Microplastics and the unknown risks

How are microplastics formed?

Microplastics are all around us, from the high peaks of the Himalayas to the depths of the Atlantic Ocean. Since its invention in the 1950s, we have been using more and more plastic. Plastic has unique properties. It’s cheap, long lasting, and has many applications. But it is a persistent material that slowly breaks down into ever smaller plastic particles: microplastics.

What are microplastics?

We define microplastics as small, man-made polymer-containing materials with dimensions (length/width/height) smaller than 5 millimetres. The term microplastics also includes nanoplastics, with dimensions smaller than 100 nanometres. Microplastics consist of a complex cocktail. There are wide variations in polymer type, size, and shape. Microplastics also carry additives, impurities, microbiota, and various contaminants.

The 4 main sources of microplastics

In our recent research on microplastics, we identified the origins of microplastics and measures to take against them. We found that the following 4 sources are the main causes of microplastics:

1. Abrasion of car tyres (~35%)
2. Litter: plastic film, bags, packets, and other materials are not discarded properly in all areas. They often end up in the soil or the water, where they break up into microplastics.
3. Use of agricultural foil
4. Textiles: abrasion of clothing mainly produces microplastics in the air and in wastewater, for example after washing clothes.

Primary and secondary microplastics

We distinguish between primary and secondary microplastics. Primary microplastics are added deliberately by humans. Secondary microplastics are formed as a result of the degradation of plastic objects.

Distinction in plastics

Primary microplastics originate mainly from pre-production pellets, scrub particles in cosmetics, grains from artificial turf fields, and abrasive cleaning agents. Degradation of plastic into secondary microplastics occurs during use of a plastic product, and when plastic is left lying around as waste. Under the influence of certain factors, ever-smaller plastic particles are formed. Examples include:

• UV light
• friction
• heat

These plastic particles then come into contact with humans through:

• air
• water
• our food
• soil

Microplastics in cosmetics

Possibly thousands of personal care products sold by companies all over the world contain tiny grains of plastic. The cosmetics industry calls these microplastics microbeads. But we also find microplastics in other products, including fleece jumpers or a plate of mussels.

Microplastics in the air

There is still relatively little known about the concentration of microplastics in the air and the effect on the environment and our health. Our knowledge of the distribution of particulate matter is very useful in our research, because microplastics exhibit the same behaviour.

With that knowledge, we can reuse existing tools. For example, a measurement campaign focussing on exposure to microplastics in the air indoors and outside, in which we measure concentration differences in various locations.

Microplastics and their effect on humans

The World Health Organization (WHO) has reported an overview of exposure through food and the inhalation of nanoplastic and microplastic particles, and the possible consequences of such exposure for human health. It also emphasises a rising public awareness and an overwhelming consensus among all stakeholders that plastics do not belong in the environment.

Measures must be taken to limit exposure to microplastics. For this reason, in the Netherlands we apply the precautionary principle, which means that the use, formation, and spread of microplastics must be minimised.

70% reduction in microplastics by 2050

We’re going to be using increasing amounts of plastic, which will inevitably lead to an increase in microplastics. According to the Dutch government’s precautionary principle, we must minimise exposure to these plastic particles.

Our research shows that a reduction in microplastics of around 70% by 2050 is achievable through the maximum deployment of 17 mitigation strategies.

Research and knowledge partners

We work closely with various research partners, such as Utrecht University, University Medical Center Utrecht, and Maastricht University. We also collaborate with knowledge partners such as the National Institute for Public Health and the Environment, scientific networks such as TI Coast, and industrial partners.

We work on confidential and often highly complex projects with stakeholders throughout the entire value chain.

Microplastics research topics

We do research on materials or products in which microplastics could pose a problem. In this way, we’re working towards a more sustainable future. Our research focuses on the following 5 topics:

1. Sources & environment
2. Measuring & detecting
3. Understanding how microplastics are formed
4. Exposure and health effects
5. Systemic insight and mitigation

With these topics, we strive to develop and support measures to reduce microplastics.