The ‘plastic soup’ polluting our oceans contains toxic chemicals, which could be posing risks to marine species and humans. Changes in the ways we produce and consume plastic are urgently needed to reduce the levels of contamination caused by ocean plastics, according to a new IUCN co-authored analysis paper.
The paper, published in Environmental Sciences Europe, looked at the chemical contamination caused by ocean plastics, reviewed impacts and identified solutions.
Microplastics – plastic particles smaller than 5 mm in diameter – have been shown to be contaminated with toxic chemicals. These microplastics are small enough to be ingested by marine species, potentially affecting species’ and human health as they enter the food chain. Of particular concern are endocrine disrupting chemicals, which affect reproduction, birth rates and thyroid function, leading to an increased incidence of hormone-sensitive cancers. Nanoplastics – under 100 nm in diameter – are associated with suspected chemical and physical impacts on human health.
About eight million tonnes of plastic end up in the ocean each year. Marine species ingest potentially contaminated plastics directly, and by eating contaminated prey, according to the paper. Seabirds are particularly vulnerable, with studies showing the presence of additives used as flame retardants in plastics, as well as foams and textiles, which were discovered in their stomachs and fatty tissue.
“Looking at the scale of the marine plastic problem today and at the projections for future growth in production of plastic globally, it is clear we are in the midst of a major crisis,” says Carl Gustaf Lundin, Director of IUCN’s Global Marine and Polar Programme. “We need urgent action to reduce the toxic chemicals leaching into our oceans from plastic. These contaminants could increasingly harm marine life as well as humans, in ways we do not yet fully understand.”
To reduce the amount of contaminants in marine plastics, the authors recommend addressing issues in the life-cycle design of plastic products, and creating products that minimise the use of hazardous substances, an approach known as ‘green chemistry’. They also concluded that the development of best practice codes for industry is likely to be more efficient than reliance on ‘end-of-pipe’ solutions; and that existing scientific evidence and precautionary principles should drive action from scientists, industry, policy and civil society to curb the leaking of plastics into the marine environment in the short term.
Improved understanding of the multitude of sources of plastic-borne contaminants and how they enter the ecosystem is also needed to tackle the issue, according to the paper. The authors have categorised these sources into four categories: intended and unintended chemicals in the production process, chemicals released during recycling and chemicals absorbed into plastics from polluted water.
“Societies need to act at multiple levels,” says Joao Sousa, IUCN Project Manager for Marine Plastics, a co-author of the report. “Developed countries need to identify and adopt less harmful production processes and promote alternatives, whilst sound waste management and awareness-raising should be the main priority for developing nations.”
The paper was authored by members of a working group associated with the Stockholm and Basel Conventions – multilateral environmental agreements aimed at protecting human health and the environment from hazardous chemicals and wastes – and other authors.
Learn more about IUCN’s work to reduce marine plastic pollution around the world here.
You can access the full paper here.