A new technique discovers that plastic bottles contain thousands of nanoparticles capable of infiltrating cells

In recent years, numerous studies have found traces of plastic in the most remote places in the world, including both polar circles. Concern about this type of contamination has led to bans on plastic cutlery or glitter. This material not only contaminates complete objects that take centuries to degrade, but also the smaller particles that are released from it. Microplastics, fragments ranging from five millimeters to one millionth of a meter, fifty times thinner than a human hair, have focused attention until now, but it is known that plastic can continue to be divided into even smaller fractions, almost to infinity.

Nanoplastics, up to a billionth of a meter, are so small that they can pass through all human tissues, travel through the bloodstream and reach the brain or placenta of pregnant women. Although there is concern about its effects on health, studies are in the initial stages and even knowledge about its presence is limited. This week, researchers at Columbia University publish in the magazine PNAS an analysis in which they studied whether there were nanoplastics in bottled water, what type and in what quantities. Using a technique called Raman stimulated scattering microscopyone of whose inventors is Wei Min, co-author of the study, detected that, on average, around a quarter of a million of these plastic pieces could be found in each liter.

One of the most frequent components found among these nanoplastics was PET (polyethylene terephthalate), the material from which plastic bottles are usually made. According to those responsible for the study, these particles can be released when the bottles are heated, when they are squeezed or when the cap is opened and closed. However, polyamide was more abundant, a type of nylon that, according to co-author Beizhan Yan in a statement from Columbia University (USA), probably comes from the plastic filters used before bottling. water to, supposedly, purify it. The rest of the most common materials found are usually used in various industrial processes related to bottling.

“Methods had been developed to see nanoparticles, but it was not known what they were looking at,” explains Naixin Qian, co-author of the study. With the new method they have been able to observe the quantities of nanoparticles from seven types of ordinary plastics and count them individually. However, this selection only represents 10% of the particles found. It is not known if the rest are remains of plastic or other types of particles, something that shows how complicated it is to analyze such tiny elements and how much is still unknown about the composition of many things we consume.

In a review of studies published in January by eBioMedicine It is noted that increasing evidence suggests that exposure to microplastics and nanoplastics can have negative effects on various human organs. However, the authors point out that the mechanisms by which these effects could occur or whether long-term exposure to these particles increases the risk of disease are unknown issues. In general, although the effects of some specific particles have been studied to evaluate their toxicity, there are many of them, which – as this study shows – are abundant in commonly consumed products or in the environment, and which have not been studied with detail. The authors of the work, led by Jorge Bernardino de la Serna, from Imperial College London, state that future studies should investigate exposure to micro- and nanoplastics, considering realistic concentrations, the susceptibility of each individual to these substances or the necessary dose. to have a significant negative effect.

The authors of the study want to use their technique to also analyze tap water, where, in a much lower concentration than in bottled water, microplastics have also been found. In a world where nearly 400 million tons of plastic are produced each year and the material is used to make almost everything, there are endless opportunities for plastic nanoparticles to continue to be released and dispersed throughout the environment or integrate into organisms. of living beings. Identifying more precisely the quantities and composition of these particles is a step to evaluate the dimension of the problem, its possible effects on health and begin to think about ways to reduce potential threats.

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