Centre for Sustainable Planning and Environments blog

By Danni Sinnett and Issy Bray

Across Europe there is a vast legacy of contaminated sites from past industrial, commercial and military activity, waste disposal, mineral extraction and other uses. WHO Europe published a report examining the Urban redevelopment of contaminated sites, which summarises the findings from an expert discussion which considered a review of the evidence on environmental and health impacts of remediation, a suite of European redevelopment case studies and a reflection on the applicability of impact assessment tools during remediation and redevelopment processes.

This blog focuses on the findings from our evidence review commissioned by WHO Europe. The review sought to answer the question: to what extent does the remediation and subsequent redevelopment of contaminated sites reduce environmental and health risks to new and existing populations and ecological systems, and are there any effects on equity in terms of the distribution of risks and outcomes or the identification of disadvantaged groups either pre- or post-remediation?

A search strategy was developed that brought together three sets of terms related to: the contaminants (e.g. lead, polyaromatic hydrocarbons) and land uses (e.g. mining, industrial); remediation and redevelopment; and the outcomes related to health (e.g. mortality, cancer). A search of standard academic databases resulted in 6903 papers. The titles and abstracts of these were then screened based on whether they reported changes in outcomes related to the environment or human health, in either new or existing populations, as a result of the remediation and, where possible, subsequent redevelopment of contaminated sites.

The vast majority of studies report soil and water concentrations, outcomes related to ecotoxicological or human health, or risk assessments pre-remediation, the findings from laboratory or field-scale experiments testing the efficacy of remediation technologies, the results of studies that model exposure or provide commentaries or reviews of remediation technologies. This meant that only 50 papers met the criteria for full-text screening.

In total sixteen papers based on outcomes related to health were taken forward to evidence synthesis:

• Three studies that examine the outcomes related to the health of new residents following remediation and redevelopment of contaminated sites;
• Nine studies that examine the outcomes related to the health of children in existing neighbourhoods previously exposed to lead (n=8) and chromium (n=1) following remediation and public health campaigns to reduce exposure (e.g. by removing hand to mouth behaviour in children, improved hygiene and home cleaning);
• Four studies that examine the outcomes related to the health in existing populations following remediation of contaminated sites.

Most of these studies were set in the United Sites and focused on reductions in blood lead concentrations in children, following a combination of soil remediation and/or public health campaigns to reduce exposure. Two further studies examined the impacts of remediation on soil contaminated with chromium and sediments contaminated with polychlorinated biphenyls (PCBs). Some studies suggest that soil cover alone is not sufficient without an excavation of contaminated surface soils to prevent upward migration, and area-wide remediation is required to prevent recontamination of residential gardens. Although it appears that soil remediation is largely responsible for the declines in soil, water, dust and blood concentrations, there is also consistent evidence that public health campaigns are effective at reducing exposure pathways where existing populations are present.

The evidence suggests that remediation via removal, capping, and replacing soil, with planting vegetation on bare soils is effective at reducing concentrations of lead and chromium in blood and urine in children, although this approach to remediation is not considered sustainable. Very few of the studies explicitly considered equity in their study design or reporting of outcomes, despite it being widely reported in the environmental justice literature that disadvantaged groups are more likely to live near contaminated sites.

The review considered a further 31 studies related to environmental outcomes following full-scale remediation and/or redevelopment of contaminated sites. Eighteen studies examined various environmental outcomes following remediation of inorganic contaminants, including metals and metalloids, and asbestos, mainly through removal and/or capping of soil and thirteen studies examined the environmental outcomes following remediation of organic contaminants including pesticides, PCBs, total petroleum hydrocarbons and polyaromatic hydrocarbons.

The nature of research and development of remediation methods for contaminated land mean that there are very few studies in the academic literature that report on the outcomes related to human and environmental health following full scale remediation. Instead, the literature focuses on laboratory and pilot studies, with the results of long-term monitoring programmes tending to not be available in the public domain. In addition, the report summarises other limitations in the evidence and provides recommendations to improve the quality of evidence.

Overall, the review found that there is consistent evidence that, when best practice is employed, remediation of contaminated soils is effective at reducing both direct and indirect exposure to pollution in nearby populations and for reducing environmental risk.

By Helen Hoyle….

A new book chapter by Dr Helen Hoyle highlights why a nuanced approach to urban greenspace provision is essential to human mental and physical wellbeing.

https://link.springer.com/chapter/10.1007%2F978-3-030-44480-8_2

There will be an online book launch of Naturally Challenged, 08 October 2020, 17.00 BST. Please join the discussion by booking a ticket on Eventbrite.

The Covid-19 pandemic has heightened our awareness of the mental and physical wellbeing benefits of access to ‘urban nature’ in parks, gardens, green and blue spaces. The monetary value of these benefits is increasingly reported, for example, recent UK research estimated the human wellbeing value of frequent use of local parks and green spaces at £34.2bn/yr¹, with the NHS saving £111m/yr¹ based solely on reduction in GP visits. Earlier research found the total annual financial value of active visits to England’s parks, woodlands and beaches to be £2.18 bn².

Yet to optimise the benefits of ‘urban nature’ for people, policymakers and practitioners must be mindful that variability in nature itself matters; variability in flowering and colour, biodiversity and tidiness all have specific impacts on human wellbeing, whilst at the same time socio-cultural diversity –differences in age, sex, professional background and whether people have a background of migration from another country, and how nature-connected people are, all have a bearing on how they relate to or value ‘urban nature’.

My own research³ has revealed a critical threshold flower cover of 27% as key to provoking the ‘wow factor’ amongst people spending time in parks and gardens. Most people find colourful flowering plants stimulating and exciting, boosting their mood and short-term happiness, whereas leafy green planting supports calm relaxation. This is extremely important for planting designers, because focal displays of vibrant, flowering plants can be strategically positioned to provoke human delight, yet green background planting must be prioritised elsewhere to support mental restoration.

Recent research across Europe has also confirmed appreciation of wilder grasslands and meadows in our urban parks and gardens. This may seem like good news at a time when austerity makes any alternative impossible in many urban green spaces, yet a more nuanced consideration⁴ of this appreciation shows that i) context matters: although people are appreciative of grasslands and meadows, some prefer neater, short-cut grass immediately outside their homes; ii) once people are aware of the habitat-value of taller meadows to urban invertebrates they are more prepared to accept them, even when they may appear brown and unkempt, beyond the flowering season; iii) ‘Cues to care’ matter: people like to see neat mown edges ‘framing’ an area of longer meadow or grassland, showing the area is being managed deliberately, and allowing access at the edge of footways. Although most people are not good at recognising biodiversity at the species level, they gain considerable wellbeing benefits from experiencing it. My recent interviews with parkrun participants confirm this, with one commenting on his own eagerness to see if there were birds on a lake as he ran or walked through a park, although he didn’t know any more than that if they were swans or ducks.

Research has also shown differences in the response to ‘urban nature’ between women and men. My own research in woodlands, shrubs and herbaceous planting of varying structural naturalness indicated that women found all types of planting more mentally restorative than men³ and perceived higher levels of ‘naturalness’⁵, regardless of the style of planting they walked through. In our work on urban meadow introduction with local authority land managers in Bedfordshire, we found that there was a preference for meadow style planting over traditional herbaceous and formal bedding styles, but the effect was stronger for women. People working in landscape, environmental and horticultural professionals also demonstrate contrasting perceptions and preferences to those of non-professionals, with professionals usually preferring wilder more naturalistic styles than other members of the public. They need to be mindful of this when planning and designing green spaces for other people.

Supporters of the ‘Biophilia hypothesis’ advocate that humans are hard-wired to bond closely with the natural world. Yet for some first-generation migrants with BAME backgrounds, ‘nature’ may appear too wild, dirty and inhospitable and they may be less supportive of urban grasslands than others, preferring tidier, manicured green spaces.  This applies to some communities in Luton, Bedfordshire, where I have recently worked on the Futureproofing Luton project, co-producing an arboretum-meadow on a former minigolf site in Wardown Park, with the Parks Service and children from Riverbank Primary School. Parks and greenspaces are often designed with a white wilderness view of the world, and scant consideration for local needs and priorities. Engaging local people to co-create and co-produce the form of urban nature which best supports their wellbeing is an urgent priority. Nature-connection is developed through individual or community experiences over the life-course, often with roots in childhood experiences of nature within urban woodlands and greenspaces. Working with children to explore and highlight the benefits of urban nature for climate change adaptation and mitigation, biodiversity and human wellbeing, as in the Futureproofing Luton project, provides a positive approach to futureproofing our greenspaces.

¹Fields in Trust, (2018). Revaluing Parks and Green Spaces.

http://www.fieldsintrust.org/Upload/file/research/Revaluing-Parks-and-Green-Spaces-Report.pdf

² White et al. (2016). Recreational physical activity in natural environments and implications for health: A population based cross-sectional study in England. Preventive Medicine 91, 383-388.

³Hoyle et al. (2017). All about the ‘wow factor’? The relationships between aesthetics, restorative effect and perceived biodiversity in designed urban planting. Landscape and Urban Planning, 164, 109-123 https://www.sciencedirect.com/science/article/pii/S0169204617300701

⁴Hoyle et al. (2017). “Not in their front yard” The opportunities and challenges of introducing perennial urban meadows: A local authority stakeholder perspective. Urban Forestry & Urban Greening, 25, 139-149. https://www.sciencedirect.com/science/article/pii/S1618866716305489

⁵Hoyle et al. (2019).  What determines how we see nature? Perceptions of naturalness in designed urban green spaces. People Nat.; 00:1–14.

https://besjournals.onlinelibrary.wiley.com/doi/full/10.1002/pan3.19

…by Helen Hoyle

In my previous piece I discussed how the colour and degree of naturalness of planting in urban green spaces influence peoples’ perceptions and preferences. In addition, people with different socio-cultural backgrounds often experience the same type of planting differently, with some gaining greater wellbeing benefits from brightly coloured non-native meadows and others finding a more subtly coloured native perennial meadow more restorative.

‘Socio-cultural’ is a term used in research at the intersection of people and ‘nature’ to describe both socio-demographic characteristics, such as age, sex, and whether people have a background of migration from another country, and cultural factors including people’s deep underlying or held ‘values’ including ‘nature-connection’. There is strong evidence that peoples’ perceptions and preferences as expressed on a single day are strongly related to these underlying values.

My own research has generated some interesting learning in relation to gender differences in perceptions. Findings from 1400 participants who walked through woodlands, shrubs and herbaceous planting of different degrees of naturalness, indicate that women found the planting more mentally restorative than men¹ and perceived higher levels of ‘naturalness’² regardless of the style of planting they walked through. In our work on urban meadow introduction with local authority land managers in Bedfordshire³, we found that there was a preference for meadow style planting over traditional herbaceous and formal bedding styles, but the effect was stronger for women, concurring with earlier research conducted in the Netherlands showing that women were more appreciative of gardens than men, particularly wild and romantic ones, and that men were more likely to own a ‘manicured’ garden. Landscape, environmental and horticultural professionals also demonstrate contrasting perceptions and preferences to those of non-professionals. My own research has consistently shown that professionals find spending time in green spaces less restorative than other people, maybe because this is their usual ‘work’ environment. Professionals usually prefer a wilder more naturalistic style than other research participants, so need to be mindful of this when planning and designing green spaces for other people.

Researchers and practitioners supporting the ‘Biophilia hypothesis’ advocate that humans are hard-wired to bond closely with the natural world. Yet we all know people, particularly those living in urban areas, to which this does not apply. For some first-generation migrants with BAME backgrounds, ‘nature’ may appear too wild, dirty and inhospitable. This applies within some communities in Luton, Bedfordshire, where the I am now working with a local primary school to introduce an arboretum-meadow.  My own research has shown that people who are more ‘nature-connected’ both appreciate the aesthetic qualities of different green spaces and feel more mentally restored than the less nature-connected. This raises important questions. Should we ‘educate’ urban communities to know more about nature, thereby making them more nature-connected, so they can experience heightened wellbeing benefits from ‘nature’? An alternative view is that ‘contact, emotion, compassion, meaning and beauty are pathways to nature-connection.’⁴ I strongly support this view that ‘nature connection’ / ’nature orientation’ / ‘ecocentricity’ is developed through individual or community experiences over the life-course, often with roots in childhood experiences of nature within urban woodlands and greenspaces. During my own research, participants expressing appreciation for woodlands in Fairlands Valley Park Stevenage, Hertfordshire, recounted visits to Monks Wood 50 years ago as children, or more recent visits with grandchildren to create imaginary woodland characters and stories.

During the COVID-19 pandemic more people have done physical activity and sought mental restoration in parks and greenspaces than ever before. In the months to come, as lockdown eases further, it will be interesting to see if people continue to use and value these spaces, and whether this impacts on their nature-connection.

¹Hoyle et al. (2017). All about the ‘wow factor’? The relationships between aesthetics, restorative effect and perceived biodiversity in designed urban planting. Landscape and Urban Planning, 164, 109-123

²Hoyle et al. (2019).  What determines how we see nature? Perceptions of naturalness in designed urban green spaces. People Nat.; 00:1–14.

³Southon et al. (2017). Biodiverse perennial meadows have aesthetic value and increase residents’ perceptions of site quality in urban green-space. Landscape and Urban Planning, 158, 105-118.

⁴Lumber et al. (2017) Beyond knowing nature: Contact, emotion, compassion, meaning, and beauty are pathways to nature connection* E-mail: ryan.lumber@dmu.ac.ukAffiliation School of Applied Social Sciences, De Montfort University, Leicester, United Kingdom . http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0177186