A recent study published in the journal Proceedings of the National Academy of Sciences has raised concerns by revealing that almost all brands of bottled water analysed contain traces of microplastics. The study used advanced spectroscopy techniques to analyse 25 brands distributed across several countries, identifying the invisible particles in thousands of samples. According to the scientists, the only exception was a UK brand, which showed no traces of microplastics under the conditions of the analysis.
The research, led by scientists at Columbia University and Rutgers University, deepens the understanding of the magnitude of microplastic contamination in ingested products, an issue of concern to both consumers and health authorities. The particles, invisible to the naked eye, have been linked by previous studies to possible risks to human health, although the concrete effects are still being evaluated.
240,000 microplastics per litre
The scientific analysis revealed surprising figures about the amount of microplastics present in most of the waters studied. Using substrate-enhanced Raman spectroscopy, the experts detected, in some cases, up to 240,000 microplastic fragments per litre of water. According to the article, the particles analysed were less than five microns in size, which is worrying because of how easily they could pass through the body’s physiological barriers.
A investigação, liderada por cientistas da Universidade de Columbia e da Universidade de Rutgers, aprofunda a magnitude da contaminação por microplásticos em produtos ingeridos, uma questão que preocupa tanto os consumidores como as autoridades sanitárias. As partículas, imperceptíveis a olho nu, têm sido associadas por estudos anteriores a possíveis riscos para a saúde humana, embora os efeitos concretos continuem em avaliação.
240.000 microplásticos por litro
A análise científica revelou números surpreendentes sobre a quantidade de microplásticos presentes na maioria das águas estudadas. Utilizando espectroscopia Raman aprimorada com substrato, os especialistas detectaram, em alguns casos, até 240.000 fragmentos de microplásticos por litro de água. De acordo com o artigo, as partículas analisadas apresentavam tamanhos inferiores a cinco micras, o que é preocupante devido à facilidade com que poderiam atravessar as barreiras fisiológicas do organismo.
The researchers explained that ‘the measured concentrations exceed previous estimates by one to two orders of magnitude’. This data implies that the levels detected are significantly higher than those collected by traditional analyses, which often failed to identify nanometric particles. Co-author Beizhan Yan warned in the press release: ‘Each bottle consumed may contain a worrying amount of plastic particles that the consumer is unaware of.’
The study also noted the variability of concentrations between brands and batches. Although all but one sample contained these contaminants, the amount was highly variable, with some recording less than 100,000 particles per litre and others multiplying that number widely.
Microplastics come from packaging
The study not only quantified the presence of microplastics, but also identified their main source. The scientists determined that the vast majority of the particles found chemically corresponded to polyethylene terephthalate (PET), the plastic polymer commonly used in bottles. Through their analysis technique, they established that the release of microfragments occurs mainly during bottling and storage, although the process can intensify under certain temperature conditions.
The team indicated in the article that ‘PET constitutes the dominant fraction of microplastics detected in the samples’. In addition, they found traces of other polymers, such as polyethylene or polypropylene, likely present in the caps or machines used during the industrial process. The experts clarified that contamination by microplastics is not always related to geographical location or brand, but may depend on the manufacturing process and storage time.
However, the researchers pointed out that the only sample free of microplastics came from a bottling company in the United Kingdom. According to the article, the production conditions and quality control at this factory appear to be exceptional compared to the others.
Uncertainty about health risks
Given the discovery of microplastics in almost all bottled water evaluated, the study authors emphasise the lack of certainty about the health impact of this constant exposure. Although the presence of particles intensifies public concern, experts insist that “there is still insufficient evidence to determine whether there is a tangible impact on human health”.
The Columbia University team says that smaller microplastics, less than 1 micron in size, are more likely to pass through cell barriers. Professor Phoebe Stapleton warned in the study: ‘It is not known what the fate of these microplastics is once they enter the human body and whether their effects may be cumulative or transient.’ For now, international organisations such as the World Health Organisation (WHO) are calling for more research before setting specific regulatory limits for the bottled water industry.
