Levels of microplastics—tiny particles smaller than about one-fifth of an inch— in drinking water don’t appear to be a health risk. However, more research is needed to assess how microplastics may impact human health and the environment, the World Health Organisation (WHO) has warned.
Following the release of an analysis of current research related to microplastics in drinking-water recently, the UN health agency has also called for a reduction in plastic pollution to benefit the environment and reduce human exposure.
“We urgently need to know more about the health impact of microplastics because they are everywhere - including in our drinking-water,” said Dr Maria Neira, Director, Department of Public Health, Environment and Social Determinants of Health, at WHO.
“Based on the limited information we have, microplastics in drinking water don’t appear to pose a health risk at current levels. But we need to find out more. We also need to stop the rise in plastic pollution worldwide.”
“We are not alarmed,” WHO technical officer Jennifer de France said. “With the data that we have, we can say that we believe the risk to be low, but at the same time, we can’t rule out conclusively that there might never be a risk in the future.”
According to the analysis, which summarizes the latest knowledge on microplastics in drinking-water, microplastics larger than 150 micrometres are not likely to be absorbed in the human body and uptake of smaller particles is expected to be limited. Absorption and distribution of very small microplastic particles including in the nano size range may, however, be higher, although the data is extremely limited.
Further research is needed to obtain a more accurate assessment of exposure to microplastics and their potential impacts on human health. These include developing standard methods for measuring microplastic particles in water; more studies on the sources and occurrence of microplastics in fresh water; and the efficacy of different treatment processes.
The WHO has recommended drinking-water suppliers and regulators prioritize removing microbial pathogens and chemicals that are known risks to human health, such as those causing deadly diarrhoeal diseases.