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Community gardens and allotments are being trialled as a nature-based solution to mitigate multiple health and social, economic, and environmental/climate issues in Belfast. However, working in close proximity to urban lead-contaminated soils and ingestion of site-grown produce may pose significant health risks to community members unless remediating action is undertaken. Current research indicates that organic soil amendments adsorb common urban metal contaminants, particularly lead, and thus may limit plant/crop uptake and consequent human health risks after ingestion. This research seeks to investigate health risks associated with ingesting soils and vegetables grown in lead-contaminated and biochar-remediated soils in Lower Botanic Gardens, Belfast, using controlled pot experiments and concurrent field plots. Pots and plots will comprise combinations of high and low lead concentrations in soil, high and low lead concentrations in soil amended with 5%w/w biochar, and seeded with leaf (lettuce), bulb (garlic), and root (carrot) vegetables. Following a standard growth period, the pre- and post-growth soils, and vegetables will be tested using the Unified BARGE Method in vitro bioaccessibility methodology to determine the bioaccessible fraction for lead derived from soils and vegetables with and without biochar remediation. This will then give an indication of ingestion risk associated with biochar-amended and non-amended lead-contaminated soils, and different soil-grown vegetables. It is anticipated that there may be a mild-moderate risk of lead absorption in the gut after ingestion of non-amended contaminated soils; followed by a reduced risk posed by ingestion of site-grown vegetables with a risk hierarchy of carrot > garlic > lettuce; and a further reduced risk from produce grown in biochar-amended soils. These results would support the use of soil amendments to improve the scope of greening nature-based solutions on typically unfeasible contaminated sites, with the ultimate goal of enhancing health and social, economic, and environmental/climate conditions in urban areas.

To identify factors that patients consider when choosing between future in-person, video, or telephone visits.Telemedicine has been rapidly integrated into ambulatory neurology in response to the COVID-19 pandemic.Ambulatory neurology patients at a single center were contacted via telephone to complete: (1) a survey quantifying likelihood of scheduling a future telemedicine visit, and (2) a semi-structured qualitative interview following their visit in March 2021. Data were processed using the principles of thematic analysis.Of 2493 visits, 39% assented to post-visit feedback; 74% were in-person visits and 13% video and telephone. Patients with in-person visits were less likely than those with video and telephone visits to "definitely" consider a future telemedicine visit (36 vs. 59 and 62%, respectively; p 0.001). Patients considered five key factors when scheduling future visits: "Pros of Visit Type," "Barriers to Telemedicine," "Situational Context," "Inherent Beliefs," and "Extrinsic Variables." Patients with telemedicine visits considered convenience as a pro, while those with in-person visits cited improved quality of care. Accessibility and user familiarity were considered barriers to telemedicine by patients with in-person and telephone visits, whereas system limitations were prevalent among patients with video visits. Patients agreed that stable conditions can be monitored via telemedicine, whereas physical examination warrants an in-person visit. Telemedicine was inherently considered equivalent to in-person care by patients with telephone visits. Awareness of telemedicine must be improved for patients with in-person visits.Across visit types, patients agree that telemedicine is convenient and effective in many circumstances. Future care delivery models should incorporate the patient perspective to implement hybrid models where telemedicine is an adjunct to in-person visits in ambulatory neurology.

Chronic kidney disease (CKD), a collective term for many causes of progressive renal failure, is increasing worldwide due to ageing, obesity and diabetes. However, these factors cannot explain the many environmental clusters of renal disease that are known to occur globally. This study uses data from the UK Renal Registry (UKRR) including CKD of uncertain aetiology (CKDu) to investigate environmental factors in Belfast, UK. Urbanisation has been reported to have an increasing impact on soils. Using an urban soil geochemistry database of elemental concentrations of potentially toxic elements (PTEs), we investigated the association of the standardised incidence rates (SIRs) of both CKD and CKD of uncertain aetiology (CKDu) with environmental factors (PTEs), controlling for social deprivation. A compositional data analysis approach was used through balances (a special class of log contrasts) to identify elemental balances associated with CKDu. A statistically significant relationship was observed between CKD with the social deprivation measures of employment, income and education (significance levels of 0.001, 0.01 and 0.001, respectively), which have been used as a proxy for socio-economic factors such as smoking. Using three alternative regression methods (linear, generalised linear and Tweedie models), the elemental balances of Cr/Ni and As/Mo were found to produce the largest correlation with CKDu. Geogenic and atmospheric pollution deposition, traffic and brake wear emissions have been cited as sources for these PTEs which have been linked to kidney damage. This research, thus, sheds light on the increasing global burden of CKD and, in particular, the environmental and anthropogenic factors that may be linked to CKDu, particularly environmental PTEs linked to urbanisation. The Tellus Project was funded by the Department of Enterprise, Trade and Investment (NI) and by the ‘Building Sustainable Prosperity’ fund of the EU Regional Development Programme. Chemical analysis of the urban soil samples was co-financed by the Northern Ireland Environment Agency. The Northern Ireland Statistics and Research Agency (NISRA) is thanked for providing the multiple deprivation measures (MDMs). The study received ethics approval in March 2018, NHS National Research Ethics Committee REC reference: 15/EM/0366. We thank all the UK Renal Centres for providing data to the UK Renal Registry. The views and opinions expressed in this article are those of the authors and do not reflect the views of the UK Renal Registry or UK Renal Association. JJE and VPG received financial support through the project METhods for COmpositional analysis of DAta (CODAMET), Ministerio de Ciencia, Innovación y Universidades, Spain (Ref: RTI2018-095518-B-C21/C22, 2019-2021).

Recent reviews of the impact of air pollution on human health have shown scientific evidence for the detrimental effects of air pollutants, including environmental toxins which may become blood-borne and translocate to tissues such as the liver, brain and kidney. Atmospheric pollution deposition from traffic and brake wear emissions have been discovered to be important potential sources of toxic metals including arsenic (As), cadmium (Cd), iron (Fe), molybdenum (Mo), lead (Pb), tin (Sn), antimony (Sb), Uranium (U) and Zinc (Zn). Chronic kidney disease (CKD), a collective term for many causes of progressive renal failure, is increasing worldwide due to ageing and a general increase in obesity and diabetes. CKD attributed to unknown aetiology (termed CKDu) is an increasing issue globally with the occurrence of geographic clusters appearing to suggest potential underlying environmental causes of CKDu. This study uses data from the UK Renal Registry including Chronic Kidney Disease of uncertain aetiology (CKDu) to investigate the impact of environmental toxins including air pollution data on human health. Using an urban soil geochemistry database of total element concentrations of potentially toxic elements (PTEs), we examine the spatial statistical relationship between Standardised Incidence Rates (SIRs) of CKDu with environmental toxins and air pollution data. A compositional data analysis approach is used with the use of balances (a special class of log contrasts) to find an elemental balance associated with CKD and CKDu. Using a compositional data analysis approach, informed by the selected PTEs and air pollution balance approach, regression analysis (using glm with log link) reveal a statistically significant correlation between CKD for all SIRs for the age group >16 years and the identified balance of Mo/Zn (significance level of 0.001) and the MDM domains of employment, income and health (significance levels of 0.001, 0.01 and 0.05 respectively). Results from the compositional balance approach indicate an association with the air pollutants SO2, CO, Benzene, PM10 and PM2.5. However, the relationship between CKD for all SIRs >16 years and these air pollutants was not found to be statistically significant. The findings from this work allow a greater understanding of the link between human health and environmental toxins from anthropogenic sources including air pollution.

Significance MRI data suggest that the thickness of the human cortex appears to decrease during childhood development. However, the underlying microstructural mechanisms are unknown. Using multiple quantitative neuroimaging methods that are sensitive to microstructural tissue content, we found that gray matter tissue and its adjacent white matter in high-level visual cortex show tissue growth related to myelination. Increased myelin alters the contrast between gray and white matter in MRI images and, in turn, affects the apparent cortical boundary. These findings are important because they suggest that cortex does not thin during childhood but instead gets more myelinated. Our data impact understanding of typical and atypical brain development, and clinical conditions implicating myelin including dyslexia, autism, and multiple sclerosis., Human cortex appears to thin during childhood development. However, the underlying microstructural mechanisms are unknown. Using functional magnetic resonance imaging (fMRI), quantitative MRI (qMRI), and diffusion MRI (dMRI) in children and adults, we tested what quantitative changes occur to gray and white matter in ventral temporal cortex (VTC) from childhood to adulthood, and how these changes relate to cortical thinning. T1 relaxation time from qMRI and mean diffusivity (MD) from dMRI provide independent and complementary measurements of microstructural properties of gray and white matter tissue. In face- and character-selective regions in lateral VTC, T1 and MD decreased from age 5 to adulthood in mid and deep cortex, as well as in their adjacent white matter. T1 reduction also occurred longitudinally in children’s brain regions. T1 and MD decreases 1) were consistent with tissue growth related to myelination, which we verified with adult histological myelin stains, and 2) were correlated with apparent cortical thinning. In contrast, in place-selective cortex in medial VTC, we found no development of T1 or MD after age 5, and thickness was related to cortical morphology. These findings suggest that lateral VTC likely becomes more myelinated from childhood to adulthood, affecting the contrast of MR images and, in turn, the apparent gray–white boundary. These findings are important because they suggest that VTC does not thin during childhood but instead gets more myelinated. Our data have broad ramifications for understanding both typical and atypical brain development using advanced in vivo quantitative measurements and clinical conditions implicating myelin.

The occurrence of environmental clusters of Chronic Kidney Disease of uncertain aetiology (CKDu), where there is no known cause for the onset of kidney dysfunction, is a concern globally. Waterborne exposure pathways in the environment may result in indirect or direct ingestion of trace elements with potential health risks. This research examines the relationship between Standardised Incidence Rates (SIRs) of CKDu and the log-ratio balances of Potentially Toxic Elements (PTEs) in regional stream water. Compositional elemental balances were created and regression was used to identify the balances most associated with log-transformed SIR CKDu. At the regional scale, a statistically significant relationship was found between log (CKDu SIR) and the elemental balance Al/As which effectively delineates different geological domains across Northern Ireland. Following stratification by basalt bedrock (the dominant bedrock geology for SIR CKDu), the balance Al/Fe was identified as significantly associated with log (CKDu SIR). Superficial deposits, dissolved organic carbon and pH may act as controls on the balance of Al and Fe. With a high proportion of private water supplies registered in these areas, this research highlights the importance of considering bedrock geology and superficial deposits in understanding multi-element interactions of waterborne environmental toxins and potential links with environmental clusters of CKDu. We would like to acknowledge and thank our esteemed colleague and friend Vera Pawlowsky-Glahn who has been instrumental in the development of this research, pioneering the importance of Compositional Data Analysis (CoDA) in the study of health and the environment. For several of us, Vera provided our first introduction to CoDA and over many years has aided our shared understanding and increased awareness of the need to address the compositional nature of data such as soil and water geochemistry in our research. We are pleased to have this work on the use of compositional balances in exploring the explanatory environmental factors related to chronic kidney disease of uncertain aetiology included in this Festschrift. It represents an exciting field of innovative research where an acknowledgement of CoDA principles is vital if we are to understand fully the critical relationship between our health and the environment.

The waste rock, tailings and soil around an abandoned mine site in Gorno (northwest Italy) contain elevated concentrations of potentially toxic elements (PTE) exceeding the permissible limits for residential uses. Specifically, the maximum concentrations of As, Cd, Pb, and Zn were 107 mg/kg, 340 mg/kg, 1064 mg/kg, and 148 433 mg/kg, respectively. A site-specific human health risk assessment (HHRA) was conducted for residential and recreational exposure scenarios, using an approach based on Risk Based Corrective Action (RBCA) method, refined by incorporating oral bioaccessibility data. Oral bioaccessibility analyses were performed by simulating the human digestion process in vitro (Unified BARGE Method). Detailed analysis of oral bioaccessible fraction (BAF i.e. ratio of bioaccessible concentrations to total concentrations on 1) for 50% of the samples, indicating potential human health risks. This study provides information for site-specific risk assessments and planning future research.

This research uses an urban soil geochemistry database of elemental concentration to examine the potential relationship between Standardised Incidence Rates (SIRs) of Chronic Kidney Disease (CKD) of uncertain aetiology (CKDu), and cumulative low level geogenic and diffuse anthropogenic contamination of soils with PTEs. A compositional data analysis approach was applied to determine the elemental balance(s) of the geochemical data showing the greatest association with CKDu. The research concludes that both anthropogenic and geogenic factors may be contributing influences to explain high incidences of CKDu, up to 12 times greater in some Super Output Areas (SOAs) than would be expected for the average population. The role of As, Cr, Cu, Pb, Sb and Mo was highlighted, which may be linked to anthropogenic sources such as historical industrial sources, atmospheric pollution deposition and brake emissions. Geogenic factors were shown to be important in areas with elevated relative concentrations of naturally occurring potentially toxic elements (PTEs).

Antibiotic resistance genes (ARGs) constitute emerging environmental pollutants and pose risks to public health. Toxic metals are known to select for metal-resistant bacteria in metal-contaminated soils, but there is growing concern that metal contaminants can also act as co-selective agents thereby causing environmental proliferation of antibiotic resistance. In this study, we quantified ARGs and selected mobile genetic elements (MGEs) known to constitute potential ARG hosts in 50 archived urban and suburban soils from the Belfast metropolitan area using a high-throughput qPCR ARG chip. ARG prevalence was linked to concentrations of individual metals and a soil metal toxicity index calculated based on the relative toxicity of different metals to soil microbial processes. A total of 164 ARGs were detected across the 50 soils analyzed with an average absolute abundance of 3.4 × 107 ARG gene copies per gram of soil. A significant correlation between abundance of ARGs and MGEs was observed, suggesting the importance of horizontal gene transfer for ARG dissemination. Network analysis revealed significant co-occurrence patterns between specific metals (As, Cd, Co, Cr, Cu. Hg, Ni and Zn) and associated ARGs. Path analysis further indicated that the soil metal toxicity index significantly affected the number of detected ARGs (λ = 0.32, P < 0.001) and the abundance of metal co-occurring ARGs (λ = 0.612, P < 0.001) via effects on MGEs. Collectively, our results indicate a role of soil metals in co-selection of ARGs and MGEs in urban and semi-urban soils and suggest a risk for environmental ARG dissemination via horizontal gene transfer.

Microstructural mechanisms underlying apparent cortical thinning during childhood development are unknown. Using functional, quantitative, and diffusion magnetic resonance imaging in children and adults, we tested if tissue growth (lower T1 relaxation time and mean diffusivity (MD)) or pruning (higher T1 and MD) underlies cortical thinning in ventral temporal cortex (VTC). After age 5, T1 and MD decreased in mid and deep cortex of functionally-defined regions in lateral VTC, and in their adjacent white matter. T1 and MD decreases were (i) consistent with tissue growth related to myelin proliferation, which we verified with adult postmortem histology and (ii) correlated with apparent cortical thinning. Thus, contrary to prevailing theories, cortical tissue does not thin during childhood, it becomes more myelinated, shifting the gray-white matter boundary deeper into cortex. As tissue growth is prominent in regions with protracted functional development, our data suggest an intriguing hypothesis that functional development and myelination are interlinked.

Inductively coupled plasma (ICP) following aqua regia digestion and X-ray fluorescence (XRF) are both geochemical techniques used to determine 'total' concentrations of elements in soil. The aim of this study is to compare these techniques, identify elements for which inconsistencies occur and investigate why they arise. A study area (∼14,000 km(2)) with a variety of total concentration controls and a large geochemical dataset (n = 7950) was selected. Principal component analysis determined underlying variance in a dataset composed of both geogenic and anthropogenic elements. Where inconsistencies between the techniques were identified, further numerical and spatial analysis was completed. The techniques are more consistent for elements of geogenic sources and lead, whereas other elements of anthropogenic sources show less consistency within rural samples. XRF is affected by sample matrix, while the form of element affects ICP concentrations. Depending on their use in environmental studies, different outcomes would be expected from the techniques employed, suggesting the choice of analytical technique for geochemical analyses may be more critical than realised.

Geogenic nickel (Ni), vanadium (V) and chromium (Cr) are present at elevated levels in soils in Northern Ireland. Whilst Ni, V and Cr total soil concentrations share common geological origins, their respective levels of oral bioaccessibility are influenced by different soil-geochemical factors. Oral bioaccessibility extractions were carried out on 145 soil samples overlying 9 different bedrock types to measure the bioaccessible portions of Ni, V and Cr. Principal component analysis identified two components (PC1 and PC2) accounting for 69% of variance across 13 variables from the Northern Ireland Tellus Survey geochemical data. PC1 was associated with underlying basalt bedrock, higher bioaccessible Cr concentrations and lower Ni bioaccessibility. PC2 was associated with regional variance in soil chemistry and hosted factors accounting for higher Ni and V bioaccessibility. Eight percent of total V was solubilised by gastric extraction on average across the study area. High median proportions of bioaccessible Ni were observed in soils overlying sedimentary rock types. Whilst Cr bioaccessible fractions were low (max = 5.4%), the highest measured bioaccessible Cr concentration reached 10.0 mg kg−1, explained by factors linked to PC1 including high total Cr concentrations in soils overlying basalt bedrock.

Underlying bedrock is often the source of elevated levels of potentially toxic elements (PTEs) (including Ni and Cr) in soils, which can be at concentrations exceeding regulatory guidelines for the protection of human health. However geogenic contaminants are often not significantly bioavailable to humans as they are bound tightly within the soil matrix. Therefore oral bioaccessibility testing can be used to refine human health risk assessment by quantifying bioaccessible PTEs in soils, but should be augmented with soil mineralogy data to support its use in risk assessment. Elemental mapping using Electro Probe Microanalysis (EPMA) and mineralogical mapping using QEMSCAN®, an automated mineral/phase analysis system based on a scanning electron microscope, were combined with quantitative X-ray Diffraction (XRD) and previous oral bioaccessibility and non-specific sequential extraction (CISED) results for 3 soil samples overlying Palaeogene basalt lavas in Northern Ireland, to determine the effect of soil mineralogy on oral bioaccessibility of Ni and Cr. Results indicate that Cr concentrations are principally related to recalcitrant chrome spinel and primary iron oxides, which explains the relatively low bioaccessibility of Cr. In contrast, Ni is more widely dispersed within the soils, with a proportion of total Ni found in carbonates and weathering products, including secondary iron oxides and precursor clay minerals, leading to the higher oral bioaccessibility measurements recorded for Ni than Cr.

Increasing urbanisation has a direct impact on soil quality, resulting in elevated concentrations of potentially toxic elements (PTEs) in soils. This research aims to assess if soil PTE concentrations can be used as an ‘urbanisation tracer’ by investigating geogenic and anthropogenic source contributions and controls, and considering PTE enrichment across historical urban development zones. The UK cities of Belfast and Sheffield are chosen as study areas, where available shallow and deep concentrations of PTEs in soil are compared to identify geogenic and anthropogenic contributions to PTEs. Cluster analysis and principal component analysis are used to elucidate the main controls over PTE concentrations. Pollution indices indicate that different periods of historical development are linked to enrichment of different PTEs. Urban subdomains are identified and background values calculated using various methodologies and compared to generic site assessment criteria. Exceedances for a number of the PTEs considered suggest a potential human health risk could be posed across subdomains of both Belfast and Sheffield. This research suggests that airborne diffuse contamination from often historical sources such as traffic, domestic combustion and industrial processes contribute greatly to soil contamination within urban environments. The relationship between historical development and differing PTEs is a novel finding, suggesting that PTEs have the potential for use as ‘urbanisation tracers’. The investigative methodology employed has potential applications for decision makers, urban planners, regulators and developers of urban areas.

Correlation analyses were conducted on nickel (Ni), vanadium (V) and zinc (Zn) oral bioaccessible fractions (BAFs) and selected geochemistry parameters to identify specific controls exerted over trace element bioaccessibility. BAFs were determined by previous research using the unified BARGE method. Total trace element concentrations and soil geochemical parameters were analysed as part of the Geological Survey of Northern Ireland Tellus Project. Correlation analysis included Ni, V and Zn BAFs against their total concentrations, pH, estimated soil organic carbon (SOC) and a further eight element oxides. BAF data were divided into three separate generic bedrock classifications of basalt, lithic arenite and mudstone prior to analysis, resulting in an increase in average correlation coefficients between BAFs and geochemical parameters. Sulphur trioxide and SOC, spatially correlated with upland peat soils, exhibited significant positive correlations with all BAFs in gastric and gastro-intestinal digestion phases, with such effects being strongest in the lithic arenite bedrock group. Significant negative relationships with bioaccessible Ni, V and Zn and their associated total concentrations were observed for the basalt group. Major element oxides were associated with reduced oral trace element bioaccessibility, with Al2O3 resulting in the highest number of significant negative correlations followed by Fe2O3. spatial mapping showed that metal oxides were present at reduced levels in peat soils. The findings illustrate how specific geology and soil geochemistry exert controls over trace element bioaccessibility, with soil chemical factors having a stronger influence on BAF results than relative geogenic abundance. In general, higher Ni, V and Zn bioaccessibility is expected in peat soil types.

The production of Portland cement is well acknowledged as having as significant impact on the environment, accounting for 8% of global CO2 emissions (4bn tonnes per annum). Concrete is the most widely used material in the world and therefore has vast potential to absorb high volumes of waste and by-product materials. These materials can act as partial replacements as supplementary cementitious materials or total replacements and perform as binders in geopolymer concretes. The use of Pulverised Fuel Ash (PFA) from coal-fired electricity generating stations to substitute Ordinary Portland Cement (OPC) is well established. Quantifying the potential environmental benefit of using such materials can be difficult. The life cycle assessment (LCA) methodology, internationally standardised through ISO14040 series, may be used to quantify the environmental impact of products and processes. This paper outlines the use of the LCA methodology to compare the environmental impact of OPC precast concrete products to PFA precast concrete products in a Malaysian context. The four stages of LCA are detailed and consequences of designating materials as a by-product or waste are discussed. A review of other LCA studies completed in Malaysia for the built environment are also presented so as to identify which impact assessment methods are most frequently used.

Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg(-1)) and mineralisation (199.8 mg kg(-1)) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg(-1)) and granite (36.0 mg kg(-1)) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land.

We compare a suite of Polycyclic Aromatic Hydrocarbons (Parent PAHs) in soils and air across an urban area (Belfast UK). Isomeric PAH ratios suggest that soil PAHs are mainly from a combustion source. Fugacity modelling across a range of soil temperatures predicts that four ring and larger PAHs from pyrene to indeno[1,2,3–cd]pyrene all partition strongly (>98%) to the soil compartment. This modelling also implies that these PAHs do not experience losses through partitioning to other phases (air, water) due to soil temperature effects. Such modelling may help in understanding the overall contaminant distribution in soils. The air and soil data together with modelling suggests that care must be taken when considering isomeric ratios of compounds with mass lighter than 178 (i.e. phenanthrene and anthracene) in the soil phase. Comparison of duplicate and replicate samples suggest that field sampling of duplicates dominates uncertainty and validated methodologies for selection of field duplicates and lab splitting are required. As the urban soil four ring PAHs are at equilibrium in the soil phase, and have characteristic ratios that are dominated by a combustion source that is a single controlling factor over spatial distribution, methods that calculate background concentrations can be compared.

The environmental quality of land can be assessed by calculating relevant threshold values, which differentiate between concentrations of elements resulting from geogenic and diffuse anthropogenic sources and concentrations generated by point sources of elements. A simple process allowing the calculation of these typical threshold values (TTVs) was applied across a region of highly complex geology (Northern Ireland) to six elements of interest; arsenic, chromium, copper, lead, nickel and vanadium. Three methods for identifying domains (areas where a readily identifiable factor can be shown to control the concentration of an element) were used: k-means cluster analysis, boxplots and empirical cumulative distribution functions (ECDF). The ECDF method was most efficient at determining areas of both elevated and reduced concentrations and was used to identify domains in this investigation. Two statistical methods for calculating normal background concentrations (NBCs) and upper limits of geochemical baseline variation (ULBLs), currently used in conjunction with legislative regimes in the UK and Finland respectively, were applied within each domain. The NBC methodology was constructed to run within a specific legislative framework, and its use on this soil geochemical data set was influenced by the presence of skewed distributions and outliers. In contrast, the ULBL methodology was found to calculate more appropriate TTVs that were generally more conservative than the NBCs. TTVs indicate what a "typical" concentration of an element would be within a defined geographical area and should be considered alongside the risk that each of the elements pose in these areas to determine potential risk to receptors.

Potentially toxic elements (PTEs) including nickel and chromium are often present in soils overlying basalt at concentrations above regulatory guidance values due to the presence of these elements in underlying geology. Oral bioaccessibility testing allows the risk posed by PTEs to human health to be assessed; however, bioaccessibility is controlled by factors including mineralogy, particle size, solid-phase speciation and encapsulation. X-ray diffraction was used to characterise the mineralogy of 12 soil samples overlying Palaeogene basalt lavas in Northern Ireland, and non-specific sequential extraction coupled with chemometric analysis was used to determine the distribution of elements amongst soil components in 3 of these samples. The data obtained were related to total concentration and oral bioaccessible concentration to determine whether a relationship exists between the overall concentrations of PTEs, their bioaccessibility and the soils mineralogy and geochemistry. Gastric phase bioaccessible fraction (BAF %) ranged from 0.4 to 5.4 % for chromium in soils overlying basalt and bioaccessible and total chromium concentrations are positively correlated. In contrast, the range of gastric phase BAF for nickel was greater (1.4–43.8 %), while no significant correlation was observed between bioaccessible and total nickel concentrations. However, nickel BAF was inversely correlated with total concentration. Solid-phase fractionation information showed that bioaccessible nickel was associated with calcium carbonate, aluminium oxide, iron oxide and clay-related components, while bioaccessible chromium was associated with clay-related components. This suggests that weathering significantly affects nickel bioaccessibility, but does not have the same effect on the bioaccessibility of chromium.

This study is the first investigation of biodegradation of carbon disulphide (CS2) in soil that provides estimates of degradation rates and identifies intermediate degradation products and carbon isotope signatures of degradation. Microcosm studies were undertaken under anaerobic conditions using soil and groundwater recovered from CS2-contaminated sites. Proposed degradation mechanisms were validated using equilibrium speciation modelling of concentrations and carbon isotope ratios. A first-order degradation rate constant of 1.25 × 10-2 h-1 was obtained for biological degradation with soil. Carbonyl sulphide (COS) and hydrogen sulphide (H2S) were found to be intermediates of degradation, but did not accumulate in vials. A 13C/12C enrichment factor of -7.5 ± 0.8 ‰ was obtained for degradation within microcosms with both soil and groundwater whereas a 13C/12C enrichment factor of -23.0 ± 2.1 ‰ was obtained for degradation with site groundwater alone. It can be concluded that biological degradation of both CS2-contaminated soil and groundwater is likely to occur in the field suggesting that natural attenuation may be an appropriate remedial tool at some sites. The presence of biodegradation by-products including COS and H2S indicates that biodegradation of CS2 is occurring and stable carbon isotopes are a promising tool to quantify CS2 degradation.

Oral bioaccessibility and solid phase distribution of potentially toxic elements (PTE) from extractive waste streams were investigated to assess the potential human health risk posed by abandoned mines. The solid phase distribution along with micro-X-ray fluorescence (micro-XRF) and scanning electron microscopy (SEM) analysis were also performed. The results showed that the total concentrations of PTE were higher in

Mining activities have led to the introduction of high levels of heavy metal (HM) concentrations in soils. This has attracted governmental and public attention due to their non-biodegradable nature and hazards posed to human health and the environment. However, total concentrations of HM are poor indicators of actual risk hazard to human health and can lead to overestimation of risk. In this study, oral bioaccessibility (the fraction available for absorption via oral ingestion), was used to refine human health risk assessment. Solid phase distribution of the HM was also investigated to characterize HM distribution and behavior in the extractive waste streams and impacted soil. The study was undertaken at an abandoned mine site from Campello Monti, in the Southern Italian Alps used for Ni exploitation from 1863 to 1940s. The results showed that total concentrations of HM were high and reached upto 7400 mg/kg for Ni due to parent material, however, only 11% was bioaccessible. Detailed analysis showed that the bioaccessible fraction (BAF) of Ni, Cu and As varied from 0.5 to 21%, 2 to 47%, and 7 to 28%, respectively. The variation can be attributed to the difference in pH, organic matter content and mineralogical composition of the samples. Results of non-specific sequential extraction showed that non-mobile forms of the elements were associated with the residual and Fe-oxides components of the matrix. The present study highlights that including bioaccessibility and solid phase distribution can refine and inform risk assessment of abandoned mine sites.

The production of Portland cement is well acknowledged as having a significant impact on the environment, accounting for 8% of global CO2 emissions (4bn tonnes per annum). Concrete is the most widely used man-made material in the world and therefore has a vast potential to absorb high volumes of waste and by-product materials. These materials can act as partial replacements, i.e. supplementary cementitious materials, or total replacements and be the cement-like precursors for geopolymer concretes. The LowCoPreCon project brings together academic and industrial partners from the UK and Malaysia with the aim of identifying available waste streams with which to manufacture geopolymer concretes on a commercial scale. Initial laboratory work was conducted by academic partners to design geopolymer concretes that had both optimum strength and workability. These mixes were then used in factory trials to successfully cast structural elements, including building blocks, wall slabs and staircases. To determine the potential environmental benefits of geopolymer concrete, a detailed life cycle assessment will be conducted. Two demonstration projects using the novel material will be constructed in Malaysia; a domestic building and a FlexiArch bridge.