Distinguishing realistic environmental risks of nanoplastics by investigating fate and toxicology in real-world scenarios

Contamination of marine environments by plastic debris is a visually obvious and undesirable consequence of dramatic increases in production and use of plastics in consumer products over the last 50 years. Pieces of plastic have been found in marine environments worldwide and the need to establish levels of contamination and consequences of plastic debris has become a high priority to inform policy. Nanoplastics are manufactured (primary particles) for use in products or form by fragmentation of larger pieces (secondary particles); however, their appearance and properties appear to be indistinguishable after release to the environment. The abundance and persistence of nanoplastics presents a chronic and increasing human-induced change of marine environments on a massive scale for which assessment of risk is an urgent priority. Nanomaterials have unique properties because of their size and there is concern for unexpected toxicity in organisms because nanoplastics may be transported across cell membranes and may persist within the gut and interfere with processes of the digestive system. Investigations of nanomaterial toxicology have been conducted for over ten years, but many of these early studies do not provide the information needed for environmental scientists to assess the risks nanomaterials pose to the environment. This project is focused on providing critical information to enhance the environmental risk assessment of nanoplastics, and is based on real-world exposure scenarios. In particular, we will investigate interactions with microorganisms present in natural seawater on the formation of microorg-agglomerates of nanoplastics and how these microorg-agglomerates have different properties and therefore different environmental effects compared to nanoplastic particles. We will investigate how toxic substances associate with microorg-agglomerates and influence where nanoplastics accumulate within test marine environments (mesocosms) and whether the toxic substances are released to fish. Toxicology and effects of nanoplastics in fish and marine invertebrates after ingestion will be studied considering a variety of endpoints with a design that will enable effects to be modelled across concentrations and sizes of nanoplastics. The outcome of this project (RealRiskNano) will be to provide risk assessors with urgently needed information to evaluate the realistic risk that nanoplastics pose in marine ecosystems.

Impact Summary- Distinguishing realistic environmental risks of nanoplastics by investigating fate and toxicology in real-world scenarios (RealRiskNano) (Henry, Thompson, Gutierrez, Rowland)
Anticipated outcomes of RealRiskNano: We intend to provide critical information to enable environmentally relevant risk assessments to be developed based on relations between both nanoplastic particle size and concentration, and biological effects in organisms. The importance of microorganisms in natural seawater on formation of microorg-agglomerates of nanoplastics and how these environmentally relevant particles sorb co-contaminants, accumulate in environmental compartments, and effect organisms in marine mesocosms will be determined.

Who will benefit and timeline: Benefits of the project will begin in year one of the project, will continue throughout the project, and will persist into the future as project outcomes will influence risk assessments of nanoplastics in the environment and formation of policy.

1. Government agencies in the UK with responsibility for environmental protection such as Defra, the Environment Agency, and government laboratories with responsibility for fish/shelfish disease such as the Centre for Environment Fisheries and Aquaculture Science (CEFAS), and companies involved in the environmental hazard and risk assessment of nanomaterials.

2. Government agencies in other countries. Dr. Henry is closely integrated into environmental nanoscience research initiatives in the US (Lead PI on US environmental Protection Agency grant in nanotoxicology, and current Lead PI on U.S. NSF project on the environmental effects of nanomaterials). Agencies within the US that will benefit from the results include the US EPA, NSF, National Institutes of Standards (with whom TB Henry has published numerous articles. TB Henry is currently project leader for EU FP7 project MARMICROTOX investgiating effects of microplastics in marine organisms. Members of the EU Commission are recognizing the importance yet lack of knowledge on nanoplastics and hence will benefit from (RealRiskNano).

3. Risk assessors in both the private and public sector are asking for research to provide the information required to characterize the risk of nanomaterials and to guide regulatory agencies on how to approach risk management of nanotechnologies.

4. The nanotechnology industry is a key player that requires information on the environmental effects of nanotechnology and is keenly aware of properly conducting environmental research to address public concerns relating to new technologies. RealRiskNano aims to resolve realistic risks of nanomaterials, and members of the nanotechnology industry will benfit from this urgently required information.

5. Shelfish harvesters/aquaculturists- understanding the presence and real risks of nanoplastics in filter feeding organisms for human consumption is important for this industry for protection of their products and markets.

How will beneficiaries benefit: It is our intent to clarify the real risks that are posed by nanoplastics in marine environments. There have been numerous overstatements, mis-statements, and lack of reproducible results on the toxicology of nanomaterials in the literature and our objective is to clarify this area of environmental science. Identifying the real risks of nanoplastics in marine environments will enable risk assessors and policy makers provide more appropriate management of this important environmental issue. With real risks understood, dedication of suitable resources will be supported, private industries can plan how to consider the environmental implications of their business, and the general public can be advised. Resources for management of environmental problems are limited and must be appropriately dedicated, understanding the real risks of nanoplastics will impact this process by providing information needed for decision making.