Mapping metallic contamination of soils in the Lower Foyle catchment

Using the Tellus and Tellus Border geochemistry data, the distribution of metals in topsoils in and around Derry–Londonderry has been mapped and assessed. The concentrations of metals have been compared with the UK Environment Agency’s Soil Guideline Values (SGVs). Of 763 samples analysed, only 11 samples exceed the SGV for arsenic and two for that of cadmium. Of these 13 sites, only two were within an urban area. Concentrations of metal in the rural sub-catchments appear to be mainly determined by the underlying geology. Using a geographic information system (GIS) and multi-element plots (spidergrams) for analysis, the geological background was modelled at a sub-catchment scale in order to determine whether high soil metal concentrations were of natural origin or a consequence of anthropogenic activities. The level of enrichment due to contamination was calculated for 12 metals and metalloids. In the urban area of Derry–Londonderry, levels of arsenic, cadmium and seven other elements are slightly enhanced due to anthropogenic activities. However, as the enrichment factors do not exceed a factor of 3 these enhancements are classified as minor. Possible modern and historic sources of contamination are likely to be buildings, households and waste disposal, hospitals and medical facilities, surface run-off from road traffic, manufacturing industries, coal disposal and sewage works

Extremely high He isotope ratios in MORB-source mantle from the proto-Iceland plume

The high <sup>3</sup>He/<sup>4</sup>He ratio of volcanic rocks thought to be derived from mantle plumes is taken as evidence for the existence of a mantle reservoir that has remained largely undegassed since the Earth's accretion. The helium isotope composition of this reservoir places constraints on the origin of volatiles within the Earth and on the evolution and structure of the Earth's mantle. Here we show that olivine phenocrysts in picritic basalts presumably derived from the proto-Iceland plume at Baffin Island, Canada, have the highest magmatic <sup>3</sup>He/<sup>4</sup>He ratios yet recorded. A strong correlation between <sup>3</sup>He/<sup>4</sup>He and <sup>87</sup>Sr/<sup>86</sup>Sr, <sup>143</sup>Nd/<sup>144</sup>Nd and trace element ratios demonstrate that the <sup>3</sup>He-rich end-member is present in basalts that are derived from large-volume melts of depleted upper-mantle rocks. This reservoir is consistent with the recharging of depleted upper-mantle rocks by small volumes of primordial volatile-rich lower-mantle material at a thermal boundary layer between convectively isolated reservoirs. The highest <sup>3</sup>He/<sup>4</sup>He basalts from Hawaii and Iceland plot on the observed mixing trend. This indicates that a <sup>3</sup>He-recharged depleted mantle (HRDM) reservoir may be the principal source of high <sup>3</sup>He/<sup>4</sup>He in mantle plumes, and may explain why the helium concentration of the 'plume' component in ocean island basalts is lower than that predicted for a two-layer, steady-state model of mantle structure

Geochemistry and related studies of Clyde Estuary sediments

Geochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1 m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity

Human impact on sediment quality in the Clyde post-industrial catchment, Glasgow

Potential chemical contamination of the ground and of watercourses is one of the legacies of the UK’s past industrialisation. Resulting chemical pollution poses current and future threats, as many substances are toxic in high concentrations, and their occurrence could have long-term implications for ecosystems and human health

The chemical quality of the Clyde

Potential chemical contamination of the ground and of watercourses is one of the legacies of the UK’s past industrialisation. Contaminants can be toxic in high concentrations, and so potentially hazardous to people and the environment. It is therefore vital to understand the levels of contaminants to control their environmental impacts and protect the health of communities

Sediment quality in the River Clyde catchment

Chemical pollution from past industrial development poses current and future environmental threats, as many substances are toxic in high concentrations, and could have longterm implications for ecosystems and human health

A case study to identify urban diffuse pollution in the Light Burn Catchment, Glasgow, UK. Stage 3 contribution to: Wade, R et al. (2013) A critical review Of urban diffuse pollution control: methodologies to identify sources, pathways and mitigation measures with multiple benefits. CRW2012/1.

This report is the BGS contribution to Stage 3 of the CRW2012/1 Project ‘A critical review of urban diffuse pollution control: Methodologies to identify sources, pathways and mitigation measures with multiple benefits’. A case study of a typical Scottish urban environment is presented. The report documents work to identify and characterise urban diffuse pollution sources and pathways in a case study stream catchment in Glasgow based on existing information. The findings of this report have been used to support the required research outputs for stages 1, 2 and 3 of the CREW project CRW2012/1

Research summary. A critical review Of urban diffuse pollution control: methodologies to identify sources, pathways and mitigation measures with multiple benefits. CRW2012/1.

The main aim of this research was to inform the development of policy to support implementation of the Water Environment and Water Services (Scotland) Act 2003 and the Flood Risk Management (Scotland) Act (2009). Surface water management in urban areas is increasingly important in policy areas concerned with flooding and pollution, in addition to these policy areas benefits can be realised in health and well-being (through green space provision or improvement), in traffic management, in operation and maintenance delivery (and cost savings) for urban areas, and in biodiversity and climate change planning. Therefore to support guidance on surface water management there is a need to: 1. Develop integrated tools that are relevant to understanding sources, pathways and mitigation of diffuse contaminants. 2. Critically assess which methods best identify sources and pathways for a given urban environment and/or readily available information. 3. Identify mitigation strategies, from source to end-of-pipe that meet the twin challenge of diffuse pollution prevention and multiple benefits in terms of cost, energy and water sustainability