197 research outputs found

    User guide for the BGS Methane and Carbon Dioxide from Natural Sources and Coal Mining Dataset for Great Britain

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    This report presents a description and review of the methodology developed by the British Geological Survey (BGS) to produce an assessment of the potential hazard from Methane and Carbon Dioxide from Natural Sources and Coal Mining in Great Britain. The methodology is briefly described in this report. The purpose of the user guide is to enable those licensing this dataset to have a better appreciation of how the dataset has been created and therefore a better understanding of the potential applications and limitations that the dataset may have

    Soil uranium, soil gas radon and indoor radon empirical relationships in the UK and other European countries

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    Least squares (LS) regression analysis is used to develop empirical relationships between uranium in the ground, radon in soil and radon in dwellings to assist in the development of a geogenic radon potential map for Europe. The data sets used are (i) estimated uranium in the <2mm fraction of topsoils derived from airborne gamma spectrometry data, (ii) U measured in the <2mm fraction of topsoil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. Linear relationships between radon in dwellings and uranium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given uranium or soil gas radon concentration in the ground. UK regression models are compared with published data for other European countries

    Variation in soil chemistry related to different classes and eras of urbanisation in the London area

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    Systematic mapping of the chemical environment of urban areas from around the world has demonstrated the strong impact of urbanisation on topsoil geochemical distributions originally controlled by the underlying parent material (PM). The variance of some elements including As, Ba, Ca, Cr, Cu, Mo, P, Pb, Sb, Se, Sn and Zn in urban domains appears to be impacted by a mixture of geogenic and anthropogenic controls. This study evaluates how soil chemistry has been influenced by different eras of urbanisation within London and other UK urban areas using (a) the pre-1940 Dudley Stamp First Land Utilisation Survey data and (b) the modern urban domain principally defined by the aggregate classes of the 2007 Land Cover Map. In the London area, calcium, and possibly a substantial proportion of Cu, Pb, Sn and Zn enrichment observed in soils impacted by pre-1940 urbanisation relative to soils impacted only by post-1940 urbanisation, may be partly related to the destruction of buildings during the period 1940–1941 rather than from the disposal or aerial dispersion of coal ash from domestic fires. Some Pb, Cu, Sb, Sb, Sn and Zn contamination appears to be caused by road traffic (leaded petrol and brake dust). The relationships between pre- and post-1940 urbanised areas in London also characterise most of 20 other urban centres in England and Wales for which BGS holds soil chemistry data

    Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal

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    Least squares (LS), Theil’s (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated 226Ra in the <2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m−3 whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m−3 for a moderately permeable geological unit to about 40 Bq m−3 for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m−3 is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil 226Ra ratio shows that whereas the published data are generally clustered with no obvious correlation, the data from this study have substantially different relationships depending largely on the permeability of the underlying geology. Models for the relatively impermeable geological units plot parallel to the average indoor radon: soil 226Ra model but with lower indoor radon: soil 226Ra ratios, whilst the models for the permeable geological units plot parallel to the average indoor radon: soil 226Ra model but with higher than average indoor radon: soil 226Ra ratios

    Participating in a fruit and vegetable intervention trial improves longer term fruit and vegetable consumption and barriers to fruit and vegetable consumption: A follow-up of the ADIT study

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    Background: Fruit and vegetable (FV) based intervention studies can be effective in increasing short term FV consumption. However, the longer term efficacy of such interventions is still unclear. The aim of the current study was to examine the maintenance of change in FV consumption 18-months after cessation of a FV intervention and to examine the effect of participating in a FV intervention on barriers to FV consumption. Methods: A follow-up of a randomised controlled FV trial in 83 older adults (habitually consuming ≤2 portions/day) was conducted. At baseline, participants were assigned to continue consuming ≤2 portions FV/day or consume ≥5 portions FV/day for 16-weeks. We assessed FV intake and barriers to FV consumption at baseline, end of intervention and 18-months post-intervention. Results: At 18-months, mean FV intakes in both groups were greater than baseline. The 5 portions/day group continued to show greater increases in FV consumption at 18-months than the 2 portions/day group (p < 0.01). At 18-months, both groups reported greater liking (p < 0.01) and ease in consuming FV (p = 0.001) while difficulties with consuming FV decreased (p < 0.001). The 2 portions/day group reported greater awareness of FV recommendations at 18-months (p < 0.001). Conclusions: Participating in a FV intervention can lead to longer-term positive changes in FV consumption regardless of original group allocation. Trial registration: Clinical Trials.gov NCT00858728

    User guide for the BGS Soil Chemistry Data for environmental assessments (May 2014)

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    This report presents a description and review of the methodologies developed by the British Geological Survey (BGS) to produce a national scale assessment of the concentrations of selected potentially harmful elements (arsenic, cadmium, chromium, nickel lead) in rural topsoils and of these chemical elements plus copper, tin and zinc in urban topsoils. The methodologies are described briefly in this report and in four scientific papers

    London region atlas of topsoil geochemistry

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    The London Region Atlas of Topsoil Geochemistry (LRA) is a further step towards understanding the chemical quality of soils in London, following a previous project called London Earth carried out by the British Geological Survey (BGS) (Johnson et al., 2010[1]). The main advantage of the LRA is that it includes soil geochemical data from the counties surrounding London; placing the city within the context of its rural hinterland, allowing assessments of the impact of urbanisation on soil quality. The London Region Atlas of Topsoil Geochemistry is a product derived from the BGS Geochemical Baseline Survey of the Environment (G-BASE[2]) project. The London Region Geochemical Dataset (LRD, n=8400), on which the atlas is based, includes TOPSOIL data from two complementary surveys: i) the urban London Earth (LOND) and ii) the rural South East England (SEEN). The LRA covers the Greater London Authority (GLA) and its outskirts in a rectangular area of 80x62 km. This extends from British National Grid coordinates Easting 490000–570000, and Northing 153000–215000. The urban LOND and the rural SEEN surveys contribute with 6801 and 1599 samples respectively to the LRD. The concentrations of 44 inorganic chemical elements (Al2O3, CaO, Fe2O3, K2O, MgO, MnO, Na2O, P2O5, SiO2, TiO2, Ag, As, Ba, Bi, Br, Cd, Ce, Co, Cr, Cs, Cu, Ga, Ge, Hf, I, La, Mo, Nb, Nd, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Th, U, V, W, Y, Zn and Zr), loss on ignition (LOI) and pH in topsoil are included in the LRA. For each element, a map showing the distribution in topsoil across the atlas area and a one-page sketch of descriptive statistics and graphs are presented. Statistics and graphs for whole dataset (LRD), London urban subset (LOND) and London surroundings rural subset (SEEN), as well as graphs of topsoil element concentrations over each simplified geology unit are shown. The LRD has been used already in a study aiming to detect geogenic (geological) signatures and controls on soil chemistry in the London region (Appleton et al., 2013[3]). It includes maps showing the distribution of Al, Si, La and I (and Th, Ca, Mn, As, Pb and Zr in supplementary material) and it is concluded that the spatial distribution of a range of elements is primarily controlled by the rocks from where soil derives, and that these geogenic patterns are still recognisable inside the urban centre. Other studies have been done that are based on data in the LRD, namely using the LOND subset or part of it. The main focus of these studies was the mercury content (Scheib et al., 2010[4]), the influence of land use on geochemistry (Knights and Scheib, 2011[5]; Lark and Scheib, 2013[6]); the bioaccessibility of pollutants such as As and Pb (Appleton et al., 2012[7]; Appleton et al., 2012[8]; Cave, 2012[9]; Appleton et al., 2013[10]; Cave et al., 2013[11]) and the lability of lead in soils (Mao et al., 2014[12]); the determination of normal background concentrations of contaminants in English soil (Ander et al., 2013[13]) and the contribution of geochemical and other environmental data to the future of the cities (Ludden et al., 2015[14]). The London Region Atlas of Topsoil Geochemistry formally presents detailed information for all chemical elements in the LRD. This information can be easily visualised and elements compared as its production and layout is standardised. Differences in topsoil element concentrations between the centre of the city and its outskirts can be assessed by observing the map and comparing statistics and graphs reported for the LOND and SEEN subsets respectively. This urban/rural contrast is particularly evident for elements such as Pb, Sb, Sn, Cu and Zn, for which mean concentrations in the urban environment are two to three times higher than those observed in the rural environment. This is a typical indicator suite of urban soil pollution reported in several other cities in the UK also (Fordyce et al., 2005[15])

    Sources, mobility and bioaccessibility of potentially harmful elements in UK soils

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    Potentially harmful elements (PHE) occur both naturally from geogenic sources and from anthropogenic derived pollution. Anthropogenic sources can be further categorised into those derived from point sources. A point source is a single identifiable source which is confined to a very small area such as that arising from disposal of waste material or from an industrial plant. Diffuse pollution arises where substances are widely used and dispersed over an area as a result of land use activities, often associated with urban development. Examples of diffuse pollution include atmospheric deposition of contaminants arising from industry, domestic coal fires and traffic exhaust, and disposal of domestic coal ash. The total concentration and the chemical form and hence the mobility of the PHE in a soil is highly dependent on the source

    Geological controls on radon potential in Northern Ireland

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    Moderate and high radon potential in Northern Ireland is associated mainly with (i) the Neoproterozoic psammites, semipelites, meta-limestones, volcanics and mafic intrusives of Counties Londonderry and Tyrone; (ii) Silurian Hawick Group greywackes and, to a much more limited extent Gala Group greywackes, in the southern sector of Counties Armagh and Down; (iii) Ordovician and Silurian acid intrusives and volcanics in eastern Counties Londonderry and Tyrone; (iv) Middle-Late Devonian conglomerates in County Tyrone; (v) Lower Carboniferous (Dinantian) limestone in the western sector of Northern Ireland, especially in County Fermanagh; (vi) Palaeogene and Late Caledonian acid intrusive rocks of the Mourne Mountains Complex, Slieve Gullion Complex and Newry Granodiorite Complex in the SE sector in County Down and County Armagh. Moderate to high radon potential is sometimes associated with glacio-fluvial sand and gravel deposits where these overlie a range of bedrocks, some of which have relatively low radon potential. In this latter case the enhanced radon potential is probably caused by the high permeability of superficial deposits. Radon potential tends to be lower when bedrocks characterised by moderate or high radon potential are overlain by relatively impermeable silt-clay alluvium, glaciolacustrine, and lacustrine deposits; peat; and glacial till and moraine. Redistribution of rock debris derived from uranium-rich bedrocks, such as the Mourne Mountains granites, through glacial, alluvial and other processes can also result in higher radon potential being associated with superficial deposits relative to underlying bedrock
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