Researchers around the world have been able to detect microplastics in numerous drinking water samples, both in bottles and in tap water. The World Health Organization (WHO) has now investigated whether and what the consequences of microplastics are for health. In fact, the result is more reassuring than one might expect: Up until now, there has been no detailed evidence that microplastics in drinking water are harmful to health.
However, the WHO is not giving the all-clear, as the study situation is very sparse. The organization brought together 50 current studies for the study, but only nine of them deal specifically with the topic of microplastics in drinking water.
It is also problematic that scientists have not yet set a standard definition for microplastics. The most common category is particles smaller than five millimeters. But only the smallest particles are important for the occurrence in drinking water. These particles are at most one micron, i.e. one thousandth of a millimeter, in size. The WHO does not assume that particles larger than 150 microns accumulate in the body. The opposite is assumed for smaller particles. However, there is no evidence for this.
It is also still unclear how microplastics affect human health. Studies have so far been carried out on rats and mice, but the results cannot be extrapolated to humans, if at all. In the studies, the animals were exposed to such high concentrations of plastic that, calculated on humans, they would not be attainable.
Therefore, the WHO currently assumes that microplastics, as they are now present in large quantities, do not pose a health risk. Nevertheless, further investigations are necessary.
drinking water in Germany
In fact, microplastics were detected in drinking water samples in Germany in 2017. On average, two and a half microplastic particles floated in one liter of water from Dortmund and Hamburg. For comparison: other countries had up to 100,000 plastic particles in one liter of water. Sewage treatment plants in Germany remove most of the plastic from the water. The only problem is that the plastic is then found in the sewage sludge and, for example through fertilization, gets back into the environment. It is also possible for microplastics to get into the groundwater.