Danielle Sinnett

An integrated tool to assess the role of new planting in PM10 capture and the human health benefits: a case study in London.

The role of vegetation in mitigating the effects of PM(10) pollution has been highlighted as one potential benefit of urban greenspace. An integrated modelling approach is presented which utilises air dispersion (ADMS-Urban) and particulate interception (UFORE) to predict the PM(10) concentrations both before and after greenspace establishment, using a 10 x 10 km area of East London Green Grid (ELGG) as a case study. The corresponding health benefits, in terms of premature mortality and respiratory hospital admissions, as a result of the reduced exposure of the local population are also modelled. PM(10) capture from the scenario comprising 75% grassland, 20% sycamore maple (Acer pseudoplatanus L.) and 5% Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) was estimated to be 90.41 t yr(-1), equating to 0.009 t ha(-1) yr(-1) over the whole study area. The human health modelling estimated that 2 deaths and 2 hospital admissions would be averted per year.

Deposition and solubility of airborne metals to four plant species grown at varying distances from two heavily trafficked roads in London

In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility.

Sustainable management of urban pollution: an integrated approach

This paper presents a new decision-support framework and software platform for an integrated assessment of options for sustainable management of urban pollution. The framework involves three steps: (1) mapping the flow of pollutants associated with human activities in the urban environment; (2) modelling the fate and transport of pollutants; and (3) quantifying the environmental, health and socio-economic impacts of urban pollution. It comprises a suite of different models and tools to support sustainability appraisals including life cycle assessment, substance flow analysis, source and pollutants characterisation, pollutant fate and transport modelling, health impact analysis, ecological impact assessment, and multi-criteria decision analysis. The framework can be used at different levels, from simple screening studies to more detailed assessments. The paper describes the decision-support framework and outlines several case studies to demonstrate its application. The software tool is available free of charge at www.pureframework.org. Practical applications: The PUrE framework and software platform can be applied to assess and compare the sustainability of different technologies, products, human activities or policies. Example applications of the framework have so far included sustainability comparisons of technologies for thermal treatment of municipal solid waste; generation of electricity from coal and biomass; environmental and health impacts of a mixture of pollutants in Sheffield; the role of urban green space in reducing the levels of particulate matter in London and the impacts of environmental policy on legacy pollution in Avenmouth.

Handbook on Green Infrastructure

Green infrastructure is widely recognised as a valuable resource in our towns and cities and it is therefore crucial to understand, create, protect and manage this resource. This Handbook sets the context for green infrastructure as a means to make urban environments more resilient, sustainable, liveable and equitable. It then provides a comprehensive and authoritative account for those seeking to achieve sustainable green infrastructure in urban environments of how to plan, design and implement green infrastructure at different spatial scales.

Plants growing on contaminated and brownfield sites appropriate for use in Organisation for Economic Co‐operation and Development terrestrial plant growth test

The Organisation for Economic Co-operation and Development (OECD) terrestrial plant test is often used for the ecological risk assessment of contaminated land. However, its origins in plant protection product testing mean that the species recommended in the OECD guidelines are unlikely to occur on contaminated land. Six alternative species were tested on contaminated soils from a former Zn smelter and a metal fragmentizer with elevated concentrations of Cd, Cu, Pb, and Zn. The response of the alternative species was compared with that of two species recommended by the OECD: Lolium perenne (perennial ryegrass) and Trifolium pratense (red clover). Urtica dioica (stinging nettle) and Poa annua (annual meadowgrass) had low emergence rates in the control soil and so may be considered unsuitable. Festuca rubra (Chewings fescue), Holcus lanatus (Yorkshire fog), Senecio vulgaris (common groundsel), and Verbascum thapsus (great mullein) offer good alternatives to the OECD species. In particular, H. lanatus and S. vulgaris were more sensitive to the soils with moderate concentrations of Cd, Cu, Pb, and Zn than the OECD species.

Food-chain transfer of cadmium and zinc from contaminated Urtica dioica to Helix aspersa and Lumbricus terrestris

The present study examines the potential of Urtica dioica as an ecologically relevant species for use in ecotoxicological testing. It is prevalent in degraded ecosystems and is a food source for invertebrates. Urtica dioica grown in hydroponic solutions containing from less than 0.003 to 5.7 mg Cd/L or from 0.02 to 41.9 mg Zn/L accumulated metals resulting in leaf tissue concentrations in the range of 0.10 to 24.9 mg Cd/kg or 22.5 to 2,772.0 mg Zn/kg. No toxicological effects were apparent except at the highest concentrations tested, suggesting that this species may be an important pathway for transfer of metals to primary plant consumers. Helix aspersa and Lumbricus terrestris were fed the Cd- and Zn-rich leaves of U. dioica for six and four weeks, respectively. Cadmium and Zn body load increased with increasing metal concentration in the leaves (p < 0.001). Ratios of invertebrate metal concentration to leaf metal concentration were in the range of 1:0.03 to 1:1.4 for Cd and 1:0.2 to 1:2.8 for Zn in H. aspersa and 1:0.002 to 1:3.9 for Cd and 1:0.2 to 1:8.8 for Zn in L. terrestris. Helix aspersa Cd and Zn tissue concentrations (15.5 and 1,220.2 mg/kg, respectively) were approximately threefold those in L. terrestris when both species were fed nettle leaves with concentrations of approximately 23 mg Cd/kg and 3,400 mg Zn/kg. Models demonstrate that L. terrestris Cd tissue concentrations (r2 = 0.74, p < 0.001) and H. aspersa Zn tissue concentrations (r(2) = 0.69, p < 0.001) can be estimated from concentrations of Cd and Zn within the leaves of U. dioica and suggest that reasonably reproducible results can be obtained using these species for ecotoxicological testing.

Food-chain transfer of zinc from contaminated Urtica dioica and Acer pseudoplatanus L. to the aphids Microlophium carnosum and Drepanosiphum platanoidis Schrank.

This study examines the food-chain transfer of Zn from two plant species, Urtica dioica (stinging nettle) and Acer pseudoplatanus (sycamore maple), into their corresponding aphid species, Microlophium carnosum and Drepanosiphum platanoidis. The plants were grown in a hydroponic system using solutions with increasing concentrations of Zn from 0.02 to 41.9 mg Zn/l. Above-ground tissue concentrations in U. dioica and M. carnosum increased with increasing Zn exposure (p < 0.001). Zn concentrations in A. pseudoplatanus also increased with solution concentration from the control to the 9.8 mg Zn/l solution, above which concentrations remained constant. Zn concentrations in both D. platanoidis and the phloem tissue of A. pseudoplatanus were not affected by the Zn concentration in the watering solution. It appears that A. pseudoplatanus was able to limit Zn transport in the phloem, resulting in constant Zn exposure to the aphids. Zn concentrations in D. platanoidis were around three times those in M. carnosum.

The future of green infrastructure

From its origins in nineteenth-century parks green, infrastructure has been an ever-evolving component of cities. This chapter makes some observations based on a number of key trends in society and emerging patterns of green infrastructure provision to make some suggestions for the future. It looks at how our cities and their citizens are changing and the response required if green infrastructure, in terms of its form and function, is to remain relevant. In addition to our cities shaping green infrastructure, it in turn has a fundamental role to play in future-proofing our cities from challenges, such as climate change, and threats to natural ecosystems and their services on which our health and well-being depend. The management of green infrastructure is also likely to evolve the future, particularly in times of austerity, and require ever greater degrees of collaboration between professions and sectors. However, the future, it is argued, also holds new opportunities for green infrastructure, for example, in terms of new technologies to improve is delivery, streamline its management and monitoring, and facilitate community involvement. What is clear is that green infrastructure will need to be a flexible and dynamic resource that is capable of adapting to cities of the future.

Raising the standard: Developing a benchmark for green infrastructure

Green infrastructure (GI) is globally recognised as an essential component of liveable and sustainable places. It is valued for its multifunctionality and the connectedness of the individual features to each other, the surrounding countryside and urban populations. It brings together many land uses (e.g. parks, gardens, cemeteries, allotments, nature reserves, surface water), urban design (e.g. street trees, landscaping) and functional features (e.g. sustainable urban drainage systems, green roofs) operating at differing spatial scales. It is widely acknowledged that GI is the primary mechanism for delivering ecosystem services in towns and cities, and there is a substantial body of research demonstrating the multiple benefits of GI to urban populations. Despite this evidence base, there is still considerable uncertainty about the best way to design, deliver and maintain GI. This paper presents an emerging benchmark that has been developed through a combination of literature review and engagement with key stakeholders. It provides a suite of standards that are flexible enough to be used across different spatial scales depending on the specific needs of the location, covering the form and function of GI including nature conservation, water management, health and well-being, environmental and design quality. It allows an assessment of GI policy, and the planning, design, delivery and long-term management of GI in new and existing places, ensuring that current good practice is adopted at all stages. The development of the benchmark to date is summarised along with the outcome of preliminary testing using the outline planning applications for two contrasting mixed-use developments. This found that the benchmark performed well, with standards set at a level to ensure that high-quality GI is rewarded but without requiring a level of GI provision and quality that would only be expected on truly exemplary developments. Plans for the future development and testing of the benchmark are provided.

Green infrastructure and biodiversity in the city: principles and design

Globally urbanisation is posing a significant threat to biodiversity. Yet, human health and well-being depend on ecosystem services, which in turn are largely dependent on biodiversity. Despite a range of initiatives and mechanisms to promote nature conservation in cities it is declining. This chapter provides a summary of features in cities that are associated with greater abundance and richness of a number of species often studied in urban environments: birds, butterflies, pollinators and plants. The most common features identified include proximity to natural habitats, habitat heterogeneity, presence of native species, patch size and management practices. This is followed by some suggestions of how green infrastructure could be planned and designed to increase biodiversity. The chapter then finishes with some challenges and opportunities for green infrastructure and nature conservation.