Microplastics in water

WHO recently published a report into microplastics in drinking water. The report says that microplastics ‘are ubiquitous in the environment and have been detected in a broad range of concentrations in marine water, wastewater, fresh water, food, air and drinking water, both bottled and tap water’. Based on the limited information currently available, there is no proof that this points to a health risk. However, WHO says that more research is needed to gain a clearer picture of the exact impact of microplastics. The organisation also calls for a reduction in plastic pollution. KWR researchers subscribe to these statements, and also call for less plastic pollution and more research into the impact of plastic particles on human health and the environment.

What research is currently ongoing in the Netherlands?

For some time now, KWR, in close collaboration with universities and other research institutes, has studied the presence and risks of microplastics in water. KWR conducts the research for water managers and drinking water utilities.

The question for water managers, for instance, concerns the precise number of particles present today in water in the Netherlands. In the NWO Domain Applied and Engineering Sciences (AES), the ongoing Technologies for the Risk Assessment of MicroPlastics (TRAMP) research project aims to measure the amount of micro- and nanoplastics in the water. To do this, a method for the precise measurement of the numbers of micro- and nanoplastics first needs to be developed.

Other research focuses for example on establishing how many plastics reach the environment via wastewater treatment plant processes, and whether these particles can also be retained – with The Great Bubble Barrier for instance.

Research is also being carried out in the Netherlands on microplastics in marine water, and Rijkswaterstaat and the Wadden Academy want to know how many particles were released as a result of the MSC Zoe disaster. The measurements from other projects can also help them get an answer.

Because of water-quality concerns, water utilities want to know whether particles might also occur in their drinking water. New research methods have been developed to this end, and we are today capable of making reliable measurements in the range of 10 to 500 micrometres (a thousandth of a millimetre). We are expecting the results of this research in 2020.

Follow-up research is aimed at the further development of the method to measure even smaller particles, about which little is known. Thanks to the new measurement methods, we will soon also be able to say more about the removal of these particles. Lastly, it is important to know what the possible origin of the particles in drinking water is.

In early 2019, a large-scale research effort was launched by the Netherlands Organisation for Health Research and Development (ZonMw) into the impact of micro- and nanoplastics on our health. This includes joint research by RIVM and KWR into whether microorganisms on plastics can promote the spread of diseases and antimicrobial resistance.

What do we already know about the Dutch situation?

Several research projects have demonstrated that plastics are present in water from wastewater treatment, large rivers and lakes in the Netherlands. But no single study has systematically examined plastic particles in drinking water. One reason for this is that the research methods to detect plastic particles in water were still under development. Researchers at WUR say that much international research is not yet really useful. Despite the uncertainty about the precision of the measurement data, they do conclude that a picture emerges in which untreated water contains more particles than water that has undergone drinking water treatment. Groundwater as well seems to have lower amounts of plastic particles than does surface water. The researchers also conclude that it is highly likely that this applies to the Netherlands situation as well.