22 August 2019: The World Health Organization (WHO) has released an analysis that finds improving wastewater and drinking water treatment can simultaneously improve human health and reduce most microplastics found in drinking water. To improve health and environment, the WHO recommends that policymakers and the public implement measures to better manage and reduce plastics use.

The publication titled, ‘Microplastics in Drinking-Water,’ is the WHO’s first effort to examine the potential human health risks from exposure to microplastics, and it focuses on the impacts of microplastics exposure through drinking water. The report examines the evidence on microplastics in the water cycle, the potential health impacts from exposure, and the removal of microplastics during treatment of wastewater and drinking water. The analysis finds that microplastics larger than 150 micrometres “are not likely to be absorbed in the human body,” and the uptake of smaller particles is likely to be limited. Although data is limited, the report states that absorption and distribution of very small microplastics, including nano-plastics, may be higher. The report concludes that further research is necessary to have a more accurate assessment of microplastic exposure and their impacts on human health.

WHO Director, Department of Public Health, Environment and Social Determinants of Health, Maria Neira, explained “we urgently need to know more about the health impact of microplastics because they are everywhere – including in our drinking-water.” She stressed the importance of finding out more about microplastics in drinking water and of stopping “the rise in plastic pollution worldwide.”

Per the report, the key sources of microplastic pollution are terrestrial run-off and wastewater effluent. The most common plastic particles found in drinking water are plastic bottle fragments. Wastewater treatment can remove over 90 percent of microplastics, and conventional drinking-water treatment generally removes particles smaller than a micrometre. The highest removal comes from tertiary treatment like filtration. The report concludes that water treatment processes “can effectively remove microplastics.”

The report concludes that water treatment processes “can effectively remove microplastics.”

However, the report stresses that a significant proportion of the global population does not currently have access to adequate water and sewage treatment and that wastewater and drinking water treatment may not be optimized to remove microplastics. By improving wastewater treatment, the report suggests governments, regulators, drinking-water suppliers and communities simultaneously tackle microplastics. It recommends water suppliers optimize water treatment processes for particle removal and microbial safety, which will also improve the removal of microplastic particles.

To better understand the human health risks from microplastics and inform management actions, the report recommends further analysis on the sources and occurrence of microplastics in freshwater and throughout the water supply chain and on the efficacy of different treatment processes. The report also recommends developing standard methodologies for measuring microplastics in freshwater. To reduce microplastic pollution, the report suggests a number of actions, such as improving recycling programs and circular economy solutions, decreasing industrial waste inputs into the environment and reducing littering. [WHO Press Release] [UN News Story] [Report Information Sheet] [Publication: Microplastics in Drinking-Water] [Climate Action Story on WHO Report]