Occurrence of microplastics in raw and treated drinking water

The presence of plastics in aquatic environments is a growing concern across the EU. This study explored the amount of microplastic particles present in raw and treated water at three water-treatment plants in the Czech Republic. While treated water contained fewer particles than raw1 fresh water, the amount found in treated water was not negligible, and largely comprised tiny particles of <10 micrometres (μm) in diameter. Ways to filter microplastics from potable water must be identified and their risk to humans, sources and routes into drinking water determined, say the researchers, Science for Environment Policy reports.

Highlights

• Microplastics were present in all water samples from different treatment plants.
• The concentration of microplastics was higher in raw water than in treated water.
• Particles of 1–10 μm were the most abundant, accounting for up to 95%.
• Polyethylene terephthalate, polypropylene and polyethylene microplastics prevailed.

Abstract

The study investigates the content of microplastic particles in freshwater and drinking water. Specifically, three water treatment plants (WTPs) supplied by different kinds of water bodies were selected and their raw and treated water was analysed for microplastics (MPs). Microplastics were found in all water samples and their average abundance ranged from 1473 ± 34 to 3605 ± 497 particles L−1 in raw water and from 338 ± 76 to 628 ± 28 particles L−1 in treated water, depending on the WTP. This study is one of very few that determine microplastics down to the size of 1 μm, while MPs smaller than 10 μm were the most plentiful in both raw and treated water samples, accounting for up to 95%. Further, MPs were divided into three categories according to their shape. Fragments clearly prevailed at two of the WTPs and fibres together with fragments predominated at one case. Despite 12 different materials forming the microplastics being identified, the majority of the MPs (>70%) comprised of PET (polyethylene terephthalate), PP (polypropylene) and PE (polyethylene). This study contributes to fill the knowledge gap in the field of emerging microplastic pollution of drinking water and water sources, which is of concern due to the potential exposure of microplastics to humans.