Plastic is an integral part of modern life. But as it breaks down into tiny particles – known as micro- and nanoplastics – scientists are increasingly asking whether these fragments could affect human health.
This question was explored by toxicologist Hubert Dirven from the Norwegian Institute of Public Health and North Atlantic Microplastic Centre (NAMC) during a presentation at the plastic conference at One Ocean Week in Bergen. The annual event brings together experts from science, government, NGOs and industry to address challenges related to ocean sustainability, including plastic pollution.
Microplastics are defined as particles smaller than 5 millimeters, while nanoplastics are even smaller, measuring less than one micrometer. They form as plastic degrades through exposure to sunlight, heat, waves, and biological activity.
Plastics are also source of chemicals. According to a recent report from the PlastChem report 16 000 chemicals can be present in plastics and can leach from the plastics.
Humans are exposed to micro- and nanoplastics through air, food, and drinking water. Evidence suggests that such plastics may already be present in the body, but how much we absorb — and how long they remain — is still largely unknown.
Laboratory studies indicate that nanoplastics can interact with biological systems. Observed effects include oxidative stress, inflammation, DNA damage, and changes in cellular function, sometimes leading to cell death. However, what these findings mean for long-term human health is still unclear.
Significant knowledge gaps remain. Measuring real-world exposure is difficult, and many experiments rely on concentrations far higher than those typically encountered. Analytical methods are still developing, and contamination during sampling remains a challenge.
The diversity of plastic types further complicates the picture. Differences in size, shape, and chemical composition make it difficult to draw firm conclusions about potential health risks.
According to the Norwegian Institute of Public Health, research in this field is still in its early stages. Although plastic particles are likely present in the human body, this does not necessarily imply harm. At the same time, there is not yet enough evidence to determine the actual health implications and more research is needed to prepare a knowledge based risk assessment.
Photo: Bergen Næringsråd