A new study published in the Proceedings of the National Academy of Sciences (PNAS) has revealed concerning findings about the presence of nanoplastics in bottled water. Researchers discovered that the average bottle of water contains approximately 250,000 fragments of these tiny plastic particles. Nanoplastics, which are thousands of times smaller than microplastics, have the potential to disrupt cellular machinery and pose significant health risks.

According to the coauthor of the study, Beizhan Yan from Columbia University, microplastics are already known to be present in various environments, from alpine regions to deep trenches and even New York City water. However, measuring microplastics is relatively easier compared to nanoplastics. The smaller size of nanoplastics makes them more dangerous because they can easily enter the human body and cross different barriers.

The impact of both micro- and nanoplastics on the human body has been extensively studied. A previous research article in The Lancet highlighted the various dangerous effects of these particles, including oxidative stress, inflammation, immune dysfunction, altered metabolism, impaired cell proliferation, disrupted microbial pathways, abnormal organ development, and the potential for carcinogenicity.

With the knowledge of these potential risks, scientists aimed to determine the specific plastic polymers that people are ingesting and their quantities to assess the danger of exposure. The PNAS study utilized a new laser imaging method that could identify plastics of even smaller sizes than before. By filtering water from three common brands, the researchers could trap particles measured in billionths of a meter and analyze them.

Interestingly, the study found that although nanoplastics comprised just 10 percent of the total nanoparticles identified, there were also unidentified particles such as microscopic clays, metals, and degraded plastics that the imaging technology couldn't detect. The mere presence of these smaller particles could interfere with bodily functions, similar to how sand disrupts an engine.

The chemical structure of plastics is what makes them particularly concerning. Due to their similarity to the chemistry of living organisms, plastics can mimic or disrupt crucial biological functions by imitating the structure of chemical messengers. The study identified a range of plastics in the bottled water, with polyethylene terephthalate (PET), the material used for the bottles' structure, being the most prevalent. Other potentially harmful nanoplastics found included nylon, polystyrene (Styrofoam), and polyvinyl chloride (PVC).

The research also revealed an ironic finding: the presence of plastic compounds matching those used in reverse-osmosis filters, suggesting that the plastics may have leached into the water during the filtration process. Furthermore, certain dangerous particles like PVC and polystyrene seemed to have entered the bottles from the source water itself, possibly due to emissions from plastic plants contaminating the environment.

The health risks posed by nanoplastics are of particular concern, especially to vulnerable populations such as the elderly and the very young. These tiny particles can cross the blood-brain barrier, potentially leading to neural degeneration in older individuals. Exposure to micro- and nanoplastics may also result in cell damage in the nervous system, increasing the risk of nervous system disorders and behavioral changes. Nanoplastics can even cross the placenta, potentially harming a developing fetus by interfering with cell processes, damaging organ cells, and impacting normal growth.

As the extent of environmental contamination by nanoplastics becomes evident through this study, further research is needed to understand the full health implications. It is crucial to address the sources of nanoplastic pollution and develop strategies to reduce the presence of these harmful particles in our environment and consumer products.