More microplastics in tap or bottled water? Surprise ahead! 💧

The water we drink, whether bottled or from the tap, contains microplastics so small that they escape current regulations. A recent study reveals that these particles, often smaller than 20 microns, could penetrate our bodies, raising questions about their long-term effects.


Researchers from CNRS and the University of Toulouse analyzed the presence of microplastics in ten brands of bottled water and a sample of tap water. Their results, published in the journal PLOS Water, show that 98% of the detected microplastics measure less than 20 microns, a critical size not covered by European standards. These invisible particles could cross the intestinal barrier and reach the blood and organs.

Variable concentrations depending on the brand

The researchers observed a wide variability in microplastic concentrations, ranging from 0.001 to 0.250 micrograms per liter. This disparity suggests that the choice of brand directly influences exposure to these pollutants. PET bottles, often criticized, do not appear to be the main source of contamination.

The study highlights that the detected microplastics likely come from water treatment and distribution processes. The identified particles include polyethylene, polypropylene, and polyamide, polymers commonly used in the industry.

An innovative detection method

Thanks to Raman microspectroscopy, scientists were able to identify particles as small as 1 micron. This technical advancement paves the way for a better understanding of plastic contamination. The authors advocate for a revision of European standards to include these smaller microplastics, deemed more dangerous to health.

The method allows for the analysis of samples at a reasonable cost, which could facilitate its adoption by industries and regulators. It also offers better resolution than current techniques, which are limited to particles larger than 20 microns.

Tap water also affected

The study reveals that tap water in the city of Toulouse contains more microplastics than some bottled waters. This contamination is linked to water treatment, particularly from the Garonne River. Filtration and distribution processes seem to play a key role in introducing these particles.

The researchers identified 0.096 micrograms of microplastics per liter in tap water, a higher concentration than in 8 out of the 10 bottled water brands studied. This shows that contamination sources are multiple.

Health implications still unclear

While microplastics are omnipresent, their health effects remain poorly understood. The World Health Organization (WHO) considers particles smaller than 10 microns to be the most concerning. Researchers call for further studies to assess the real risks and adapt regulations accordingly.

Microplastics could cross the intestinal barrier and reach the circulatory system, even organs. However, current studies do not yet prove a direct link between their ingestion and specific pathologies.

Towards better regulation

The results of this study could encourage authorities to revise water quality standards. Scientists hope that the industry and institutions will use these data to limit contamination at the source. Better detection of fine microplastics is essential to protect public health.

The European Commission is currently proposing to assess plastic contamination starting from 20 microns. The study's authors advocate for revising this limit to include particles from 1 to 20 microns, deemed more dangerous.

To go further: What is Raman microspectroscopy?

Raman microspectroscopy is an analysis technique that allows the identification of the chemical composition of materials at a microscopic scale. It relies on the interaction between laser light and the molecules of a sample, producing a unique signature called a Raman spectrum. This method is particularly useful for studying particles invisible to the naked eye, such as microplastics.

Unlike other techniques, Raman microspectroscopy offers high spatial resolution, enabling the detection of particles smaller than 1 micron. It is non-destructive, meaning the sample remains intact after analysis. This makes it a valuable tool for scientific research and industrial applications.

In the field of microplastics, this method has allowed the identification of very small particles, escaping traditional techniques. It has revealed that 98% of microplastics in drinking water measure less than 20 microns, a key discovery for revising detection and regulation standards.

Raman microspectroscopy is also used in other fields, such as biology, medicine, and materials science. Its growing adoption could revolutionize how we study and manage microscopic pollutants, paving the way for more effective solutions to protect the environment and human health.