IAP-26-071

Tyre additives in freshwater and terrestrial environments: occurrence, behaviour, and fate in a changing climate

Tyres release a complex mixture of additives and transformation products, many of which remain poorly characterised in the environment. Road-associated freshwaters and soils are particularly vulnerable because they receive tyre-wear particles and associated chemicals directly from runoff. There is increasing concern around the hazards and risk that these chemicals may pose in these ecosystems.

This PhD will investigate how climate-related pressures, including altered rainfall, flooding and drying cycles, temperature and UV exposure, influence the release, transformation, persistence and ecological relevance of tyre additives in these systems.

Tyre-derived contaminants are increasingly recognised as an emerging environmental pollutant of global concern, yet significant knowledge gaps remain regarding their environmental behaviour and impacts. The project will provide an opportunity to address these knowledge gaps through an interdisciplinary combination of environmental and analytical chemistry, field surveys, experimentation, and statistical approaches to tackle an environmental issue of growing international significance.

The successful student will work at the interface of environmental chemistry, pollution science and climate change research, generating evidence that could inform future environmental monitoring, chemical prioritisation and risk management strategies to promote ecosystem resilience.

Tyre-derived particles and associated chemicals are an important but poorly characterised source of pollution in freshwater and terrestrial environments. Road-associated aquatic environments, including rivers, ditches, ponds, pools and retention basins, may receive concentrated inputs of tyre-wear particles and additives through runoff. These habitats are often biodiverse and ecologically connected, but they are also exposed to multiple interacting stressors, including chemical pollution, altered hydrology, flooding, drying, temperature extremes and UV exposure.

A systematic review will first establish the current evidence base, identify priority compounds and transformation products, and refine the environmental matrices and conditions examined during the subsequent work. A pilot UK field survey will then assess the occurrence of tyre-derived contaminants in selected road-associated environments, followed by seasonal sampling across relevant matrices, including water, soil, sediment and biological material.

Controlled leaching experiments will investigate how climate-relevant conditions, including temperature, moisture and repeated flooding and drying cycles, affect the release of additives from tyre-wear particles. Microcosm experiments will build on these findings to examine contaminant persistence, degradation and transformation under environmentally realistic conditions. Where appropriate, measured concentrations and chemical profiles will be interpreted alongside available toxicity or environmental-effects evidence to assess their potential ecological significance.

The project will retain a strong analytical chemistry focus through high-resolution targeted and non-targeted analysis of tyre additives and transformation products using facilities at UKCEH and Heriot-Watt University, including pyrolysis GC-(FID/)MS, LC-MS/MS, ICP-MS,GC-MS and LC/GC-q-TOF.

A particular strength of the project is the opportunity to combine targeted analysis of known tyre-derived contaminants with advanced non-target screening approaches, enabling the discovery and characterisation of previously unknown additives and transformation products in environmental samples.

The student will receive training in environmental sampling, experimental design, sample preparation, chemical analysis, data interpretation, FAIR data management and science-policy translation. Collaboration with JNCC will provide a stakeholder perspective and support translation of the findings into evidence for chemical prioritisation, monitoring and conservation-relevant management.
The student will be part of a multidisciplinary research environment spanning environmental chemistry, ecotoxicology and environmental monitoring, providing opportunities to develop a broad and highly transferable skillset.

Year 1

• Systematic literature review to establish the current evidence base for tyre pollution in freshwater and freshwater systems.
• Build on and further develop methods to analyse tyre additives using targeted methods such as GC-MS, LC-MS/MS.
• Design and carry out a pilot UK-based field sampling campaign of tyre additives across relevant matrices, including water, soil, sediment and biological material.

Year 2

• Carry out additional seasonal fieldwork to extend the Year 1 pilot study to investigate seasonality of tyre additive occurrence at the selected field sites.
• Carry out leaching experiments to investigate the effects of climate conditions (e.g. temperature, repeated wetting and drying cycles) on the release of tyre additives from tyre-wear particles into freshwater environments.
• Build on and further develop methods to analyse tyre additives using non-targeted screening techniques such as LC/GC-q-TOF.

Year 3

• Conduct microcosm experiments to investigate the fate of tyre additives, for instance measuring their degradation rates, transformation pathways and potential ecological relevance under realistic environmental conditions.
• Apply high-resolution mass spectrometry approaches to identify and characterise transformation products formed under different climate-related scenarios.

Year 3.5

• Integrate evidence from field surveys, leaching studies, and microcosm experiments.
• Complete thesis writing and viva preparation.

The student will gain experience in environmental sampling, organic contaminant analysis, and environmental chemistry, alongside skills in data analysis and statistics, FAIR data management, digital science, and scientific communication. The project will involve targeted and untargeted chemical analysis of a range of tyre additives and transformation products, with this part of the work supervised by experts in environmental analytical chemistry at the UK Centre for Ecology & Hydrology (UKCEH) and Heriot-Watt University.

The student will have access to a range of state-of-the-art analytical equipment, such as pyrolysis GC-(FID/)MS, LC-MS/MS, GC-MS, ICP-MS and LC/GC-q-TOF.

Applicants are not expected to have experience in all these techniques. We welcome candidates with a background in environmental chemistry, analytical chemistry, environmental science or a related discipline who are enthusiastic about developing expertise in advanced analytical methods and environmental pollution research.

Through this project, the student will gain highly valued skills in environmental analytical chemistry, high-resolution mass spectrometry, targeted and non-target screening workflows, experimental design, environmental data analysis, and research communication.

The student will also gain experience of science-policy translation through engagement with JNCC, supporting the ambition of the Iapetus programme to train researchers who can link mechanistic science with conservation practice and environmental decision-making.