Prokaryotic, Microeukaryotic, and Fungal Composition in a Long-Term Polychlorinated Biphenyl-Contaminated Brownfield.

Polychlorinated biphenyls (PCBs) are recognized as persistent organic pollutants and accumulate in organisms, soils, waters, and sediments, causing major health and ecological perturbations. Literature reported PCB bio-transformation by fungi and bacteria in vitro, but data about the in situ impact of those compounds on microbial communities remained scarce while being useful to guide biotransformation assays. The present work investigated for the first time microbial diversity from the three-domains-of-life in a long-term contaminated brownfield (a former factory land). Soil samples were ranked according to their PCB concentrations, and a significant increase in abundance was shown according to increased concentrations. Microbial communities structure showed a segregation from the least to the most PCB-polluted samples. Among the identified microorganisms, Bacteria belonging to Gammaproteobacteria class, as well as Fungi affiliated to Saccharomycetes class or Pleurotaceae family, including some species known to transform some PCBs were abundantly retrieved in the highly polluted soil samples.

Field assessment of trace element phytoextraction by different Populus clones established on brownfields in southern Quebec (Canada).

Fast-growing hybrid poplars have been tested for their potential to remove trace elements (TE) from polluted soil in several temperate regions. Despite their potential, they have rarely been tested in countries with a cold temperate climate. The current study screened four different Populus hybrids for phytoextraction of four TEs (i.e., As, Cu, Pb, and Zn) on an abandoned brownfield site in southern Quebec (Canada). The main results showed that under the current experimental conditions, the most important traits determining the actual phytoextraction rate are Biological Concentration Factor (BCF) and TE accumulation in the aboveground biomass, rather than biomass productivity. Although the overall performance of the chosen hybrids was rather poor, the presence of poplar stands enhanced the movement of mobile contaminants in soil, which led to an increase in their concentration in the root zone. This aspect suggests possible strategies for using these plants with high transpiration rates in future phytoremediation projects, including either possible rotation with more effective TE phytoextractor plants (e.g., hyperaccumulators) that can remove high TE amounts that have migrated from the deeper soil layers following poplar plantation, or phytostabilization.

Although the use of fast-growing woody species is commonly reported as a feasible option for the phytoextraction of TEs in temperate climates, most available information pertains to only a few species, mostly willows. This is one of the few studies reporting the results of a field test carried out in a cold temperate region, in which different poplar hybrid clones were tested for their potential in TEs phytoextraction. This research determined that although the studied poplar genotypes have no potential under these experimental conditions, the increase in TE concentration observed in the rhizosphere after two years suggests possible alternative phytoremediation strategies (phytostabilization) for managing polluted sites in cold temperate climates.

Digital tools for brownfield redevelopment: Stakeholder perspectives and opportunities.

Brownfield redevelopment is a complex process often involving a wide range of stakeholders holding differing priorities and opinions. The use of digital systems and products for decision making, modelling, and supporting discussion has been recognised throughout literature and industry. The inclusion of stakeholder preferences is an important consideration in the design and development of impactful digital tools and decision support systems. In this study, we present findings from stakeholder consultation with professionals from the UK brownfield sector with the aim of informing the design of future digital tools and systems. Our research investigates two broad themes; digitalisation and the use of digital tools across the sector; and perceptions of key brownfield challenge areas where digital tools could help better inform decision-makers. The methodology employed for this study comprises the collection of data and information using a combination of interviews and an online questionnaire. The results from these methods were evaluated both qualitatively and quantitatively. Findings reveal a disparity in levels of digital capability between stakeholder groups including between technical stakeholder types, and that cross-discipline communication of important issues may be aided by the development of carefully designed digital tools. To this end, we present seven core principles to guide the design and implementation of future digital tools for the brownfield sector. These principles are that future digital tools should be: (1) Stakeholder driven, (2) Problem centred, (3) Visual, (4) Intuitive, (5) Interactive, (6) Interoperable, and (7) Geospatial data driven.

Typical groundwater contamination in the vicinity of industrial brownfields and basic methods of their treatment.

The article deals with simple methods of decontamination of groundwater from the vicinity of brownfields contaminated with organic and inorganic substances. In the literature, thousands of articles on this issue at various sophisticated levels of knowledge can be found. The articles are mostly suitable as an extension of scientific knowledge; however, regarding potential costs and respectively scale-up problems, the applications are limited. It turns out that the vast majority of contaminated water can be effectively decontaminated by simple methods, in a coagulation-sedimentation sequence → simple oxidation and reduction methods for separated water (Fenton reaction, photocatalysis, ozonation, reductive dehalogenation with zero metals) → adsorption of remaining pollutants on simple sorbents, eg on biochar → (possibly bioremediation or advanced physical methods such as membrane filtration) → final purification on activated carbon. Due to the usually limited volume loads of soils with pollutants in the vicinity of brownfields, it is not economically advantageous to build demanding decontamination units for water purification. Usually, the simplest solution is the system to pump-and-treat around the source of contamination, with the main emphasis on highly effective removal of pollutants from water that returns underground. Groundwater was taken from boreholes leading to the saturated zone in the vicinity of several selected industrial brownfields. The solutions are shown on individual typical cases.

Demonstration Laboratory of Industry 4.0 Retrofitting and Operator 4.0 Solutions: Education towards Industry 5.0.

One of the main challenges of Industry 4.0 is how advanced sensors and sensing technologies can be applied through the Internet of Things layers of existing manufacturing. This is the so-called Brownfield Industry 4.0, where the different types and ages of machines and processes need to be digitalized. Smart retrofitting is the umbrella term for solutions to show how we can digitalize manufacturing machines. This problem is critical in the case of solutions to support human workers. The Operator 4.0 concept shows how we can efficiently support workers on the shop floor. The key indicator is the readiness level of a company, and the main bottleneck is the technical knowledge of the employees. This study proposes an education framework and a related Operator 4.0 laboratory that prepares students for the development and application of Industry 5.0 technologies. The concept of intelligent space is proposed as a basis of the educational framework, which can solve the problem of monitoring the stochastic nature of operators in production processes. The components of the intelligent space are detailed through the layers of the IoT in the form of a case study conducted at the laboratory. The applicability of indoor positioning systems is described with the integration of machine-, operator- and environment-based sensor data to obtain real-time information from the shop floor. The digital twin of the laboratory is developed in a discrete event simulator, which integrates the data from the shop floor and can control the production based on the simulation results. The presented framework can be utilized to design education for the generation of Industry 5.0.

Evaluation and Potential Uses of Site Investigation Soil Contamination Data Submitted to Uk Local Government.

There has been considerable brownfield development in the UK since 2000 due to increasing demand for new housing, combined with local opposition to building on greenbelt land. To facilitate this, extensive site investigations have been carried out and the reports submitted to local government as part of the planning process. This research investigates whether this largely untapped resource of site investigation data can be used to improve understanding of potentially toxic elements (PTE) and persistent organic pollutants (POP) at a local scale. The PTE/POP data were extracted from 1707 soil samples across 120 brownfield sites in an urban/suburban region. The samples were analysed to determine the effect of site location, historical use and site age on PTE/POP concentrations. Box plots indicating statistical results together with GIS maps of PTE/POP sample data provided the optimal visualisation of results. The dataset was shown to be a valuable resource, although further exploitation would be enhanced by digitisation of the submitted data. The paper explores potential applications of this data, including background concentrations and anthropogenic enrichment factors for PTE/POP. The results were summarised in a table for the PTE/POP and a preliminary risk assessment process chart to inform developers/regulators on potential PTE/POP levels on brownfield sites on a local scale. This information could focus design and resources for developers for site investigations and risk assessments and improve planning and regulatory guidance. The lack of predictability in PTE/POP results across sites have emphasised the ongoing need for intrusive site investigation on new brownfield developments.

Criteria for Preliminary Risk Assessment of Brownfield Site: An International Survey of Experts.

Comprehensive risk assessment of brownfield sites requires a broad range of knowledge and multi-disciplinary expertise. Whilst the identification of criteria requirements for preliminary risk assessment has received some attention, there appears to be no studies that have specifically examined professional perspectives relating to these requirements. Yet, variations in professional practitioners' assessments may have significant consequences for the assessment of risks, and how the criteria are imparted to stakeholders. This study aims to identify the criteria requirements for preliminary risk assessment, using the pollutant linkage model (Source-Pathway-Receptor), and explores cross-disciplinary professional perspectives related to these requirements. To this end, this study commenced with a systematic review to identify various criteria streams required for the preliminary risk assessment of brownfield sites. Thereafter, a questionnaire survey was design and shared with brownfield site professionals. Quantitative analysis of the survey responses (n = 76) reveals disciplines have markedly different priorities relating to the same hazard. For instance, geophysicists, geochemists, and hydrologists do not raise concerns regarding ground movement that can result from the removal of storage and tanks, whilst the same hazard was considered as having a high importance by other professions (such as geologists and geotechnical engineers). This example, amongst others revealed in the study, underpins potential issues and implications for various stakeholders compiling and/or using preliminary risk assessment criteria. This study clarifies both the key criteria requirements for the preliminary risk assessment of brownfield sites, as well as the importance of recognising how variation in professionals' perceptions plays in the risk assessment process. Although, specialist knowledge is essential for brownfield site investigation, so is the maintaining a broad-based view of other experts coming from different backgrounds, as this renders holistic risk assessment insights.

Heavy metal background levels and pollution temporal trend assessment within the marine sediments facing a brownfield area (Gulf of Pozzuoli, Southern Italy).

In this study, site-specific natural background levels (NBLs) were determined for 18 elements (Al, As, Be, Cd, Co, Cu, Cr, Fe, Hg, K, Mn, Mo, Ni, Pb, Tl, U, V, and Zn) in two sediment cores collected offshore the Bagnoli-Coroglio brownfield site (Gulf of Pozzuoli, southern Italy) to accurately assess the degree of contamination and the historical trends in Heavy Metals (HMs) enrichment. This objective was pursued taking in account the high temporal and spatial variability of the geochemical properties of the area due to the local geothermal activity. Moreover, the temporal variation of Polycyclic Aromatic Hydrocarbons (PAHs) was investigated.226Ra was used as an extraordinary marker to confirm 210Pb dating. It especially allowed defining the geochronological framework of the sediment core closer the brownfield up to around 1500, providing compelling support to correlate the investigated elements' occurrences with natural geogenic dynamic. Sediment samples were accurately dated and analyzed for chemical and particle size composition. The contamination factor (Cf) and the pollution load index (PLI) showed very high enrichment of Cd, Cu, Hg, Pb, and Zn. The contamination profiles of HMs and PAHs follow the same pattern in both sediment cores, increasing from deep to upper layers. The highest contamination levels for HMs and PAHs were observed between 10 and 30 cm, corresponding to the periods of most intense industrial activity. Decreasing trends of pollutants were observed in the surface layers (0-10 cm), probably affected by a natural attenuation process due to the cessation of industrial activities.

Asbestos contamination on brownfield development sites in the UK.

The development of brownfield sites in the UK requires site investigation for contamination as part of the regulatory planning process. This site investigation includes the collection of soil samples that are analysed for asbestos contamination. This research project analyses this untapped resource of brownfield asbestos data, using site investigation data submitted to a local Borough Council, in Surrey, UK. Over 100 site investigation reports were collected. This paper presents the trends in asbestos testing from 2001 to 2019 and data on the location, concentration, form and type of asbestos found in this Borough. The rate of asbestos detection has increased significantly, reflecting improvements in asbestos measuring techniques, to a rate of 22% for all samples tested between 2016 and 2019. The concentrations of asbestos found were very low, with 74% of samples having concentrations below the limit of detection of the laboratory and were predominantly of fibrous form. A significant proportion of samples contained more carcinogenic amphibole type. Most of the asbestos was found in the top 1 m of Made Ground soil. Site history was found to be important with gas works having the highest asbestos detection rate, though a detection rate of 10% was found in soil samples on former residential sites. This information is important to inform and update risk assessment for site workers and site remediation in relation to asbestos. Hence based upon these results, a qualitative risk chart for asbestos is presented to provide guidance and in-sight into asbestos on brownfield sites for local authorities and developers.

Comparison of the effectiveness of biochar vs. magnesite amendments to immobilize metals and restore a polluted soil.

Here we addressed the remediation of a soil severely contaminated by Cu, Cd, Pb and Zn. In this regard, we tested the capacity of magnesite and biochar, inorganic and organic soil amendments, respectively, to reduce metal availability and improve soil properties. To this end, 1-kg pots containing the polluted soil were amended with either magnesite or biochar. Metal availability and soil properties were then measured at days 15 and 75. Also, to evaluate the impact of the two treatments on plant growth, we conducted experimental trials with Brassica juncea L. and compost addition. Both amendments, but particularly magnesite, markedly decreased metal availability. Soil properties were also enhanced, as reflected by increases in the cation exchangeable capacity. However, plant growth was inhibited by magnesite amendment. This observation could be attributable to an increase in soil pH and cation exchange capacity as well as a high Mg concentration. In contrast, biochar increased biomass production but decreased the quantity of metals recovered when the plants are harvested. In conclusion, on the basis of our results, we propose magnesite as a suitable approach for stabilizing contaminated soils (or even spoil heaps) where revegetation is not a priority. In contrast, although biochar has a lower, but still significant, capacity to immobilize metals, it can be used to restore natural soil properties and thus favor plant growth.

Thermal desorption treatment of petroleum hydrocarbon-contaminated soils of tundra, taiga, and forest steppe landscapes.

The results of field, analytical, and experimental research at a number of production facilities reflect the properties of oil-contaminated soils in 3 landscapes: the permafrost treeless Arctic ecosystem, boreal forest, and temperate-climate grassland-woodland ecotone. Laboratory studies have revealed the concentrations of petroleum hydrocarbons in soils, ranging from medium levels of 2000-3000 mg/kg to critical figures over 5000 mg/kg, being 2-25 times higher than the permissible content of oil products in soils. The experimentally applied thermal effects for the oil products desorption from the soil allowed finding an optimal regime: the treatment temperature from 25 to 250 °C reduces the concentrations to an acceptable value. The conditions are environmentally sound, given that the complete combustion point of humates is ca. 450 °C. The outcomes suggest the eco-friendly solution for soil remediation, preserving the soil fertility in fragile cold environments and in more resilient temperate climates, where revitalized brownfields are essential for food production.

Effects of Brownfield Remediation on Total Gaseous Mercury Concentrations in an Urban Landscape.

In order to obtain a better perspective of the impacts of brownfields on the land-atmosphere exchange of mercury in urban areas, total gaseous mercury (TGM) was measured at two heights (1.8 m and 42.7 m) prior to 2011-2012 and after 2015-2016 for the remediation of a brownfield and installation of a parking lot adjacent to the Syracuse Center of Excellence in Syracuse, NY, USA. Prior to brownfield remediation, the annual average TGM concentrations were 1.6 ± 0.6 and 1.4 ± 0.4 ng · m - 3 at the ground and upper heights, respectively. After brownfield remediation, the annual average TGM concentrations decreased by 32% and 22% at the ground and the upper height, respectively. Mercury soil flux measurements during summer after remediation showed net TGM deposition of 1.7 ng · m - 2 · day - 1 suggesting that the site transitioned from a mercury source to a net mercury sink. Measurements from the Atmospheric Mercury Network (AMNet) indicate that there was no regional decrease in TGM concentrations during the study period. This study demonstrates that evasion from mercury-contaminated soil significantly increased local TGM concentrations, which was subsequently mitigated after soil restoration. Considering the large number of brownfields, they may be an important source of mercury emissions source to local urban ecosystems and warrant future study at additional locations.

Physical activity-related health and economic benefits of building walkable neighbourhoods: a modelled comparison between brownfield and greenfield developments.

BACKGROUND: A consensus is emerging in the literature that urban form can impact health by either facilitating or deterring physical activity (PA). However, there is a lack of evidence measuring population health and the economic benefits relating to alternative urban forms. We examined the issue of housing people within two distinct types of urban development forms: a medium-density brownfield development in an established area with existing amenities (e.g. daily living destinations, transit), and a low-density suburban greenfield development. We predicted the health and economic benefits of a brownfield development compared with a greenfield development through their influence on PA. METHODS: We combined a new Walkability Planning Support System (Walkability PSS) with a quantitative health impact assessment model. We used the Walkability PSS to estimate the probability of residents' transport walking, based on their exposure to urban form in the brownfield and greenfield developments. We developed the underlying algorithms of the Walkability PSS using multi-level multivariate logistic regression analysis based on self-reported data for transport walking from the Victorian Integrated Survey of Transport and Activity 2009-10 and objectively measured urban form in the developments. We derived the difference in transport walking minutes per week based on the probability of transport walking in each of the developments and the average transport walking time per week among those who reported any transport walking. We then used the well-established method of the proportional multi-cohort multi-state life table model to translate the difference in transport walking minutes per week into health and economic benefits. RESULTS: If adult residents living in the greenfield neighbourhood were instead exposed to the urban development form observed in a brownfield neighbourhood, the incidence and mortality of physical inactivity-related chronic diseases would decrease. Over the life course of the exposed population (21,000), we estimated 1600 health-adjusted life years gained and economic benefits of A$94 million. DISCUSSION: Our findings indicate that planning policies that create walkable neighbourhoods with access to shops, services and public transport will lead to substantial health and economic benefits associated with reduced incidence of physical inactivity related diseases and premature death.

Soil microbial response to metal contamination in a vegetated and urban brownfield.

The ubiquity of urban brownfields presents not only a challenge for environmental managers but also an opportunity to study the functional aspects of degraded ecosystems that are in close contact with human habitation. In this study, we investigate the soil microbial community response to heavy metal contamination at Liberty State Park (LSP), an urban brownfield in Jersey City, NJ, USA. Heavy metal contamination of the soils at LSP is heterogeneous, varying widely across site and among metals. We collected soils along a previously mapped gradient of metal contamination at LSP and sampled soil from a local and uncontaminated reference site (Hutcheson Memorial Forest (HMF)) for comparison. For all soils, we measured soil heavy metal concentrations, soil organic carbon content, bacterial density, and extracellular phosphatase activity as a proxy of ecosystem functioning. Additionally, we analyzed the microbial community composition using high-throughput sequencing. Data show that some sites within LSP have significantly higher phosphatase activity compared to HMF, indicating that some heavily contaminated LSP soils are highly functional. We also found that soil organic carbon and bacterial density have a significant and positive relationship with phosphatase activity. The microbial community analyses showed that the bacterial communities were sensitive to heavy metals and that the composition was significantly affected in particular by copper, zinc, and lead. The fungal communities, however, did not vary significantly with heavy metals. Our results shed important light on the composition and functioning of urban brownfield soils. A deeper understanding of these unique ecosystems is required for successful remediation, restoration and urban sustainability.

Polycyclic aromatic hydrocarbons in the sediments of the Gulfs of Naples and Salerno, Southern Italy: Status, sources and ecological risk.

This study investigated the spatial distribution, potential sources, and toxic effects of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Gulfs of Naples and Salerno (NaSa Gulfs), Southern Italy. The investigation focused on the coastal sea sediments of the Bagnoli brownfield site within the Gulf of Naples. The ∑16PAHs in the sediments of the NaSa Gulfs outside of the Bagnoli brownfield site have concentrations that ranged from 9.58 to 15,818 µg/kg, with a geometric mean (Gmean) of 234 µg/kg. High-molecular weight PAHs (HMW PAHs) contributed to over 80% of the ∑16PAHs. The concentration of ∑16PAHs in the Gulf of Naples was twice as high as that in Salerno (768 µg/kg and 317 µg/kg, respectively), and the ∑16PAHs levels in the Bagnoli brownfield site exceeded that in the NaSa Gulfs by over three orders of magnitude. The molecular distributions of PAHs studies suggested biomass/coal combustion as their main sources. Based on the analysis of the toxic equivalent quantity and sediment quality guideline quotient, the contamination of PAHs in sediments may pose significant toxicity and biological risks to marine organisms.

An Information System for Brownfield Regeneration: providing customised information according to stakeholders' characteristics and needs.

In the EU brownfield presence is still considered a widespread problem. Even though, in the last decades, many research projects and initiatives developed a wealth of methods, guidelines, tools and technologies aimed at supporting brownfield regeneration. However, this variety of products had and still has a limited practical impact on brownfield revitalisation success, because they are not used in their entire potential due to their scarce visibility. Also, another problem that stakeholders face is finding customised information. To overcome this non-visibility and not-sufficient customisation of information, the Information System for Brownfield Regeneration (ISBR) has been developed, based on Artificial Neural Networks, which allows understanding stakeholders' information needs by providing tailored information. The ISBR has been tested by stakeholders from the EU project TIMBRE case studies, located in the Czech Republic, Germany, Poland and Romania. Data gained during tests allowed to understand stakeholders' information needs. Overall, stakeholders showed to be concerned first on remediation aspects, then on benchmarking information, which are valuable to improve practices in the complex field of brownfield regeneration, and then on the relatively new issue of sustainability applied to brownfield regeneration and remediation. Mature markets confirmed their interest for remediation-related aspects, highlighting the central role that risk assessment plays in the process. Emerging markets showed to seek information and tools for strategic and planning issues, like brownfield inventories and georeferenced data sets. Results led to conclude that a new improved platform, combining the ISBR functionalities with geo-referenced ones, would be useful and could represent a further research application.

Habitat connectivity and local conditions shape taxonomic and functional diversity of arthropods on green roofs.

Increasing development of urban environments creates high pressure on green spaces with potential negative impacts on biodiversity and ecosystem services. There is growing evidence that green roofs - rooftops covered with vegetation - can contribute mitigate the loss of urban green spaces by providing new habitats for numerous arthropod species. Whether green roofs can contribute to enhance taxonomic and functional diversity and increase connectivity across urbanized areas remains, however, largely unknown. Furthermore, only limited information is available on how environmental conditions shape green roof arthropod communities. We investigated the community composition of arthropods (Apidae, Curculionidae, Araneae and Carabidae) on 40 green roofs and 40 green sites at ground level in the city of Zurich, Switzerland. We assessed how the site's environmental variables (such as area, height, vegetation, substrate and connectivity among sites) affect species richness and functional diversity using generalized linear models. We used an extension of co-inertia analysis (RLQ) and fourth-corner analysis to highlight the mechanism underlying community assemblages across taxonomic groups on green roof and ground communities. Species richness was higher at ground-level sites, while no difference in functional diversity was found between green roofs and ground sites. Green roof arthropod diversity increased with higher connectivity and plant species richness, irrespective of substrate depth, height and area of green roofs. The species trait analysis reviewed the mechanisms related to the environmental predictors that shape the species assemblages of the different taxa at ground and roof sites. Our study shows the important contribution of green roofs in maintaining high functional diversity of arthropod communities across different taxonomic groups, despite their lower species richness compared with ground sites. Species communities on green roofs revealed to be characterized by specific trait assemblages. The study also provides details on the environmental conditions that influence arthropod diversity and gives new perspectives on how the design of green roofs can be improved to increase their ecological value. Furthermore, the study highlights the importance of integrating green roofs in planning policies which aim to enhance urban habitat connectivity.

Targeted selection of brownfields from portfolios for sustainable regeneration: User experiences from five cases testing the Timbre Brownfield Prioritization Tool.

Prioritizing brownfields for redevelopment in real estate portfolios can contribute to more sustainable regeneration and land management. Owners of large real estate and brownfield portfolios are challenged to allocate their limited resources to the development of the most critical or promising sites, in terms of time and cost efficiency. Authorities worried about the negative impacts of brownfields - in particular in the case of potential contamination - on the environment and society also need to prioritize their resources to those brownfields that most urgently deserve attention and intervention. Yet, numerous factors have to be considered for prioritizing actions, in particular when adhering to sustainability principles. Several multiple-criteria decision analysis (MCDA) approaches and tools have been suggested in order to support these actors in managing their brownfield portfolios. Based on lessons learned from the literature on success factors, sustainability assessment and MCDA approaches, researchers from a recent EU project have developed the web-based Timbre Brownfield Prioritization Tool (TBPT). It facilitates assessment and prioritization of a portfolio of sites on the basis of the probability of successful and sustainable regeneration or according to individually specified objectives. This paper introduces the challenges of brownfield portfolio management in general and reports about the application of the TBPT in five cases: practical test-uses by two large institutional land owners from Germany, a local and a regional administrative body from the Czech Republic, and an expert from a national environmental authority from Romania. Based on literature requirements for sustainability assessment tools and on the end-users' feedbacks from the practical tests, we discuss the TBPT's strengths and weaknesses in order to inform and give recommendations for future development of prioritization tools.

Comparison of international approaches to sustainable remediation.

Since mid-to-late 2000s growing interest for sustainable remediation has emerged in initiatives from several international and national organisations as well as other initiatives from networks and forums. This reflects a realisation that risk-management activities can about bring environmental, social, and economic impacts (positive or negative) in addition to achieving risk-based remediation goals. These ideas have begun to develop as a new discipline of "sustainable remediation". The various initiatives have now published a number of frameworks, standards, white papers, road maps and operative guidelines. The similarities and differences in the approaches by these outputs and general trends have been identified. The comparison is based on a set of criteria developed in discussion with members of these various initiatives, and identifies a range of similarities between their publications. Overall the comparison demonstrates a high level of consensus across definitions and principles, which leads to the conclusion that there is a shared understanding of what sustainable remediation is both across countries and stakeholder groups. Publications do differ in points of detail, in particular about the operational aspects of sustainable remediation assessment. These differences likely result from differences in context and legal framework. As this analysis was carried out its findings were debated with members of the various international initiatives, many of whom have been included as authors. Hence the outcomes described in this paper can be seen as the result of a sort of multi-level debate among international experts (authors) and so can offer a starting point to new sustainable remediation initiatives (for example in other countries) that aim to start developing their own documents.

Investigating Heavy Metal Pollution in Mining Brownfield and Its Policy Implications: A Case Study of the Bayan Obo Rare Earth Mine, Inner Mongolia, China.

The rapid urbanization of China and associated demand for land resources necessitates remediation, redevelopment, and reclamation of contaminated soil. Before these measures are taken, a basic investigation and inventory of heavy metal (HM) pollution levels in contaminated soil is necessary for establishing and implementing the redevelopment plan. In the present study, to identify the policy implications of inventorying and mapping HM pollution of soil in brownfields throughout China, the Bayan Obo giant rare earth element (REE)-Nb-Fe ore deposit of Baotou in Inner Mongolia, China, which is the largest REE mineral deposit in the world, was taken as a case study. Soil samples from 24 sites in Bayan Obo mining area (MA) and 76 sites in mine tailing area (TA) were collected for determining contents of soil HMs (Cr, Cd, Pb, Cu, and Zn). The results showed that the average concentrations of Cr, Cd, Pb, Cu, and Zn in both MA and TA were all higher than their corresponding background values for Inner Mongolia but lower than the Class II criteria of the National Soil Quality Standards of China (GB 15618-1995). Enrichment factor (EF) analysis of the soil samples indicated that the soil in the brownfield sites was highly enriched with Cr, Cd, Pb, Cu, and Zn compared to the corresponding background values. In MA, the EF for Cd was the highest among the studied elements, while in TA, the EF for Cr (3.45) was the highest, closely followed by the EF for Cd (3.34). The potential ecological risk index (RI) indicated a moderate potential ecological risk from the studied HMs in MA and a low potential ecological risk in TA, and the results of RI also suggested that the soil was most heavily polluted by Cd. According to the spatial distribution maps of HM, contamination hot-spots were primarily located near mining-related high-pollution plants. Based on the results, policy recommendations are proposed related to brownfield management in urban planning.