 13C nuclear magnetic resonance, pyrolysis – gas chromatography, Rock-Eval, and C. H, and O methods. Carbon and hydrogen isotopic compositions and uranium contents have been determined. Results indicate that the bitumens consist mainly of aromatic structures (Fa ≈ 60%) and have undergone a late oxidation process. Similarities in carbon isotopic composition (−27.5‰ > δ13C > −28.2‰) between barren bitumens (U 13C-enriched bitumens could have formed directly by hydrogenation of amorphous carbon, whereas mineralized, isotopically light bitumens from Cluff Lake (δ13C ≈ 48‰) may result from the polymerization of light hydrocarbons around uraninite grains.

We evaluated the ability of the native microbiota in a low-temperature, sulfidic natural hydrocarbon seep (Zodletone) to metabolize short-chain hydrocarbons. n-Propane and n-pentane were metabolized under sulfate-reducing conditions in initial enrichments and in sediment-free subcultures. Carbon isotope analysis of residual propane in active enrichments showed that propane became enriched in (13)C by 6.7 (+/-2.0) per thousand, indicating a biological mechanism for propane loss. The detection of n-propylsuccinic and isopropylsuccinic acids in active propane-degrading enrichments provided evidence for anaerobic biodegradation via a fumarate addition pathway. A eubacterial 16S rRNA gene survey of sediment-free enrichments showed that the majority of the sequenced clones were phylogenetically affiliated within the Deltaproteobacteria. Such sequences were most closely affiliated with clones retrieved from hydrocarbon-impacted marine ecosystems, volatile fatty acid metabolizers, hydrogen users, and with a novel Deltaproteobacterial lineage. Other cloned sequences were affiliated with the Firmicutes and Chloroflexi phyla. The sequenced clones were only distantly (95%) related to other reported low-molecular-weight alkane-degrading sulfate-reducing populations. This work documents the potential for anaerobic short-chain n-alkane metabolism for the first time in a terrestrial environment, provides evidence for a fumarate addition mechanism for n-propane activation under these conditions, and reveals microbial community members present in such enrichments.

Biomarkers are compounds, generally hydrocarbons, present in crude oils and source rocks whose carbon skeletons can be readily related to a precursor molecule occurring in the original source material. The use of biomarkers in source rock extracts and crude oils for the purpose of determining source materials, thermal maturity, extent of biodegradation and migration and for making oil/oil and oil/source rock correlation studies has been well documented. One of the major problems with this approach is the possibility of contamination either naturally, through crude oil migration, or artificially during sample collection or work-up procedures. A solution to this potential problem can be found in the use of biomarkers produced by kerogen pyrolysis. The actual isolation of the kerogen eliminates any potential contaminants and pyrolysis of the kerogen produces indigenous biomarkers. In this paper it is intended to review progress that has been made in the study of biomarkers produced by kerogen pyrolysis. The various techniques that have been used in this approach will be discussed and examples given to show, in particular, the distributions of triterpanes and steranes produced by kerogen pyrolysis. In addition, results obtained from a combination of hydrous pyrolysis to artificially mature kerogens, and anhydrous pyrolysis to characterize the artificially matured kerogens, will be discussed. Certain biomarkers such as the C 28 -bisnorhopane and gammacerane are not produced during anhydrous pyrolysis and possible reasons for these observations will be discussed. Finally, the production of sulphur-containing compounds during pyrolysis reactions will be briefly discussed with reference to their role as possible indicators of maturity and depositional environments.

In the past decade, environmental forensics has emerged as a discipline directed toward determining parties liable for causing spills of contaminants into the environment. Such investigations, while geared toward determining the guilty parties in order to recover costs of the cleanup and remediation, require various questions to be addressed. These include determination of the nature of the product; Where did it come from?; Extent of weathering, if any; How long has it been there?; and Is it degrading naturally? Traditionally, these studies have been addressed through utilization of techniques such as gas chromatography (GC) and gas chromatography–mass spectrometry (GCMS). However, in recent years, stable isotopes, primarily determined through the use of combined gas chromatography–isotope ratio mass spectrometry (GCIRMS), have emerged as an equally important tool in environmental forensics. For relatively low molecular, volatile compounds such as MTBE, BTEX, or chlorinated solvents, the isotopes, primarily carbon and hydrogen, have been used extensively for evaluating the onset of natural attenuation. For larger molecules such as PCBs or PAHs, in which the effects of biodegradation on the isotope composition of these molecules is minimal, the isotopic fingerprints of the individual compounds can be used for correlation purposes. In this paper, a brief introduction to isotope geochemistry will be given, followed by a review of applications of stable isotopes to a variety of environmental problems. While the review may not necessarily be exhaustive, it will provide a comprehensive overview of areas where isotopes have been used and potential applications for the future. Most of the review is concerned with carbon and hydrogen isotopes, although a brief overview of the emerging area of chlorine isotopes will also be discussed.