Bottled water? Better not to drink it, scientists say

Muscles, bones, fat, and… microplastic – this could soon be the composition of the human body. Those who often reach for bottled water are much more likely to feel the effects of synthetic particle accumulation in their tissues. The threat is enormous, yet still largely ignored.

Drinking tap water pays off

Scientists from Concordia University in Montreal decided to investigate how much bottled water threatens human health. To do this, they analyzed 141 scientific studies published between 2018 and 2024. The results are alarming: while each of us consumes between 39,000 and 52,000 microplastic particles per year, people who regularly drink beverages from single-use plastic bottles absorb 90,000 more particles than consumers of ordinary tap water.

The meta-analysis, published in Journal of Hazardous Materials in September this year, points out that although the long-term effects of micro- and nanoplastic accumulation in living organisms are not fully understood, current medical knowledge indicates that it increases the risk of developing chronic respiratory and nervous system diseases, fertility disorders, and even cancers.

A simple calculation shows that if you stop drinking water from single-use plastic bottles for a year, switching instead to tap water or beverages sold in glass bottles, you can reduce the health risk by up to two-thirds.

Where does the plastic in water come from?

According to the Canadian researchers, the main sources of nano- and microplastics in bottled water are two materials: polyethylene terephthalate (PET) and high-density polyethylene (HDPE), the latter mainly used for bottle caps. Particles ranging from less than 1 micrometer to over 100 nanometers are released from the bottle’s structure during filling, transport, opening, and closing. Their release is also accelerated by sunlight and temperature differences – the lower the plastic quality (as in typical single-use bottles), the higher the risk of contamination.

According to scientists from the University of London, particles smaller than 1.5 µm can easily pass through the mucous membranes of the digestive system. Once in the bloodstream, they are carried throughout the body, reaching key organs – from the lungs to endocrine glands and the brain.
Unfortunately, there are still no standardized methods for testing bottled water – there are several techniques, but some cannot identify the type of material, while others miss the smallest and most dangerous particles. The most accurate technologies are also the most expensive, which makes their large-scale use difficult.

Bottled water only in exceptional cases

When buying a bottle of water in a supermarket, we must be aware that it contains micro- and nanoplastics. The longer we carry it around and the more often we open it, the more of these controversial particles we consume. Drinks in single-use plastic packaging simply do not belong in a person’s daily diet – their use should be limited to an absolute minimum.

The authors of the study suggest that plastic bottles should carry a warning about the potential harmfulness of nano- and microplastics. They argue that a broad public awareness campaign is needed to highlight both the health risks of synthetic particles and the broader environmental context – every beverage purchased means another package that may end up in the ocean, adding to global plastic pollution.

People need to understand that the issue is not acute toxicity but chronic toxicity, explains Sarah Sajedi, one of the study’s authors. The fact that you drink bottled water a few times a week and feel fine doesn’t mean you won’t pay for this ignorance with your health in ten or fifteen years.

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Source:
Sarah Sajedi, Chunjiang An, Zhi Chen, Unveiling the hidden chronic health risks of nano- and microplastics in single-use plastic water bottles: A review, Journal of Hazardous Materials, Volume 495, 2025, 138948, ISSN 0304-3894, https://doi.org/10.1016/j.jhazmat.2025.138948.