The presence of microplastics or nanoplastics in water intended for human consumption - even in very small quantities - is a reason for growing citizen and scientific attention. The recent publication in the journal PNAS of a study that indicated that thanks to a new analysis system, it is suspected that water packaged in single-use plastic bottles may contain hundreds of thousands of nanoplastics not counted until now, once again justifies the need to increase the study and control of this potential source of contamination and threat to health.
In the context of new research and analysis methods, a study led by the Institute of Environmental Diagnosis and Water Studies (IDAEA) of the Superior Council of
Scientific Research (CSIC) in collaboration with the Barcelona Institute for Global Health (ISGlobal), now shows that the problem is also present in packaged waters sold in Spain. The results of this work have been published in the journal Chemosphere (December 2023)
The team responsible for the work has developed a high-resolution methodology that allows quantifying the amount of microplastics and nanoplastics present in water (between 0.7 and 20 micrometers (or microns, µm), as well as the chemical additives released into the water. .
One of the most striking details of the study is that after analyzing 280 samples of bottled water from 20 brands sold in Spain, "only 1 sample was free of micro- or nanoplastic polymers," as detailed in their published article. The study has a scientific purpose and does not indicate the brands of the bottles analyzed.
The results show an average concentration of 359 nanograms of micro- and nanoplastics per liter of water, an amount comparable to that obtained in tap water found in a previous study carried out by the same group. “Most studies quantify micro- and nanoplastics as the number of particles in a given volume,” declares Marinella Farré, researcher at IDAEA-CSIC and co-author of the work.
The methodology of the present study, based on liquid chromatography coupled to high-resolution mass spectrometry, allows them to be quantified by mass units. “This method is a great advance, since we can quantify particles of different shapes and extremely small sizes, something that does not happen with other techniques,” he clarifies.
The team analyzed 280 water samples from 20 commercial brands of bottled water, considering 1.5L and 0.5L bottles. Considering that an adult drinks 2 liters of water a day, the authors estimate an intake of 262 micrograms of plastic particles per year. “The European Food Safety Agency does not set any limit on the maximum safe amount of intake of micro- and nanoplastics. However, our methodology is key for future directives to establish this limit taking into account the mass of the polymer, and not the number of particles,” reports IDAEA-CSIC researcher and co-author of the study Marta Llorca.
Comparing the results of this study with a previous one by the same group that analyzed tap water in Barcelona, the concentration of micro- and nanoplastics is similar. “The main difference we found is the type of polymer: in tap water we found more polyethylene (PE) and polypropylene (PP), while in bottled water we detected mostly polypropylene terephthalate (PET), although also polyethylene,” he indicates. Cristina Villanueva, ISGlobal researcher and author of the study.
“However, we cannot ignore the enormous environmental impact that bottled water causes, especially due to the immense production of plastic waste,” Llorca remarks. The work has also detected 28 plastic additives in the bottled water samples. These chemical compounds are mainly stabilizers and plasticizers that are added to the main plastic polymer to give it greater strength, hardness or flexibility. However, these can migrate from the plastic itself to the water and also have a high toxicity for cells. “Our toxicity study showed that three types of plasticizers presented a greater risk to human health and, therefore, should be considered in risk analyzes for consumers,” concludes Farré.
