Radon as an anthropogenic indoor air pollutant as exemplified by radium dial watches and other uranium- and radium- containing artefacts

Radon is generally regarded as a naturally occurring radiological hazard but we report here measurements of significant, hazardous radon concentrations that arise from man-made sources, e.g. radium-dial watches. This study is an examination and assessment of health risks from radium and uranium found in historical artefacts, and the radon that emanates from them. This includes radium-dial watches, the main focus, plus clocks, aircraft instruments, and ornaments and artefacts made of uranium glass / uranium-glazed. Such objects were very popular in the 1930s and 1940s and are still readily available today. A collection of 30 radium-dial pocket and wrist watches was measured and shown to be capable of giving rise to radon concentrations two orders of magnitude greater than the UK Domestic Action Level of 200 Bq•m-3 in unventilated or poorly ventilated rooms. Furthermore, individual watches are capable of giving rise to radon concentrations in excess of the UK Domestic Action Level. We also highlight a gap in remediation protocols, which are focused on preventing radon entering buildings from outside, with regard to internally-generated radon hazards. Radon as arising from man-made objects such as radium-dial watches should be considered appropriately in radon protocols and guidelines

3D imaging of natural volcanic ash fragments and comparison with experimentally-vesiculated volcanic glass

Volcanic particles in ash clouds can cause adverse effects on human health as well as having the potential to cause critical damage to aircraft. In order to improve understanding of the underlying causes for the damage caused by volcanic particles we examined their appearance in 3D using confocal microscopy. We present here results of 3D imaging of volcanic glass particles from two Icelandic volcanoes together with experimentally-vesiculated volcanic glass. True colour 3D images were obtained using an Olympus LEXT 3D laser scanning reflectance confocal microscope. The images show bubble structure, fracture patterns, shape morphology and characteristics of grains. Simulated fragments and bubbles compare well with real material from the Icelandic events, with similar overall bubble sizes. 3D laser confocal microscopy imaging of volcanic glass fragments helps in examining the structure of volcanic particles and hence has the potential of leading to improved understanding of their potential impact

Assessing low-maturity organic matter in shales using Raman spectroscopy : effects of sample preparation and operating procedure

Laser Raman spectroscopy is used to assess the thermal maturity of organic matter in sedimentary rocks, particularly organic-rich mudstones. However, discrepancies exist between quantified Raman spectral parameters and maturity values obtained by vitrinite reflectance. This has prevented the adoption of a standard protocol for the determination of thermal maturity of organic matter (OM) by Raman spectroscopy. We have examined the factors influencing the Raman spectra obtained from low-maturity OM in potential shale gas reservoir rocks. The inconsistencies in Raman results obtained are due to three main factors that are critically evaluated: (1) different operational procedures, including experiment setup and spectral processing methods; (2) different methods of sample preparation; (3) the analysis of diverse types of OM. These factors are scrutinized to determine the sources of inconsistency and potential bias in Raman results, and guidance is offered on the development of robust and reproducible analytical protocols. We present two new Raman parameters for un-deconvolved spectra named the DA1/GA ratio (area ratio of 1100–1400 cm−1/1550–1650 cm−1) and SSA (scaled spectrum area: sum of total area between 1100 and 1700 cm−1) that offer potential maturity proxies. An automated spreadsheet procedure is presented that processes raw Raman spectra and calculates several of the most commonly used Raman parameters, including the two new variables

Radon as a carcinogenic built-environmental pollutant

Radon (222Rn) has been highlighted by a number of authors as a significant public health concern. For example, it is the second most significant cause of lung cancer after tobacco smoking (ca. 1,000-2,000 and 21,000 deaths per year in the UK and USA respectively; US EPA, 2003; Darby et al., 2005; Dixon, 2006; HPA, 2009), yet a very high proportion of the general public appears to be unaware of the risk. This chapter deals with topical radon issues such as radon in the workplace; radon in homes; exposure to radon during leisure activities; radon and water; measurement and monitoring; seasonal correction; remediation; cancer risks; cost-benefit analysis and cost-effectiveness; mapping; future policies; and further research. This assessment of the state of radon research is focused on the UK as an example of a country where radon has been on the governmental agenda since the late 1970s, but also highlights radon issues throughout the world in, for example, the USA, Europe and Asia

Characterising radon emanations from radium-dial watches

Research during the latter half of 2011 has indicated that in addition to the hazard arising from the radium content of radium-dial watches, significant radon concentrations that exceed the UK Domestic and Workplace Action Levels of 200 Bq/m3 and 400 Bq/m3, respectively, can arise from watches stored in the built environment (1). In an extension to that earlier research, the radon emanations from the watches are being investigated in order to evaluate the radon hazard and the effective radium content of the watches. These radon measurements are made by placing the watches in a sealed chamber in a closed loop with a Durridge RAD7. We report here preliminary results from this ongoing investigation which suggest that radon emanation is not necessarily a straightforward function of radium content, as anticipated, but also depends on chamber temperature and humidity impacting upon watch-dependent factors such as design, construction, materials and wear-and-tear. Reference. 1. Gillmore G K, Crockett R G M, Denman A R, Flowers A, Harris R; Radium dial watches, a potentially hazardous legacy? Environment International. 45, 91–98. 2012. doi:10.1016/j.envint.2012.03.013

Expanding and Testing a Computational Method for Predicting the Ground State Reduction Potentials of Organic Molecules on the Basis of Empirical Correlation to Experiment

A method for predicting the ground state reduction potentials of organic molecules on the basis of the correlation of computed energy differences between the starting S-0 and one-electron-reduced D-0 species with experimental reduction potentials in acetonitrile has been expanded to cover 3.5 V of potential range and 74 compounds across 6 broad families of molecules. Utilizing the conductor-like polarizable continuum model of implicit solvent allows a global correlation that is computationally efficient and has improved accuracy, with r(2) \u3e 0.98 in all cases and root mean square deviation errors of(mean absolute deviationsmV) for either B3LYP/6-311+G(d,p) or B3LYP//6-31G(d) with an appropriate choice of radii (UAKS or UA0). The correlations are proven to be robust across a wide range of structures and potentials, including four larger (27-28 heavy atoms) and more conformationally flexible photochromic molecules not used in calibrating the correlation. The method is also proven to be robust to a number of minor student mistakes or methodological inconsistencies

A rapid method for determining organic matter maturity using laser Raman spectroscopy : application to Carboniferous organic-rich mudstones and coals

A simple and rapid automated Raman maturity method is calibrated using a suite of Carboniferous organic-rich mudstones and coals from the Inch of Ferryton-1 borehole in the Midland Valley of Scotland. Sediments in the borehole have been thermally matured by intrusion of a quartz dolerite sill, generating vitrinite reflectance (VR) values ranging from 0.5 to 6.0%VRo. Calibration curves are tested on eight other UK wells penetrating Carboniferous shales and coals in the Midland Valley and southern Pennine Basin. The G-band full-width at half-maximum (G-FWHM) is the best Raman parameter to estimate the thermal maturity of organic matter (OM) in the oil and gas window (0.5 to 3%VRo) and has a very strong correlation with VRo