Other Ocean Events
Back to Blue will be participating in
the
following events:
World Ocean Summit & Expo
2025
Sewage and wastewater pollution 101
Slowing
the chemical tide: safeguarding human and ocean health amid
chemical pollution
Hazardous chemicals in plastics - the discussions at INC
Scientific evidence of the health impacts of plastics is growing. We are now aware of over 10,000 chemicals that can leach out of plastic products into the land, ocean and humans, potentially disrupting the body’s processes and causing cancer. Many unknowns remain, but a consensus is gradually emerging about the need to change our relationship with plastic.
Ahead of the final round of talks to develop a global plastic treaty in November, the Plastic Health Council, a coalition of medical experts and campaigners from around the world, submitted an open letter to delegates calling on them to put scientific evidence at the heart of the agreement and to acknowledge plastic as a public health crisis. Back to Blue assesses some of the key research directions and emerging data on plastic’s complex impacts on human and marine health.
Microplastics everywhere
One of the most consequential yet least visible types of plastic pollution are microplastics, tiny particles measuring under five millimetres. The smallest of them, with a diameter of 1-100 nanometres, are called nanoplastics. Many micro- and nanoplastics are formed by the fragmentation of larger plastic particles, but they can also arise from other sources, such as tyre abrasion, synthetic clothing and cosmetic products made with microbeads.
One of the most consequential yet least visible types of plastic pollution are microplastics, tiny particles measuring under five millimetres
They have been found in all parts of the human body, entering through ingestion, inhalation or skin exposure. Even infants and toddlers may consume microplastics daily when they drink water or milk heated in plastic containers in the microwave, which has been found to release microplastics into food. Food packaging is potentially harmful as well; over 3,000 chemicals from food packaging have also been detected in human bodies. There are still significant knowledge gaps in our scientific understanding of the impact of microplastics on human health, but recent research suggests significant adverse health impacts, including increased risk of cancer, respiratory disorders and gastrointestinal illness.
Another risk posed by microplastics is antimicrobial resistance, a global public health issue that occurs when microbes such as bacteria no longer respond to antimicrobial treatments. The surface area of microplastics is an ideal environment for breeding drug-resistant bacteria; a recent study showed that pathogenic E. coli could survive on plastics for 28 days while still retaining its ability to cause disease. Antimicrobial resistance is associated with millions of deaths and was directly responsible for over 1.27 million deaths in 2019 alone.
Other contaminants that interact with microbes have been known to absorb on to microplastics. Waste plastics can therefore act as a reservoir for human pathogens that can survive difficult environmental conditions and retain the ability to cause infection. There is the potential for zoonotic transmission to humans through contact with contaminated food or water—a further risk posed by plastic waste polluting bodies of water.
The surface area of microplastics is an ideal environment for breeding drug-resistant bacteria
Endocrine disruptors
One particular concern arising from microplastic consumption is endocrine disruptors. These chemicals can imitate or interfere with the body’s hormonal system, known as the endocrine system—some chemicals used routinely in plastics, such as bisphenol A (BPA), phthalates and some brominated flame retardants, fall into this category. They have been found in various bodies of water, including in drinking water, often as a result of wastewater discharge or industrial activities.
Exposure is disproportionately high in low-income and minority populations, who are more likely to live in polluted areas with inadequate waste management infrastructure, resulting in disparities in the rates of chronic conditions. Recent research has associated endocrine disruptors with conditions such as breast, prostate and testes cancer, infertility, metabolic disorders like obesity and diabetes, asthma, and neurodevelopmental conditions like autism spectrum disorder.
Exposure to endocrine disruptors begins in the antenatal period. Chemicals associated with plastics, such as bisphenols and perfluoroalkyls, are transferred from the mother to the foetus via the placenta. Research suggests that these chemicals can change the characteristics of foetal stem cells and disrupt their normal development, even at low concentrations. However, researchers note that these chemicals begin to clear from the body after ingestion stops, and hormone levels can return to normal within weeks of sustained attempts to reduce them. It is therefore crucial to end the production of food-contact plastics that use these chemicals—and stop their flow into our ocean
Ocean impacts
Over 10 million tonnes of plastics enter water systems annually. As the plastics break down, they absorb chemicals and contaminants on to their surface, causing significant pollution in the marine system and exposing marine animals to harmful substances.
Scientists have reported a variety of devastating effects in marine ecosystems. These include organisms being exposed to pathogens and dying as a result of ingesting plastic, animals becoming entangled in larger pieces of plastic waste, and disruptions in the photosynthesis process of phytoplankton, which reduces feeding at the lower end of the food chain.
These all have adverse consequences for broader marine and human health. Shellfish and other forms of seafood are particularly concerning as they accumulate and retain microplastics: a recent study of mussels in the Adriatic Sea identified seven polymers in over half of the mussels studied, with three of the polymers (polyamide, polyvinyl chloride and polystyrene) classified as hazardous in Europe. The researchers estimated that just one serving of mussels would cause consumers to ingest 22.7 microplastic particles.
Shellfish and other forms of seafood are particularly concerning as they accumulate and retain microplastics
The need for science diplomacy and multi-level governance
Science diplomacy—diplomatic processes informed and supported by scientific evidence—has helped make major strides in solving some global environmental issues, such as the actions taken via the Montreal Protocol to reverse the depletion of the ozone layer. However, the complexities of plastic pollution mean that existing policies and initiatives have so far been insufficient to address the problem, and international law lacks clear foundations for regulating plastic pollution. If progress continues to move slowly, damage to the environment and human health will continue to increase.
Addressing the global plastic pollution crisis will require co-ordinated action across all relevant stakeholder communities, including scientists, industry, civil society and policymakers. The UN-led process to create a legally binding global treaty on plastic pollution presents a crucial opportunity to integrate these diverse groups and facilitate meaningful, lasting change.
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