A UK knowledge transfer research project has been launched to examine the impact of microplastics on human health as a crucial forerunner to the regulatory powers needed to tackle plastic’s presence in our food and drinking water.

Leading the project is Dr Nabil Hajji, Technical Director of Toxicology at the Water Research Centre (WRc), an RSK Group company. WRc is working with Queen Mary University of London on the 24-month Knowledge Transfer Partnership project, funded by Innovate UK.

Dr Hajji said: “The fact that microplastics are present in seafood and our marine environment is well-documented, along with the toxicity concerns associated with this. However, the deeper understanding of the potential risks that this material presents to human health has been lacking.

“The World Health Organisation (WHO) and the EU Commission have emphasised these knowledge gaps and urged the scientific community to investigate this further. Understanding how the toxicity of microplastics impacts on our health is the first step to putting regulatory measures in place to protect people from any risks we identify.”

He added, “Plastic pollution is expected to more than double by 2030 with some 40% of plastic recognised as a single use material remaining persistent in the environment. In addition, as it is degraded over time, it creates microplastics (less than 5mm) and nanoplastics (less than 0.1mm) – this is the substance being ingested by animals and people.”

“Until we develop a risk assessment, we lack the sound scientific knowledge to empower our regulators. The UK Committee on Toxicity of Chemicals in Food, Consumer Products, and the Environment (COT) has also echoed this concern. It recommends research prioritises a risk assessment for microplastics by establishing standardised methods for the quantification of different microplastics in various food sources (including water), and gathering information on absorption and accumulation, as well as profiling related toxicities.”

Dr Hajji said the project will see WRc use a chemical imaging system, incorporating quantum laser technology, to identify and classify the chemicals presents in the microplastics. This will identify chemicals that can impact key pathways of human disease.

“The risk to human health will be tested in relevant human tissue and in silico (computer) models as recommended by the Organisation for Economic Co-operation and Development. At Queen Mary University of London we will perform a nanoliter-scale (one billionth of a litre) analysis for microplastic biomarkers for toxicity.

“The combined risk assessment and toxicology testing will be the first-of-its-kind for the development of a microplastic risk assessment consulting service in the UK. Methods developed as part of this work will be validated and recommended to the Organisation for Economic Co-operation and Development to create global standard protocols for microplastic risk assessment.”

The project stages are:

Collection and sample preparation: The comprehensive microplastics analysis strategy begins with the systematic collection of more than 1,000 water samples from various locations in the UK, including diverse water bodies and drinking water sources.

Microplastics detection and identification. To detect and identify microplastics, the team will employ a state-of-the-art technology that integrates laser and infra-red imaging analysis systems and other technologies for microplastics detection. This cutting-edge approach will allow the team to precisely capture microplastic particles and determine their composition.

Chemical risk assessment. Identified microplastic-associated chemicals will be subjected to a risk assessment based on publicly available data. However, considering the vast number of chemicals associated with plastics (over 13,000), and the limited toxicology data available for most of them, the team will employ advanced methodologies (i.e. computer models testing called in silico tests). These models utilize sophisticated machine learning algorithms to establish relationships between chemical structures and toxicity, providing predictive insights.

In vitro human tissue testing. The team will also use in vitro human tissue testing too – which will involve replicating human tissue models to assess how microplastics and associated chemicals interact with biological systems. These models are essential for deciphering microplastics’ toxicity mechanisms and identifying relevant biomarkers for toxicological assessments. The team will investigate the loss of intestinal barrier function as significant route for microplastic ingestion via water and food. Carcinogenicity and genotoxicity tests will be employed as OECD-recommended assays to investigate potential cell changes and genome damage. Furthermore, angiogenesis and immune system alteration will explored to identify the formation of new vasculature (angiogenesis) and its impact on the immune system responses induced by microplastic chemicals.

The final stage is a deep screen and search for the identification of sensitive microplastic biomarkers. For that, data generated for example from proteomics, undergoes rigorous bioinformatics analysis, and all information (list of chemicals, in silico, in vitro as well as biomarker analysis) is integrated to provide a comprehensive and accurate microplastic risk assessment.