How useful are databases in environmental and criminal forensics?

Advances in computational and information technologies have facilitated the acquisition of geospatial information for regional and national soil and geology databases. These have been completed for a range of purposes from geological and soil baseline mapping to economic prospecting and land resource assessment, but have become increasingly used for forensic purposes. On the question of provenance of a questioned sample, the geologist or soil scientist will draw invariably on prior expert knowledge and available digital map and database sources in a ‘pseudo Bayesian’ approach. The context of this paper is the debate on whether existing (digital) geology and soil databases are indeed useful and suitable for forensic inferences. Published and new case studies are used to explore issues of completeness, consistency, compatibility and applicability in relation to the use of digital geology and soil databases in environmental and criminal forensics. One key theme that emerges is that, despite an acknowledgement that databases can be neither exhaustive nor precise enough to portray spatial variability at the scene of crime scale, coupled with expert knowledge, they play an invaluable role in providing background or
reference material in a criminal investigation. Moreover databases can offer an independent control set of samples.

Coping with the wash

With the growth in the use of fast ferries on routes previously served by conventional ships, increasing numbers of wash problems have been reported. Here, we describe these problems and explain the differences between different vessels’ wash characteristics. Measures are described which can be used to manage the resultant risk to the users of the coastal environment.

Performance Evaluation of Two-Stage Electrokinetic Washing as Soil Remediation Method for Lead Removal using Different Wash Solutions

The study explores the application of a two-stage electrokinetic washing system on remediation of lead (Pb) contaminated soil. The process involved an initial soil washing, followed by an electrokinetic process. The use of electrokinetic process in soil washing not only provided additional driving force for transporting the desorbed Pb away from the soil but also reduced the high usage of wash solution. In this study, the effect of NaNO3, HNO3, citric acid and EDTA as wash solutions on two-stage electrokinetic washing system were evaluated. The results revealed that a two-stage electrokinetic washing process enhanced Pb removal efficiency by 2.52-9.08% and 4.98-20.45% in comparison to a normal electrokinetic process and normal washing process, respectively. Low pH and adequate current were the most important criteria in the removal process as they provided superior desorption and transport properties. The effect of chelating by EDTA was less dominant as it delayed the removal process by forming a transport loop in anode region between Pb ion and complexes. HNO3 was not suitable as wash solution in electrokinetic washing in spite of offering highest removal efficiency as it caused pH fluctuation in the cathode chamber, corroded graphite anode and showed high power consumption. In contrast, citric acid not only yielded high Pb removal efficiency with low power consumption but also maintained a low soil: solution ratio of 1 g: <1 mL, stable pH and electrode integrity. Possible transport mechanisms for Pb under each wash solution are also discussed in this work.

Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness

Mapped topographic features are important for understanding processes that sculpt the Earth’s surface. This paper presents maps that are the primary product of an exercise that brought together 27 researchers with an interest in landform mapping wherein the efficacy and causes of variation in mapping were tested using novel synthetic DEMs containing drumlins. The variation between interpreters (e.g. mapping philosophy, experience) and across the study region (e.g. woodland prevalence) opens these factors up to assessment. A priori known answers in the synthetics increase the number and strength of conclusions that may be drawn with respect to a traditional comparative study. Initial results suggest that overall detection rates are relatively low (34–40%), but reliability of mapping is higher (72–86%). The maps form a reference dataset.

Early Medieval Settlement in North County Antrim: the significance of Doonmore and Drumadoon

The excavated north Antrim sites of Doonmore and Drumadoon are compared and attention is drawn to a group of like monuments in the same barony, here termed fortified outcrops. These are argued to be a type influenced by settlements in Argyll and introduced by the Dál Riata to Ulster through ‘counterstream migration’.