Current cohorts

Cohort 1 (2025 start) - Pollution in Urban Landscapes

Projects within this cohort are working towards delivering a non-toxic urban environment

Ruby Woollard - University of Sheffield

Project: Understanding and managing the impact of multiple pollutant sources on urban soil health and function

Partner: Natural England

Healthy soils are essential for supporting urban greenspaces, which provide crucial ecosystem services and habitats for biodiversity. However, urban soils are threatened by pollutants such as toxic metals, persistent organic pollutants (POPs), and black carbon, which have been found to have negative effects on soil health and function.

While much of this pollution originates from fossil fuel combustion and industrial activities, greenspace management can also contribute to pollutant accumulation. Gardeners and allotment holders, focused on plant growth and crop yield, may unintentionally introduce harmful chemicals through the use of synthetic fertilisers, herbicides, pesticides, and fungicides - potentially compromising soil health and its ability to support biodiversity.

My PhD investigates how common urban growing management practices (e.g. conventional versus organic) affect the soil chemical environment, with a particular focus on black carbon and its interactions with metals and POPs. I will explore experimentally and observationally how these interactions affect key ecosystem engineers, including earthworms and mycorrhizal fungi. This research aims to identify pathways for more sustainable management of garden and allotment soils, to inform policy and promote healthier urban ecosystems.

Contact: rmwoollard1@sheffield.ac.uk

Eve Hotston - University of Sheffield

Project title: Combining nature and technology to tackle the urban chemical pollution challenge

Partner: Henkel

Urban environments face increasing pressure from pollutants in wastewater and stormwater, from pharmaceutical pollution to antimicrobial resistance genes. This project investigates both nature-based solutions (such as constructed wetlands) and technology-based treatments (including ozonation and UV) to evaluate their effectiveness in removing different pollutant types and transformation products. Microorganisms within constructed wetlands are able to remove pollutants, offering a sustainable treatment approach to water treatment. The aim of this project is to use laboratory testing of different methods, field investigations and desk-based reviews to create a ‘treatment toolbox’ to help urban systems identify the most effective combination of solutions for cleaner and more sustainable water management. 

Contact: EHotston1@sheffield.ac.uk 

Holly Mellor - University of Sheffield

Project: Urban systems and policy: Mapping urban systems and driving policy change

Partner: Office for Environmental Protection

My project addresses the challenge of chemical pollution in urban environments from a policy standpoint. Current environmental regulations are often designed and implemented within policy silos, which makes it difficult to capture cross-cutting challenges or understand how different chemicals interact with one another in specific contexts. There is also limited evidence on how to identify human sources (both domestic and industrial) of chemical pollution in cities in order to design effective interventions. 

Over the course of my project, I aim to map the urban ecosystem and the chemicals used within it to identify key points of intervention and pathways for improving sustainability outcomes across all levels of governance. This process will involve producing a systematic evidence map of chemical risks to urban ecosystems, then developing a causal loop diagram in order to assess potential intervention points.

Contact: HAMellor1@sheffield.ac.uk 

Hayley Waller - UKCEH

Project: Valuing the environmental impact of chemical pollution in urban environments

Partner: Defra

My project is developing a proof-of-concept chemical risk assessment framework that brings together chemical hazard and exposure data, and ecological data (i.e., species habitat and coverage).  This integrated data will be utilised to assess impact of chemicals at both taxonomic and community level, and on their associated ecosystem functions at an urban regional scale and to quantify economic impact values.  Using available data from the UK freshwater biodiversity ECOMIX research project across Yorkshire, my project will apply a best-case data scenario to validate and revise assumptions from the initial framework and incorporate a spatial approach to chemical risk assessment in urban centres.  The framework will be used to predict hazard in the current state and under future scenarios.

My project will also use social science methods to understand peoples’ preferences and explore communicating risk, whilst uncovering how behavioural interventions can alter the impact of potential pollution incidences.

Contact: trf538@york.ac.uk 

George Mennell – University of York
Project: Does green infrastructure position affect local-scale exposure to urban air pollution (and does it reinforce social inequity)?
Partner: UK Health Security Agency

This project aims to assess the role of urban green infrastructure (UGI) in the dispersion and removal of air pollutants in cities – a critical public health issue that is responsible for millions of annual deaths worldwide.

Using data from strategically placed air quality sensors in York, Leeds, Manchester and Hull, pollutant levels will be assessed on gradients away from pollution sources. These will be placed in locations where the effect of different vegetation types and spatial structures can be determined on air pollution levels, focusing on barrier, dispersion and removal effects. Local communities will be engaged during the monitoring process to foster a sense of responsibility. From the results of the air quality monitoring, a fine-scale model will be created or adapted to assess the benefits of urban green infrastructure, allowing spatial predictions of pollutant concentrations near different types of UGI.

The research and model implementation will place a focus on fine-particulate matter (< PM 2.5), which behaves more like a gaseous entity and is less understood than larger particles. It will also seek to explore the implications of UGI provision in terms of social equity and levels of pollutant exposure for different local communities.

Contact: gwm506@york.ac.uk 

Ulrika Goodwin - University of York

Project: Demystifying the unknown: A system-based approach to characterising and prioritising the chemical exposome of the urban aquatic environment.

Partner: The Rivers Trust

The modern urban aquatic environment is subjected to an extensive and complex mixture of chemicals originating from many sources. While over 350,000 chemicals are in use globally, only a small fraction have been systematically studied for their occurrence, distribution, and ecotoxicological effects in aquatic ecosystems.

The PhD is undertaken at the University of York with supervisors also based at UK Centre for Ecology & Hydrology and The Rivers Trust.

The overarching aim of this PhD is to holistically understand the multi-compartment chemical exposome in the urban aquatic environment, develop a transferrable approach to move non-targeted environmental monitoring towards prioritisation within the chemical exposome for potential hazards, and work with stakeholders to prioritise investment in solutions which best reduce the occurrence of these pollutants.  

Contact: sg2238@york.ac.uk   

Marie Faraut - University of York

Project: Prioritisation of chemical pollutants in urban environments

Partner: Beiersdorf AG

A large number of chemicals are used and released into urban environments. Their transformation, under the influence of abiotic and biotic processes, leads to the formation of additional derivative products, thus generating a complex mixture of thousands of compounds with varying modes of action and multiple routes of exposure for living organisms, including humans. Current approaches to chemical monitoring and management focus on a limited number of substances, which can lead to underestimation and under-management of risks.

This project aims to develop methods and a framework for prioritizing chemicals that may pose a risk to human health and urban ecosystems. It involves developing approaches to estimate emissions and the formation of chemical pollutants in urban environments, designing modelling and experimental screening tools to prioritise substances according to their exposure, hazard, and risk, and proposing a prioritisation framework that can be applied by urban managers, policy makers, and chemical producers to guide monitoring, substitution, and mitigation programs. Various tools will be used, including quantitative structure-activity relationships (QSAR), machine learning models, expert chemical transformation systems, data from in vitro tests and alternative non-animal methodologies (e.g., the Tox21 project), as well as cutting-edge non-targeted monitoring approaches such as high-resolution mass spectrometry (LC-MS/MS).

Contact: klf547@york.ac.uk 

Jayde Broadbent - University of York

Project: Identifying levers for reducing the exposure of urban wildlife to chemical contamination

Partner: Natural England, Fera, UKCEH

Urban areas are hotspots for chemical contamination due to human activities and are only expected to expand. Although urban expansion is often detrimental for biodiversity, some species are flourishing in these human-modified environments, exploiting new habitats and resources. However, this also increases their exposure to both lethal and sub-lethal effects of chemical pollution.

This project investigates how red foxes (Vulpes vulpes), an opportunistic omnivore, well adapted to urban environments, can serve as a sentinel species for identifying, monitoring, and mitigating chemical contamination by uncovering key levers for reducing exposure among urban wildlife.

Foxes have a widespread distribution, diverse diet, and live in close proximity to humans, meaning they are exposed to a myriad of contaminants. Urban development, gardening practices, pest control and waste management all contribute to chemical pollution in urban areas, and create a mosaic of pollution levels across urban landscapes. This project takes an interdisciplinary approach to quantify the chemicals that may pose the highest relative risk, systematically map exposure routes, and find solution-oriented approaches to urban management. Through improved policies and practices, the project aims to ensure clean, green cities that work for both people and wildlife.

Contact: jrt585@york.ac.uk 

Olivia Mescall - University of York

Project: Does chemical exposure in urban systems drive microbial community structure and function to mitigate pollution risks?

Partner: Unilever,  Scymaris

Chemical pollution from urban environments pose a major risk to environmental and public health. The dispersal of chemicals through and from urban systems is facilitated by aquatic systems (rivers, lakes, wastewater etc.). Microbial communities and their ability to adapt rapidly to chemical exposure plays an important role in ensuring the resilience of aquatic based ecosystem services, and in reducing environmental exposure of pollution through biodegradation. This project combines analytical chemistry, microbiological and molecular approaches to determine the extent to which chemical exposure in urban systems is driving adaptation within aquatic microbial communities, and the impact that this is having on microbial community structure, function and resilience. This project has chemical industry-wide policy and regulatory applications, as adapted microbial inoculations are currently excluded from persistence and biodegradability screening. In addition, laboratory-based adaptation will be simulated using pre- or semi-continuous exposure to demonstrate rates and extent of adaptation to chemical exposure and the impact it has on community structure and function. This will then be used to help shape the Organisation for Economic Co-operation and Development (OECD) biodegradation test guidelines and regulatory frameworks for deriving both chemical classification and risk.

Contact: olivia.mescall@york.ac.uk