Over seven billion tonnes of plastic waste have been generated globally, with about 80% accumulating in the environment. While plastic pollution’s impact on marine life is well-known, researchers at PolyU have highlighted a critical yet often overlooked issue: the microbial threats associated with plastic waste.

Microbes feeding on compounds in plastics form distinctive communities in aquatic and terrestrial environments, known as the “plastisphere”, which is expanding rapidly. The challenges posed by this expanding plastisphere has been unveiled through research led by Professor Jin Ling Nathanael, Assistant Professor of the Department of Civil and Environmental Engineering and Department of Health Technology and Informatics.

The research is led by Prof. Jin (left) and Dr Li Changchao, a Postdoctoral Fellow at the Department of Civil and Environmental Engineering (right), is the first author.

Environmental and health risks imposed by the plastisphere

Professor Jin’s team analysed the microbial communities in the plastisphere and its associated natural environments, covering freshwater, seawater, and terrestrial ecosystems. They found that microbial communities in the plastisphere consist of fragile networks of specialised microorganisms rarely encountered in nature. These microbial communities also boast a pronounced ability to decompose organic compounds, potentially increasing the release of greenhouse gases and accelerating carbon turnover.

The research also uncovered health risks associated with the plastisphere, such as enabling bacteria that release harmful substances to thrive, particularly in freshwater ecosystems. Moreover, the potential of the plastisphere to carry pathogens across ecosystems poses risks to humans, animals, and plants.

Professor Jin explained, “As viruses can survive longer and are more infectious in the plastisphere, this may accelerate the spread of pathogens and also prompt disease outbreaks.”

The research paper, published in the journal The Innovation, has been recognised as its Most Popular Paper from 2020 to 2024. The team was also invited to discuss this critical issue in the journal Nature.

The plastisphere has a pronounced ability to decompose organic compounds, potentially accelerating carbon turnover, and harbours more pathogens that pose health risks.

Mapping the trajectory of the plastisphere

To address these microbial threats, Professor Jin’s team is actively collaborating with global partners to collect plastic samples and create a comprehensive planetary catalogue of hazardous plastisphere microbiomes. This effort aims to track the flow of associated risks.

Professor Jin stated, “Through enhanced mapping and tracking, the project will deepen our understanding of microbial migrations on plastics, enabling more accurate risk assessments and targeted interventions in critical areas. The data can also serve as guidance for more effective environmental policies and public health strategies, particularly in regions most affected by plastic pollution.”

The team is developing a model to assess and quantify the microbial impacts of plastic pollution. This model, based on existing plastic presence data and future emission scenarios, will be validated through simulation experiments.