4 things you didn’t know about microplastics pollution

Pollution ranks among the 10 risks with the most severe expected impact over the next decade, according to the World Economic Forum’s Global Risks Report 2025. Plastics are one of the main pollutants, with 19 million tonnes leaking into land, rivers and coastlines every year. Microplastics make up a big part of this – estimates suggest they represent more than 90% of all plastic on the ocean surface.

Microplastics are pieces of plastic less than five millimetres wide. They can be manufactured at that size (primary microplastics), like microbeads used in cosmetics, or result from the degradation of larger plastic items (secondary microplastics).

Beyond their impact on our oceans and other bodies of water, microplastics affect wide swathes of our natural world and even human health – and we’re only beginning to understand them.

Photosynthesis is vital for plants’ survival. However, a new study finds that microplastics exposure reduces plants’ ability to photosynthesize by an average of up to 12% across terrestrial plants and algae. For terrestrial crops, the impact could range up to 18%. The study projects that this slowdown could result in yield losses of 13.5% for crops such as corn and rice, and 7% in seafood production over the next 25 years. This could seriously challenge food security and deeply affect the global economy, Scientific American reports.

As the capacity of plants to photosynthesize decreases, so does their ability to draw carbon dioxide from the air and store it. This means carbon sinks such as forests and kelp beds will absorb less, making it harder to fight global warming.

Microplastics contained in water are consumed by plants and animals ranging from plankton and fish to land animals and humans. They have been found in a large number of foods and drinks, from fish and shellfish to fruit, vegetables and beer.

Research from Cornell University, conducted in more than 100 countries between 1990 and 2018, showed that consumption had increased more than sixfold in Asia, Africa and the Americas. We ingest nearly 60% of these microplastics from aquatic sources, especially seafood, but we also breathe them in. South Asia and Southeast Asia were found to have the highest inhalation and consumption rates.

Microplastics have been associated with an increase in the risk of heart attack and stroke, as well as affecting reproduction and growth in some species. They have been found in everything from human brains to the placentas of newly-born babies.

Researchers at the University of Boston also found that bacteria exposed to microplastics can become resistant to antibiotics, further adding to the growing threat of antimicrobial resistance (AMR).

Experiments with the common E. coli bacteria showed that bacteria can attach to microplastics, forming a biofilm that acts like a barrier that antibiotics cannot pierce. While bacteria can attach to other surfaces, the biofilms formed on microplastics are much thicker and stronger.

A new peer-reviewed study also suggests that microplastics can move into the brain, where they are attacked and engulfed by immune cells, blocking blood vessels. In experiments with mice, a team from Beijing University found that the animals they tested showed decreased motor function as the microplastics moved through brain blood vessels.

Similarly, a study of seabirds found evidence of neurodegeneration in very young chicks with high levels of ingested plastic, which they had been fed by their parents. The scientists behind the study suggested that the impact could be similar to Alzheimer’s in humans. In addition, they found that microplastics had disrupted the chicks’ stomach, liver and kidney functions.

These findings further add to the mounting evidence of the impact microplastics could have on the brain.

The researchers at Cornell University who studied the penetration of microplastics into the food chain suggest that removing 99% of aquatic plastic debris from our oceans and bodies of water can decrease human exposure by more than half.

However, alongside removing existing plastic more effectively, the use of new plastics and microplastics must be reduced. With many countries committed to reducing plastic pollution, the World Economic Forum’s Global Plastic Action Partnership (GPAP) aims to translate these pledges into concrete action. It has established 25 national partnerships to achieve this mission —making it the world’s largest initiative tackling plastic pollution. GPAP brings together governments, businesses, and communities to drive inclusive, evidence-based, and locally led solutions that advance a circular economy. Most recently, it launched grants to support non-profits and community initiatives fighting both plastic pollution and biodiversity loss.