David J. Roberts

The origin of faeces by means of biomarker detection

One of the defining characteristics of a biomarker is the retention, during diagenesis, of structural characteristics indicative of its original biogenic source (Peters and Moldowan, 1993). Since the 1960s an increasing interest has developed in the use of environmental biomarker compounds to monitor levels of human and animal waste introduced to marine and terrestrial environments; the relative stability of these compounds enabling both spatial and long-term temporal studies to be realized (e.g., Walker et al., 1982; Vivian, 1986; Evershed and Bethell, 1996 and references therein). The specificity of particular biomarkers for different faecal sources makes their use particularly attractive especially in circumstances where deducing the origin of sewage constituting a pollution event is crucial. Research into organicmatter in the marine and terrestrial environments over the last 20 years has led to the development of two main groups of organic compounds found in faecal matter that can be used to monitor sewage, namely: 5b-stanols and bile acids. This communication provides an overview for researchers not necessarily familiar with molecular methods of sewage monitoring. The two compound classes will be considered separately, and then their integration and future development discussed.

Lipid biomarkers of manuring practice in relict anthropogenic soils

This investigation tests the extent to which free soil lipids reflect known manuring practices associated with a relict twelfth-to nineteenth-century anthropogenic deep top soil in West Mainland Orkney. The results demonstrate that total lipid extracts reflect the expected spatial variability in manuring intensity across the deep top soil area, declining with distance from the farmstead. Specific organic manure inputs are also identified; the presence of campesterol, sitosterol and 5β-stigmastanol confirm expected composted turf and ruminant animal manure application to the deep top soil area. A departure from the expected results is the presence of coprostanol, reflecting omnivorous animal manure deposition and confirmed as pig manure through the identification of hyodeoxycholic acid. These analyses establish that lipid biomarkers of past land-management activity are retained in medieval to early modern relict landscapes, and that they allow more precise identification of manure sources and patterns of deposition than conventional pedological techniques. Further, they suggest that historic documentation forms only a partial record of manuring practices

Chromatographic and hyphenated methods for elemental speciation analysis in environmental media

This review discusses chromatographic techniques that permit the analysis of speciated metals in the environment using conventional detectors, such as UV, and element-specific detectors, such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry. The importance of determining precise elemental forms in hazardous waste-contaminated soil, water and biota in terms of toxicity is outlined. Previous reviews on this subject are described and recent research on this subject is discussed. Most of the work cited has been performed in the 1990s and a table summarizing the chromatographic method and the detector system used, including brief comments on the work, is included to enable quick reference.

The application of steroidal biomarkers to track the abandonment of a Roman wastewater course at the Agora (Athens, Greece)

A subterranean, stone-built, sediment-filled culvert discovered during excavations at the Agora (Athens, Greece) was dated to the Roman period on the basis of its characteristic construction and associated finds, including coins. The location of the culvert relative to other adjacent watercourses and an ancient river bed suggested that the structure was a sewer. This was confirmed through a multi-molecular biomarker approach based on analysis of the bile acids associated with sediment filling the sewer, using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The acid fraction contained predominantly deoxycholic and lithocholic acids, while the neutral steroid fraction comprised a complex mixture of ∆ 5 sterol and 5β- and 5α-stanols, dominated by coprostanol, suggesting the presence of faecal matter of predominantly human origin. The concentrations of neutral and acidic faecal biomarkers were observed to vary in tandem, with the highest concentrations being found in the sediment at the base of the fill in the culvert. A reduction in concentration occurred with decreasing depth of the fill, with concentrations in the uppermost samples being little different from control samples of sediment taken beyond the confines of the culvert. The enhanced concentration of bile acids relative to 5β-stanols compared with fresh human faeces must reflect the enhanced diagenetic stability of the former, thereby making bile acids the possibly preferred biomarker for this type of study. The quantitative data obtained suggest that the culvert fell rapidly out of use, possibly coinciding with the Slavic incursion in AD 582‐3.

Distribution and speciation of cadmium in the terrestrial snail, Helix aspersa.

ConclusionsCadmium is taken up by terrestrial snails living in an environment with a relatively high cadmium concentration. The metal becomes bound to protein with a molecular weight of approximately 22,000 daltons. This cadmium-protein complex concentrates in the digestive gland and is present in a form which is soluble in water, (though difficult to extract efficiently). That no efficient excretion mechanism exists for this soluble complex implies that it cannot traverse the cell wall. The failure to 450

Analysis of polychlorinated naphthalenes, polychlorinated biphenyls and polychlorinated terphenyls via carbon skeleton gas-liquid chromatography

Mixtures of polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs) and organo-chlorine pesticides have been determined by carbon skeleton gas chromatography (GC)-Polychlorinated terphenyls (PCTs) have also been investigated. Using hydrogen as the carrier gas, on-column catalytic reduction of PCNs to naphthalene was quantitative for a 3% palladium catalyst at 305°. PCBs were reduced to biphenyl and PCTs to a mixture of o-, m-, and p-terphenyl under similar conditions. PCBs and PCNs were also analysed successfully on a 5% platinum catalyst at 180°. The products of catalytic reduction were identified by GC-mass spectrometry. The method allows detection of nanogram quantities of polychlorinated species.

Acute ethanol decreases NPY mRNA but not POMC mRNA in the arcuate nucleus.

The acute effects of ethanol and acetaldehyde on neuropeptide mRNA expression in the arcuate nucleus (ARC) was assessed. Acetaldehyde was increased in blood following ethanol with cyanamide (a potent inhibitor of aldehyde dehydrogenase) administration. Acetaldehyde is a toxin which can cause a variety of adverse effects following ethanol ingestion in some Oriental people with a genetic lower activity of aldehyde dehydrogenase. Neuropeptide Y (NPY) mRNA levels in ARC were significantly decreased in response to ethanol in the presence or absence of cyanamide compared to control. In contrast, proopiomelanocortin mRNA in ARC was not changed. These novel findings suggest that ethanol suppresses NPY gene expression in ARC and may play a role in ethanol-induced changes in neuronal function.

Rapid screening of banknotes for the presence of controlled substances by thermal desorption atmospheric pressure chemical ionisation tandem mass spectrometry

The ability to thermally desorb directly particulate matter, trapped on filter meshes, into the atmospheric pressure chemical ionisation source of a tandem mass spectrometer allowed the simultaneous detection of a range of controlled substances within complex matrices with a high degree of confidence. Dust samples were collected from bundles of banknotes using simple apparatus attached to a portable vacuum cleaner. This technique was employed without additional clean-up procedures, rendering the overall method extremely rapid. The intensities recorded for characteristic gas phase ion transitions allow the determination of the amounts of contaminants present. It has been reported that a significant proportion of bundles of banknotes are contaminated with cocaine. This study found that cocaine and heroin (and two related opiates) were present above the detection threshold on UK banknotes from general circulation. Differences in both the frequency and degree of contamination were apparent between bundles of banknotes from general circulation and those suspected of being associated with the trafficking of drugs. In addition, a significant number of bundles of banknotes, confiscated by H.M. Customs and Excise, were found to be contaminated with detectable levels of tetrahydrocannabinol and 3,4-methylenedioxymethylamphetamine.

Poly-chlorinated biphenyls, poly-chlorinated naphthalenes and polynuclear aromatic hydrocarbons in severn estuary (U.K.) sediments

Abstract Sediments taken from the upper part of the Severn Estuary have been extracted by cyclic steam distillation into hexane. Analysis of the extract revealed a variety of organic pollutants including alkanes and several poly-nuclear aromatic hydrocarbons (PNAs). A PCB residue was detected and quantified using the technique of carbon-skeleton gas chromatography employing a 3% palladium catalyst and 2% RbCl salt column. The level of PCB in the sediments was found to be of the order of 1 ppm. No significant levels of poly-chlorinated napthalene (PCN) or DDT and related species were found. Organic contamination of one sediment (Arlingham) was found to be associated with the coal particles present in the sample. Levels of contamination at Arlingham were thus shown to be a function of sample composition rather than of the geographical location of the site.

Polychlorinated naphthalenes, polychlorinated biphenyls and ΣDDT residues in British birds of prey

Abstract Tissue samples (muscle, liver and kidney) from small raptors (kestrels) have been extracted by steam extraction into hexane and the levels of ΣDDT, PCB, PCN and PCT determined by carbon skeleton-gas chromatography. A 3% palladium catalyst, and a 2% RbCl salt column coupled to a mass spectrometer were used for the determination. Significant quantities of ΣDDT and PCBs were found in all samples. Only trace amounts of PCTs were found. The relative concentrations of ΣDDT and PCB may be rationalised with the environment from which the sample was taken.